Re: Gibson exhaust installation

From: Klaus Wilkens (klaus@buffnet.net)
Date: Mon Feb 23 1998 - 21:08:27 EST


Jeff,

I mentioned the diverter valve because somewhere a Chevette was brought into this
thread. Now that I think back didn't the older 3.9 Daks have air pumps ?

KW

Jeff Lee wrote:

> 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



This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:08:14 EDT