Rear muffler query.

[Mad4slalom]

Hi all, does anyone have any experience or suggestions of a stock looking and fitting( ie straight replacement ) for the stock c3 mufflers that will give just a bit more v8 sound, without the volume or droning of a cherry bomb or similar type of aftermarket option. ( were the LT1 mufflers any different to the stock 350 vette ?) I Just saw a beautiful white 67 ish fastback mustang with blue stripe in Truro .he was queuing on the opposite carriageway and had just that bit more audible presence when he pulled away. Sounded Perfect.

 

[Roscobbc]

When I first got my C3 20 years+ ago the very first thing I simply had to do was A. buy a pair of headers B. buy a pair of mufflers.
As you have already noted Cherry Bombs sound too strident. TBH, I had always done this with every car I've every owned, from old school Mini Cooper glass packs on 3.8 Jags to Thrush turn-o-lock glass packs and header mufflers on Yank V8's.
I had used Simon's mufflers - made for years in Denmark or somewhere similar and marketed here in the UK as Jetex -

Jetex Exhausts Ltd – Products

jetex.co.uk

Available in polished stainless or satin black mild steel they are an absorbsion tube muffler but always used ceramic wool rather than glass fibre which wouldn't oil or coke-up and end-up getting really unpleasantly noisy. I had mine on the Vette for at least 10 years with no corrosion......they did get a little louder after a time.
If you want to replace your existing mufflers on a visually like of like basis simply search for the correct tube diameter and case length approximately the same as your existing mufflers (perhaps even a little longer if you want) and get your favourite exhaust shop to make-up the required brackets and tube bends to fit them.
Bonus is they will look stock, even sound a little 'softer' on idle than stock but progessively get louder as you hit the gas pedal.......never loud enough to attrack the old bill, but in a really nice way without the drone of some baffled mufflers. Remember that a larger (even oversized) diameter pipe will always sound deeper.

 

[Emc]

If you need to replace the whole system then definitely a 2"to2.5" is a fantastic system

 

[Mad4slalom]

If you need to replace the whole system then definitely a 2"to2.5" is a fantastic system

I think wait and do a 2.5 inch system as per the LT1, were the LT1 mufflers different other than the diameter. ? Not really interested in tubed headers as I like the classic rams horns and stock look. I believe LT1 ram’s horns were bigger diameter? So would be up for a set of those if anyone has a pair under the bench ( mr Cricket ?). Be interested on a system price Gavin or a good used one if anyone changed to side exhausts . Half the fun of vetting is planning your next project and improvement and hunting down and collecting the bits in advance

 

[Roscobbc]

Forgot to mention about using 2.5" diameter rather than 2.25" (or 2.00"?) of stock SBC system......doesn't BB go from 2.50" to 2.25" on rear section? - can't remember.

 

[Mr. Cricket]

I think wait and do a 2.5 inch system as per the LT1, were the LT1 mufflers different other than the diameter. ? Not really interested in tubed headers as I like the classic rams horns and stock look. I believe LT1 ram’s horns were bigger diameter? So would be up for a set of those if anyone has a pair under the bench ( mr Cricket ?). Be interested on a system price Gavin or a good used one if anyone changed to side exhausts . Half the fun of vetting is planning your next project and improvement and hunting down and collecting the bits in advance

I haven't got any Garry sorry. The exhaust manifolds on the LT-1 are two inch so the exhaust is swaged out to 2 1/2. When I bought it, it was way too quiet and as I'd always wanted some Cherry Bombs on something I went with those and they were 2" IT WAS LOUD with added POP, BANG and a rolling thunder type racket when you eased off. I then grew up some and changed them out after a few years for 2 1/2" as the smaller one's were choking the engine and power was noticeably down. They had a totally different sound and one I didn't like and droned like hell. They lasted a couple of months before they came out. As the LT-1 is all original I thought sod it and went back to stock with an off road version from Corvette Kingdom. A bit too quiet not but jebus it goes like a rocket and I can now hear the rat a tat tat of the solid lifters agin.

I had a bone stock 220HP auto '72 and that needed a full exhaust and went with resonators (the type you see in side pipes) under the car and glass packs where the normal silencers fit. It made for a better look from behind and sounded like a big block. Might be worth looking into?

 

[Mad4slalom]

I haven't got any Garry sorry. The exhaust manifolds on the LT-1 are two inch so the exhaust is swaged out to 2 1/2. When I bought it, it was way too quiet and as I'd always wanted some Cherry Bombs on something I went with those and they were 2" IT WAS LOUD with added POP, BANG and a rolling thunder type racket when you eased off. I then grew up some and changed them out after a few years for 2 1/2" as the smaller one's were choking the engine and power was noticeably down. They had a totally different sound and one I didn't like and droned like hell. They lasted a couple of months before they came out. As the LT-1 is all original I thought sod it and went back to stock with an off road version from Corvette Kingdom. A bit too quiet not but jebus it goes like a rocket and I can now hear the rat a tat tat of the solid lifters agin.

I had a bone stock 220HP auto '72 and that needed a full exhaust and went with resonators (the type you see in side pipes) under the car and glass packs where the normal silencers fit. It made for a better look from behind and sounded like a big block. Might be worth looking into?

View attachment 24015

Thanks stuart, great info , and very informative. So the chambered pipes do away with the mufferscompletely?. The lt 1rams horn manifolds that swage out to 2.5” for the bigger system, are they bigger than mine, or is it only the system that is bigger?
Thanks again

 

[Mr. Cricket]

Thanks stuart, great info , and very informative. So the chambered pipes do away with the mufferscompletely?. The lt 1rams horn manifolds that swage out to 2.5” for the bigger system, are they bigger than mine, or is it only the system that is bigger?
Thanks again

Stock exhaust on the LT-1 is 2 1/2" so there's a short section that reduces from 2 1/2 to 2" to connect to the rams horns. I suppose you could just replace the existing mufflers with glass packs and see if that gets you where you want to be and if not then fit the resonators.

 

[Roscobbc]

Presuming the LT1 uses the same mufflers and tail pipes as big block?......if so I'm sure inlet pipe to mufflers is 2.5" - tail pipe trim is 2.5", yet actual tail pipe is 2.25" diameter

 

[Mr. Cricket]

Presuming the LT1 uses the same mufflers and tail pipes as big block?......if so I'm sure inlet pipe to mufflers is 2.5" - tail pipe trim is 2.5", yet actual tail pipe is 2.25" diameter

LT-1 is a small block Ross. I can get a clearer pic later when I'm farting around in the garage

 

[Roscobbc]

I thought that LT1 being the highest output small block 'shared' mufflers and rear section with big block......could be wrong though!

 

[Mad4slalom]

Stock exhaust on the LT-1 is 2 1/2" so there's a short section that reduces from 2 1/2 to 2" to connect to the rams horns. I suppose you could just replace the existing mufflers with glass packs and see if that gets you where you want to be and if not then fit the resonators.

Got you, so that sounds like all small block rams horns are the same regardless of base ir LT1 . ?

 

[Mr. Cricket]

I thought that LT1 being the highest output small block 'shared' mufflers and rear section with big block......could be wrong though!

Could be the case but with how GM put these things together from the parts bin I doubt it

Got you, so that sounds like all small block rams horns are the same regardless of base ir LT1 . ?

Don't forget, the LT-1 was equipped with SMOG so the manifolds have the air injection connections.

My codes are

 

[Just Me]

If you need to replace the whole system then definitely a 2"to2.5" is a fantastic system

I think so too

 

[Roscobbc]

Even the most powerful small block will be ok with 2.5" system

 

[Mr. Cricket]

Even the most powerful small block will be ok with 2.5" system

I always find it strange to see a mix of decimal and imperial but it did remind me of a new trainee air conditioning engineer I trained. I asked him to measure a wall to find the centre so we could hang a wall mounted unit. He came back and said 8 mtrs, 7 foot and 4 inches. That was probably near 40 years ago and he's still with us and one of the best engineers out there.

 

[Roscobbc]

Hate metric - I think, visualise in Imperial. A yard is a bit more than a metre. An inch is fractionally more than 25 mm. One can 'visualise' a few 'thou. After all one thousanth of an inch is the diamater of a Knat's cock....right, agreed?

 

[johng]

Except that a yard is a bit less than a metre.

 

[Roscobbc]

Except that a yard is a bit less than a metre.

Yes - that's what I meant......no room for errors then!

 

[Mad4slalom]

I always find it strange to see a mix of decimal and imperial but it did remind me of a new trainee air conditioning engineer I trained. I asked him to measure a wall to find the centre so we could hang a wall mounted unit. He came back and said 8 mtrs, 7 foot and 4 inches. That was probably near 40 years ago and he's still with us and one of the best engineers out there.

Like the french language, where they for no reason chuck in the odd english word such as weekend or sandwich !