Thread: DID THE TOP-SWAP little or no HP gain and other afterswap issues

did a top swap from 97" Grand Prix GTP over onto my Grand Prix GT Running a CAI and a flowmaster exhaust.

Went through changed everything over all new gaskets from the heads up, had both heads Fully redone and what not, well i am now driving the car and i have a few problems someone might have some insight on.

First - i keep pulling the a code for a high idle "P0507"

Second thing the car hesitates when you step on it and has some lag all threw pick up but you can let off and floor it sometimes and it will pick up fairly smoothly but not to often, when i have the BBV hooked up to my vacuum lines i can only pull a max of 3 pounds of boost if i completely bypass it i can pull a max of 4 - 4 1/2 pounds and even with this i feel my car has the same if not less power as before the swap something has got to be wrong somewhere maybe a common problem with the top-swap situaton?

i know for sure this is nothing near what my car should or could put out at this point with the SC add on heads and valves all redone i should get way more power, my mom has the 04" GTP and when you lay into the peddle she moves and breaks the tires lose, at this point its a joke to get my car to break the tires loose

I have been very disappointed since the swap please help me figure this out i love Grand Prix and dont want to get off on the wrong foot with the first one of my own ya know cause once a car makes ya have a bad state a mind about it its kinda hard to have any hopes about them now or later.

well i hope to get some insight on this soon, also just thought about it, what about tuning, i need to get things tuned in i think some how and i dont have 200 dollars an hour to have Turbolabs down the street dyno tune it, is there someway to get around it or get it somewhere for pretty cheap.

thank!


please just anyone with any kinda helpful input would be so awesome this car at this point has just got me so dang frustrated id like to start ripping my hair out

Did you at least get a base tune or Canned Tune for the swap ? If not no wonder it runs like sh!t. Also check your vac lines and spray brake cleaner around the tb gasket and lim\supercharger gasket. It could have leaks there too. If the idle changes while spraying the brake cleaner near them then that's the source of the leak.

i have not had any idea of what to do for tuning, do i need to have a company tune it, is there a cheap tuner out there thats worth buying but no i have not tuned it at all, the dealer told me my PCM should self adjust for the supercharger that 98 and up SE GT And GTP models all the the PCM's and self adjust to the readings it gets.

what should i do to get it tuned/adjusted to start off.

also the car runs fairly good just dont feel like im getting any more power than before the swap.

They told you the PCM should self adjust.. I hope that dealership goes out of business. You need to get either a GTP PCM with gears edited or get a canned tune from one of the vendors with the tranny changed.

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

what do you mean by vendor? i would rather take the PCM outta my car and have the tune done on it. What are some more details on places to go to get it tuned.....

No vac leak, ive replaced all hoses and everything in that area.

Originally Posted by crrider999

what do you mean by vendor? i would rather take the PCM outta my car and have the tune done on it. What are some more details on places to go to get it tuned.....

Vendor = ZZP/Intense/3800Performance or Have someone locally with a HP tuner that knows what they are doing do it for you. You could also send it over to Reptile and he could hook you up.

As to the Vac Leak, just because you replaced the hoses doesnt mean you dont have a vac leak. Get ya some carb cleaner while the car is running and start spraying all around the lower intake/SC/TB if it boggs down you have a leak sir.

ill try with some break clean / starter fluid / carb clean or whatever i got floating around tomorrow, and you dont happen to know any people that do tuning in utah do ya? i been told there is a copany up in salt lake who does PCM programming at least i think thats what i heard when i had my camaro and was thinking about fixing it up.

good lord that thing needs a tune. The GT file is way too aggressive for a blower. I'm surprised you were able to drive around. Do you have a scanner? what supporting mods do you have?

find someone locally with a powertuner or hptuners to upload the correct bin for you. You might have to pull some timing in the gtp bin file due to lack there of supporting mods.

ill just copy and paste what i answered in my PM to you...

a) are you 100% you put everything together correctly and you have no vacuum leaks?

b) you absolutely need a tune in order to run the car correctly. without it your car will never run well.

c) have you put any other mods on the car with the top swap or do you intend to blow it up?

got any idea of what it will cost if i take it to a local shop to have it tuned and do you know of any company in utah who do custom tunes

A basic dyno tune around here would run $500, but you need to start off with the right fueling and spark tables. I'm surprised the car actually drives, just don't blow it up.

Originally Posted by crrider999

got any idea of what it will cost if i take it to a local shop to have it tuned and do you know of any company in utah who do custom tunes

you need a whole entirely different bin file, you can't do a WOT tune on a dyno untill you have the basic gtp bin you need. Reptile already replied to this post. Send him your pcm, like tonight.

On the same note, don't drive the car, lean 02's and crazy knock. Your going to blow your motor, especially if your goosing it.

Send it to reptile today.

Just send it to Reptile all ready and quit effing around with trying to find someone to do it locally. After you get the right tuning from reptile then you can work on tweaking it and such. Trust us Reptile knows his sh!t.

after you get a proper tune, I know a couple of tuners and 1 dynotuner in Denver.... not sure if that's local enough for you. (some people will drive from Utah to Denver, so...)

planned on sending it out first thing in the morning, only down fall out of a car tell i get it back haha but yeah rep will have his hands on it soon enough!

I plan on having a Company called TurboLabs Dyno tune everything and tweak it all in after i get a few more things done, whats the place in called, if they know what there doing and work with 3.8s more it might be worth a trip out there, im 45 minutes south of Salt lake city so its a bit of a trip but nothing is to far if someone really wants something and i do want every penny in this car to count ya know.