ITB Golf exhaust

[Ralf]

Grassroots Motorsports magazine just had an article about race exhausts and they tried a few different setups that also showed power made/lost and also sound readings for each setup.
What I would like to know is what you guys are running. My current setup is a Techtonics header with a straight through glasspack type muffler that terminates with a turn down just forward of the rear axle beam. I pass sound control just fine, but it seems with it terminating under the car the sound is amplified in the car. Even with ear plugs in I get some ringing.
Would the current glasspack muffler be too loud if I put in an over the axle pipe and exit it out of the stock location? What else could I do to keep from going deaf?

[Dave Zaslow]

Ralf,

I had a Rabbit and now have a Golf III. Both had the exhaust exit out the back (stock location). The Rabbit started out with a Supertrapp with 0 end plates for racing and just a few for transport. I then moved to a Borla from TT which you can look through and has little restriction. I now have the latter setup on the Golf. It is quiet, loudest has been low 90's dB for both cars.

I have driven other's cars with your set-up and found it annoying that I cannot hear other cars around me when I need to. It is lighter though....

DZ

[MSPERBER]

Ten years running an ITB first gen GTI, final setup has been a puckett header to a straight pipe exiting out the pass side before the tire, we run with a 15 gal cell mounted low taking up space from the orginal passage. In the southeast we never break 95 dbs, but with ear plugs I still get a little ringing at the end of the day.

[shwah]

I have run a TT header to a glass pack to a turn down and the same with an over axle out the back. I have the out the back on the car now, and still have a turndown, pointed away from the sound meter, with no issues. Could probably get away with no muffler, unless it is cold outside. We run in April and October at Blackhawk, so I leave a muffler on it.

I saw a torque bump in the longer pipe, but that was using too big 2.5" tubing. I'll do some tailpipe length testing with the 2.25" when we finally do the small diameter header primary testing...

[Flyinglizard]

I use the glaaspack in the shifter tunnel, to a 2in EMT bend, out the driver side. I chain the pipe to the axle bracket. Small chains hold the whole thing up.

[racer_tim]

Ralf, it's a RACE car. Expect some dis-comfort. I too run the exact same setup on my Limited Prep G (H now) Wabbit GTI. Header to a flex pipe, to a cherry bomb glass pack, to a 45 degree turn down in front of the axle. I did have a full system, over the axle through a flow master exiting out the stock location, but needed to knock off some weight, so I went with the simplest solution.

I don't wear ear plugs and also think the ringing in my ears and head ache after a session could also be adrenalin.

[Ralf]

I ran without ear plugs once in a morning session and never want to do that again. I didn't regain my hearing until the next morning. I'm already collecting disability from the VA for slight hearing loss from 20 years in the Air Force. I've been around full throttle engine runs and lots of take offs and never experienced hearing loss like the 20 minute qualifying session without ear plugs in.

[Flyinglizard]

A body/brain that is not under stress from sound or heat will go faster over the time period of the race. If your head really likes the car shut off at the end of the race, chances are the exhaust is too load for you to make good racing decisions.
IMHO the pipe stopping under the middle of the car just makes the car a sounding chamber. The power increase might be nil over the turn out to the side,in front of the tire.
As an old guy that did not wear ear plugs sooner,and cant hear sxit now, put the pipe out the side and/or wear plugs.
MM

[shwah]

I would not drive my car with any of the exhuast configurations I have used, without earplugs. Did so once by accident. It is bearable with the rear exit, but way more comfortable with the plugs.

[S2_ITBVW]

I need to add "earplugs" to my shopping list.

[S2_ITBVW]

Sorry, but I have to comment one more time in order to post a link in a new thread.

[billf]

Seems one reads rules over again when building a new car. These two rules would seem to NOT allow the use of an under body, or turned down exhaust...I believe.

IT rules paragraph 1 g. "Exhaust shall exit behind the driver, and shall be directed away from the car body."

Glossary defines "Body - All parts of the car licked by the airstream and situated above the belly-pan/floor with the exception of the roll bar or cage." (Bold and underlined are mine.)

Since the "turn downed pipe" is below that point defined as the "body", I question its legality.

Plese show me how I can use the pipe below the car...I really need it. I have raced three cars with the pipe ending in a turn-down, and only now saw the words clearly.:(

Any thoughts?

Bill

[billf]

As a health care professional, I would also add this to the statement made by racer_tim, where he said, "I don't wear ear plugs and also think the ringing in my ears and head ache after a session could also be adrenalin."

Adrenalin (medically known as epinephrine), is a body's reaction to flight-or-fight situations. All functions needed for fight-or flight of the organism are inhanced (additional nutrition, revamped blood flow to muscles, brain, liver, increased vision, etc)...ergo, hearing by nature's design would not be impared (ringing in the ears hampers hearing).

Drug books don't list tinnitis as being a reaction to epinephrine, either.

I suggest that the tinnitis one has from the race car is a symptom of inner ear damage, caused by loud noise (exhaust), demonstrated by how long it takes to resolve...hours, to days, or forever (as is mine), depending on its severity. Drug induced tinnitis would be gone in minutes (the time it takes for the drug to be metabolized).

Incidentally, the headache is potentially from carbon monoxide, so one might also check for openings in the body.

I hope this makes one think of ear plugs for our tender inner ears.

Bill:024:

[Gary L]

Bill - I don't currently have a "turn-down" exhaust, but I have in the past; here's my cut on that rule. The phrase "...directed away from the car body" means just that - it's pointed in a direction that is not towards the car body. The fact that it's not adjacent to the car body is irrelevant.

[jimbbski]

I have raced cars with their exhaust directed downward and that ended before the rear axle. To LOUD! The whole car body becomes a sound chamber.

My current car has a 4-2-1 header into a glasspack muffler with a tail pipe that follows the stock configuration over the axle and below the fuel tank. It ends in a convential oval muffler (2.5 inch dia.) that had been modified to shorten the route the gases have to travel. I think it adds very little backpressure beyond what the glasspack adds and tones done the rasp you get using only a glasspack. I like the sound and its not going to damage your heading.

I once raced a friends car that had it's exhaust end just past the header, Tech didn't chatch it and it was only for this race. I was going to "fix" his exhaust after this race and before the next race as part of the payment to him for letting me drive his car. After 30 minutes my ears had a ringing in them for 2 days afterward.

[Joe Camilleri]

I have a Puckett header to a mandrel 90° and glass pack exiting in front of the RR tire. Never had a sound issue or need to wear ear plugs.

http://gallery.me.com/joecam06#100008/DSC03331