intake backfire, engine sluttering

[midnight03]

hey I put a 3 inch universal cone filter(3.00" Mouth Air Filter 6" Base, 5" Tall, 5" Top) on my stock piping and when I started it up and rev'd the car a little the filter is very loud and when I let go of the gas it sounds like it back fires a little back to the filter, and around 3,000RPMS the engine slutters. I haven't taken a ride yet but I think the engine slutters cause you can't rev past 4,000RPMS?? But anyways is the loud filter sound and backfiring sound normal when having a cone filter? [:I]

[Mike-in-Orange]

Yeah, there's a cutoff so you can't overrev the engine in neutral, so that's most likely causing the stutter you're noticing.

As for all the new sounds you're hearing - by removing the stock airbox and putting in that cone filter you've removed all the silencers, except of course the baffling in the stock intake tube. Yep, there's all kinds of new sounds coming out now! I have Adam's V.A.K. intake/uppercharge system on my car and you can really hear that turbo! I did notice that under pretty normal acceleration (like from a stoplight when you're stuck in traffic) that things actually sound pretty "normal"

[sakigt]

Backfiring? If it sounds like a stutter going back to the "intake" the its only compressor surge. You get this normally but never hear it.

[midnight03]

is it possible that the filter is too small?

[Mike-in-Orange]

Yeah, SakiGT makea a good point - you should not be having any real backfiring; that would be bad.

The size of the filter isn't what's revealing the sounds you're hearing, it's the opening up of the intake and elimination of all the silencers. Otherwise the size of that filter sounds pretty normal.

[midnight03]

I dunno it sounds weird I'll try to get a video of it, also I haven't got a breather yet for that little tube that comes from the valve cover could that cause any problems?

[Mike-in-Orange]

quote:midnight03 Posted - 06/29/2004 : 8:19:50 PM
I dunno it sounds weird I'll try to get a video of it, also I haven't got a breather yet for that little tube that comes from the valve cover could that cause any problems?

That little tube is really just to release the normal pressure built up in an internal combustion engine. The factory vents it to the bottom of the airbox before the air filter. You are now venting to atmosphere, which is a no-no as far as the EPA is concerned. You will also be blowing oil vapor into your engine bay, which will condense into a bit of a mess if you don't do something about it!

Now you've got me thinking....a dangerous thing at times. Just where is this cone filter sitting? Just at the end of the stock intake pipe that normally attaches to the stock airbox? If so, you've got to be sucking a ton of really hot air into the turbo. Not the best way to gain horsepower. Most aftermarket cold air intakes at least make an attempt at placing the cone filter close to the wheel well where cold(er) air is actually available.

While I appreciate you're desire to gain some power without having to spend a ton of cash, I think you'd be better served by going with one of two options:

1. Pick up Jim's "brand X" turbo intake pipe and a K&N drop in filter for you stock air box, then remove the white donut silencer and maybe the snorkle silencer as well. You'll be drawing cool air from where the engineers intended, but you'll increase airflow into the turbo because of the freer flowing K&N and Jim's very cool smooth walled 3" intake pipe. You can also keep that hose connected in front of your stock air filter. About $100 for the pipe, $30 for the filter

2. Pick up Adam's V.A.K. intake/uppercharge pipe. This will get you a nice rigid pipe for the intercooler to turbo pipe, plus an intake that will give you the option of using either your stock air box or a cone filter that tucks well into the "cool" air opening by the wheel well. Using the full kit will have you hooking up that pressure relief hose so that it dumps straight into the intake. Some hate this idea as it allows that oil vapor directly into the turbo, others say there isn't enough oil to do any damage. You can splice a catch can into this line to catch the oil vapor and still vent back into the intake so the EPA is happy. About $350 for the intake, $80 for a catch can.

Now I gotcha thinking, huh???? Sorry you ever brought this up, aren't you?????

[DREAM2]

If you can rev over 4000 rpm in your driveway, it's because your hitting the rev limiter. It freaked me out for a second the first time I did this after installing my K&N. Then I realized what it was.
Take you car for a ride and it should be fine. The backfiring is the result of what the rev limiter is doing.

[midnight03]

quote:Originally posted by DREAM2

If you can rev over 4000 rpm in your driveway, it's because your hitting the rev limiter. It freaked me out for a second the first time I did this after installing my K&N. Then I realized what it was.
Take you car for a ride and it should be fine. The backfiring is the result of what the rev limiter is doing.

good to hear, I got worried about it also [^]