twin exhaust?

pimpin_col · rice boy Joined: 23 Sep 2002 Posts: 29

about october some blocke was talking about twin dumpers on his gemin. just woindering if he or anyone else has done this yet?? im thinking about putting 2 huge twin mufflers out the back of me gem wagon. get the whole 300ZX look cranking. which side of the diff would u run the split? at the engine pipe? before the dif? after? will a pipe fit over the diff on the left side? can u squeeze 2 in on the right? or would u just run a Y where it goes over the diff. any help would be sweet thanks col..

BlueTC · petrol head Joined: 22 Oct 2002 Posts: 1148

I heard that if twin dumpers on a gem would make it sound similar to a beetle, and people may hassle you and ask if you have a V8 in it,

give it a go and tell us how it went,

regards

Gene FJ20DET · Posted: Sun Jan 26, 2003 12:56 am Post subject: Re: twin exhaust?

a guy in tge QLD gem club had it, he had a Y piece after the diff (theres no room for 2 to come over the diff at all.) it sounds normal, no difference
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Benjamin · backyard mechanic Joined: 05 Oct 2001 Posts: 525

That it would. I have been thinking about a twin system for my wagon exiting in front of the rear wheels, altho I would prefer to split the extractors off and have a 4-into-2 system. That would sound neat, more like a Subaru then Very Happy

Gene FJ20DET · Posted: Sun Jan 26, 2003 3:41 pm Post subject: Re: twin exhaust?

its illegal unless u have a coupe or wagon,
"exhaust must exit from under the vehical a minimum or 30cm from the rear doors"
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pyr0 · tinkerer Joined: 15 May 2002 Posts: 118

it was me asking about the twin exhaust thing i never did it but i had the guy's at superflow ( exhaust place near my house) and they said it could be done from the extractors changing them from 4-2-1 to 4-2 and have twin pipes out the rear of the car.

pyr0

pyr0 · tinkerer Joined: 15 May 2002 Posts: 118

it was me asking about the twin exhaust thing i never did it but i had the guy's at superflow ( exhaust place near my house) and they said it could be done from the extractors changing them from 4-2-1 to 4-2 and have twin pipes out the rear of the car.

pyr0

Gene FJ20DET · Posted: Sun Jan 26, 2003 7:42 pm Post subject: Re: twin exhaust?

yeah and the back presure would be shit unless u had 2 pipes max of 1.25" and that would just look super gay
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Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

To increase back pressure, he could run a pair of three inch pipes, and then weld on some ball valves as the exhaust tips. To increase back pressure, simply close off the valves.

pyr0 · tinkerer Joined: 15 May 2002 Posts: 118

to get sufficent back pressur any way it's only the 1st 3feet of exhaust that must be the 1 1/2 so you could have the 3 feet of 1 1/2 then weld it up to a 2 1/2 if u want.
just what ive herd on the topic of back pressure.

pyr0

badboygem · tinkerer Joined: 31 Aug 2002 Posts: 132

heres a good question....maybe ben might be able to solve....i been tryin to work out wheather a 2 1/4" would be good enough for a lightly modified turbo g200. i know the answer is 99% no but i have a 2 1/2" on it at the moment and no matter how hard fast fit exhaust tried...they couldnt get the bloody thing to stop hittin the diff. so how does a 3inch dump into twin 2 inches?? coz ive looked up in there and im sure twin 2" would fit over the diff but hey im only a dumb kid what do i know. and then just adapt the twin into 1 3inch again thru a 3" lukey muff right at the back. any thoughts would be appreciated.

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

First off, about the back pressure, I was being sarcastic about the taps in the tailpipes in case anyone was wondering. Back pressure reduces horespower. Less back pressure = more horsepower.

I am running a 2 1/4" exhaust on my g200 turbo right now, I am currently building a new exhaust as I think its restrictive for the hp I am chasing. I made 200hp at wheels at 19psi with the 2 1/4" exhaust and crappy super turbo muffler. I expect it to make about 220 with my new system, which will be 2.5". Dont know for sure yet, will post results when finished and dynoed again. Will be difficult to tell as using bigger cam and slightly more comrpession as well.

Anyway, if the exhaust it supported properly, and snugs up against the floorpan, then a 2.5" tailpipe will clear the diff OK. I dont konw of anyone with a 3" that doesn't bang. It also hugely depends on how low the car is too.

Ben Wight

badboygem · tinkerer Joined: 31 Aug 2002 Posts: 132

so 2 1/4 would be fine if i was only looking for around 160hp at the wheels??

Gene FJ20DET · Posted: Mon Jan 27, 2003 6:25 pm Post subject: Re: twin exhaust?

yes it would be.

ben
why not run a 3" manderl system?? thats what im goin with Very Happy

also why more compresion?? go less and more boost Very Happy

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