Exhaust alternatives?
Discussion
I have a standard system fittem to my '90 C4, with after market tail pipes.
It sounds nice..but i want a louder rumble, with maybe more performance.
The manifolds look restrictive. I.e cast iron/single down pipe. Are the cats a legal requirement on a 1990? What about C02 sensors if they were dispensed with etc..
I have looked at Borla exhausts, but tbh i'm not totally sure.
Any feedback would be appreciated.
It sounds nice..but i want a louder rumble, with maybe more performance.
The manifolds look restrictive. I.e cast iron/single down pipe. Are the cats a legal requirement on a 1990? What about C02 sensors if they were dispensed with etc..
I have looked at Borla exhausts, but tbh i'm not totally sure.
Any feedback would be appreciated.
Not sure about the legality of cats the big problem you will have is fooling the ECU if you remove them as without the O2 sensors you could have loads of problems.
Had a Corsa cat back system on my C4 which was very good except it has 4 rear pipes but only 2 are used and 2 are dummy which is pants.
Checkout the corvette Forum in the US as there are bound to be endless threads about it there.....
Had a Corsa cat back system on my C4 which was very good except it has 4 rear pipes but only 2 are used and 2 are dummy which is pants.
Checkout the corvette Forum in the US as there are bound to be endless threads about it there.....
Thanks VHR.
I have looked at the US forum, which suggest a multitude of applications, Borla, Corsa etc.. but being in the US deosn't help with obtaining them.
Where's best here to purchase any decent pipes...recommendations/links?
I'm not bothered whether the cats stay or go...i guess i just want to increase the grumble
Thanks for your help.
I have looked at the US forum, which suggest a multitude of applications, Borla, Corsa etc.. but being in the US deosn't help with obtaining them.
Where's best here to purchase any decent pipes...recommendations/links?
I'm not bothered whether the cats stay or go...i guess i just want to increase the grumble
Thanks for your help.
You could try Keith Beschi at www.eurovettes.com as I know he does C4 bits.
Try chopping off the rear boxes and replacing them with a bit of stainless pipe and some nice dual tailpipes.
I did this on my 1993 (now owned by someone else) about 4 years ago and it still sounds superb and has had no resultant problems or error codes. It's a cheaper alternative to a new system
I did this on my 1993 (now owned by someone else) about 4 years ago and it still sounds superb and has had no resultant problems or error codes. It's a cheaper alternative to a new system
Wayne,
Easy solution is to remove the two massive rear boxes and replace with a straight through pipe. I had this done on mine, but also had the original LT1 tailpipes welded onto the end of the straight thro' so as to retain the original look. It is some loud now when booted, but once cruising its not to unpleasant at all.
Easy solution is to remove the two massive rear boxes and replace with a straight through pipe. I had this done on mine, but also had the original LT1 tailpipes welded onto the end of the straight thro' so as to retain the original look. It is some loud now when booted, but once cruising its not to unpleasant at all.
I had some aftermarket rear boxes put on my 1990 (can't remember which make) and had the central cat simply knocked out, i.e. the honeycomb smashed and the cat shell put back onto the car.
Made a great noise then, in fact better than my standard Z06 now!
Made a great noise then, in fact better than my standard Z06 now!
Edited by godzilla on Wednesday 23 August 17:11
Cat smashing is a cheap way to make a sort of straight through cat-less system - did it to my MX6 when I had that!
The manifolds are a tubular type on the 90 - you've got an L98 engine in that. However there are a few ponies to be picked up with aftermarket headers, although no idea how much, and if it's an auto, you should be careful over changing items if its going to push the power up the rev range - expecially as the L98 is primarily designed for torque.
A common ailment with early C4's is a blocked cat (and precats if post-86), and legally the best thing to do with a pre-92 is to do away with them (you don't need them for emissions limits in the uk, but if it were a post 92 car if it had a cat it has to keep it/them).
Personally I wouldn't go with the removing the rear box solution, when the cats are restrictive/get clogged, I've got a dual system on mine. It came from Ecklers (via Keith of Eurovettes), and basically replaces the exhaust system from the manifold flange (i.e you keep your manifolds), two pipes run the length of the car to some (fairly) stock back boxes. With the L98, pretty sure there is jsut the one o2 sensor in the left hand down pipe (well before cats), this is screwed into the new pipe and voila - no problems with fault codes or driveability.
Mine were stainless (albeit only 304 I think) and cost about £350 delivered about 5 years ago. New back boxes these days are about £120 and up (you can get silly on these...)
The manifolds are a tubular type on the 90 - you've got an L98 engine in that. However there are a few ponies to be picked up with aftermarket headers, although no idea how much, and if it's an auto, you should be careful over changing items if its going to push the power up the rev range - expecially as the L98 is primarily designed for torque.
A common ailment with early C4's is a blocked cat (and precats if post-86), and legally the best thing to do with a pre-92 is to do away with them (you don't need them for emissions limits in the uk, but if it were a post 92 car if it had a cat it has to keep it/them).
Personally I wouldn't go with the removing the rear box solution, when the cats are restrictive/get clogged, I've got a dual system on mine. It came from Ecklers (via Keith of Eurovettes), and basically replaces the exhaust system from the manifold flange (i.e you keep your manifolds), two pipes run the length of the car to some (fairly) stock back boxes. With the L98, pretty sure there is jsut the one o2 sensor in the left hand down pipe (well before cats), this is screwed into the new pipe and voila - no problems with fault codes or driveability.
Mine were stainless (albeit only 304 I think) and cost about £350 delivered about 5 years ago. New back boxes these days are about £120 and up (you can get silly on these...)
Thanks guys..some good ideas here.
Sounds like keeping the manifolds would be the way to go..especially as i prefer big low down torque to high rev hp.
I'm still awaiting my Haynes, is it my understanding that my exhaust has 2 pre cats..down from the manifold, which collects into the main centre box..which is the main cat converter. It is this I may adapt.
And change the rear boxes.
Sounds like keeping the manifolds would be the way to go..especially as i prefer big low down torque to high rev hp.
I'm still awaiting my Haynes, is it my understanding that my exhaust has 2 pre cats..down from the manifold, which collects into the main centre box..which is the main cat converter. It is this I may adapt.
And change the rear boxes. waynester said:
Thanks VHR.
I have looked at the US forum, which suggest a multitude of applications, Borla, Corsa etc.. but being in the US deosn't help with obtaining them.
Where's best here to purchase any decent pipes...recommendations/links?
I'm not bothered whether the cats stay or go...i guess i just want to increase the grumble
Thanks for your help.
I have looked at the US forum, which suggest a multitude of applications, Borla, Corsa etc.. but being in the US deosn't help with obtaining them.
Where's best here to purchase any decent pipes...recommendations/links?
I'm not bothered whether the cats stay or go...i guess i just want to increase the grumble
Thanks for your help.
US Automotive in Bedford or thereabouts stock Borla, possibly may do Corsa too. They have a website with product list ande certainly do C5 exhausts so probably do C4
Gassing Station | Corvettes | Top of Page | What's New | My Stuff