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Jk exhaust fitted now down on power

Posted: 06 Mar 2011, 10:09
by pionte
The exhaust silencer on the van was totally shot, probably shouldnt have passed the MOT last year and definitely wouldnt have passed this time around, more a colander than a silencer , so last week I ordered one from JK and fitted it ( bloody nightmare !) any how I couldn't afford £600 for a stainless system at the mo as was made redundant 5 months ago and money scarce !

So the only option to keep the van on the road was a cheapo from JK, it was actually the same as the one that came off I think, Anyhow since fitting the van is now underpowered, before she was actually quite eager and surprisingly fast, easily cruising at 70 and hitting an Indicated 90 if pushed, now she feel strangled, needing many more gear changes and full throttle just to maintain speed, I would guesstimate at least 20 % down on oooomphh

Has any one else had a similar experience with these cheap exhausts?

I am guessing that the silencer is just too restrictive? the c/o reading for the MOT was 2.5 % so well within spec, should I try adjusting the mixture/ or maybe advancing the the ignition timing slightly ? or wait till I get another job and save up for a SS system!!

Re: Jk exhaust fitted now down on power

Posted: 06 Mar 2011, 10:54
by peasant
I was driving around for a while without any silencer at all (old one shot, waiting for new one to arrive), but other than a "sporty" grumble and an annoying turbo whistle I couldn't really detect any performance improvement. It sounded quicker, but that's about all.

The silencer that's fitted now is an OEM part (i.e. not a straight through one), bloody heavy yoke of a thing , stuffed with baffles to the gills. You would think, if anything, that a cheapo part should be less restrictive.

Someone on here bought an Eberspaecher silencer the other week from GSF and that was straight through.

Anyhow ...im my case the silencer made no difference other than reducing the noise levels by quite some margin.


E D I T
just noticed that my post is somewhat irrelevant, as mine is a diesel

Re: Jk exhaust fitted now down on power

Posted: 06 Mar 2011, 11:49
by eatcustard
Is the silencer OK?
As in the baffles have not collapsed.

Re: Jk exhaust fitted now down on power

Posted: 07 Mar 2011, 11:19
by Oldjets
easily cruising at 70 and hitting an Indicated 90 if pushed...

Could I have one of those please!
(hope you get the exhaust sorted)

Oldjets
Autosleeper Trooper 1.9 DG

Re: Jk exhaust fitted now down on power

Posted: 07 Mar 2011, 18:10
by pionte
Oldjets wrote:easily cruising at 70 and hitting an Indicated 90 if pushed...

Could I have one of those please!
(hope you get the exhaust sorted)

Oldjets
Autosleeper Trooper 1.9 DG
I could give you my old exhaust System.....

My engine has only done 90k and usually runs as sweet as a nut, at 70 mph it just needed 1/4 throttle to maintain the speed, now I rekon i would have to push the pedal through the floor to even get up there !

The new silencer all looks fine, no rattles from inside so dont think that the baffles have collapsed or come loose, just must be more restrictive


I will remove the carb and check that there is no issues after the winter lay up, just seems to be a huge difference after fitting the new silencer.

Re: Jk exhaust fitted now down on power

Posted: 07 Mar 2011, 18:21
by AdrianC
Oldjets wrote:easily cruising at 70 and hitting an Indicated 90 if pushed...

Could I have one of those please!

It's called a "2.1"...

Re: Jk exhaust fitted now down on power

Posted: 07 Mar 2011, 22:25
by hammy44
put your old silencer on and see if there is any difference that will indicate if its the baffles are shot

Re: Jk exhaust fitted now down on power

Posted: 07 Mar 2011, 23:38
by milky
i agree with Hammy,leave the carb alone till you have tried the old exhaust ,the new one shouldnt restrict power like that,maybe its been made wrong inside

Re: Jk exhaust fitted now down on power

Posted: 09 Mar 2011, 13:49
by faggie
are you shure its not the engine at fault have you done a compression check to eliminate the engine ,

Re: Jk exhaust fitted now down on power

Posted: 09 Mar 2011, 19:22
by ELVIS
Picked a JX exhaust up from GSF last week. made by Eberspacher is a straight thr' design unlike original ones so less restrictive.