Took silencer out...car sputering

OregonMustang

New Member
May 18, 2004
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Newberg,OR
Ok...

I took my stock scliencer off the air box...and well my car is sputering and running a little rich at low rpm's. Anyone else see this?

P.S. I was running 91 octane in my car for 4.5 years then switched to 89 for about 5 tanks after gas prices went crazy...now I'm just recently back to 92 octane. Could this be the culprit?

P.S. I'm getting my DiabloSport Preditor tommorrow or Friday so I hope it can help me out a little.

:shrug:
 
Well, what year is your car, and is your timing increased. If you have stock timing, there is no reason you should be running premium gas. Your mustang will run like complete crap on premium if the timing is stock. Maybe you should look into this.
 
tygr1 said:
""Your mustang will run like complete crap on premium if the timing is stock. Maybe you should look into this.""

WTF?? Who ever told you that BS?
The owners manual tell you to use 87 octane on GT's. Not on cobras. Sorry for the confusion. :(
 
Removing the air silencer alone won't cause sputtering. How do you know it is "running a little rich at low RPMs" ? Could be a bad tank of gas, clogged fuel fiter, IAC, air filter, etc, etc, etc. I'd first go back and double ck that you didn't upset anything when you removed the air silencer. Did you take the air cleaner assembly apart when you did this? If yes, dbl check that it is properly put back together. (It can be kinda tricky with the round clamp they use to fasten it all together.)
 
inferno9898 said:
:bs: dyno graphs

The air silencer-ectomy is a mostly a "trade off" mod I believe. Removing it will give you a few hp and a different sound, but at the expense of a few lost ft-lbs of torque at the low end. So decide which means more to you. Either way, it doesn't really change much so don't sweat it too much either way.

And re octane levels in gasoline, a regular GT is designed for 87. Only reason to go up is if you're getting detonation; otherwise, higher octane levels don't really do anything for the car, performance-wise.
 
dkshadow said:
Yeah cause when youre racing... dyno sheets are what matters huh? ;)
I took my air silencer off and it felt sluggish on the low end and it didnt feel any different up top. The only thing was that it made my exhaust seem louder.


Im not trying to discredit you or anything, but seem and felt are the same words that ricers use to describe their body kits and stickers. i havent seen anything that factually that goes against the silencer mod, and thus i must :bs:
 
inferno9898 said:
Im not trying to discredit you or anything, but seem and felt are the same words that ricers use to describe their body kits and stickers. i havent seen anything that factually that goes against the silencer mod, and thus i must :bs:


When I changed my midpipe... I felt i gained some power and guess what I did. When I removed the silencer my car didnt respond the same way before and was sluggish. If that makes me comparable to a ricer I guess I am :)
 
Q's Stang said:
but theres nothing wrong w/ running premium gas in a GT? not gonna be too rich for the engine or anything is it?

While there tend to be a few schools of thought on this question, the consensus seems to be that it's not really bad for the engine, but not really good either.

Gas grading is all about octane, which is a measurement of gas' resistance to engine knock/detonation/pre-ignition. Engines which require premium gas tend to be those that have higher compression ratios - which means a gas is needed that burns efficiently at a higher tempatures. But using premium in a "regular" compression engine, well, it might not burn completely (temps not as high), and so may over time leave gunk behind (carbon). That's not good.

I'm no expert, and it seems many people here use premium with no bad effects... :shrug:

But in terms of performance, premium gas in a stock GT will not give any more performance over standard gas. It also doesn't have any special additives to clean your engine, etc. that regular does not.
 
If you have a stock engine no mods than you are just throwing your money away running premium gas, your cars computer is set up for 87 octane. I removed my air silencer and it ran worse low rpm's , any thing above 4200 rpms was fine, so i put mine back in...just my own experience..
 
It has always totally baffled me why people run premium gas in their GT's when there is no reason too. Premium is not a cleaner gas...its just a different octane. Our car is meant to run on regular (87 or 89 is some places). Removing the air silencer should not cause any spuddering.