Snort, pop, and boom on deceleration w/ SSI's and MB911 muffler

ken_xman · 07-21-2005, 05:56 AM

My 87 3.2 w/stock chip, SSI's , and Bens type R 2in/ 2out muffler, seems to snort and pop on deceleration a lot more than the GHL Bypass and single out GHL I had before.

With SSI's and dual out muffler, do I need a Wong chip to correct the fuel mixture? .....or should I be learning how to adjust my AIR/ FUEL Mix?

DW SD · 07-21-2005, 06:15 AM

Mine does this too, to a certain extent. I have the exact same exhaust setup, though I do have Steve's chip, too.

With reduced backpressure more unburned air / fuel makes its way into the exhaust system add the more readily available oxygen, you will have a mini explosion in the pipes.

Steve Wong has a similar setup on his car and so I bought the programmed chip that he runs on his car. My car idled much smoother and revved much better with his chip. I never dyno'ed, but suspect you'd find more power. I did the 8k DME upgrade, too, which is what Steve recommended. My car had the 2k chip, initially. It is definitely MUCH smoother.

juanbenae · juanbenae's Garage

a fix all would be don't decel, keep your foot in it at all times.

Zeke · 07-21-2005, 07:15 AM

You must have an air leak somewhere, probably at the SSI/muffler union. Ben's muffler flanges are not always straight. Ask me how I know.

ken_xman · 07-21-2005, 07:16 AM

good call zeke. I will snug it up & try

mb911 · mb911's Garage

Thanks milt!!!!!!!!!

anyhow typically you need a wong chip for the 3.2 with ssis and those flanges were dead on

Elombard · 07-21-2005, 09:00 AM

Could it be you are hearing it now and before it was muffled?

ken_xman · 07-21-2005, 09:13 AM

Well, maybe before my neighbor could hear it, and now the guy 2 blocks down can hear it fine.
Actually it is almost a backfire sound. Sounds like unburnt fuel & hot exhaust.
I do think that it has got increased gurgle frequency as well.

cbeers · 07-21-2005, 09:48 AM

I am running a Borla SS with a Fabspeed cat bypass pipe and a SW chip programmed for that set up. I too, get gurgling and noise, not a back fire, but a lot of rumbling sounds. I asked about it with my mechanic and he said it was the design of the Borla, no baffles, or little baffles or something like that. So, I just enjoy it.

I had thought it was the seals too, but I replaced all of those and it still rumbles.....

YMMV

-Chris

ken_xman · 07-21-2005, 10:03 AM

I really like the sound the way it is. I just want to be sure I am not f.ing something up.