Re: Gibson exhaust installation

From: Jeff Lee (jlee@atlanta.nsc.com)
Date: Mon Feb 23 1998 - 11:04:04 EST


Klaus Wilkens wrote:
>
> Very well put. That's why header manufacturers usually offer headers with
> smaller primaries for the street and larger ones for race applications.
>
> Also the Bap Bap bap an be caused by a defective diverter valve on air pump
> equipped cars.
>
> KW
>

Klaus,

Is the Bap Bap Bap sound you guys are referring to the sputter and
popping noise that comes from the exhaust during closed throttle
deceleration? I have a 98 V8 5spd with the stock exhaust system (for the
moment ;} ), and the sputtering and popping is quite prominent during
hard deceleration in low gears.

My understanding of this phenomenon is that it is caused by minor
amounts of unburned fuel entering the hot exhaust system and igniting,
due to incomplete combustion during hard deceleration. Although I would
have expected the SBEC to compensate for this by backing off the fuel
flow, I have been told by a number of folks on this list that this is
normal with the V8.

Are you saying that this popping sound is not normal, and is caused by a
defective diverter valve? Do the 98 Magnum engines even have an air
pump? Can anybody else shed some light on this?

Thanks.

jeff
98 RC 4x2 V8 5spd 3.55SG flares



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