I've had my current exhaust system on the 90 Vert for about 6 years and I have had enough of it. It's loud, causes the interior to vibrate and is generally annoying on trips over 30mins. After doing a class at Spring Mountain, I fell in love with the nice quiet sound of the stock C6s I got to run around the track. I think I have become "old".

My current setup:
Hooker Coated LTs -> Hooker Y-Pipe -> 3" "Test" pipe -> Flowmaster 50 cat-back (Force II?)

Even tho I don't have to worry about emissions testing, I plan to add a cat. Magnaflow cats are pretty reasonably priced and they seem to have a wide variety of styles - hopefully I can find one to work.

The big question is: What should I do for the mufflers/cat-back portion? Cost is a major concern. I'd rather not lose too much power, either - it's still a stock L98. I need something reasonably quiet.

I saw in one of the other threads about adapting a stock LT1 system. I don't really know what that setup looks like or how easy it would be to do. Would that kill most of the noise w/o completely choking the engine?

I'm open to suggestions. My current system is driving me nuts.

Thanks!

Naturally occuring muffler silencer.....

(and readily available in many stores)....

Since you're concerned with cost, I'd probably add the cat back in like stated and then buy the stock replacement type mufflers with a balance tube in the y pipe (dynomax makes the mufflers and pipes). I'd also look for a set of take off/used ones since people usually want to get rid of them cheap.

Someone will inevitable suggest corsas, but that's an 1100 option.

Matthew

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actually i have 3 cats and Corsa's are not really that quiet, although when at cruise it is sweet musicality and a tad quieter but not quiet,

I wish ir sounds like a mustang though, don't flame me here....

in all cases my opinion is if you want to replace the system , you are going to part with a limb, unless your parts are in resell-able condition....

additionally, you may try to switch out the muffs first, the stuff ahead of them could stay put, and you may find a result that you will like....

Quote:

It was my understanding that the stock LTx catback is not really a bottleneck for the stock engine. As for killing most of the noise, I've got a stock LT4 (295HP/310TQ on a Mustang dyno) and inside, it's quiet. In fact, the tires on it are louder than the exhaust...

I did try something like the banana pic. I tried putting a towel in each of the inner pipes hoping it would kill off some of the noise but no joy. Too bad, making an NPP style exhaust would have been pretty easy and fun.

As for the Corsas, I'm not convinced they would do what I am looking for. I've haven't experienced them personally but from the vids, they seem anything but quiet. No droning at cruise would be nice but there is no way I could justify $1k+ for a cat-back unless it included a turbo. I didn't even want to pay $350 for the one I have.

tobijohn, that sounds a lot like what I am looking for. I'd like to be able to hear the radio when I'm driving to work. And, if it works well with an LT4, my lowly L98 should be happy with it.

Does anyone have a pic of the LTx exhaust? I'd like to see just what I would be getting myself into.

Thanks for all the help guys!

Here's a pic of just the exhaust system from my LT4 (after the cats):




I cut the pipes off leading to the resonator:




and had new pipes from my headers welded to it:

Nice pics!

So with that setup, I'd have to get the LT1 hangers and have a shop bend 2 pipes to go from the 3" headers to the resonator (2.5"?). Looks fairly simple assuming I can find a decent shop around here.

The only prob I see is the cat. It doesn't look like there would be enough room to shove it in there. If the system is quiet enough w/o a cat I could survive.

I have a couple of Random Technologies bullet cats in there - hopefully you can fit something similar:

Sweet! Those pics really help. It looks like I might actually be able to make this work. Even tucks under an x-brace.

Magnaflow has a Spun Cat that is pretty cheap that might work in place of the RTs that seem to be quite a bit more expensive. Not SS tho.

Now I just need to find an LT1 exhaust system.

LT1 exhaust is the easy part... just don't get sucked into the expensive assholes on ebay thinking its made of gold.

Check with Dino's Corvette Salvage. He is close enough to you for a days drive. Shipping a stock LT1 exhaust isn't practical - its welded!

One last thought... get the stock LT1, have have it cut up... who cares!

Then put an x-pipe in it! Add the high flow cats and you are done.

I thought about having it cut. There seems to be quite a bit of long straights in the pics so welding it back together should fairly easy. Didn't think about the x-pipe... good idea.

Dino's might work if I have to but it's about 900mi round trip. That's about $100 in gas and probably 15hrs of driving.

There's a few people parting out LTx cars on CF. I'll see if I can strike a deal over there.

If all else fails, one of my coworkers has a 92 and I'm sure he'll never notice his exhaust missing when he leaves work

I have Corsa. It is one of the BEST upgrades I did to my C4. It is a close tie with the Hurst shifter. However, the shifter was really a luxury and wasn't needed, whereas the exhaust was!

I had cut off the LT1 muffs and installed elims. Ohmygod. The din was deafening. The resonance was at times painful. The 1700~2100 RPM range was just devestating.

I then added Hooker resonator tips. These were glass packs and did help break the din.

But the final straw was when I nearly failed inspection. The dB was 94.7, with a limit of 95. That is in the range of damaging to hearing. I pulled the trigger and bought a Corsa system. That was 2002.

In 2006, I had been dealing with a huge noise. I found that the center resonator had come apart! The stainless between the vertical welds that hold the outer pipe to the inner had fracture. Once I contacted Corsa, they had a new resonator and header pipes to me with 3 days. GREAT customer service. Apparently, they are aware of this problem, because the new center section has small holes drilled into the bottom rear of the resonators. I am assume that is a moisture drain. I know of a couple other folks with similar issues, and were supported just as promptly.

I got REAL lucky when I went after a Corsa system for bastet44s 87 LT1 project. I bought them of ebay for chump change!!! A real chevy dealer in Upstate NY was unloading the last of their C4 stuff... and I got a full on LT1 catback for $705, shipped. I don't see any now, but keep an eye out.

Go to the CF C4 parts section. There is a guy with a whole bunch of cheap or free parts, including a free set of LT1 mufflers. Hope this helps.