Oreca Race System v Akrapovic Evolution (Decat)
- Thread starter Kazumz
- Start date
The pointless second exit says it all to me, the akra is built for show, the oreca is built for go. When I had my 197 I didn't consider any other for that reason. Plus the second exit just slows exhaust gasses down. It's there purely to make people think it's special. As most people are easily fooled. In my opinion. Not meaning to cause offence. Those clio 197 and 200s belong on the b roads. Why not get the thing that improves it's ability the most. On a naturally aspirated engine an efficient exhaust system is all about the speed the gasses are travelling. It wants to be as small diameter as possible without being restrictive to keep speeds up, a second exit cisco doing the same as increasing the diameter unnecessarily thus slowing gasses down and decreasing torque, which these cars don't have much of anyway. Induction follows a similar principal. Only give your engine what it needs, too little and it will struggle, to much and it will struggle. Like us not enough water and we die, too much and we drown. (Exaggerated)
TB Rich
Paid Member
On a 197 that's fine, you wouldn't obviously notice a missing tailpipe. On a 200 with it's f'off holes either side of the diffuser it would look stupid having fumes and flames out one hole only.
No one here is running an NA build worthy anyway, if I kept with an F4R then once the head and ITBs etc were on then if I wanted to scrabble around for yet those last few bhp then sure you go single exit... otherwise I'll take build quality, fitment, sound quality and frankly kudos (and thus resale) of the Akra over a nasty sounding Oreca. In a forest they sound great, on the road not so! I've run a countless combination of exhaust setups on the 200 and Akra trumps all by a mile because somehow it stays pleasant whilst cruising. The Orcea sounds just like when I had my fully cat less, resonator less, Superpsprint race backbox only - Harsh.
krash67
Gold Member
The old age story of restriction against over size is one that is always been debated and tested. Majority of tests have shown that motors pushing 400hp through either a 2 1/2" diameter exhaust against 3" have seen very little difference in overall performance. Where one marginally provides more torque & BHP at the bottom end (i.e. 2.5") the reverse can be seen at the other end of the rev range. And we are only talking one or two BHP/Nm and as mentioned this seen on units pushing 400bhp.
As for the lesser bhp F4R. I personally don't think its going to make a vast hoots difference, considering the biggest deficiency in utilising the power/torque is the human numpty sat behind the wheel!
But as they say every little helps.......but only if you can utilise it!
As for the lesser bhp F4R. I personally don't think its going to make a vast hoots difference, considering the biggest deficiency in utilising the power/torque is the human numpty sat behind the wheel!
But as they say every little helps.......but only if you can utilise it!
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The exhaust with its two exits is not pointless, it will and does have an effect on how well the diffuser works. the quantity of that effect is up for grabs but it does have an effect.
And not stand any chance of making a track day, nah I'll stick with the Akra(which fails on a R3 mani if you rev it out beyond 6.5k
Any chance?
Its supposed to be about 96db which should be ok for most tracks. All the MSV ones.
I've got one on order but its about 2 weeks away.
TB Rich
Paid Member
96dB static is likely to be borderline obnoxious on full chat to be honest.
My Akrapovic (with R3 manifold and thus pre-cat delete), was 87dB static and I may or may not have had problems at a recent track day which has a 100dB static and also drive-by meters in place.
My Supersprint on the same manifold with a centre silencer was 99dB staticmg: drive-by noise, no chance!!
That same exhaust without a centre silencer, never tested but easily well over 100dB! Sounded just like an Oreca aswell, which was very raspy and certainly not for my tastes. Fine in a forest because it was pure rally car but on the street just reminded me of a 90's Honda B-series with a bean can for a backbox. I guess the Orcea with pre-cat still in place will be slightly more cultured though...
So after all that waffle.....you may be ok with the standard manifold and pre-cat in place on an Orcea for tracks with drive by, however not a hoot IMO if you ever deviate from that and fit an aftermarket manifold (R3, Toyo, Ktec).
My Akrapovic (with R3 manifold and thus pre-cat delete), was 87dB static and I may or may not have had problems at a recent track day which has a 100dB static and also drive-by meters in place.
My Supersprint on the same manifold with a centre silencer was 99dB static
mg: drive-by noise, no chance!!That same exhaust without a centre silencer, never tested but easily well over 100dB! Sounded just like an Oreca aswell, which was very raspy and certainly not for my tastes. Fine in a forest because it was pure rally car but on the street just reminded me of a 90's Honda B-series with a bean can for a backbox. I guess the Orcea with pre-cat still in place will be slightly more cultured though...
So after all that waffle.....you may be ok with the standard manifold and pre-cat in place on an Orcea for tracks with drive by, however not a hoot IMO if you ever deviate from that and fit an aftermarket manifold (R3, Toyo, Ktec).
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