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

I have the G3 intakes and Berk exhaust on my Z and definitely felt the increase in power and acceleration as soon as I installed them.

well the acceleration feels heavier. but around 4k rpm it climbs faster, i can feel that. The sound how ever, doesnt seem very responsive? mmm thats how i would describe it, especially second gear (changing from 3k-3.5k in first to second) when i floor it, it just feels more 'heavy'.

The sensors on the Gen3, does it matter which way it goes in?

i do know the y pipe is 2.75inch, and rest is 2.5inch.

btw, how can i get it tuned? i am in australia. take it to dealer?

Make sure the sensors are oriented the same way they were in stock configuration.

I'm going to get a tune from Stillen soon so I'll keep everybody updated once it happens. Stillen also thought it was wierd that my car ran worse when ambient temps r cold. could my fuel pump be bad, and unable to provide enough fuel for cold weather?

I know what u mean. For some reason my car only feels a bit faster with gears/g3/exhaust. Seemed like I was better off just stock with test pipes lol

my car feels like its reving up as quick as it did stock but the power delivery feels as if my wheels r slipping or the clutch is not fully engaged. I used to feel a nice difference in power for the first 2000 miles on this setup but all of the sudden, overnight, it doesn't drive as well. almost like I got a bad tank of gas. that's what I thought it was at first so I let the tank run low and filled up at a different gas station and reset the ecu. 150 miles after reset and still no change. I'm confused......:ugh2:

I also hear a little pinging below 3000 rpm when I give the car some gas. I noticed it today when my window was down. anybody got any ideas what could b causing this. I checked all intake fittings and they r all secure.

Try Tunehouse if u r in Sydney they are pretty good

Probably something isn't bolted down well, and the MAF sensors are moving around under load.

As a consequence, you will get MAF sensor misreads, which may be telling the ECU to add too much fuel.

That would correspond with being down on power and blowing out black smoke (i.e., unburnt fuel).

Other possibilities include damaged MAF sensors (unlikely) or a vacuum leak somewhere either before or immediately after the primary O2 (quite possible).

Whatever is causing the noise (hopefully not actual engine knock...) may be alerting the knock sesnor to pull timing.

thanks for the info. like I stated before I'm going to go to Stillen and get an uprev tune and get the car looked over. just today I heard a kind of squeaky tick sound coming from the drivers side of the engine bay. increased in sound with Rpms. I really hope I don't need to go to nissan for warranty work.

this isn't to make you feel stupid, but you didn't accidentally put regular gas or go to a different station than normal did you? You said you heard pinging so i'm just making sure.

no worries, it's a valid question. I put nothing but 91 octane in my car. it was the same station I always go to. I changed stations after I thought I got bad gas. are the g3s supposed to be able to be moved around in the engine bay? I can move mine like they r just laying in the front bumper for support, if they are moving under load like jordo suggested would that cause the problem I'm having? I had Stillen install my intakes so if there is a problem with the install I'll take it back to them to have things done right.

as far as being able to move them I have no idea to be honest. I'm sure if Stillen put them in then they were done right.. I would imagine anyway.

can somebody who has the g3's chime in here and tell me if their intakes are able to be moved around in the engine bay or if they are firmly in place. I would greatly appreciate it.

I would imagine that unless they have some sort of mount somewhere that they would move at least some. If it's just the silicone that is holding the pipe in place then that would cause a lot more movement. Did you look over the DIY on the install on here and see if there are any other areas that secure the intake?

It's possible that it's like that to allow for engine movement when under load too.

as a matter of fact I did look over ak370's write up his g3 DIY. I noticed that the area where u r supposed to dremel out the vent for the stock intake is not even there any more. the whole plastic piece is gone. this piece of plastic is supposed to be dremeled out just big enough to fit the intake pipes through. I would figure that this is the only support for the piping and would sufficiently hold everything in place. as my intake stands now it has no support and are just basically dangling in the front bumper.

I'm a little disappointed in the install by the Stillen mechanic at this point, seems he took a shortcut and never dremeled out this part and just took it out all together:(

Where abouts in Austarlia are you?

Try mark at MRCDyno (castle hill)

Join zclub.com.au as well!

That could very well be the problem. The MAF sensors do NOT like to be moved around -- they are VERY sensitive to airflow tumble.

Shouldn't be too hard to have some brackets made up to hold it in place. Alternatively, order the parts that were removed from Nissan (or see if the shop still has them lying around) and then have them cut to use as supports.

I'd take care of that before getting the tune -- the tune won't help if the ECU's getting erratic MAF signals.

thanks for the advice, I will definantly check into that. ill probably have that all checked before it goes in for a tune. thanks;)

That is an interesting turn of events. Hopefully you can get that squared away without putting out any more cash........

we'll see.... I'll post after all is said and done to let yall know what the verdict is. hopefully it will help anyone else who has this problem.

If he did take them out completely, then you could just get some sort of rubber mat type of stuff and wrap it around the pipe until it fits securely... if not that then maybe some kind of hose cover.

those r both good ideas. I'm going to try and see if I can get them secured better to try to limit movement. I'm also going to get the exhaust bolts checked to see if any of them have loosened enough to cause a small leak near the primary o2 as jordo suggested. I just don't undertsand how my car can run beautifully for 2000 miles after my exhaust install then fall flat on its face overnight.

It's frustrating when it comes to modding, and also when your car doesn't run the right way. Luckily these are actually pretty mild mods and likely is an easy fix that is probably something simple. Just try to relax... you'll get it straight.