Outer Limits 4x4 Board

Sorry to bring this up again, but after reading through all the threads on this im still a bit confused and hoping someone might be able to point me in the right direction.

Maybe the info in this thread could be put towards the bible ??

anyway...

Motor TB42 Dual fuel.


at the moment im thinking of getting:

Lukey Extractors
2 1/2" exhaust with a lukey sports muffer and then another hotdog or something at the end to quiet things down (I do a lot of highway miles)

The bloke i talked to suggested this and specificly mentioned that these motors are quite loud and WILL drone unless u put the extra muffler / hotdog at the end.

After talking to this guy, I went a had a good read on OL and found that Pacemakers / Genie seem to be the prefered brand. (I also found that Lukey Extractors WONT warranty for LPG) Im hoping the others will, but couldnt find anything to confirm.

Pacemakers seem to offer a special flange to help free flowing exhaust, but Genie seem to offer something called "interference" headers which help with low down torque. Althought all of them seem to supply Dyno charts showing a overgain in torque and power...even at low revs....

Im also having troubles with brands of mufflers, finding only one that gives CFM ratings. (Super turbo)

My next worry, is to do Mandrel bends or not...this seems to be a 50/50 thing as some ppl swear by them, but others say it offers bugger all increase and some restriction is GOOD for a 4by to increase torque and engine braking.

and the NEXT thing is stainless or mildsteel ? is it worth going to stainless for the better sound and longevity? Are there any other advantages to it ?


Thanks in advance

Glen.

Im just about to do the same on a Gq 4.2 diesel. (non turbo)

Got the extractors myself

getting a 2.5 mandrel bend exhaust
2 mufflers
heavy 2mm tubing
all fitted for around $500


stainless is double in price
mandel bends added about $120 to the price above.

I put pacemaker extractors and a 2.5 system on my old gq petrol. What a difference it was a flyer only problem being it did drone. If costs are an issue don't bother with the mandrel bends or the stainless, but go for two mufflers to get rid of the drone.

The cost isnt really a issue.... I just really want to get it right the first time and have the best exhaust for my purpose. Did u lose any bottom end with the pacemakers ?

OK exhaust now fitted.
(98 Gq DX 4.2 diesel ute - stock motor apart from snorkel)

Definetly a power increase. Definetly a driveability increase.
Seems like it needs less throttle at 100 (my speed kept creeping up)
Rolls fwd a lot more without throttle.

I also did some stop watch work before and after the new exhaust.
5th gear acceleration times improved.
75 -> 100 was averaging 19.5 secs
now 17.5 secs.
Same stretch of road, same weather cond, same direction. No other changes to vehicle.

I got a set of extractors 2nd hand. new 2.5 inch mandrel bent system.
1 small muffler. (they recommended 2nd muffler for wagons though to stop echo thru cab)

Cost $500 to get all fitted.
Im happy I did the change. For my own reasons I didnt want to fit a turbo.

Cheers all.

edit: sound increased very little - girlfriend couldnt notice difference.
BUT - you can now hear the gas running out the extractors under acceleration. (slight hissing sound) unexpected - but so cool...

Draven if anything i gained. First thing on a petrol, extractors and exhaust. I am certain you will not be disappointed. Second thing a good tune after fitment.

Well...I booked the Mav in for Pacemakers and a 2 1/2" system for Monday....Ill let everyone know how it goes once i get it back.

xw383 wrote:I put pacemaker extractors and a 2.5 system on my old gq petrol. What a difference it was a flyer only problem being it did drone. .

same system fitted to mine, did 0 to power, all it did was to make noise.