Bad weekend at VIR... oh... and how can I make this car quiet? (supertraps?)

[panozracing]

Originally Posted by Cobra4B

Do they make the car measurably quieter?

By adding the supertrapp cap onto the existing muffler and pipe (stock GTS stuff) we were able to pass the barber sound limit of I think 85db.

Unfortunately because I put the cap on the end of the existing pipe the exhaust was shot back at the car and it burn the plastic around the pipe.

[Cobra4B]

What kind of dbs were you producing w/o the supertraps?

[panozracing]

I have no idea. the only track that checks is Barber and Daytona. At daytona they didnt say anything ever and barber said I was 1 db over what they allow.

[jmimac351]

Brian, one of my money pits, I mean projects, is a '92 Fox body mustang with a nasty 347 in it. Since I'm not a kid anymore I searched high and low for a quiet muffler. Everything I came across seemed to point to the Dynomax Super Turbo muffler. I haven't bought these yet but likely will.

http://www.mustang50magazine.com/tec...son/index.html

http://www.dynomax.com/products/superturbo.html

[NZGTRA17]

Originally Posted by Cobra4B

The shop has asked that we come up when it's re-done to watch them run it on the dyno etc. etc. to verify all is in proper working order before we take delivery.

It could be poor work, or it could be a bad MSD distributor, freak rocker arms backing off (as you experienced Kel), and junk in the carb. We'll see.

Brian, what was the outcome of re-running the car on the dyno?

What issues were found and what has been done to rectify them?

Kel.

[Cobra4B]

Originally Posted by NZGTRA17

Brian, what was the outcome of re-running the car on the dyno?

What issues were found and what has been done to rectify them?

Kel.

Sorry I've been off of here for a bit... got a new jetski and have been enjoying summer beach living.

My father picked up the car last Friday and it made 312, 312, 314 back to back to back while he watched it prior to loading it on the trailer. Everything works properly now and new Flowmaster 50series 3-chamber mufflers were put in. Apparently the car is much quieter, but obviously still loud at WOT. They tried to fit a Flowmaster 70 series, but it just wouldn't work.

Some things found/fixed:

* Car was loosing fuel pressure at high rpms, re-worked the fuel filter setup w/ a single canister filter between the fuel cel and pump, no more after pump filter.

* Rocker arms being "pigeon toed" is 100% normal with AFR 165s on the SBF, AFR moves the valve position. Shop verified on some of their shop race cars w/ 165s. Nothing was loose there, I was wrong and used to seeing LSX setups which are 100% parallel. We may be getting shaft mount rockers to better center the roller tip on the valve. Most shops/people just run them as they are. Currently we have stud mount rockers... comp pro magnum from what I remember.

* Fan switch issue - fan switch wiring was 100% re-worked... the setup was a carryover from the EFI/PCM setup and was beign over-juiced. All works now... car won't get over 195 coolant temp now. The other issue was that there was obviously air in the system back when we got it the first time that I fixed.

* Valve-covers leaking, breathers spewing oil - Turns out the wrong gasket was used for the VC, they tried to re-use the ones made for the stock VCs which need to be encapsulated in a ridge. The composites need flat cork gaskets to seal. As for the breathers we'll be doing a catch can setup.

* Carb etc. - Well when the bowls were pulled apart one fo the jets was about to fall out and must have been letting fuel by. Also there was an odd black subastance on everything. All has been cleaned and 100% re-tuned w/ proper jet settings and bowl levels. The car doesn't diesel on shutoff anymore and the headers don't glow.

I think that's about it... we'll have the car at VIR in 2 weeks w/ NASA to try a shakedown again. I was supposed to be in the UTCC but had to pull out. Will be running in HPDE 3 to play w/ the car.

[Cobrafang]

That is great news. Post one of those dyno runs for us.

[Cobra4B]

Don't have an updated dyno-graph... I'm sure it looks like the other one I had but pulled out to 6500 vs. 6000.

[carhauler]

I have Supertrapps on my #40 GTS, they work well enough to pass Lime Rock's strict noise limits. If you mount them correctly they won't melt the bodywork.