Short of turbo or head porting, what else can be done?
 

I've the feeling I may've run out of reasonable possibilities for boosting N/A low to midrange performance. Outside of wrapped header and "S"-pipe, insulated 3" CAI, bypassed TB "coolant" heating, ported TB, light weight crank pulley (dynamic performance only and I'm not comfortable with undersize), the perhaps controversial benefits of a smooth bore TB spacer (:P), and a 2-1/2" dual "scuba-back" exhaust, what's left? (Yeah, I know there's an expensive optimized "chip" solution available, but expensive isn't a good fit for me :(.)

Oh, yeah, I should mention, I'm not into replacing the "scuba" tank. That may well be an advantage for high rpm performance, especially turbo, but I just don't see it for low to mid-range N/A -- the 1.75" outlet is not far from my original Eclipse 2" turbo exhaust piping and it made 195 HP no problem. I'm getting some 50% more than that now from various mods, but the pipe after the cat is still 2".

Gut it. Or lose weight :)

I agree with FTO, lighter is faster. Unfortunately shaving a few hundred pounds ain't easy. OTOH adding a turbo kit is relatively easy but not inexpensive. 220 ft lbs of tq at 3800rpm is a lot of fun though!

What's this optimized "chip" you speak of? Surely not the 5 whp with 93 octane for $500 Unichip? Surely not another IAT resistor "chip"?

Well, I just added 28 lbs in the form of a trailer hitch, but the idea there is purely utilitarian (as is the spare tire :)). As for my weight, according to the bathroom scale I'm under 140 lbs as it is, not sure I want to do much better than that :P!

I totally believe it is :)!

I was thinking of the Unichip, though I wouldn't want to be forced to a higher gasoline octane regardless.

My neighbor seems to strongly believe in "chipping" for improved performance, but I'm not sure he's ever done it himself. He mentions what other P/U truck owners have said.

Here's a test article I ran across:
http://www.carperformancechipreviews.com/

And another:
http://www.engineperformancechipreview.com/reviews.html

Thinking of the GTE, check out this eBay offering and video:
http://cgi.ebay.com/ebaymotors/Honda...-/250742506406

This site has a better price, install PDF, plus other toys :):
http://www.performancechiptuning.com...mance+Chip/11/

I gather "Stage 1" is an IAT mod and "Stage 2" is an adjustable rear O2 sensor mod.

A few more videos:

Lastly, an article by Popular Mechanics:
http://www.popularmechanics.com/cars...ileage/1802932

I'd love to learn of something at an affordable price that actually worked, but no, $500 for 5 WHP doesn't hold that much appeal for me :(!

It appears that lightening the XB or yourself is not a viable option. :)

Boost is best! ...but $5k is a lot to invest in a <$20k car with little to no resale value improvement.

The Unichip is a good N/A piggyback but as optimized as the Toyota ECU already is, there just isn't a lot of room for improvement. Unfortunately the Unichip doesn't offer O2 sensor signal modifcation, mostly just more ignition timing advance. It does have a switch to toggle between 87 and 91 octane timing maps though.

"Chipping" can and does work great. The greatest improvement is for turbo cars since the boost psi can be raised. The biggest problem for Toyota owners is that the Toyota ECU code is un-cracked and they change it frequently to prevent it being cracked/hacked. While most manufacturer's ECUs can be re-programmed, the best you can do with a Toyo is to alter ECU sensor signals, which is not as effective.

"Stage I" chips do as you stated. They simply alter the IAT signal which tells the ECU that the incoming air charge is colder/denser than actual. This causes the ECU to run more ign timing advance and add more fuel. The problem is that in closed loop (CL) the O2 sensor feedback overrides the extra fuel and returns the AFR to 14.7:1. The optimal air/fuel ratio for emissions is 14.7:1. The optimal AFR for torque is ~13.5:1. You may still get the extra timing advance but now you're relying heavily on the knock sensor to detect pre-ignition and/or detonation and retard the spark accordingly. IMO, small hp/tq gains at best with small loss of mpg.

"Stage II" chips are more promising but have their own problems. I'm running a "stage II chip" of sorts, the Split Second Enricher. It's essentially a O2 sensor signal modifier. When my MAP (manifold air pressure) transitions from vacuum to boost it activates and skews the primary wideband O2 sensor signal telling the ECU that the AFR is too lean. The ECU responds by adding fuel resulting in a AFR of 12.5:1 (adjustable from 12:1 to 14:1). This works great for CL boost but how to trigger it when N/A? The SSE includes an internal MAP sensor and in theory can be set to activate at 4 in Hg vacuum but you'd have to ask SS if that's a viable option since the device is designed for boost applications. You could also use an external trigger such as a TPS activated switch to activate the SSE at whatever TP you'd like to see 13.5:1 instead of 14.7:1.

Having said all that, the big problem I see with the "stage II chips" you linked to is that none of them appear to include a 'switch'. Without one the chip would be active all the time changing your actual AFR from 14.7 to ~13.5. Great for power, not so great for mpg, emissions or your cats, despite their snake-oil claims of increased mpg.

Now as if I haven't said waaaay too much already, I must add that I don't know how much hp or tq can be gained from a N/A 2AZ-FE by altering the AFR from stoich (14.7) to 13.5, only that theoretically there should be a gain. In my case most of the unburnt fuel from running richer than stoich AFR is added to reduce combustion chamber temps to compensate for boost. If you're interested in pursuing AFR enrichment as a means of adding hp and tq, PM me and I think we can figure something out.

I loved that Popular Mechanics article although I think they missed the mark on water/meth injection. WMI is a great way to greatly reduce IAT, combustion chamber temps, boost octane and make more power. They simply showed that injecting water alone adds nothing.

Whew...

BTW, I find it very interesting that chip review #1 rated GTE best and noted that Engine Performance Power Chip was a "possible GTE knock-off with poor instructions" while review # 2 said the exact opposite. It was also very interesting to see how many "chips" actually lost power and mpg. Interesting but hardly surprising.

So much for the credibilty of those chip reviews, IMO. Jet Chip was well rated by both but I was warned against them by TC1 owners who said that they add nothing.

Good see your in B-more.You may have seen the teal xb with Tsudo dual
exhaust?

Yeah, that was part of my point with those links, there's a lot of inconsistency, which suggests to me that here and there a "chip" offering may actually have some benefits, but it very much depends on the specific car. Jet may "work" on one, but not another, likewise GTE. I searched reviews on both the recommended "chips" and both have thumbs down reports. I guess on the positive side, at least they typically appear to provide satisfaction guaranteed return policies, obviously though, not products one can be sure of when ordering (despite their seeming to have one for practically every vehicle ever made :))!

Hey Hon! What part of B-more you live in? I'm southwest of the city in BC. I recall seeing a gold RS 5 in my hood but don't recall seeing your teal box. You ever see my NBM around?

By far the best "chips" available are the ones that replace or allow tuning the ECU tables and especially on factory turbo cars. This is where the chip makers get their big HP/TQ improvement claims from. Since the ECU controls the boost pressure, they can raise the boost and easily add big power. Not nearly so much on N/A engines. Since all you can do to a Toyota is alter a few sensor signals, there isn't a lot to be gained. With others like Honda and VW you can actually re-tune the ECU.

Well, Jet Chip had a little scam going for the Supra community where they would claim to do this and that, and slap on their label, but everyone in the Supra community knows that our (or their :P) ECUs can't be reflashed. I wouldn't trust them on anything else.

You may be able to regrind cams for cheap, head port work yourself, and get a cheap piggyback and learn to tune it yourself properly. Those are the cheap stuff that can help, along with changing the rest of your exhaust. It gets expensive from there...

As for your 140 lbs, chop off any un-needed arms and body parts for lighter weight!

i have the unichip which i thourghly enjoy. i do notice a difference the few times ive had to take it off. the chip stock is worthless but using it the i/h/e combo i have it def is a boost. and there is also a difference between 87-93 which is how mines mapped. call it or not. my mpg went up quite a bit when i switched to the 93 setting. and i have proof. i did the same 3 hr trip on 87 did about 267 on the tank driving 6-70. did it on 93 and went 304. no variance in trip or gas station and so far its held up i hit 300 easy now on a tank. however when i do stomp it that gas does drop. so there is something to be gaind from the chip. there was a thread on here ages ago about that chip and the dyno runs to prove it. im sure someone can find it. other than that


camshafts? my buddy replaced his on his pontiac so maybe we can too?

aslo whats is porting? i've heard that before too

Porting can be done to like the intake manifold and cylinders in the engine it takes out all the little ruff spots inside to make the air flow or cylinder movement more clean and high flow. if you port the cylinder though you will more than likely have to get new bigger piston heads. but a port and polish on a aftermarket intake manifold can make for big power gains if done right :)

The only further porting I'd consider would be the head, about all that's still untouched, but that fuel enrichment idea is interesting. Anybody know if our ECU ever goes open loop except at cold start and deceleration? I would think the only other possibility would be WOT, but it may continue to monitor the wide-band even then. Though, perhaps under heavy load it enrichens already! Did you analyze any of that during your adventures Fred? I'm suspecting you already have all the instrumentation necessary to observe exactly how the ECU behaves under load in N/A.

Of course I can. :P
https://www.scionlife.com/forums/sho...d.php?t=186368

Unfortunately, all the dyno charts (page 5 of the thread) have been deleted from photobucket, so you can't look at them anymore, but from what he said the most significant gains where below the top-end peak horsepower where they are much more useable on the street. The link in his quoted post below does take you to some #'s where you can see reasonable gains of +10% hp & tq with the unichip from 4800-5100 rpm as compared to the intake & exhaust #'s without the unichip. I'm guessing you might see more improvement on a car with a header also.

ya elway!!! i miss him. hes cool. but yea. hey cionide. next summer im touring in the box. im making it out to you.

Yes, our ECU enters open loop at a certain load level and enrichens the AFR to ~12.5:1. The point it enters OL depends on numerous factors but IMO it feels just about right for a NA DD. For boost it stays in CL a little too long for my taste which is why I added the SSE to compensate and why the FIC and other piggybacks include or offer an O2 sensor signal modifier for CL fuel tuning.

The more I think about CL enrichment for a NA application, the less worthwhile it seems. All you could really do is enrich the AFR a little sooner and maybe increase tq a bit sooner. The SSE costs $200 and likely wouldn't add much. Cams, valves and head work seem to be the ticket for the NA 2AZ-FE.

^^^ and im interestedi nthe cams/valvues thing. cause it might be more afforadble for me to do that.

this is a daily driver till it becomes an antique. i figure the more i can do N/a the more impressive it is to me and the less strain on the car itself. the way i see it 4gs over a year or two is better for me than 5g drop one time on a turbo. setup

I can def vouch for that. once i hit around 4k it just comes to life. it briefly reminded me of vtec. how it only really kicks in when u need it. i've toyed with it where i would from 3800-4200 and just listen to the tone change. its actually helps me stay at 60-65mph on the highway. i dont like the drone at 70 which is pushing into the late 3-4 range

Cams, larger valves and head work should cost you around $3000 and possibly get you to 225 whp and 200 wtq with header, full exhaust, CAI, Unichip, etc. Add another $500 to get the Unichip re-tuned for the cams. Add the cost of the header, exhaust, CAI and Unichip and you're looking at $4000-5000.

A $5000 turbo kit can easily have you making 350 whp and 350 wtq. It's easy to see why so few go the NA route past the usual IHE point. Of course there are other things to consider such as clutches, trans, etc. with a turbo that you don't have to worry about with a low power NA build.

There's always the $4000 250whp/wtq turbo option I've mentioned before. Descendant tuner kit, 440cc inj's and gauges. Actually since you already have the Unichip, you could use larger inj's, add $500 for a tune and make 300whp/wtq pretty safely on the stock block. I forget, are you MT or AT?

Yeah, after you mentioned the SSE I spent time learning about it and looks like it's calibrated at least down to 4 in-Hg, and so probably could be used N/A. That's what got me wondering how the ECU already behaved and suspecting enrichment was likely already part of its load trim. If it's already dropping the AFR as far as 12.5, then it's hard to imagine even a switched stage 2 mod being desirable -- over-enrichment would waste fuel, risk the piston rings and cylinder linings, and probably accomplish little in terms of performance. Boost is a different situation since that begins well before WOT, it just extends the intake manifold range to include positive pressure -- the SSE providing an engine protection the ECU isn't programed for. I imagine my Eclipse ECU has that boost enrichment trim already in it's map. Very interesting stuff!

I'll have to do some reading up on header porting. Trouble is, I suspect it's necessary to strip the head in order to do that safely (no particles sneaking into inconvenient places), so that's liable to be shop cost for both the strip and the rebuild. Cams are probably reaching a bit and since most that fool with this stuff are looking for peak HP, not low to midrange torque -- probably especially expensive :(. Course, the counter to all this is I rarely ask for the performance available now, and even with a largely gentle throttle foot, mpg is impacted. Though as I said, interesting stuff.

Just a quick update. No luck finding a 2AZ-FE head porting article yet, but still looking. Did find a price example for having a particular shop in CA do a P&P for stock head components -- apparently $700. Also found the price for a Brian Cower N/A or F/I street camshaft for stock valves is $600 (also requires an install kit). Seeming a tad expensive for the serious cheapskate :(! Also, no info yet what HP & torque improvement is realizable via a P&P alone.

PS. I haven't spotted any endorsements of it yet, but if anyone's interested in the Bill Gude 2AZ-FE performance package, here's the website:

http://www.monstermarketplace.com/sc...ion-tc-xb-2-4l

From reading threads touching on professionally ported heads and after market cams, the message I'm getting is cams are good for higher end power, but hurt lower to mid torque, plus porting the head also tends to hurt torque -- the more extensive the port, the more loss of lower to mid torque.

That really isn't sounding too attractive to me, though I don't yet understand why porting alone would hurt torque (OE VVT-i and cams).

Well there is no over-enrichment because the ECU really does ignore the O2 sensor in open loop. Adding the SSE had zero effect on my open loop AFR, only closed loop.

Yes, there's no over-enrichment if the ECU is truly OL, but if it's enriching as part of its CL map, then there could be. Given a wide-band sensor (allowing accurate tracking well away from 14.7:1 AFR), I don't see why it would be in any hurry to go OL. I'm not saying it doesn't go OL, just that it seems unlikely it would automatically go OL with a wide-band just because the engine operating conditions require a richer than 14.7:1 AFR. Should this be the case, then it seems to me messing with N/A O2 sensor readings could cause over enrichment. The "Stage 2" GTE I linked has a slide adjustment marked "economy" at one end and "power" at the other. I'm guessing if the engine starts to stumble with a maxed "power" setting (over enrichment), the procedure is to ease it back until the engine becomes stable under heavy load.

Planning to continue poking around, but this Wiki article provides a lot of insight into head intake/exhaust passage porting:

http://en.wikipedia.org/wiki/Cylinder_head_porting

Another issue is material removal within the head cylinder domes may improve flow, but it also results in increased volume and reduced compression. A fix could be to shave the head a little to compensate, but that could also result in inadequate valve-piston clearance. Tricky stuff!

Seems clear that if low to mid torque is going to be preserved, it's necessary to be exceedingly careful about any porting work on the intake side of the head -- and not even smoothing and polishing is safe in the neighborhood of the injectors and intake valves (the 2AZ-FE uses a tumble design to improve air flow into the cylinders and passage shape effects that, plus some wall roughness assists evaporation of any residual fuel). I'm guessing turbulence reduction by smoothing any misalignment of the runners to the head could be permissible as long as there's no particular increase in port dimension. However, traditional HP oriented porting where both sides of the port are matched to the typically larger gasket openings would be a bad move. My takeaway is, even though porting may significantly improve flow (though not necessarily), it's very possible to not only not improve, but actually impair engine performance. Interesting!

There is no CL enrichment with our ECU. There is 14.7 in CL and 12.5 in OL and nothing in between. Remember that when the SSE is active, it's altering the wide band O2 sensor signal to tell the ECU that the AFR is leaner than 14.7. The ECU never sees any enrichment. It sees 14.7 when the AFR is actually whatever AFR you set the SSE to provide. AFR is not factored in by the ECU when determining when to enter OL, only load.

I imagine that the stage II GTE works the same as the SSE by modifying the oem wide band O2 sensor signal to the ECU. It tells the ECU that the AFR is say 16:1, the ECU then adds fuel to get back to 14.7 however this is actually say 13.5:1 now. This can easily be monitored using a wide band AFR gauge and a scan tool. E.g., when my SSE is active I see 12.3:1 on my UEGO gauge and see 14.7:1 on the scan tool. There will be no change in heavy load AFR since the O2 feedback is ignored by the ECU in OL.

OK, so you said specifically the ECU doesn't support any AFR other than 14.7:1 (regardless of engine load conditions). In the ECU parlance then, there is no such thing as enrichment, only 14.7:1 closed loop plus an open ended open loop mode. Yes, that surprises me, but if that's the way it is, then that's the way it is :)!

I've heard that Porsche stays in closed loop and changes AFR based on load. This seems like a better approach to me but for whatever reason, Toyota chose to use closed loop only for low load conditions. Perhaps because the average Toyota probably spends 99% of it's time in CL. I imagine Porsche isn't the only manufacturer to use O2 feedback in high load or alter AFR in closed loop but I'm not sure who does what.

We can still have CL AFR enrichment but only when we modify the O2 signal and effectively lie to the ECU about the measured AFR. Luckily for me Toyota's method works out great for my setup. 12.5:1 would be too lean for me to safely run 6 psi boost but by adding larger inj's I ended up with 11.5:1 in OL. Were I to add even larger inj's the OL AFR would be too rich without additional management. 440cc started as a best guess and turned out to be ideal for my application.

That's great the 440s worked out so well, good guess :)! Reminds me of the 1G Eclipse MAF upgrade where a 2G MAF is installed with larger injectors so the OE ECU will still control FI properly.

I guess having an OE wide-band is convenient for those few who choose to go F/I, but it seems odd Toyota specifies one if they're not going to use it (could have been included with a TRD supercharger). If they do it, I wouldn't be surprised if most manufacturers do it, so maybe it's part of the OBDII world so AFR can be monitored/logged for diagnostic purposes. Otherwise, I'd think they'd just go narrow-band for both since it's cheaper. Could be CL enrichment is reserved for performance cars, wonder if the zippy Honda's have it :)?

I'm AT sadly. the funny thing is my buddys boosted TC RSMILLER hits around 225 to the wheels now. and the amount of speed is NUTS. so if i got that doing cams/head work. i would have a slight advantage as i would have no lag time. second i floor it it goes. though i do love the sound of blow off values. such a wonder full sound.

I think Toyota uses a wide band for speed and accuracy. Narrow band O2 sensors are slow and inaccurate. When the AFR goes rich or lean it doesn't really tell the ECU how rich or lean it is. The ECU has to guess how much fuel to add or subtract. With a wide band the ECU reacts faster and more accurately determines how much fuel to add or subtract. The WB O2 allows Toyota to maintain stoich AFR much more accurately than it could with a NB O2. This is very important for clean emissions and fuel economy.

From what I gather most manufacturers use closed and open loop states much the same as Toyota. Porsche being the exception rather than the rule. Honda also handles CL and OL like Toyota. It appears to be the OBDII norm.

Actually your buddy would have the advantage even if you both had the same whp. With a turbo he'll have a much wider powerband and a lot more tq. The N/A engine will have a narrow powerband peaking in the upper rpm range and would greatly benefit from extending the rev limit. An N/A build is also much more suited to a MT than a AT. Your N/A engine would be more like a Honda. You also need more gear ratios to keep it in it's narrower powerband. A 6 speed MT would be great.

Honestly I think adding a turbo is much better than heads and cams for a number of reasons. It's easier to install and much easier to remove when you sell the car.

Also, to hit 225whp N/A would most likely require higher compression pistons as well. So you'd need headwork, pistons, larger valves, cams, valve springs, 93 octane, extended rev limit, intake, header, full exhaust, balance shaft delete, pulleys, tune, etc.

haha well fuk. did i ever mention how much i love you two.i basically ask all the questions the lurkers dont want to haha

I love you too Bro. :) TRD Sparks has the Descendant Tuner kit on sale for $2850 and they accept credit cards. :)

wait wait wait.

http://trdsparks.com/displayparts.ph...&parts_id=1336

yes?? for at??

next summer man. next summer.

Unfortunately, that's just the installation kit, doesn't include the limited slip differential itself :(! You need both!

http://www.trdsparks.com/displaypart...&parts_id=1310

.

Not to mention the AT to MT swap!