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car seems slow

jrb1027

jrb1027

New member
Hi I just bought a GTP and love it, except for one thing, its not as fast as i think it should be. First ill let you know the mods.
-1.8 SLP roller rockers with SLP pushrods
-gto ls6 valve springs
-Gen V blower 3.4 modular pulley
-SLP ceramic coated headers
-2.5in catback
-SD hood ram air/cold air intake
-custom programmed pcm
With all these mods im only getting a 7.2 0-60

Other problems I noitice
-when I shift into 4th at WOT the car stutters untill i let the throttle up and get back on it.
-after a good hard run it shuts off after 2-3 seconds when I start it back of while its still hot. If i keep the rpms up for about 10 seconds it will stay running.

I really want to know if this is normal behavior from a gtp or is something dramatically wrong.

Anyone with similar mods what are your 0-60 times

Thx, Jake
 


First off, shifting into 4th gear at WOT is just asking the transmission to kill itself. So don't do that.

There is no reason to be going over 130 mph anyway.

Second, do you have anyway of knowing anything about how the car is running. Like any gauges.......... aeroforce scangauge, wideband o2 sensor for air to fuel ratio etc etc etc.
 
Thank-you for the reply unfortunately I only have a boost guage it's pushing about 12psi. I just got the car so I haven't had time to order the aero force, would I be better off with the aero force or a scanner.

Forgot to mention its a 2000 with 125k has a northstat tb and LS maf
 
Car sounds a cluster **** of problems then.

But either way you need a way to monitor what the car is doing. Aeroforce's are easy to use and because they fit in a pod, easier to glance at than a hand held scanner in your lap.
 
How close are you to PRJ? He's around indy. He'd be able to look at your tune and see if you are even tuned for the maf and tb.
 


PRJ? im new to the gtp world I assume he has a shop. But yea im an hour and a half from indy that i would like to get in touch with him.

-More background of car The car spent a lot of time in a garage the past 2 years as it was mainly a show car and the guy upgraded to a g8. The guy I bought it from was my best friends co-worker. It has ALOT of suspension and brake work, I estimated he put about 10k of aftermarket parts on it. I only paid 3600 and got extra supercharger GEN3 extra hood and 2 sets of custom wheels.

- previous owner also told me last time it was tuned there was 1-2*kr and he had it tuned back some, however he thinks it was false due to engine mounts.

I really want to get this thing running right and im not opposed to spending some hard earned money to do it.

Should I go ahead and get the aeroforce now if I plan to have it checked out by prj?
 
I bet that you are knocking like crazy with that gen v and a 3.4. Find a way to scan - aeroforce

Just because the previous owner says they only saw 1-2* does not mean you aren't getting more than that now.
 
A 3.4 on a Gen V with just those mods and nothing to scan...yea I bet its knocking. The exact reason I won't buy a modded car from someone unless I really knew them. Oh and keep shifting in 4th a WOT and you'll be replacing your tranny.
 
jrb1027 said:
PRJ? im new to the gtp world I assume he has a shop. But yea im an hour and a half from indy that i would like to get in touch with him.

-More background of car The car spent a lot of time in a garage the past 2 years as it was mainly a show car and the guy upgraded to a g8. The guy I bought it from was my best friends co-worker. It has ALOT of suspension and brake work, I estimated he put about 10k of aftermarket parts on it. I only paid 3600 and got extra supercharger GEN3 extra hood and 2 sets of custom wheels.

- previous owner also told me last time it was tuned there was 1-2*kr and he had it tuned back some, however he thinks it was false due to engine mounts.

I really want to get this thing running right and im not opposed to spending some hard earned money to do it.

Should I go ahead and get the aeroforce now if I plan to have it checked out by prj?
Click to expand...

Prjperformance.com

You should buy a Aeroforce now to scan for knock before you kiss a piston goodbye...meanwhile I suggest you drive like a grandma and don't beat on the car until you can scan.

I would also have prj check it out for you. You bought a modify car without really knowing it so there's is no telling what could of been done and the owner may or may not of told you the 100% truth.

Assuming it probably has a MPS hub on it I would also suggest buying a larger pulley meanwhile till you solve your issues like a stock sized 3.8
 
-As far as the 4th at WOT goes, it never happend I thought I was in 4th but was actually going into 3rd it was only 100mph so it couldnt have been 4th, ive only had it to 120 so far.
-I just dropped it off at the mechanic to get a new axle, oil leak, and he said he would scan the kr for me.
-I pm'd a member about an aeroforce and should be getting that soon.
-Now im going to try to contact PRJ and see if he can check it out for me
-monday its going to the body shop for new paint on the hood and the spoiler, ill be getting rid of the orange on the spoiler lip.

Id like to thank everyone that has contributed to this thread, if it wasnt for you guys I would be pretty lost right now.
 


You can also use a $20 part and Android app ($5) and scan just as well with a smart phone. I will record what your engine is doing as well and can reset codes. A quick and easy set up until you get everything straight, then I'd invest in the aeroforce. Just my$.02
 
I already got the aeroforce, a fellow member sold me one it should be here soon. Does anyone know what my car should run in the quarter assuming i get the issues sorted out. The mods are listed in the post #1 and #4.
 


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