2004 GT Top Swap (Lots of Pictures)

I should be worried, mechanically everythign will bolt up directly to the L26 from the L67, except the TB will have to have a custom adapter made.

Electrically everything plugs in except the BARO sensor needs to be wiring in completely, because the L26 doesnt have a BARO sensor. The MAP sensor will need to have the wires spliced into, no big deal. The BBV will also have to be completely wiring in which doesn't sound too bad.

Another member on here (duane9586) has done an L32 swap on his 05 GP GT. So he is giving me alot of insight into the BARO and BBV sensors. He was tuned from Will and Overkill via canned tune, and he is now running like a 3.4 pulley so I will feel pretty safe with my 3.8 pulley.

Oh by the way, I am doing a U-bend delete also ot help with knock and I will always be running PREMIUM FUEL.

custom adapter that ZZP sells...

Quote:

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Originally Posted by Bio248

custom adapter that ZZP sells...

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That is for adapting an L67 TB to a Gen V blower not the other way around. I am going to fab up my own bracket.

good thing i read. youre right.

Good News! Small breakthrough in getting all my information today. Figured out exactly how to wire up the BARO sensor. I have this diagram and a PCM pinouts diagram so I am good to go there! Now I just have to figure out how to wire the BBV. I don't understand how some people say I don't need to wire the BBV up? I just assume I do. Anyone have any info on this?
http://www.grandprixforums.net/membe...ct-iat-maf.gif

you dont need to wire the BBV up, but if you dont you have to make sure the car doesnt think its hooked up and tries to dump boost when it cant. either you hook it up and run the car as intended, or you leave it run on vacuum and you tune the car so it doesnt use it how it used it.

get it? i never had mine hooked up to the PCM and most guys who top swap don't because its another piece of the puzzle that is unnecessary so long as you tune around it.

Bio,

Your kinda making sense. Basically my car will only make as much boost as the pulley allows. Stock is like 7 lbs of boost. It cant get any higher because the blower, with that size pulley will never allow it. Correct?

So without the BBV hooked up what do I lose? Remeber I am getting a mail tune and do NOT have access to a tuner myself. I do plan on driving down to Fort Wayne Indiana to Sinister Performance, who tuned my Turbocharged Grand Am, but not till I have a chance.

if you have no way of tuning around it, youll need to hook it up to the PCM so it functions correctly.

either way, boost is limited by pulley size. the BBV when dumping boost, will limit boost to 4-5 pounds regardless of pulley size. when run vacuum only, you will ALWAYS have full boost since the solenoid will never be activated via the PCM.

So basically I will just get poor fuel economy if I dont have it hooked up.

no.

you just can't use traction control.

Hmmm, not that big of a deal, but I would really like to have no CEL after the swap. I will probably wire it up. BTW what does a stock GTP run for boost in 70 degree weather.

not having it hooked up wont throw a CEL or SES, whatever you want to call it.

Anyone know of a tuner in Central Wisconsin? I suppose I could drive down to milwaukee but would prefer someone closer.

Man O man, I think I spun a rod bearing in my L36, so I was going to buy a low mileage L26 from a yard and put the L67 top end I have already on it, glad I read this. Let me know how it goes, I'll be doing this very soon, not being able to drive mine right now.

The top swap thread will cover what you need to know whitegxp....

I've been reading but would you mind posting the link? :D

http://www.grandprixforums.net/f17/t...lots-7763.html

first link in the section this thread is in.