Best Exhaust for B18c6r


another vote for skunk2

if your planning on leaving the engine stock internally and keeping the standard map then the 60mm megapower is big enough

if your going cams pistons remap etc then a megapwer R 70mm would be best
 
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skunk2 gets my vote.
custom may be lighter over the skunk2 tho.
 
if the spec 2 is good for power gains i'l buy one insted of a skunk2. only thing is with the 3 inch i was worried it would be too big for N/A
 
3" is too big for n/a 1.6 and 1.8, I'd probably go a far and say its too big for 2.0 aswell,
Everyone on here seems to think the bigger the exhaust the better.
 
jesse888 said:
3" is too big for n/a 1.6 and 1.8, I'd probably go a far and say its too big for 2.0 aswell,
Everyone on here seems to think the bigger the exhaust the better.
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Can you explain why 3" is to big. Or show any cases where people gave lost power from fitting a 3" system.

I always used to think the same. But after a good bit of research it turns out even a stock b16a will actually gain power from a 3" system. I would think this is more only at WOT and it maybe a little less responsive at part throttle use but stil power is gained throughout with the 3" fitted.

Personally I think the noise factor out weights the power gains. But if your not bothered about noise and just want max power then may aswell go 3"
 
Couple of things I can go by is someone else's research but research the same,
Dixon Cheng from Dms only supplies 2.5" exhausts to his n/a s2000 customers because 2.5" is already maximising the flow that the f20c can produce,
So what would make any other 1.6/8 or 2.0 any different?
Besides the extra cost in 3inch you've got clearance, noise, weight. It's just not beneficial when a 2.5 or 2.25 can do the job.i might be wrong but doesn't the B16b runs 2.25"? If that's enough for it to flow 180odd hp then 3" is overkill.


You may not lose power top end from going from stock to 3". But if you compare your average joe on here with bolt ons going from say ther skunk2 or buddy club or whatever to a 3" is waste of time. I'm no exhaust expert but I know for a fact 2.5" exhaust can flow enough to support over 300hp as I've done it. In fact I had a restrictive centre section when I did that on my Astra.
 
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jesse888 said:
Couple of things I can go by is someone else's research but research the same,
Dixon Cheng from Dms only supplies 2.5" exhausts to his n/a s2000 customers because 2.5" is already maximising the flow that the f20c can produce,
So what would make any other 1.6/8 or 2.0 any different?
Besides the extra cost in 3inch you've got clearance, noise, weight. It's just not beneficial when a 2.5 or 2.25 can do the job.i might be wrong but doesn't the B16b runs 2.25"? If that's enough for it to flow 180odd hp then 3" is overkill.


You may not lose power top end from going from stock to 3". But if you compare your average joe on here with bolt ons going from say ther skunk2 or buddy club or whatever to a 3" is waste of time. I'm no exhaust expert but I know for a fact 2.5" exhaust can flow enough to support over 300hp as I've done it. In fact I had a restrictive centre section when I did that on my Astra.
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2.5 inch may be enough to flow 300bhp but with a bigger exhaust an NA engine will make more power with the same setup....turbo cars are different and dont suffer from as much impact on pumping losses as on an NA with a restrictive exhaust....but a turbo car running 300bhp would see a big improvement in a 3 inch exhaust system

IMHO anything over 220bhp NA you should be looking to upgrade your exhaust to 2.75 inch to get the most out of your engine....i wouldn't go 3 inch unless forced induction or over 300bhp NA
 
Yeah your right about seeing gains with the turbo cars over 300hp. I swapped to full 3" shortly after and gain a fair bit if torque midrange but minimal gains up top.
Sorry to keep bringing s2k into I but the exhaust on the s2k where it splits is 2.25" and that flows 240.
 
Surely the majority of manifolds are 2.5" so this would be the ideal size to get considering weight/price etc?
 
Yeah this is what I'm saying, 2.5" is easily enough
 
what diameter is the buddy club spec 2 can get one in 3 days so really thinking about it as moving house so need to get things sorted in the next couple of weeks
 
An exhausts ability to flow at certain HP is irrelevent to what HP it could have with a larger exhaust. Just throw it into google if you don't believe me. You will find dosens of threads debating it but almost all will contain a link to some dyno comparison where the 3" system out performs throughout.

The point is he wants maximum power. Clearance or weight differences will be minimal if any. He already said Noise is no issue.

Sure a 2.5" system would be fine but would not be maximising the engine's potential. Also Just to point out that genericaly all these claimed 2.5" systems on the market are actualy only around 60mm external pipe diameter so only about 2.35" in reality.
 
By that math surely everyone should be running 4" exhausts?
Once you've reach peak flow capacity what's the point going any wider?
 
I don't know much about these engines but is ther any off the shelf 3" bore exhausts for these? Surely of ther was a gain over 2.5" a tuner would have picked that up and started to stock them?

Edit, answer my own question skunk2 do one? But don't they say its for the boosted cars? I'm at work so can't be searching the net all night lol
 
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jesse888 said:
By that math surely everyone should be running 4" exhausts?
Once you've reach peak flow capacity what's the point going any wider?
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jesse888 said:
I don't know much about these engines but is ther any off the shelf 3" bore exhausts for these? Surely of ther was a gain over 2.5" a tuner would have picked that up and started to stock them?

Edit, answer my own question skunk2 do one? But don't they say its for the boosted cars? I'm at work so can't be searching the net all night lol
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The jump from 2.5" to 3" is only half an inch. Not 1.5 inches. There are a few people who make them but generally it is to difficult to keep the noise down on a 3" system unless its turbo. So making a mass produced 3" system in not really going to be cost effective. As most people with the money to tune there cars generally have the money for a custom system.

You really have not got the point at all here have you. He wants maximum power so there is no reason not to go 3". Just get a Mega power RR there are loads on ebay.

Also if you notice drag cars, were ever hp counts, generally dont run any exhaust at all after the manifold.
 
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