View Full Version : Questions about auto boost


DJ_FroZone
06-06-2011, 11:41 PM
So its another summer with the box. I've done everything i can to it really n/a wise. Its quite quick but my buddies RS1 tc greddy/ptuning turbo kit is a sick beast (Swapping to 5 spd) we did it in our own garages save tuning it.

I've been toying with saving money for boost or finding a 95'+ bmw and dropping a 2jz in it. my box is auto and DD lots of driving in this thing for college and work. I hear that having a boost means a ____ ton of work maintenance wise as far as oil but if u dont hit boost all day its not bad on gas. I'm just looking for feedback on ppl with autos who boosted. I dont have the cash to swap to manual or go find a bsp manual and deal with trades n ____. I only know of descandent having a boosted option for xb2 and i think cx racing? one thing i do know is the hks blow off valve is sick and has the sound i like haha.

so any and all info would be helpful

DJ_FroZone
06-06-2011, 11:45 PM
also already have a unichip pnp harness

STCxB
06-07-2011, 04:32 AM
I know there are a few guys on here who have boosted autos, but it doesn't sound like they run more than 5-7 psi if I remember correctly.

The last post of this thread is quite helpful:
http://www.clubxb.com/forums/f67/automatic-tranny-can-handle-38822.html

ScionFred
06-08-2011, 07:32 PM
By far your best option is the Descendant Tuner kit for $3k. You'll also need 440cc injectors, a trans cooler and gauges. The amount of boost (5-7psi) will depend upon how much HP the setup makes with your exhaust. With 440cc inj's you won't need a piggyback but you can use the Unichip or another piggy if you like. Your limitations will be 260BHP (225WHP) due to the injector size. The stock AT is said to hold up to 250 whp but to get that requires larger inj's, a piggyback and a tune. Not worth it IMO unless you plan to spend $5k on a built AT but once you do that, you can crank up the boost and hp to 300 whp.

As you may remember I'm running 6 psi with my no-piggy setup making 220whp/220wtq which is good for 0-60 in ~6 secs, 1/8 in 9.2 secs and 1/4 in 14.33 @97 mph. I can't keep up with EVOs and WRXs but it is faster than a Genesis Coupe or GTI. If that's not enough, you'll need to raise your budget considerably. I believe that I am very close to the limit on the AT and 440cc inj's but the car runs like a factory turbo car and is 99% CEL-free.

I wish I could say 100% CEL-free but in the past 6 months since I finished my build I've had 2 CELs. The first was a P0101 that I reset and the second reset itself before I could read it. Still, it's good enough to pass emissions testing.

In summary, I love my no-piggy turbo XB setup and wouldn't recommend it if it didn't work so well. If you have $4000 to spend, I doubt that you'll regret it.

DJ_FroZone
06-08-2011, 11:35 PM
whats the dif between the tunner friendly and the full kit package that descendnt offers? and dont u have the CXR kit? and I suppose i could contact unichip and see if there is any advantage to keeping it when i go boost

ScionFred
06-09-2011, 02:16 AM
whats the dif between the tunner friendly and the full kit package that descendnt offers? and dont u have the CXR kit? and I suppose i could contact unichip and see if there is any advantage to keeping it when i go boost

The full kit includes 750cc fuel injectors, AEM FIC w. base tune and PnP harness. You still need gauges but you could go this route for a budget of $5k. I started with a CXR kit but the only remaining CXR parts are the SMIC and IC pipes. You could build a good setup from the CXR kit but it would take a lot of custom work and money. As sold the CXR kit is not a good choice at all.

Unichip will tell you that you need a piggyback (preferably theirs) for boost. It's what they sell after all. Just keep in mind that they don't have a base tune for your turbo setup so you'll have to find a tuner and pay him to tune it for you. The N/A tune on it now will not work with boost. Budget $500 for a good tune.

I was merely suggesting a low-cost and very effective way to get 225 whp for under $4000. If you think it's worth another $1000 to $1500 to have 250 whp and push your AT right to the edge, buy the full Descendant kit or go tuner kit with 550cc injs, keep the Unichip and have it tuned. IMO the full Descendant kit is the better value of the two options. The best overall value is the tuner kit with 440cc inj's, gauges and no piggy or tune required for under $4000.

Then again, if money is no concern, send your AT to IPT to have it built for $4000, add a $550 torque converter upgrade, crank the boost on the full Descendant kit to 12 psi and try to find any traction for your 300+ whp FWD econobox. Good luck.

DJ_FroZone
06-09-2011, 02:25 AM
hahaha i actually like the eco version for under 4k. i mean if the time comes and i just want more than 7psi. then ____ it i will just doo all that other crazy ____. my friend went to ptuning to have his tuned for 400-5. however if what you say works. i could sell my unichip (worth 300 easy)

so if i went the no piggy back mod way. would it even make a difference to have it tuned? unichip or not?

ScionFred
06-09-2011, 03:49 AM
hahaha i actually like the eco version for under 4k. i mean if the time comes and i just want more than 7psi. then ____ it i will just doo all that other crazy ____. my friend went to ptuning to have his tuned for 400-5. however if what you say works. i could sell my unichip (worth 300 easy)

so if i went the no piggy back mod way. would it even make a difference to have it tuned? unichip or not?

After re-thinking your situation I'd like to change my recomendation to the full Descendant kit. Sell the Unichip and put that money toward boost and AFR gauges. The FIC comes pre-tuned and is better than the Unichip for boost applications. Depending on which gauges you buy you could get a complete PnP kit for $4600. Call Rob at Descendant and ask him for a package price with gauges. If you run into any problems you'll have tech support from Descendant and there are lots of good FIC tuners available. World Racing even has a shop in Reading, PA and IIRC you're on this coast.

If you're still interested in my no-piggy setup, PM me and I'll try to outline the pros and cons in more detail. It's simply too much to cover here.

DJ_FroZone
06-09-2011, 03:54 AM
^^ based on what you just threw out there. i would just go with their bolt kit. now the second question is AFR gauges? like what do the gauges do? yea im in NY.

ScionFred
06-09-2011, 04:17 AM
^^ based on what you just threw out there. i would just go with their bolt kit. now the second question is AFR gauges? like what do the gauges do? yea im in NY.

AFR is air fuel ratio and is measured using a wide-band O2 sensor. It allows you to monitor your AFR so that you'll see if there's a problem. For instance AFR should be ~14.7:1 at idle, cruising and almost all part throttle driving. As you accelerate and boost builds the AFR should start to drop into the 12:1 range and at WOT it should drop into the 11:1 range. If the AFR is too lean it can cause detonation which can bend rods and/or melt pistons and valves. It's good to keep an eye on AFR even when tuned. Things can go wrong.

The other gauge to have is a boost gauge so you can monitor your boost levels. If for some reason the wastegate malfunctions it can result in a boost spike that can also cause engine damage. If your wastegate spring is 7 psi, your max boost should be 7 psi. If boost spikes above ~8 psi you may have a problem that needs to be fixed.

Talk to Rob at Descendant. He's a good guy and can tell you all about their kit and which gauges they recommend. I'm using AEM but Prosport cost a lot less. Since you're in NY, if you need a tune, Dezod is also in NY and has a lot of experience with tuning TCs with the FIC.

Since we're talking low budget boost, I should add that the CXR kit could be the basis for a reliable turbo setup. The fitment of mine was excellent and the only sub-standard pieces are the Chinese turbo and the thin-wall turbo manifold. Chinese turbos are hit and miss regarding quality. Some last only a few hundred miles while others last years. When they fail they can be re-built with Garrett internals and last much longer. The fix for the manifold is adding support braces that support the weight of the turbo and downpipe. This takes the strain off the thin manifold tubing. These braces can easily be fabbed to attach where the oem header attaches low on the block. It may be something to consider.

CXR kit - $1600
Bracing manifold - $100

Total = $1700

Cost to have CXR turbo re-built with Garrett internals - $300
Cost of genuine Garrett replacement turbo - $600

Just food for thought.