Slow acceleration after intake and exhaust
 

Hey guys

After i put in stillen gen 3 intakes and Top Speed Ypipe and exhaust, the acceleration isnt their anymore compared to the stock intake and exhaust.

just me? or everyone else. I still have stock cats.

maybe i need a tune?

I did not have a problem like this but give it some time for the ECU to adjust. Then see what happens.

A tune never hurts, especially with changes to intake (your gen3) or headers (which you didn't do). Also, sometimes subjective opinions of acceleration are all over the map compared to the real data. Quarter-mile times (same driver/track + DA correction) or a before-/after- dyno sheet would give a more realistic comparison.

You'd be surprised how many psychological factors are working against you on actually "feeling" whether the car accelerates harder or not. Aside from the internal ones, there are at least 3 key external bits of data that can throw you off: (1) The sound of the car changes, and changes differently at different RPMs, so the whole "ramp" of running through the RPMs can sound very different, and seem to sound "slower" or "faster" to you. (2) It's possible for the average acceleration to go up while the delta and delta-delta-acceleration smooths out. You're actually accelerating faster, but you don't feel as much seat-of-the-pants jerk/snap. (3) Likely your intake/exhaust shifted the power curve around. You may actually have traded worse sub-3K performance for better post-3K performance or whatever (which, if you only care about performance, is actually ok. In any track situation you're not going to spend enough time below 3K to care, but the car could actually have less instant acceleration on tap than before when you're at quarter throttle at 2K rpm bopping around around town in traffic).

i have disconnected the battery for 10min already but still same.

yep

^^ even without a tune the car shouldnt feel slower with intake and exhaust....

It depends, every car responds to some of these bolt ons slightly differently. When you move the MAF around, it can negatively affect the way some cars respond to the new MAF readings.

I would definitely get a tune, even if you didn't have those problems in order to get the most out of your parts and to make sure your A/F is completely safe.

Make sure there are no leaks, especially with the intake connections.

put some miles on the car....see if the ECU adjusts.... a few drive cycles

If not the ecu can only compensate for so much so a tune maybe be in order...does the acceleration feel heavy or loose...?

honestly, if the car is slower is must be an install or tune issue. There is just no way a car getting colder air would not produce more power. OP, did you make sure the sensors are all plugged in correctly? Check all of the connections and make sure nothing came loose or got cut, etc. Sometimes it's the little things you don't notice that create the biggest problems.

I have the same problem, just got g3's and berk exhaust installed and my car feels quite a bit slower too. it ran great for about 2000 miles now all of the sudden the car feels very sluggish, especially when it's cold out. I figure I need a tune because when it's warm outside it runs much better than when it's cold. anyone got any ideas? was going to start a thread on this but op beat me to it. also my exhaust tips got really black really fast, running rich I presume.

Thats the reason I run a short ram intake.. But what is kinda wierd is that the colder it gets the less responsive my car gets. It seems like it should pickup then. I mean a cold air intake in the summer months shouldnt be that different from a short ram intake it the colder months right?

you would think so... colder air is what usually equates to more power ... i've always heard anyway.

i'm actually curious about this, as I had considered getting a set, but if i'm going to need a tune right away then it's probably better that I hold off until I get more money together.

WHAT? Is this translated? If not, you need to use one.

To the OP:

Black residue coming from the exhaust is normal if you are running an upgraded exhaust system. The inside of my TDX is pretty dark. If you are smelling unburned fuel and your eyes are irritated after idling in place, I would agree that it's rich. Put it up on the dyno and you will know for sure