I'm new to the forum and don't currently own a Vette :cry . I'm gonna be in the market though soon. Anyway, I see that a lot of you have resonance problems with your exhaust systems. Perhaps a product like Dynamat would work to dampen the interior noise. It's mainly for stereos but they make a liner that fits under the carpet to suppress road noise and insulate against heat. I believe it's called Dynaliner and its pretty cheap. Has anyone used this on their Vette? It might even help with body rattles. Let me know what you think.

 

Welcome to the forum :cheers:


I have seen some people do this idea before some posted pics. Not sure if it helped much.

What year vette are you looking for?


[Modified by VictorRussell'92, 1:07 PM 2/11/2004]

 

I tried that idea with my 85 to avoid resonance from my Borlas. Can't say it helped that much. It seems to transfer through the whole car. From reading seems the most effective methods are moving the exhaust tips as far away from the rear bumper as possible, and plugging up one of the exhaust tips on duel exit mufflers. This is suppose to have little effect on flow and get rid of 70-80% of the resonance. Haven't tried the later yet, need to find some inserts to try it out.

 

Hmm, I'm surprised that the dynamat doesn't work. It works well with stereo applications. Oh well, thought I'd toss it out to see if it's been tried.

I'm gonna be in the market for an 89 to 94 probably. Can't decide which engine I want. Ultimately it all comes down to insurance rates as I'm only 20. I'm moving to a different job soon so it won't be for a couple months. Have any suggestion on year or options to look for or stay away from, I'm all ears. I think it would be fun to build up an L-98 and embarrass LS-1's but that's just me :D . Thanks for your input though on the dynamat.

Anyone else had experience with it?

 

It works to an extent, but no it doesnt get rid of resonance. You have a big resonance chamber behind your head that will not really let you get rid of it completely.

Adding exhaust extensions also helps, and together you can eliminate some or most of it (depending on the exact combo), but short of plugging up one exhaust pipe you cant get rid of it.

 

I haven't tried the dynamat to quiet resonance, but I'm sure it can't hurt.
I know many say that having the exhaust tips stick out past the bumper will help, but I can tell you it didn't help at all on my car. This pic shows how far they stick out now, and I can tell you it still resonates like crazy :crazy:

 

Thanks for all the replys. I guess I'll just have to try it at some point. Is the resonance worse or a vert since its open or better because it has a trunk, albeit a small one?

Also, I'm plannin on using the magnaflow catback. What can I expect from that? Anyone have sounds of it on an L-98?

 

I would think resonace on a vert would be better. There are a couple of magnaflow threads around right now. They seem to be a very popular choice! :cheers:

 

I tried Dynamat with my '94 383 and flowmaster exhaust (with no cats). That was SOOOOOOOOOOOOOOOOOOOOOO loud i had to get it off the car. I had to wear ear plugs going down the highway. I switched to no mufflers and it was so much better :yesnod: . Dynamat did nothing btw...

 

I run a hi-flow exhaust with FlowMaster cat-back and, though some passengers don't like the sound, I love it. I just finished a 450mile (each way) trip and had no problems listening to tunes while driving.

The usual advice is to buy the newest Vette you can afford, but if $$ are an issue I suggest you find a clean '89:
- It still has the MAF for easy mod adaptability (if not going above 400chp or so)
- no air bag so comes with telescope steering wheel
- has improved steering & 17" tires
- is available with either the A4 or 6-speed manual tranny
- has Z51, Z52 or FX3 handling packages as available options

If you are still deciding, pick up a copy of the "Corvette Black Book" to see what features changed from year to year.

 

I've changed mufflers three times, installed sound deadening insulation under the carpet, both front and rear sections, and stiil had the resonance problem.

Being older than many on this forum, the sound I was getting wasn't what I wanted. When I was younger it was a different story though -.

I'm currently running Walker Quiet-Flow mufflers, which was advertised as being close to stock sounding; they "ain't". Let me qualify that: at crusing speed with a steady throttle position, the exhaust is quiet, but accelerating is a different story.

I've given this a lot of thought and figure that it's a combination of CID, compression, camshaft and gutted CAT causing the problem.

So being tired of spending money on this problem without getting any positive results I decided to try what turned out to be a virtually cost free mod.

The only solution I've found (that REALLY works) is to block off one of the exhaust tips on each muffler with balled up aluminum foil.

I fired the engine, and identified which tip on each muffler was flowing the most exhaust; those are the two I chose to block. Several ***** of aluminum foil stuffed into the exhaust tip (engine off) and packed in with a long, round wooden dowel, made a difference like night and day.

Under sustained WOT the balled up foil will blow out because of all the exhaust pressure, but this can be addressed too -if you prefer the foil to stay in place.

Just drill a 5/16th hole through each exhaust tip as close to the muffler body as you can BUT still rearward of the foil. Run a bolt through the hole and secure it in place with a nut. This mod is undetectable from view and the bolt will act as a barrier to the foil blowing out.

The foil can easily be removed if you want it out for whatever reason. I use a drill bit that's about 24" long (from a home improvement project) and just drill into the foil; when the bit catches, I just pull it out. JB Weld can be used to close the drilled hole.

Someone else posted in the Tech Tips section that blocking off one tip on each muffler is a cure too.

Hope this helps.

Jake

 

Thanks everyone for their input, it's greatly appreciated. Hope to see everyone on the road soon with a shiny new vette :steering:

By the way, My 03 S-10 X-treme with only 10k on it will probably be for sale soon if anyone is interested. Thanks again for the posts!