I want a Le Mans Corvette sounding exhaust !
Discussion
I know this subject has been approached many times but im still not sure if I have found the answers to my questions yet if you know what I mean.
I have a 500 with standard exhaust system. When I purchased it a few years ago the baffles had been removed from the silencer box .
The car sounded great but I never seamed to get any pops and bangs. In a attempt to improve the sound I had the cherry-bomb silencer fitted back in the silencer box.
( nice job schole by the way) . Now it sounds much deeper and more throughty. Still not much pop or bang and definitely no louder.
So my questions are this really.
should I loose the pre-cats? , should I go for straight through pipes? . should I have a hole sports exhaust system fitted and do I need it re-mapping if I do this?
I hear some people have mentioned “sleeving” what is this and how and where is it done?. Why don’t my car pop and bang much in overrun ?
Or all or part of the above.
My aim is a deep sounding loud car with pops and bangs that doesn’t sound too tinny .
That can’t be to much to ask for can it?
Also can anyone give me an idea of costing of the above modifications.
Many thanks Stu
P.S please no one ask why???? . I love loud stuff is the answer to that!
I have a 500 with standard exhaust system. When I purchased it a few years ago the baffles had been removed from the silencer box .
The car sounded great but I never seamed to get any pops and bangs. In a attempt to improve the sound I had the cherry-bomb silencer fitted back in the silencer box.
( nice job schole by the way) . Now it sounds much deeper and more throughty. Still not much pop or bang and definitely no louder.
So my questions are this really.
should I loose the pre-cats? , should I go for straight through pipes? . should I have a hole sports exhaust system fitted and do I need it re-mapping if I do this?
I hear some people have mentioned “sleeving” what is this and how and where is it done?. Why don’t my car pop and bang much in overrun ?
Or all or part of the above.
My aim is a deep sounding loud car with pops and bangs that doesn’t sound too tinny .
That can’t be to much to ask for can it?
Also can anyone give me an idea of costing of the above modifications.
Many thanks Stu
P.S please no one ask why???? . I love loud stuff is the answer to that!
Edited by showcase on Tuesday 10th February 20:01
That’s great people thank you for all this help.
Looks like the pre-cats are going then.
Like the idea of this “V8 Enhancements Y piece”. (what is it and where do I get one from?.
Followed by an ecu with mutable maps.
How much roughly would I expect to pay for this little lot ?
Also what ecu do people use and where do i get that from?/ or who best to fit it.
Am i also right in saying if i fit v8 enhancement y piece i will loose the main cat anyway?
sorry if that bit sounds odd . im a learner still.
Looks like the pre-cats are going then.
Like the idea of this “V8 Enhancements Y piece”. (what is it and where do I get one from?.
Followed by an ecu with mutable maps.
How much roughly would I expect to pay for this little lot ?
Also what ecu do people use and where do i get that from?/ or who best to fit it.
Am i also right in saying if i fit v8 enhancement y piece i will loose the main cat anyway?
sorry if that bit sounds odd . im a learner still.
Edited by showcase on Wednesday 11th February 17:06
Edited by showcase on Wednesday 11th February 19:02
tvrlee said:
I fitted the gas flowed non-cat 'y' piece from Tim at ACT, the pre-cats had already fallen out and the silencing has been partly removed from the rear box, sounds much like a Nascar now and does pop and bang when feathering the throttle when slowing down, although not as much as 450Nicks. The performance has also improved alot, mainly due to the main cat being knackered!
what did the ACT y piece cost mate , the one i was looking at on v8 enhancments was nearly £500 ( stainless) would be nice to do it cheaper as im looking for sound more than "bling" !I have been on the ACT web site, not phoned them just yet.
I like the look of the Y piece price on there better !.
Im a little confused still though with the main cat. Where is that little bundle of joy resided?.It showes in the bible that its at the bottem of the Y piece. does that mean if i fit a brand new de-catted Y piece i will loose both the pre-cats and the main cat at the same time?.
I notice in the Steve heath bible that he is not a fan of removing the main cat.
saying "remove the pre-cats and leave the main cat in place. This seems to give most of the benefits with fewer problems". he said.
Im begining to wonder if ( i my case) de-catting is worth doing unless you remove all the cats at the same time .
. How do you then pass the emissions test at the MOT or will this not be effected if they dont know about it?.
Im guessing during the replacment of the y-piece i will not have to remove the manifolds too ?
I like the look of the Y piece price on there better !.
Im a little confused still though with the main cat. Where is that little bundle of joy resided?.It showes in the bible that its at the bottem of the Y piece. does that mean if i fit a brand new de-catted Y piece i will loose both the pre-cats and the main cat at the same time?.
I notice in the Steve heath bible that he is not a fan of removing the main cat.
saying "remove the pre-cats and leave the main cat in place. This seems to give most of the benefits with fewer problems". he said.Im begining to wonder if ( i my case) de-catting is worth doing unless you remove all the cats at the same time .
. How do you then pass the emissions test at the MOT or will this not be effected if they dont know about it?.Im guessing during the replacment of the y-piece i will not have to remove the manifolds too ?
tvrlee said:
showcase said:
I have been on the ACT web site, not phoned them just yet.
I like the look of the Y piece price on there better !.
Im a little confused still though with the main cat. Where is that little bundle of joy resided?.It showes in the bible that its at the bottem of the Y piece. does that mean if i fit a brand new de-catted Y piece i will loose both the pre-cats and the main cat at the same time?.
I notice in the Steve heath bible that he is not a fan of removing the main cat. saying "remove the pre-cats and leave the main cat in place. This seems to give most of the benefits with fewer problems". he said.
Im begining to wonder if ( i my case) de-catting is worth doing unless you remove all the cats at the same time .. How do you then pass the emissions test at the MOT or will this not be effected if they dont know about it?.
Im guessing during the replacment of the y-piece i will not have to remove the manifolds too ?
I didnt have to remove the manifolds at all, they are the only parts that remain in place, the precats are in the manifolds, just after the 4 pipes come together, the main cat is in the large section of the 'y' piece. As far as the MOT goes, i'm not sure yet, mine is due in March and i do knwow a friendly tester, although i may put in without saying anything and see what they say, worst case is to put the old 'y' piece back for the MOT and then change it again. The car definitley runs free'er without the cats, it also appears to have more torque, particulary upwrads of 3500rpm.I like the look of the Y piece price on there better !.
Im a little confused still though with the main cat. Where is that little bundle of joy resided?.It showes in the bible that its at the bottem of the Y piece. does that mean if i fit a brand new de-catted Y piece i will loose both the pre-cats and the main cat at the same time?.
I notice in the Steve heath bible that he is not a fan of removing the main cat.
saying "remove the pre-cats and leave the main cat in place. This seems to give most of the benefits with fewer problems". he said.Im begining to wonder if ( i my case) de-catting is worth doing unless you remove all the cats at the same time .
. How do you then pass the emissions test at the MOT or will this not be effected if they dont know about it?.Im guessing during the replacment of the y-piece i will not have to remove the manifolds too ?
Lee
i think i will first speak to the MOT guys next to our industral unit tomorow about the emmision thing. Then give Tim a call at ACT and get some new parts on order!
found myself looking at the pro-race wheels on the ACT site
, very nice. one thing at a time though.......VerySideways said:
Well the exhaust doesn't seem much louder to me (mine's already got the ACT sports exhaust) BUT...
1. The cold idle running seems much smoother
2. It shunts less, cold or hot, at lower rpm - in fact it doesn't appear to shunt at all now.
3. You can tell it's more willing to rev, certainly in the mid range if not at the top.
4. It seems to need less throttle to do 30mph in 3rd than it did before.
I wasn't expecting any of that, i was expecting it to be LOUD!!!
I can still make it pop and bang on the overrun by resting my foot on the throttle pedal(which i'm sure you already know about already).
Very pleased - though it was a total b
h to do. If your precats are "intact" they are very difficult to remove...
what was the best tool for removing the pre-cats in the end mate? drill? hammer ? gun? !1. The cold idle running seems much smoother
2. It shunts less, cold or hot, at lower rpm - in fact it doesn't appear to shunt at all now.
3. You can tell it's more willing to rev, certainly in the mid range if not at the top.
4. It seems to need less throttle to do 30mph in 3rd than it did before.
I wasn't expecting any of that, i was expecting it to be LOUD!!!
I can still make it pop and bang on the overrun by resting my foot on the throttle pedal(which i'm sure you already know about already).
Very pleased - though it was a total b
h to do. If your precats are "intact" they are very difficult to remove...
. Would be nice to know how different yours sounds with just the pre-cats gone. Considering you started this only yesterday and now your done. not bad going .as i dont have the ACT sports exhaust ( wich i assume is straight through pipes). should i still expect good things from the work? . pitty i dont have a sound meter handy to report my findings.
Right then , I am getting somewhere now.
Spoke first to a friendly MOT man yesterday
. he said that the car may pass without the cats. Depends on the car engine quality. He also said if it was way out then I would have to put the old catted Y piece back in 
, but if its close ( what ever that is) he can “help” it pass the test.
So that’s a result!. He has even offered me the chance to put it on the emissions tester once I have done the work just to see where I am , as it only passed a MOT 2 months ago.
Then I rang a very helpful guy at ACT ( didn’t get his name) and had a long and informative chat about my current exhaust system and what to do about it.
His advice on the matter was to leave my main exhaust system alone as I already have the cherry bombs in my silencer . Wich he said makes it almost the same as the ACT sports exhaust. Leave the ECU alone for the time being . “ if the car is running fine then don’t mess with it” kind of thing.
Fit the new ACT Y piece removing the main cat( which is the main noise muffler) , then remove the pre-cats if it’s easy enough to do so. ( some times they fall out, sometimes they are a bd to remove without taking of the manifold which can open up another host of problems.
One thing he did say of interest was “if you do take the pre-cats out , don’t leave any debris of the pre-cats lying around in the manifold shove a hoover up the pipes if you have too but the exhaust doesn’t just blow the st out . It can breath some back in !.”
So I now have a shiny new Y piece in the post ( 2 weeks) and I will post back with the results when I have completed the job. Thanks for all the help !
1 more question ! should I take the bonnet off for easy access?
Spoke first to a friendly MOT man yesterday
. he said that the car may pass without the cats. Depends on the car engine quality. He also said if it was way out then I would have to put the old catted Y piece back in , but if its close ( what ever that is) he can “help” it pass the test.So that’s a result!. He has even offered me the chance to put it on the emissions tester once I have done the work just to see where I am , as it only passed a MOT 2 months ago.
Then I rang a very helpful guy at ACT ( didn’t get his name) and had a long and informative chat about my current exhaust system and what to do about it.
His advice on the matter was to leave my main exhaust system alone as I already have the cherry bombs in my silencer . Wich he said makes it almost the same as the ACT sports exhaust. Leave the ECU alone for the time being . “ if the car is running fine then don’t mess with it” kind of thing.
Fit the new ACT Y piece removing the main cat
( which is the main noise muffler) , then remove the pre-cats if it’s easy enough to do so. ( some times they fall out, sometimes they are a bd to remove without taking of the manifold which can open up another host of problems.One thing he did say of interest was “if you do take the pre-cats out , don’t leave any debris of the pre-cats lying around in the manifold shove a hoover up the pipes if you have too but the exhaust doesn’t just blow the s
t out . It can breath some back in !.”So I now have a shiny new Y piece in the post ( 2 weeks) and I will post back with the results when I have completed the job. Thanks for all the help !
1 more question ! should I take the bonnet off for easy access?
Sorry for the long wait! , i have been to egypt
and stuff so only managed to do the work this week.
Started sunday , little monday and a couple of hours tonight.
The beast is back in the garage now fully de-catted, pre and main with the new ACT replacment y-piece.
As you may have all read , removing the pre-cats was the worst job i have done in a long time. it was a of a job. I used many tools but long masonary drill and v long screw drivers ripped it apart in the end.( average 3h each i would guess). Had to remove the hole exhaust system to get the new Y-piece in including the rear ARB.
I havent taken it to my MOT guy yet for the emmissons cheak yet.(doing that saturday hopfully). Anyway i fired it up and it sounds bloody fantastic !
, just what i was looking for.
loud,deep,burbling,grunting.....and that was just on the drive.I would have taken it for a spin but for the fact i have the bonnet in my dinning room still.
(I will use this as a oppertunity to clean the bits of body and engine bay that dont normaly get cleaned!). I will then drive it at the weekend and report back.
so far so good!
and stuff so only managed to do the work this week.Started sunday , little monday and a couple of hours tonight.
The beast is back in the garage now fully de-catted, pre and main with the new ACT replacment y-piece.
As you may have all read , removing the pre-cats was the worst job i have done in a long time. it was a
of a job. I used many tools but long masonary drill and v long screw drivers ripped it apart in the end.( average 3h each i would guess). Had to remove the hole exhaust system to get the new Y-piece in including the rear ARB.I havent taken it to my MOT guy yet for the emmissons cheak yet.(doing that saturday hopfully). Anyway i fired it up and it sounds bloody fantastic !
, just what i was looking for.loud,deep,burbling,grunting.....and that was just on the drive.I would have taken it for a spin but for the fact i have the bonnet in my dinning room still.
(I will use this as a oppertunity to clean the bits of body and engine bay that dont normaly get cleaned!). I will then drive it at the weekend and report back.
so far so good!
Wow this is a old thread !, Well i can safely say the job was well worth doing. I am very, very pleased with the results and so is every one who has listens to the before and after.I never had any pops before i de-catted and now i get some ( not all the time though but definitely lots more than it did ). Like i have said before , im not sure if the performance has improved but the engine temp is now always good ( though i do have the cooling mod on mine ).I didn't re-map either.
I haven't got round to having the emissions checked yet, though im told it will go through
. I'm sure it will help if you know the m.o.t guy quite well.No need to remove the manifolds , i did my pre-cats with them still in place, long masonry drill bit essential though.
enjoy!
I may just add before i de-cated i had :
1st) standard exhaust with all the wadding removed from the silencer box. loud but to sharp and "tinny".
2nd) i had cherry bombs fitted to my silencer box, the result was a nice deep burble but now slightly quieter
.3rd) removed the pre-cats and fitted Act Y piece ( New Y piece is important though) apart from having the Main cat removed. The pipe is much narrower at the base of the "Y" shape this should prevent the "tractor" noise effect which doesn't sound good.
For me it was important to sound deep and loud more than just loud. Straight through pipes should achieve this but was not the type of sound i was looking for.
Edited by showcase on Monday 2nd November 17:41
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