3ngin33r1

A crap one. You should always dyno and then street tune, dyno again, street tune, so on and so on..

jshimer23

I don't think the "race cat" (i'm assuming testpipe) has anything to do with your car running rich. running rich or lean has to do with the air/fuel mix, which is controlled by the ecu. Installing a higher flow cat or testpipe helps to smooth out the exhaust flow and removes some back pressure. That's it.

you also said you added the race cat to run a bit more rich to gain a few hp. well isn't exactly true either. As i've read before Rich is safe but slow, while Lean is dangerous but fast. Leaning out the A/F mix will gain power to a point (going too lean...well lets not do that). If you're trying to gain max power, you only want to make the mix more rich in areas in the rpm band that are too Lean.

hopefully whoever tuned your VAFC (adjusts A/F mix) understands these concepts. I'm not knocking the shop you went to because i don't know them, i'm just saying there ARE bad tuners out there.

Now as far as the ECU readjusting itself after the VAFC tune, I've heard it only does this for the partial throttle map. I've read it won't readjust for the WOT map. I haven't seen any actual proof on this however so take it for what it's worth.

GPW03

Yes, a street tune will be more accurate as it will relate to real weather conditions whereas on a dyno the air entering into the vehicle is forced through a fan/blower. Either way have her thrown on a dyno and do a base run to see if it matches up to your original dyno plot.

SlidinS2k

twelv

You are prolly use to the power and it does not feel as fast as before. Cars that are just as fast FEEL faster because they have more torque which will throw you back in your seat harder. My Altima and my 350Z FEEL faster but they are not. They just have more torque then my S2000.

This is to the wheels.
S2000 Supercharged 189 lbs of torque
Altima 252 lbs of torque
350Z 265 lbs of torque

BigpoppaHurtm

Just race people at the local drag strip. If you can out run fast cars and get decent times then you know its not really slow but just feels slow. This may be pointless if you dont have pre-mod times but at least you'll know if the cars in the 13's which is fast for a basic bolt ons S. For about 20 bucks it will cost less than getting it retuned.

S2000GT

hahaha and only if you apply the supplied stickers too

s2kpinoy

thanks for all the suggestions and information guys! yea when the car was tuned, it was dynoed as well....with a huge fan infront of the car. the shop does quality work, very well respected down here in houston. but yea i actually ran a friend of mine with an 03(w/ a CAI) off a roll and a dig. on the roll, id be about 1/2 a car infront, but he eventually pulls on me. Same goes from a dig, id jump about a car and he eventually catches up . i definantly set up another tune/dyno session and find out what's really going on.

Reds2kracer

Racing also depends on drivers, not saying that you're a bad driver but did you guys swap cars and see if the results are the same? If you'd gotten it dyno'ed then what kind of hp/tq are you putting down? More infos would be nice, if you guys swapped cars and still it's the same outcome then there's something wrong with yours. Hope that helps...

Silver9k

maybe your valves need adjusting?