Hamiy

I have a few question about what to do when I get my setup tuned. Most likely going to be tuned with AEM EMS or possible VAFCII.

If I get it tuned with a test-pipe and no cat, will it make better gains than w/ a cat? Or will it just be the 1-3hp same gain?

Lets say I get it tuned without the cat. What will happen if I have to put the cat back on for a day? I am guessing this will be forcing too much air out the back and their will be a pressure buildup in the cat?

Thanks for any info

m@dm@n

car isn't turbocharged, leave the cat in.

S2kracka

People have been seeing nice gains by running a testpipe instead of the cat even while close to stock.

bluesaint

you will have to re-tune it once u put test-pipe in. the exhaust flow rate will increase, which means your A/F ratio is effected.

Hamiy

What would happen if I tune it with the testpipe and then put the cat back on (for less than a day?)

s2kjay

how would i just take the cats off and im close to stock

would this be a bad thing to do..i just wanted to experiment and see how loud the car will be if i take the exhausts off

Hamiy

Heres the new question for those who have used a EMS (VAFC2 or AEM EMS)

If I tune it with the testpipe and then need to put the cat on, I will need to reset the ECU. If I then decide to put the testpipe back on, do I need to get it dyno tuned again or can I just remember the settings I used before and do this manually? Do you need the maps or whatever to tune or can you do it bye yourself? I know its unsafe to tune by yourself normally, but if I already know the settings I want, it should be fine.

Any suggestions? Can I actually tune on my own after I get the correct settings from a professional?

m@dm@n

what gains are people seeing with a test pipe?

1Ferris

The S is louder than hell with the cat and exhaust off. Completely impossible to hide from the cops if they are even a block away.

AJ PwR

About 3-4whp with a stock exhaust.