Replacement C3 Exhaust Help

[Artisam91]

Afternoon All,

It looks as though the time has come for the exhaust on my 1977 C3 to be replaced as it has worn through in a couple of places.

After a bit of googling I'm still unsure what I need to replace it with and where I can get it from!

Would anyone be able to recommend a replacement system and or supplier please? I think the current system is stock but I would be interested in increasing performance if this is a possibility - again don't know if this would trade off against economy or noise?

Any help would be hugely appreciated.

Thanks

 

[Roscobbc]

Is it a dual system (or two in to one - then back in to two?) - options are replacement with stock off the shelf type replacement. Made-up system either in mild or stainless steel running back from original cast manifolds. The same but with a set of tubular headers. I'm you'll find a specialist close by that does american car systems. What part of UK are you?

 

[Artisam91]

Thanks for the information, looks to be an X shape from memory so would be the two to one and back to two - don’t know If this has any benefit/ drawback against straight through? I’m based quite Heathrow. Cheers

 

[Roscobbc]

Theoretically that system would be the least desireable in performance terms. Depends on whether you intend to do additional things to the engine to improve performance if that is your intention then a dual system will ultimately improve performance - if exhaust done on it own gains will be limited - but it'll sound good.

 

[Daytona Vette]

I think 80s (actually 79 manufactured) Vettes have the two into one exhaust senario and hence only the one hole for the exhaust through the gearbox cross member, so difficult for a twin system - help here please is it the case that manual and auto gearboxes had a difference on the chassis, in as much as one had a welded in gearbox cross member and the other had a bolted in unit? and thus an easier possibility for some late cars to change the cross member to facilitate a dual exhaust system

 

[Roscobbc]

Auto's have bolted crossmember - manuals fixed. Would have thought Vettes with single pipe systems had two cut-outs in chassis like earlier (and later) cars - perhaps an owner on here can advise?

 

[curious bystander]

Mine's a 79 Auto - with a more or less standard exhaust - 2 into 1 and back to 2 - and there is a matching hole in the cross member on the drivers side to allow for twin single pipes if required.

 

[Alben78]

My 78 certainly had two holes in the transmission x member and had a twin pipe exhaust fitted with no problem. The original but not OE back boxes were retained and the cat deleted. It did seem to improve the performance if I remember correctly but that was more than 20 years ago

 

[Roscobbc]

The OP's near Heathrow - there is an outfit in Colnbrook that supply/install systems for American cars - I won't mention them by name as I have no idea how good they are. I remember visiting them 7 or 8 years ago when I wanted a system for my car - TBH I didn't think they knew what they were talking about back then - but they are still there so must be doing something right. Eventually had a twin 3" system made in stainless (with an 'X' pipe) from the headers back by Hayward & Scott at Basildon. Still cost close to a four figure sum. There is also Pipecraft at Basildon - been around for ever - have a good reputation for fair prices........

 

[Artisam91]

Thanks for your replies - I checked last night and there is indeed 2no holes for the exhaust. The current configuration is Y type pipe with cat so seems like it could be a good candidate for improvement. The Cat has rusted through in a couple of places.

I've found a system from corvette central for 800 dollars, bellow once taxes and shipping are applied this will also be close to four figures GBP - is this standard for a replacement system and any ideas if below will be any good?

- I'm guessing

1974-1979 Corvette Exhaust System Mufflers |Corvette Central

Exhaust system featuring Magnaflow mufflers for your 1974-1979 4-Speed or TH350 C3 Corvette. Pipes, mufflers and hanger all included.

www.corvettecentral.com

 

[Daytona Vette]

My 78 certainly had two holes in the transmission x member and had a twin pipe exhaust fitted with no problem. The original but not OE back boxes were retained and the cat deleted. It did seem to improve the performance if I remember correctly but that was more than 20 years ago

78s were dual pipes, hence "manufactured 79"

 

[Daytona Vette]

Thanks for your replies - I checked last night and there is indeed 2no holes for the exhaust. The current configuration is Y type pipe with cat so seems like it could be a good candidate for improvement. The Cat has rusted through in a couple of places.

I've found a system from corvette central for 800 dollars, bellow once taxes and shipping are applied this will also be close to four figures GBP - is this standard for a replacement system and any ideas if below will be any good?

View attachment 7684 - I'm guessing

1974-1979 Corvette Exhaust System Mufflers |Corvette Central

Exhaust system featuring Magnaflow mufflers for your 1974-1979 4-Speed or TH350 C3 Corvette. Pipes, mufflers and hanger all included.

www.corvettecentral.com

If you are going away from standard, get a quote for a bespoke dual system in Stainless Steel, from the headers back and then cost up some good Headers from UK or over the Pond - I used Pipecraft many years ago - they knew what they were doing - also Custom Chrome in Nuneaton worth the distance - they will make you anything you want and it is quality.

 

[antijam]

I had a stainless system custom made for my '71 - see here. I can certainly recommend Infinity if you fancy a trek down the M4. Even if you don't, £600 should give you an idea of cost.

 

[Alben78]

78s were dual pipes, hence "manufactured 79"

If I recall correctly my ‘78 was manufactured in October 1977. The dual pipes were added in the UK by a local exhaust supplier who removed the cat but retained the original US back boxes which had obviously been changed at some time in the US.

 

[Rogueone]

I have just bought and fitted myself a dual system with low profile Silencers £495 done.well pleased

 

[Roscobbc]

I would think that any specialist in the UK could improve on Corvette Centrals price - I should imagine freight and carriage right now is horrendous! - be brave, invest in a pair of ceramic coated headers and a system from a specialist. Do not use Cherry Bomb mufflers - a few month down the road and you'll hate the road as they gradually 'coke-up'.

 

[Alben78]

Yep, Custom Chrome in Nuneaton did mine, they also did some work for JLR when I worked there so they know their stuff.

 

[Artisam91]

I have just bought and fitted myself a dual system with low profile Silencers £495 done.well pleased

Was this an out the box bolt on? - I've been to one place in Colnbrook who have quoted me £1600 for a system after the stock manifolds which they said there would be no need to change?

I think I have an idea of what I need now but just need to find it for the right price - don't seem to be getting anywhere near 495..

Thanks again all for your help

 

[Roscobbc]

You need to be inventive. When I first replaced the system on my '68 the I sourced aftermarket mufflers very similar in size and pipe layout to stock (something like this U336300 Jetex Exhausts Ltd – Products) Chose them as they are filled with ceramic or stainless 'wool' unlike other that are filled with glass fibre. I then installed the headers. Then drove the car to the exhaust specialist and he did the rest. Can't recall how much unfortunately.

 

[Daytona Vette]

Yep, Custom Chrome in Nuneaton did mine, they also did some work for JLR when I worked there so they know their stuff.

Yes and I have had an SS System made by them - also do work for either Bentley or Rolls