...

Congrats! I'm looking forward to pics and a dyno sheet (if possible). Is Descendant tuning it or are you going to try their base tune first?

You didn't mention t-stat or plugs so fwiw the Mishimoto t-stat and 1 step colder NGK Iridium IX plugs are great additions. M1 ATF has also worked great for me but I really can't say with any certainty that it's actually better than Toyota's fuel economy oriented WS.

Yes, im well aware of the dangers of going over 250whp with an Auto 8) so no need to go into a full debate warning me of the dangers.

C) Most city driving I do I dont go over 3.5k, so the car wont be seeing much boost generally.

Then why spend all the $$ to go boost ???????

What tranny cooler? On the xB1, the Mishimoto doesn't have an integrated oil cooler, had to go stand-alone B&M for my auto turbo.

NO BASE TUNE!!! I can't stress how important this is! The base map is only preset to allow you to get to your dyno/tuner. It is NOT meant to be used as a tune.

Descendant will be doing the full install, while churches will be doing the dyno/tune.

Plugs and colder tstat weren't recommended by descendant, actually besides the radiator, they recommend a completely stock motor. If it wasn't for Rob having an extra TRD exhaust laying around, I would have went with the stock!

As far as AT fluid, I will be also staying stock. When I upgrade the valve body, then I will opt for Royal purp or something comparable.

By "base tune" I meant the tune that Descendant refers to as "bolt-on and go" and "turn-key". The reason I asked is that a fellow member tried their tune and it didn't work very well for him. There are members here who mistakenly think that "turn-key" means they don't need a $500 tune on top of the kit cost. Moot point in your case. I'm sure Churches will get it all sorted.

I find it odd that they would recommend stock heat range plugs and 200F+ ECT for 10 psi but maybe they know something that others don't. Do they at least re-gap the plugs for boost? I suppose the tuner can always pull enough timing to compensate for those detonation risks. FWIW, I've lowered my avg ECT from 200F to 170F with the Mishimoto t-stat and stock radiator and it's never exceeded oem ECT levels.

My own theory on the ATF is that Toyota switched to thinner WS solely for better CAFE and that a traditional Dex III viscosity ATF would provide better line pressure and protection. It was just a suggestion. I can't wait to see what 10 psi will do through a 1.8" exhaust. Good luck with everything.

yeah "turn key" might be a tad deceptive, it is actually meant able to drive away to your tuner. I would highly doubt that a single base map tune would suffice for every xb application, which is why some ppl report the base map as being "ok", while others do not. NOTHING compares to a custom dyno/tune job.

I will monitor temp levels in the engine bay, in anycase, thanx for the info on tstat and plugs, I will again address this issue w/ descendant, as I did with the TRD exhaust, as ROB has guaranteed me that the stock motor is all I need, with the exception of the tranny.

They are the masters of their kit, so im assuming the tune will address timing issues properly. If not, I will be back in their shop having *them* address said issues :tongue:

I'm sure that between Descendant and Churches they'll know best what you need and don't need. I was just mentioning some things that have worked well for myself and others. TBH I never even tried running the stock t-stat or plugs with boost.

Anyway, welcome to the boosted XB2 club. :)

Interested to see how this works out.

My main reason for wanting to 5 speed swap before turboing is to have the benefit of an LSD.

Soflotc had a A/T built from level 10 didnt work out too good from what I remember ended up going M/T

http://www.importperformancetrans.com/

Unfortunately I suspect that there may be good reasons why every boosted AT TC I know of who bought a valve body upgrade or built AT from either company has since done a MT swap... :(

The only boosted AT cars I know of that are still AT are running fairly low boost on stock trannies. If there is anyone out there running more than 300whp/tq through a U241E, I'd love to hear about it.

I'm on my second transmission currently, and from what I could tell the weak link wasn't the valve body in the U340E. When the trans started going, it would rev high without much power transfer, basically not building hydraulic pressure. My guess was either the hydraulic pump was failing or the torque convertor had a leak.

The problem started when I had my thermastat go bad and overheat the engine. My thinking is that when the radiator overheated it also cooked the trans. fluid passing through the shared cooler (another reason to go stand-alone). if I were upgrading, I would do the torque convertor first, the aftermarket ones braze the fins inside instead of simple welding.

I'm on my second transmission currently, and from what I could tell the weak link wasn't the valve body in the U340E. When the trans started going, it would rev high without much power transfer, basically not building hydraulic pressure. My guess was either the hydraulic pump was failing or the torque convertor had a leak.

The problem started when I had my thermastat go bad and overheat the engine. My thinking is that when the radiator overheated it also cooked the trans. fluid passing through the shared cooler (another reason to go stand-alone). if I were upgrading, I would do the torque convertor first, the aftermarket ones braze the fins inside instead of simple welding.

The whole point of the valve body modification was so that the transmission shifts faster. The transmission shifting faster actually helps the transmission not wear out as quickly. Think of it like this (generally): If you feel it, the car probably doesn't :)

As far as I know, Level 10 and IPT are not the same, so what "build" they do is different. In other cars, I've heard a lot of success stories with IPT, but I don't know much about Level 10. Also, the "build" that IPT does replaces all of the various parts of an automatic transmission. High stall torque converter, clutch packs, valve body modification, etc.

Finally, upgrading to an independant transmission oil cooler is important. The #1 killer of automatic transmissions are heat.

Our A/T code is U241E. Talk to IPT and see what they recommend for you. The flip side of a faster shifting VB upgrade is the potential to destroy the clutches from the sudden engagement with more tq than they were designed to handle. Allan Phillips (Allan Phillips Racing) told me how they destroyed a Taco trans very quickly by modifying the ECU for fast, firm shifts. The clutches no longer slipped but the friction surface was ripped off the clutches.

Oh, not sure how this helps or anything......but a lot of guys I know have had transmissions built by IPT (not for our Scions though) and they love them. IPT also happens to be 10 minutes away from me....but that doesn't really help you much :P

Can't wait to see how this turns out... I've been dying to turbo my xB but money is definitely a problem lol. Hope to see pics and possibly video soon!

Lookin' good Bro! I hope you don't have any issues with the FIC and fwiw you may want to read this TC thread about boosting with a U241E.

http://www.scionlife.com/forums/showthread.php?t=74908

Also know that the 2.5" TRD axle-back actually has a short 1.8-2.0" section where it meets the oem 1.8" mid-pipe. Eventually when you upgrade to larger exhaust you'll want to remove that also.

Lord knows I love sleepers! I went to my local drag strip tonight and like the last time it was a blast to have so many people come up and ask WTH I had under the hood! Your build sounds even steathier than mine. You'll surprise a lot of people.

You may not do any exhaust upgrades but if you do, you'll find that your turbo spools much faster, boost builds much faster and the end result is a quicker car. Then again, you may be satisfied with the oem exhaust. FWIW, 3" is optimal for power but very loud and hard to tame. You can run a 2.5" exhaust and still maintain the sleeper theme.

As dead as the XB2 FI section is, I may be as anxious as you are to see your completed build!

Thanks Clean XB. I recall reading posts from a guy with a turbo'd A/T TC making close to 300 whp and he had like 2 years on the trans with no problems. I think that most of the guys who blew their autos were beating on them pretty hard. As long as the trans can hold the tq without slipping and you don't beat on it, it should hold up pretty well. Almost everyone told me that I couldn't run boost without a piggyback but 2 years later it still runs like a factory turbo car.

I agree, a boosted XB makes a great family car that's still fun for dad. No one expects much from an XB so it's a great little sleeper. Aside from an occasional trip to the drag strip I rarely ever race anyone. What I enjoy most is simply having the power to climb long hills without downshifting constantly and being able to pass idiots that don't want to be passed on the highways.

I'm looking forward to seeing and hearing more about your boosted family truckster! LOL :)

It's not very hard to change the ~$30 wastegate spring on the car but you wouldn't want to do it often. In your case you can remove the WG which is much easier and less likely that you'll lose any tiny allen bolts or damage the diaphragm. Keep in mind that the WG cap holds pre-load on the spring so be careful when removing it so it doesn't shoot off. Make sure to get a genuine Tial spring. Cheap springs lose their temper from the heat.

In for pics and vid!

Lookin' good Bro! 230/220 is great for only 4psi. Autos are a PITA to tune. Everything has to remain in balance or the ECU won't shift correctly and on the dyno the auto keeps downshifting below ~4k rpm.

If you don't want to post your dyno sheets could you possibly PM or email them to me? I just want to compare them to mine for my own benefit.

Enjoy the new ride.

I wish there was away to override the "auto downshift" when you were in sport shift mode, or whatever it is called.

Congrats, it sounds FIERCE!

Are you using the base turbo, or did you get an upgraded one?


I wouldn't mind seeing a printout of your boost levels vs rpm :D

I wonder if there is a way to "lock" it into whatever gear you select in the sport shift mode...

ill try to get that dyno run scanned and then posted. I spent so much time yesterday getting my stock parts organized at my storage, I must have packed it away along with my manuals for the FIC.

Im not sure why toyota opted for the "sport shift" mode, as a simple PRND2L would have sufficed.......in actuality, it is not a true sport shift, It simply allows you to downshift to that gear. If the ECU detects your RPMS will be too high (5k to redline), it will not let you shift into that gear. If you are heavy in the throttle and shift to say 3rd, the ecu will downshift anyways to 2nd. Extremely frustrating as the ecu essentially controlls all shifts!!! WTF??? The only thing the ecu wont do is upshift you to the next gear, should you hit the rev limiter.......I dont see how that is any benefit?????

Dyno with an auto is a PITA already, but the scion "sport-shift mode" made it an even bigger Pain!

Thanks. Our "sport shift" mode is a joke! My 88 Mazda 626 had a true "manual mode" that allowed the driver to manually select any gear and hold it. It's so easy and cheap to do. While I appreciate being able to downshift and hold that gear, being able to prevent unwanted downshifts would be even better.

I'm looking for options but coming up empty thus far...

basically in auto xbs, the ecu controls EVERYTHING. I suspect that toyota went with the marketing "manual shift" console, to save space, taking out the need for 2+ gears, and a longer center console. Not sure if '10's and below have the same console and manual shift?

Yes indeed, the ECU has a hand in everything. I spoke with Level Ten and IPT about a manual shift controller or changing the downshift strategy and they offer nothing. I spoke wth Mr. Flash and was told the same thing. I did find some manual shift controllers that might work but they don't interface with the ECU in any way so the ECU would set DTCs and possibly go into limp mode. I did find one guy with a 1000whp Supra who is running a PCS controller with a black box ECU interface but I'm still searching to find out if it's even possible for us and what it might cost. The PCS controller alone is $750 and the black box is probably custom and very expensive.

http://www.powertraincontrolsolutions.com/mildetails.php



AFAIK 08-12 share the same shift console.

Sorry to hear about your issues but hopefully they can be corrected pretty easily. Although the P0420 can be "tuned" around, it can't be tuned out. It's easier to fix the problem than hacking the tune to correct for it. Besides which you won't pass an emission test with a CEL present or pending.

Contrary to popular misconceptions, the ECU does use the 2nd O2 sensor as a check against the primary AFR sensor and uses this info to make small corrections. Since the ECU expects to see exhaust gasses that have been burned again in the primary cat, the easy solution is to reduce the volume of gas sampled by the sensor when the cat is no longer present (header or turbo).

What kind of anti-fouler/spacer did Descendant install on the 2nd O2 sensor? I'm a big fan of the 90* angled CEL eliminators. They reduce the volume of exhaust gas measured by the O2 sensor and can further be tweaked by rotating their orientation to fine tune the CEL out. WR, Strup and Big Daddy's Garage all offer good ones in 304SS so they won't rust away quickly like the cheap plug anti-foulers do.

IMO the first step is to eliminate the P0420 CEL and see how it runs. There are likely some tune issues as well but I'm sure Chruches can sort those out. Another thing that comes to mind is that the engine always idles faster after a battery disconnect and doesn't settle down for a while. If there were a idle problem with the tune, it could be masked every time you disconnect the battery and then appear when the ECU eventually lowers the idle speed again.

Good luck and feel free to PM if you have any more questions.

I've never seen a P015A before. I wouldn't worry about it unless it keeps coming back since it may be related to the recurring P0420. It is my understanding that the ECU may adjust the AFR a little based on the 2nd O2 sensor. For example if the 2nd O2 is reading too rich the ECU may lean the AFR a little and compare readings between the primary AFR and secondary O2 again. The 2nd O2 reading rich won't cause major issues but it could contribute to your lean-AFR stalling issue. I suggest installing a proper anti-fouler ASAP as it can only help.

The back firing is just a tune issue that Churches can sort out. Although
back firing during a shift is normal. The ECU pulls a ton of timing during a shift and I often get a "pop" from 1-2 and 2-3. They can probably tune out the stalling too even with the P0420 but IMO you still want to get rid of that code. 8psi and 270 whp/wtq is a good place to be with an auto. I was talking to Justin from P-Tuning at the car show sunday and he told me the same thing Toan did about "built" U241E trans... "Don't do it!". He said they've seen nothing but problems from them.

I wouldn't reset the ECU before the tune. Let the tuner see the codes and other issues firsthand. Let him decide if he wants to reset before tuning. Good luck!


.

Here's a good explanation of the P0420 DTC from Toyota:

http://www.ncttora.com/FSM/2003/Repair_Manual/03tacoma/di/eg5vzfe/cip0420.pdf


This DTC is a 2 trip detection logic code meaning that the CEL will come on during the 2nd trip (ign on/off cycle) following a reset if the problem is present. During the first trip it should show as pending and then after you shut down and restart, the CEL will appear shortly afterward.

I don't know of any connection between idle speed, the CEL setting and subsequent stalling but that doesn't mean there isn't one. Fix the P0420 and at least you can scratch that off the list of possibilities. :)

first the bad> Churches wasnt able to sort out the stalling error at deceleration, but interestingly enough, it doesnt stall while the A/C is blowing, probably because the ECU is setting idle speed much higher to compensate for the increased load.


You are correct. The ECU does raise the idle speed with A/C on and also adds some AFR enrichment. I should mention that I too have a lean idle issue in warmer weather and turning on the A/C helps. Even my idle fuel trims are unusual. With 20% larger inj's I have idle LTFT of 0 where -20 is expected. My LTFT crusing at 60 mph is -19 as expected. My theory is that the actual IAT is colder than the sensor reads because the hot intake air at idle is cooled by the IC. Since the actual IAT is colder than the ECU thinks, it requires more fuel. IMO this is the main reason why many prefer a blow-thru MAS over a draw-thru. IAT is a very key element for the ECU to calculate air density and the fuel required. However while this IAT discrepency caused lean idle issue isn't ideal, it isn't a deal breaker. I can't remember the last time my car stalled because of this, if ever.



the good> churches agreed with you, in that the second o2 sensor does have the capability to respond with the 1st, and tell the ecu to modify the afr's, which is probably what is happening. No matter how hard the tuner modified the fuel trims at idle, the car would fall on its face at idle, or under hard deceleration. He monitored that although he instructed the FIC to be richer at idle, the stock ECU was cutting fuel trims, hence the conflict/contradiction (probably due to the CEL). he suggested either:

A) the '11 AUTO had a change in the ecu and descendant might want to look at this closer in regards to what has/hasnt changed in ecu trims from 8-10 to 11+ AUTO's.

B) The second o2 sensor is modifying the afr's at idle, and as a result, is overriding my tune, and screwing with the trims, per P0420 code.



A is possible but IMO very unlikely. I agree with you that B is the more likely cause. One more thing to check is the BOV. Although it's recirculated, I've found that a partially open BOV can still cause idle problems, even when recirculated. What is your vacuum at idle? Mine is 20-22 in hg.


With the P0420 code being out of the mix, this *SHOULD* clear up the stumbling issues at idle/decel.


That's what I'm hoping for. If not there's still a few possibilities including the BOV setting, another vacuum leak or maybe even the inj dead time setting in the FIC map.



can you say definitively that there were no changes made on the ecu for 11+ autos? although robs car is also '11, he is a M/T and is not experiencing these probs, nor did he have a need for the o2 sim. This is why im assuming this is strictly Auto related?? you would know better than me and the tuner at this point lol


No, I can't but I very much doubt that your problems are caused by a ECU change. I bet Rob has a larger exhaust that reduces the gas sample presented to the 2nd O2 sensor. He also doesn't have torque converter load on the engine at idle. Hang in there, Bro! Boosting the auto XB ain't easy but it can be done. You'll get there and enjoy the hell out of it when it all gels. :)

Rob is running stock exhaust

The O2 modifier helped with the 420 code on mine, the reason Rob told me that code was showing is that the gases were causing the 02 sensor to get too hot with out adapter.

my TRD boost gauge does not read below 20in hg, so im not sure if my actual readings are below this or not....interested in how you can read 22 in hg?

come to think of it, I thought that my vaccum readings were a little high, but I did check all piping for vac leaks to no avail.

Ive enclosed some pics with readings from my gauge. Keep in mind that this was 5 miles after a battery disc , which right now my idle is fine because I imagine the ECU is relearning yet again. let me know if you think my readings are a little high, as they have always been since I took delivery of the vehicle

pics in order:

Park Idle>Park Idle w A/C>Drive Idle>Drive idle w A/C

the drive with ac concerns me the most as this reading is rather high 18inhg. This could be due to the fuel trims the tuner modified, or the ecu reset, nevertheless, they seem rather high.

I'm feelin' those TRD gauges... nice choice. I have AEM gauges and my boost gauge simply reads a little further in vacuum and boost (30 in hg/35 psi boost). What is your elevation above sea level? This affects both vacuum and boost readings due to air density variation.

If you're between 0-1000' ASL like me, your engine vacuum might be a little low. It's too close to be sure but you could have a small vacuum leak. Small vacuum leaks have their greatest impact at idle when intake air volume is at it's lowest. A small vacuum leak can cause a lean idle condition and stalling. You should mention this to Descendant. Since they installed the kit using cheap hose clamps, they should verify that you don't have any leaks with a leakage test.

FWIW, I hate cheap, un-lined worm-gear hose clamps. The only clamp possibly less reliable is the wire spring clamp. Even oem wide-band spring clamps are better. T-bolt clamps are worth every penny. If I bought a Descendant turbo kit, before even installing it I would substitute T-bolt clamps for all the hose clamps. Then I'd never have to worry about vacuum leaks.

Not to say that you can't acheive a leak-free setup with cheap hose clamps, because it is possible. It's just more difficult and less likely. :)

Rob is running stock exhaust

The O2 modifier helped with the 420 code on mine, the reason Rob told me that code was showing is that the gases were causing the 02 sensor to get too hot with out adapter.

Interesting... I thought Rob would be sporting one of their exhaust systems.

Either way, It's not heat that causes a P0420, it's not enough oxygen in the exhaust gasses. When the primary catalyst is removed the secondary O2 sensor reads a richer (low oxygen) AFR because unburnt fuel from the primary combustion process has not been re-burned by the catalyst. The O2 sensor compares oxygen levels outside the exhaust to levels within the exhaust gasses. The reason for spacing the o2 sensor further from the exhaust gasses and reducing the gas volume it is exposed to make it read a higher oxygen concentration in the exhaust gas by reducing the sample size only on the exhaust gas side.


In fact, by removing the primary catalyst, exhaust gas temp at the secondary O2 sensor should be reduced.

I'll have to have them look at this issue tomorrow, as they will be installing the O2 sim anyhow, so they can take a look. Then I have retune appt immediately afterward.

Given the info sp2 has provided I guess it's safe to say, we've found the prob. I was just under the impression that I was nit-picking this, but seems I'm not alone. I hope this thread has served its purpose as a guildeline for autos looking to boost and precautions, if anything.

O2 fix and Redyno tomorrow and that should be the end of it. I will have a follow up with dyno sheets.

I appreciate your input as well as sp2.......now I understand that the xb2 FI section really is pretty dead! A shame given the mass market in the tC section lol


Maybe you can just suggest to descendant that you suspect a small vacuum leak and ask if they can test for one? A small leak could certainly explain the lean idle and stalling issues. Although as I said, I hate cheap worm-gear hose clamps I must admit that once you acheive a leak-free seal with them, they probably won't leak again if left alone. Well, except for coolant hoses that expand and contract a lot but that's another issue.

Good luck tommorrow and I sincerely hope everything gets sorted out 100%. You're very welcome, I'm glad I could be of some help.

I'm happy to hear that things are getting better. Did you ever find out what your elevation is Above Sea Level (ASL)? Specifically where you were when you took those pics of your vacuum readings? At 500' ASL I'm pulling 22 in hg and your vacuum seemed a little low, suggesting a possibly leak. However if you're at 2500' ASL, your engine vacuum would be the same as mine.

To adjust the BOV, remove the recirculation hose and cap the opening on the intake pipe. With the hose removed you should be able to see the valve inside the BOV. At idle your BOV should stay closed. It shouldn't flutter or move at all. If it does tighten the spring preload until it stays firmly closed, no more, no less.

You might consider replacing the hose clamps between the turbo and TB with T-bolt clamps. Hose clamps are fine for the air filter to turbo inlet. If you order them online they're pretty cheap and work a lot better. Good luck and enjoy.

If it keeps fudging up, I'll drive out and trade you all my stereo equipment for the turbo kit! :eyebrow: :pray:

I've been eyeing the Descendant kit for a while. Just need to get stuff paid off, just to put the kit on credit! Ha!

well unless Rob added exhaust last couple months,
when picked my car up in May after gauges and boost controller install, Rob took me for test drive in my car, he said was a beast compared to his with stock exhaust, haha

glad everything is working better for you now

My elevation here in SoCal is anywhere from sea level, but no more than 1000ft max, so pretty much the same as you.

I did talk to Decendant today, and they did state my vac levels were perfectly normal for this kit.....furthermore they claim back levels vary from vehicle to vehicle.

I did reclamp all my hoses, and found one attached to the intercooler that is a bit stripped and needs replacement. If this is related to the stall issues, I doubt it, but I will be replacing it tonight.

Also I'll attach pics of the bov that I took when I dismounted it. It looked normal, however I Will admit I didn't know exactly what to look for. As well, I am not sure how to inspect for a vac leak, any pointers is appreciated as always.

Bottom line is that there is no more cel and the car pulls hard and strong. The stumble at idle issues is irritating, but nothing that won't be fun trying to chase down.

I've always said that the hiatus of a build is taking on unexpected problems, and readapting/reapplying your route. What fun would it be if everything went as textbook as possible all the time????? Lol

The most likely cause for lean idle, stumbling and stalling is a vacuum leak that allows un-metered air to enter the intake after the MAS. The MAS doesn't see it so the ECU doesn't add fuel for it. The result is a lean idle but the car runs great off-idle because the leak is too small to matter when the intake air volume increases. If it's not that, there could be a problem with your idle air control valve or several other possibilities. 700cc injs flow almost double what the stock injs do and they'll never idle as smoothly. It's even possible that the ECU will eventually learn to compensate since it controls the IACV.

As for the BOV, here is a good read:

http://www.frozenboost.com/stpg.php?page_id=bov

Technically you have a bypass valve since it's recirculated and shouldn't have the same vacuum leak effect when open at idle but I have the same setup and it idles much better with the BPV closed during idle.

Anyway, I'm glad you're enjoying the boost and hope the idle problem gets resolved soon.

i have 2.5" custom back to tanabe concept g

So technically I have a CBV not a BOV and so how would i go about testing it for a leak once uninstalled???

The way to check BOV, CBV (or ByPassValve) adjustment is to look inside the BPV exhaust port with the engine idling. The piston or valve should remain closed while idling. If you rev the engine, the valve should open a little when you close the throttle and slowly close again. Kind of a moot point though since I realized that your BPV isn't adjustable. It's an oem style made for some oem turbo car. It's probably fine.

I'm not sure what else to suggest. Did Descendant install new spark plugs? Copper or iridium? Copper ND plugs didn't work very well for me but 1-step colder NGK Iridium IX pre-gapped to 0.032" work great.

Here is a DIY for a boost leak test in case you need it:

http://www.scionlife.com/forums/showthread.php?t=171012&highlight=boost+leak+test

Good luck and keep me updated on this. I'm very curious to know what the cause and solution are.

I dont know if I owe this fix to the cleaning of the maf/iat sensor itself, or the fact that the maf was not seated correctly? or a combo of both?

Either or both can cause idle problems. I'm glad you found a solution so you can really enjoy the new turbo kit. Congrats!

Thanx. Actually I partially owe most of the ideas to solutions to you, as my level of experience with turbos is somewhat mediocre. I came from a world of large displacement high torque GM vehicles (specifically N and W body platform) that were supercharged, so exhaust driven rather than belt driven is new to me.

I am interested to hit a dyno and possibly track day so that I can see what #s I'm putting down "real world", but the amount of boosted scions here in OC is very limited, so I would not know where to start looking.

I will say that if I can lay down a high 13, traction issues included, I will be 100% satisfied with the setup, as I already am.

I went over a "pre-turbo" check sheet here on a thread that gave good advice from a tuner, for prior maintenance to adding a turbo, and I will say, screw double checking that list.......TRIPLE check that list!!!!

99% of problems after initially install are usually related to maintenance not taken care of prior to the install, with the exception of some emissions codes.

Dyno testing is easy enough to find and if you want a track day just find your local drag strip and go on a "test and tune" night. You can make a lot of runs for around $20. IMO track time is a lot more valuable than dyno testing. According to my heat-soaked dyno results I should be running 14.8 @ 93 mph.

As you may have noticed, my sig is a boast but equally a challenge. I'm just waiting for someone to post a quicker time slip to make me change it. :)

BTW, you may be right about improper maintenance causing 99% of post-turbo issues but unfortunately I fell into the 1% with a mis-wired FIC harness, defective FICs and still unknown faults with the APR X-1 and/or Dezod harness. I only mention this to illustrate the lack of proper R&D present within the aftermarket that caters to such a small customer base as Scion. The mis-wired harness had never even been tested on a XB before I received a "production" sample. AEM's lack of QC is well known but mostly ignored because the FIC is so cheap and therefore popular. I won't even get into how much is wrong with the Dezod/APR-X1 "Tacoma" piggyback that almost blew my engine. :(

So are we ever gonna get to see some more pics of your turbo setup and car? I'd really like to see more of it. I just watched Descendant's installation video and was really impressed that they went so far as to fab a custom t-stat housing for better downpipe clearance. If I were buying a turbo kit today it would absolutely be from Descendant.

No rush, I just wanted to make a request for more pics, when you have time.

10psi again? I see temptation got the better of you. It's been getting to me lately too. I'm considering adding a Walbro 255LH and a return fuel system so I can run 7 or 8 psi. No plans for 10psi though. You should be close to 300 whp.

ive gotten a chance to sample 8psi for a while now....temptation has gotten the best of me.

I will say that when I boost, I normally do in sport more (-+), so in between gear I let off the throttle slightly, allowing the tranny to shift easier with decreased load.

so far I have experienced 0 tranny issues, all seems to be well

ill sample 10psi for a while and If I deem that im pushing things way too far for comfort, then ill drop back down to 8psi immediately.

Im estimating about 270 ish right now, its an absolute animal in first gear after 4k rpm

I know that im going against popular consensus in going into double digit boost, but so far I have been very conservative and responsible with the kit.

some note worth easy kills are an all motor B16 2000 ish civic (bragging 230 hp), brand new jetta GTI.

also suprised the crap out of an IS350 with loud dual exhaust as I hung on his bumper getting onto the freeway late night. he slowed down to give me the WTF??? look.

I usually dont make runs like this in any of my vehicles, in fear of unwanted attention, citations, and the like.....but just had to see where I stood in real life situations.

I understand the temptation completely and wish you good luck at 10 psi. No one really knows exactly what our trans can and can't handle but we all have our own opinions and comfort level. I just want to break into the 13's and 13.9 would be good enough for me. :)

250-275 whp is about right for 8psi although I'm not sure how much you're giving up with that stock exhaust. 10 psi should still get you into the 275-300whp range. Below is a nifty little 1/4 mile calculator that does a good job of estimating ET based on HP and weight. Stock curb weight is 3100lbs for the auto trans so just add your weight and hp guesstimate.

http://www.race-cars.net/calculators/et_calculator.html

So just to keep everyone up to date, I got the 10psi combo of springs and used those in my wastegate for about 2 days, but had issues with, so I swapped back to my 8 psi spring and will currently be trying to get some dyno #s as well a pinpoint my illusive idle shutoff problem when going into reverse, or coming to a decel off load.

What kind of issues did you have at 10 psi?


My TRD gauge would only register up to about 8.5 lbs of boost, not sure if I was using the wrong spring combo (highly doubt as descendant supplied the spring) or my TRD gauge was stuck on 8 psi, or if my wastegate was seizing (double checked the diaphragm several times), or my 8 psi tune was limiting me, or my exhaust limitations, or a combo of any of the above. The car definitely felt like it had additional horsepower than 8 psi, but as I mentioned, never got close to touching 10 on the gauge. Not sure what went wrong.

It's not uncommon to have less boost in the intake manifold than at the turbo compressor. If your wastegate is plumbed correctly it gets vacuum right from the compressor housing and it's reasonable to lose 1.5 psi of boost to the IC pipes and IC. It's also possible that you had a small boost leak.


I've already taken off the Bosch bov/crv and inspected the inner spring, and it seems to be doing its job well. The only thing I can think off is a vac leak somewhere due to my low vac levels as previously stated. I have went over all couplers and vac lines multiple times


You may want to install some small cable ties onto all of your vacuum line connections. When in boost they are also pressurized and more likely to leak or blow off.


Something to note, but not sure if related is that I made a quick Vegas trip which took me about 4 hours. While I was there, I noticed I could not get over 5 lbs of boost (with 8 lb spring), not sure if this was related to higher elevation?

Vegas is only 2000' ASL so it shouldn't make that much difference. A leak is more likely. When you first had the kit installed, were you seeing 8 psi on the gauge or 6-7 psi? If you were making 8 psi and now you're making less, the most likely cause is a leak somewhere. OTOH if you've always made 1.5 psi less than the WG spring, you could lose another ~1 psi being at 2000' ASL.



Also I blew off a charge pipe with the 10lb spring, that is another reason I opted that I'm pushing the car off too far into the gray area. Scionfred your advice for better couplers was spot on, could you point me to a link for the ones you recommended? Thanx again

You can get T-bolt clamps from many sources. I've bought them from ebay, CX Racing and ATP Turbo. They were all decent quality. You can leave the hose clamps on the intake couplers but I'd replace all the boost couplers with t-bolt clamps. Here's a link to ATP:

http://www.atpturbo.com/mm5/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=CLA

With any luck, replacing your clamps will fix your stalling issues. It may not but it certainly can't hurt anything. FWIW, I decided against raising my boost (again...). There are 2 ways I can do it but a return fuel system, FPR and pump will cost about $500 and a Greddy EMU and a tune will cost $1200+. It would be fun but it's just not worth it for another 20-30whp.

Enjoy your boost!

I have always seen the same psi on the gauge as the spring on the wastegate I.e. when I was tuned for 4lbs, I saw 4 on the gauge. When I was tuned for 8lbs, I saw 8 on the gauge. When I got to Vegas, the car was hot, and I never was able to make over 5psi with an 8lb spring.

When I got home, I swapped to the 10lbs spring, but never saw 10lbs, only 8.5 on the gauge. Since I swapped back to the 8lb, I always see 8 on the gauge at full throttle. Perplexing. That is why I opted 10lbs was too far, in addition to. Losing the IC pipe on the TB that blew off

I have used zip ties on all vac lines, I was wondering if I have an uncapped tee fitting on my wastegate, but no electronic boost controller, could that be the source?

Also thinking about pulling the plugs and posting the color here in fear of fouling them out when I blew off the pipe, the car ran terribly rich for a mile till I could pull off the Frwy ???

Hmmm... my best guess is that you had a small boost leak develop while in vegas at the same coupler that blew apart when you raised the boost to 10. That would also explain why you're back to full boost after re-attaching that coupler. I hate to keep harping on this but you'll probably keep chasing problems like this with those crappy hose clamps on boost pipes. They're fine for the intake and BOV couplers but not for the IC pipes. I'll bet Descendant uses T-bolt clamps on all of their race cars.

Can you post or PM me a photo of this uncapped fitting? If your WG is plumbed to the IM it could cause a vacum leak. If it's plumbed to the turbo, it would cause a boost leak and prevent the WG from opening when it should. It could also be the vent for the top chamber of the WG which needs to remain open to atmosphere.

Checking your plugs is never a bad idea. I doubt that they're fouled but they can still tell you a lot about how your engine is running. I still highly recommend going 1-step colder. (NGK BKR7EIX-8 works great for me) TRD recommends this with their SC and NGK recommends that for every 75-100hp you add you should go 1 step colder. Believe it or not, I actually research this stuff all the time. :)

http://www.ngksparkplugs.com/tech_support/spark_plugs/faqs/faqmodified.asp?mode=nml

Dude... it seems like it's giving you nothing but problems.

My offer to trade all my audio stuff is still on the table. I'll even throw in a barely used Canon T1i. :D

this is the tial MV-s wastegate. The right port (lower) is plummed to the turbo. The Left (top) was left open to accommodate a future electronic boost controller (which I dont plan on using). This is what im wondering is causing a vac leak.

T-bolts and plugs are coming up next check, lack of funds right now :(

the very top port on the hat of the wastegate (not shown) is capped

for reference the hat is top, while the lower is manifold side

Looks good to me and you shouldn't cap the top chamber vacuum fitting. There's a diaphragm between it and the bottom chamber so unless the diaphragm has a leak (very unlikely) there won't be any vacuum leak. If you cap it the diaphragm will have to compress the trapped air in the top chamber to open the WG valve resulting in higher boost and erratic WG operation.

I didn't know the MVS could be water-cooled. That's pretty cool (no pun intended). :)

I guess we'll have to keep chasing down the idle issue. It might not be a vacuum leak but that's all I can think of and probably the most likely cause. I was hoping that the ECU would have corrected it by now but apparently it won't be so easy. :)

Dude... it seems like it's giving you nothing but problems.

My offer to trade all my audio stuff is still on the table. I'll even throw in a barely used Canon T1i. :D

Hush! You're obviously just trying to score a deal on a very nice turbo kit!

Coincidentally, I rarely ever listen to my stereo any more either. I prefer the sweet music of a finely tuned engine. It may not be a Ferrari V-12 or a Porsche flat 6 but it's still music to my ears. :)

:lol:
good pun. yes the new version 2.0s have the water cooled ability!

but yes im happy right now on 8lbs for an auto. Honestly I think the issues I was having was the vehicles way of reminding me that 10lbs is too much for an auto!

I never expected this to be a 100% stock functioning car...that is why by the end of the year it will be parked till mid next year, and I am actively in the market for a 1st gen 1nz-fe....BONE STOCK! down to the HUBCAPS for my daily D! :bow:

till then, ill still look for a solution to this, as well as get some dyno runs/#s in :ponder:

I appreciate all the help scionfred and others have offered me so far in this project. I wouldnt have learned half of what I have so far if it wasnt for you guys. My only wish is to return the favor to the community to those wanting to boost their A/T XB

You should be happy with 8psi and auto trans. Your XB is now quicker than a stock GTI, R32, Ralliart, genesis 2.0T, etc. and the only cars in this class that are still much quicker are the quite expensive Evo and STi. It's a close call with the Cobalt SS and MS3 but you're close enough to at least keep up. That's pretty cool for a $18k econobox toaster.

A gen 1 would make an excellent DD! I went with an old Subaru Legacy wagon and while it will be great in snow and off-road, it's a gas pig at 22mpg avg. 1993 technology... but hey, I can get historic tags in 2013!

It's been my pleasure to share what I've learned here in the past few years. IMO that's the best reason for forums like this to exist: to help and get help from others. If it's social banter you're looking for, there's facebook, etc. :)

BTW, I'm 100% confident that your idle issue will be fixed eventually. Have you tried cleaning your mass air sensor yet? Simple thing but it fixed a similar problem for a boosted TC guy recently. You can buy MAS cleaner at most auto parts stores for about $5.

Thanks for summarizing everything in one post like that. It make things easier. I want to suggest a boost leak test but they're a PITA and I'm hoping that t-bolt clamps might do the trick without the leak test.

As for the tune, I recently saw where a boosted TC with similar problems fixed his lean-idle/stalling issues by subtracting less fuel in the idle cell range of the FIC fuel map. Do you know how to download and upload maps to the FIC? If so you can send me your map and I'll make some changes for you to test. If you know how to change your FIC map, you could make the changes.

Your plugs look okay but could use a cleaning. Thay're a bit sooty. They don't look bad enough to be causing the stalling issue.


Keep the faith, Bro!