exhaust opinions

R

rudevr6

New member
i had some questions about exhausts for the FSP/IT 1.8 scirocco i'm building. i 'm needing to do this on the cheap, so i planned on running it out the side using 2 1/2 in. tubing and a dynamax bullet muffler. i already have a recycled pace setter header.

what kinds exhausts are you guys running, any opinions?

thanks in advance!
 
I use a header(cheep) thats cut off at the collector and i welded 3 inch tubing, 2.5 ish foot long and the an 18 inch glass pack with a 45deg down spout cut off. I also us a stay bar that keeps the engine from rocking.
i like the glass pack cause it has rounded ends, that WONT get stuck on the trailer...... havent done any dyno test with this exaust, it was a fridaynight 11:00pm fix.... Point the exaust at the track, i think its quieter?

good luck
 
I did the same thing, except that I use about 18" of that "flex" tubing, attached to a "cherry bomb" glass pack with a 45 degree down tube, right before the rear axle.

I don't car how much the motor "rocks" with the flex pipe. I broke a bunch of collectors when I had my first Scirocco, which turned out to be a "flexi flyer" chassis wise.
 
thanks for the input,

i just needed to know that i was on the right track with the side out exhaust instead of using the over the axle exhaust (which cost more and not sure of performance gains over side out).

there were also doubts about back pressure, not sure how much that is a factor in HP gain.
 
I belive no back pressure is good, because back pressure lets more exaust stay in the combustion chamber. it like an EGR, Exaust in the cyllinder make it run cooler... but spent exaust gasses wont burn, IE weaker explosion.

MY .02
 
3" is way too big.
2.5" may only work on an engine that is borderline legal.
2.25" is correct for ITB. You'll get ~8hp not including header gains.

Max power will be made by dumping out right before rear axle beam.
Max torque can be made by going over axle to rear.
Your ears & nerves will thank you for exiting behind car.

Dont take my word for it. Call Collin at Techtonics.
 
so how do you all interpret "away from the body".... does turn-down under the car really fulfill that?
 
thats what I see on almost every IT car out there unless they need to make it to the rear to quiet it down enough to stay under 103.
 
my engine is completely stock so going with the 2.25 tubing may work better, as suggested, but i'm still gonna run it out the side and hope for the best!
 
I use 2 in EMT tubing from Home depot race parts. The 90* are nice and smooth and it is cheap. I use chains to hold it up and run ity out the rear. The booming iinside the car with short pipes is nasty.
Wear earplugs, all the time. MM
 
I run the Techtonics Race Header and full 2.25" exhaust. It has no resonators and one borla muffler, so it is one of the quieter IT cars on the track.
 
I was also looking to reduce some weight, so that's why I just went with the simpliest, straight path I could build.

I've NEVER been hit for sound, and our 3 tracks, especially Laguna Seca can be really tough, with the damp foggy conditions. At least now, all 3 tracks have the sound meter on the same side of the track, so if you want to run it out the side, the drivers side is best, since the meters are all on drivers right now.

I don't like to wear ear plugs, since I want to HEAR what's going on with the engine, not only looking at the gauges, but also by how things sound.
 
Ear plugs make your exhaust hard to hear? not mine. I can actually hear things like suspension, and tires once I plug my ears from the exhaust noise.
 
All "earplugs" are not created equal. I use a pair of Norton musician's plugs (not sure if that's the correct term, but I bought them in a music store). Plugs like these attenuate only very loud sounds, but you can still hear a whisper or normal volume without any change.

EDIT: The plugs I'm talking about are rubber or silicone with a metal insert. They are reusable rather than disposable. The insert can be removed for cleaning of the plugs. Mine came in a blue plastic case. I bought two pairs many years ago, and all 4 still work perfectly.
 
Can I be reassured that a header going into a resonator using 2 1/4" pipe can be turned down at 45* just before the axle AND NOT have any problems going above 103?

Right now my setup also includes a Borla muffler after the axle. I wanna cut it off!

Thanks!
 
Can I be reassured that a header going into a resonator using 2 1/4" pipe can be turned down at 45* just before the axle AND NOT have any problems going above 103?

Right now my setup also includes a Borla muffler after the axle. I wanna cut it off!

Thanks!
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That is what approximately half of the VW IT world runs. We don't have sound problems.
 
On the 1.7 8V C car, I just have a header to a 3' section of 2.25" straight pipe to a smooth 45 downturn below the fuel tank. No resonator or anything else. It's never been clocked above 96 dB, and usually about 94 IIRC. The earplugs are only needed on cold days to cut the booming inside the cockpit. Outside is always no problem.

Although the 1.8 16V A car didn't get finished (at least not yet), I thought the same setup would probably still be under 103 dB. Maybe it would need a resonator or light muffler after all, but I think it would at least be close without it.
 
My current mismash is whats left of the old exhaust built for running at a very strict sound track (Waterford Hills) I used to come in at 82db. The current setup gets rid of all the bends and kept the cherry bomb and I clocked in at 92. John is making me a new one thats just 2.25 with a 90 behind the driver to the ground, probably produce around 96-98 like the other 8v's I know.
 
Hi All,
Does a 94 ABA exhaust manifold fit a A 8V?? It look like it might and I can get one for a fair price.
Otherwise, i have a 84 Rabbit engine with a twin down setup to trade for A2 stuff. I dint check the code but it is auto and they often have the best engine , go figure. Mike Ogren , 352/796/1985 work
 
I know the downpipes are interchangeable A3 - A2 (and 8v-16v for that matter). Don't know about the mani. I have never had my hands on a cross flow head to see the port configuration.

Techtonics does show two different part numbers for the manifolds.

I think I have one or two dual outlet A2 manifolds somewhere. You can have one if I do.
 
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