I want a Le Mans Corvette sounding exhaust !
Discussion
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
Right, car is back together, Y piece is as it was, new 3" exhaust clamp at the bottom, mount re-attached to the block, and my precats are (mostly) sat in my magnetic parts tray by my toolbox.
I did fire the engine up just before re-attaching the y piece, just to blow out any debris without it going into the y piece. The debris came out and the car sounded like a top fuel dragster - and smelt like it too!!! Wicked
Of course now it's started snowing...
I did fire the engine up just before re-attaching the y piece, just to blow out any debris without it going into the y piece. The debris came out and the car sounded like a top fuel dragster - and smelt like it too!!! Wicked
Of course now it's started snowing...
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.......
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...
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...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 bh to do. If your precats are "intact" they are very difficult to remove...
Not sure what an ACT exhaust consists of, but mine has no cats, straight through and no back box...its quite loud, not as loud as Candy but not much is..! 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...
Claire
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 bh 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.
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 bh to do. If your precats are "intact" they are very difficult to remove...
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...
HmmmSounds like a result there Pete
showcase said:
what was the best tool for removing the pre-cats in the end mate? drill? hammer ? gun? !. 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
I think the ACT is pretty much the same as a sleeved setup.. 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 You name it - 18" long masonry drill, a couple of chisels, a couple of long screwdrivers, a couple of socket set extension bars, and a large hammer. Absolutely bloody nightmare. But worth it, it would seem!
Blues said:
im said:
I remember when I had my pre-cats out, it didn't really add to the decibel count but it did make it 'burble' a lot more.
hello mateyWas this with the SC Ian?
And why did you put them back?
Hi DavidNo - the sequence of events was:
When Standard I had the exhaust converted to straight-through this made it VERY loud and I could Pop & Bang at will.
Then, later, I had the precats out which, as I said, made it burble way more (mainly at idle) but didn't add to the overall noise level
Then, upon Supercharging, the Poping & Banging stopped but nothing else is affected (loudness/burbling etc)
I haven't put them (the pre-cats) back though David. Did your exhaust change at all upon S/C ing?
As i have said in a previous thread,i have tried everything in the exhaust pipe department and the compromise for me is no precats,Mr Fords Y piece and standard back box,the only thing i haven't tried are proper USA cherry bombs.straight through was great but just too loud for everyday town use,on my car it sounded like a tractor at low speed, and music afterwards.playing with the tune resister i found created the pops and bangs.
i have spent alot of time listening to V8's at traffic lights in the US,why don't ours sound the same ?
i have spent alot of time listening to V8's at traffic lights in the US,why don't ours sound the same ?
im said:
Blues said:
im said:
I remember when I had my pre-cats out, it didn't really add to the decibel count but it did make it 'burble' a lot more.
hello mateyWas this with the SC Ian?
And why did you put them back?
Hi DavidNo - the sequence of events was:
When Standard I had the exhaust converted to straight-through this made it VERY loud and I could Pop & Bang at will.
Then, later, I had the precats out which, as I said, made it burble way more (mainly at idle) but didn't add to the overall noise level
Then, upon Supercharging, the Poping & Banging stopped but nothing else is affected (loudness/burbling etc)
I haven't put them (the pre-cats) back though David. Did your exhaust change at all upon S/C ing?
I previously had the Offords £150 "Cherry Bomb" conversion, which i was pleased with, but got louder and louder as it matured with lots of popping and cracking on overrun. At the same time as having the SC fitted, i had the full ACT "Cherry Bomb" system fitted. This is significantly quieter, but still a lovely deep rumble, and i don't get the lunatic explosions that i used to get. I suspect this is a combination of the ACT exhaust and the SC fuelling better. On balance, I think i am happier with the current sound, but i'm now intrigued to hear what the removal of pre-cats has done to VerySideways' car
My old Chim had ACT de-catted manifolds and sleeved back boxes and sounded fantastic. Overun could easily be induced and when really hot just did it on its own accord.
It's worth mentioning a couple of things though;
Full de-cat - you WILL have MOT emissions problems unless extremely lucky. If you remove the main cat from the Y-piece it will sound too deep IMHO and more like a loud tractor. If you must go the full de-cat route I believe the ACT narrow Y-piece is the much better sound.
Pre-cats - hese make bugger all difference to the sound, many people say it does but personally I belive it's more of a placebo effect. However, as already mentioned their removal does have other benefits such as free-er revving, less shunting etc.
It's worth mentioning a couple of things though;
Full de-cat - you WILL have MOT emissions problems unless extremely lucky. If you remove the main cat from the Y-piece it will sound too deep IMHO and more like a loud tractor. If you must go the full de-cat route I believe the ACT narrow Y-piece is the much better sound.
Pre-cats - hese make bugger all difference to the sound, many people say it does but personally I belive it's more of a placebo effect. However, as already mentioned their removal does have other benefits such as free-er revving, less shunting etc.
On the yank V8`s each bank of 4 cylinders has its own exhaust. On TVR all eight run into one pipe then split into two at rear. The uneven pulseing of the yanks is down to the seperate exhausts. They sound fantastic but interestingly one of the performance upgrades is to fit an "X" pipe to blend the flow of the gases from each bank. The theory being that when onev bank fires the gases passing across the "X" pipe cause a suction drawing the pulse from the other bank and therefore speeding up exhaust gass expulsion.
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