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Performance issue?

DBGP

DBGP

New member
hey im new here and im not the greatest tech guy when it comes to cars, but i do have a question which i cant figure out, maybe you guys can help me. I have a 1998 GP GT with the 3.8L (non supercharged,) with 147*** km's on it. I have a K&N CAI, mangaflow mufflers, and new wheels. By factory it says my car has 195hp, with a stock 0-60mph in 8.1 seconds? My car should have around 210hp im guessing, and i am getting 0-60mph's in 9.9 seconds. I have had the fuel injection system cleaned, i just had a tune up with new plugs, distributor, fuel filter. Is there something else that i am missing? because i should at least be getting 8 seconds flat. Or am i just an idiot when it comes to starting off? With my new tires i am almost getting zero wheel spin when i launch off. Oh and by the way, my new wheels are abit larger and wider. Thankyou in advance.
 


plugged cat? do you have any codes showing? what are you using to measure the 0-60 times? The wheels will slow you down a tad if they are bigger than stock, but if you have little wheelspin you should be close to stock. Does it seem to pull hard or does it run smooth and feel good?
 
Well, you car isn’t exactly new any more. And your upgrades probably won’t get you 15 HP, you upgraded the best part of the exhaust system.

That being said, from the information you listed, I’d guess it is the tires. If you went to a larger OD tire your 0-60 speeds will fall off for sure.
 
Yea my wheels arent much bigger. theyre 255/55/17. But yea it still really puts you back in your seat. No i have no error codes. How would i test to see if my cat is plugged? And yea im aware that its old and prob isnt putting out the same horsepower but i wouldnt think it would be that signifigant. My friend just sits in the car with me and uses his stopwatch on his cell phone to see. Not the most accurate i know but it deffenatly wont be 2 seconds off. Thanks for the quick reply guys.
 
On a basically non-mod car that has been relatively well maintained your cat should be fine. Again this is just my opinion, you might be suffering from a bad case of 40mph WOT lagg. So if you feel the need get your PCM tuned and get your trany fluid changed.
 
just got the tranny fluid, and bottom plate changed 2 months ago. Where could i go to get my PCM tuned?
 


I was about 2 ask that very same question? A distributor? Also u'd b suprised as how bigger wheels can slow u down, i gained 9 tenths of a second on y 1/4 mile going back 2 stock rims and gettin rid of the 18's i had. Big difference.
 
40mph wot lag is the time it takes the tranny to shift from 4th to 2nd. the only thing to change that with a tune is skip shifts. that is not going to have anything to do with off the line acceleration.

are the wheels heavy?? did you spin alot?? do you have the stock wheels to try it with??
 


yea i got the stock wheels still. With those i got 8.9ish. But with the stock wheels i spun a huge amount, but with the new ones, it just make a loud irch sound and thats about it. Ill look into that pcm. So is it prob just a combination of an aging car with bigger wheels?
 
i wouldent nessicerly point it towards the ageing car. i dont know what it would be in km but i have 100,000 miles on mine and it runs like a champ.

take it to a drap strip to get a real conclusion.

maybe the car is having other issuies you dont know about..
 
think of it this way....if you could launch your car with stock wheels on it and not spin you would probably be within a half second of advertised or closer yet. add in the factor of what you are using to time it with and you are right there. IMO it is probably fine. You just have to learn to launch your car on smaller tires and not spin. Also, if your friend was in the car with you that could slow you down a little bit too.
 
Liquifire said:
think of it this way....if you could launch your car with stock wheels on it and not spin you would probably be within a half second of advertised or closer yet. add in the factor of what you are using to time it with and you are right there. IMO it is probably fine. You just have to learn to launch your car on smaller tires and not spin. Also, if your friend was in the car with you that could slow you down a little bit too.
Click to expand...

X2 Spinning is the slowest way off the line other than pushing it.:p
 
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