5-cylinder exhaust manifold design
Discussion
I think you might need to set a few firm targets, and then do the rest to suit, as at the moment, there will be too many variables, and different ways to good results.
This is how BMW do it-
and this is something to do with an F1 Toyota V10
5-1 to start off with, maybe set yourself a diameter after checking out your exhaust ports in the head, and then you've got to either see if you can tune it for a certain RPM, or just go for the closest you can depending on the space you have.
This is how BMW do it-
and this is something to do with an F1 Toyota V10
5-1 to start off with, maybe set yourself a diameter after checking out your exhaust ports in the head, and then you've got to either see if you can tune it for a certain RPM, or just go for the closest you can depending on the space you have.
Beamer V10 is interesting, more geared for torque by the looks and do the primaries go triangular into the collector?
I have all my head specs, cam duration etc. etc. I'm building this (with guidance) with a forged bottom end, billet cams, ITBs etc. etc.
The only person I can find who's done this before (aside from TWR of course) is a guy building a Volvo engine (mine's the Fiat 5-pot). He spoke with an ex-TWR bloke who gave him their manifold specs but I doubt they would be suitable for my engine - they were running something mental like 0.850" lift so god knows what the rest of the specs would be like.
I have all my head specs, cam duration etc. etc. I'm building this (with guidance) with a forged bottom end, billet cams, ITBs etc. etc.
The only person I can find who's done this before (aside from TWR of course) is a guy building a Volvo engine (mine's the Fiat 5-pot). He spoke with an ex-TWR bloke who gave him their manifold specs but I doubt they would be suitable for my engine - they were running something mental like 0.850" lift so god knows what the rest of the specs would be like.
stevieturbo said:
OEM will be packaging as much to space constraints as anything else, plus emissions equipment etc etc.
I guess a lot will depend on usage too. Is it a low rpm mildly tuned engine, a high rpm screamer ? I assume you're referring to a n/a engine too ?
Yeah but the beamer V10 is ~100BHP per litre (not bad for a production engine) so the design obviously can't be hurting it that much. Plus it is a rather elegant solution with, as you say, space constraints in mind - would love to see dyno data for a round tube manifold of the same length and csa primaries - not that it probably exists!I guess a lot will depend on usage too. Is it a low rpm mildly tuned engine, a high rpm screamer ? I assume you're referring to a n/a engine too ?
With the cam profile i'm using, we expect it to make max bhp @ around 8k and max torque @ around 5k. I'll probably have a soft limit @ around 8.5k (yep, n/a).
Edited by nedge2k on Thursday 9th February 11:41
BMW M division do put some thought into the manifolds and tune them, compared to their non M s which are usually smallest and simplest.
The M5 pipes do go oval by the looks of it, so I guess their cross sectional area needed meant a larger diameter pipe than they had the space for.
The F1 version isn't going to be of much use as it'll be expecting up to 18,000rpms or something, but it shows there is unlikely to be any 5/2/1 or 5/3/1 designs that are of any use.
Having an odd number of cyls does give that away, but you never know until it's fully modelled.
The M5 pipes do go oval by the looks of it, so I guess their cross sectional area needed meant a larger diameter pipe than they had the space for.
The F1 version isn't going to be of much use as it'll be expecting up to 18,000rpms or something, but it shows there is unlikely to be any 5/2/1 or 5/3/1 designs that are of any use.
Having an odd number of cyls does give that away, but you never know until it's fully modelled.
TheEnd said:
BMW M division do put some thought into the manifolds and tune them, compared to their non M s which are usually smallest and simplest.
The M5 pipes do go oval by the looks of it, so I guess their cross sectional area needed meant a larger diameter pipe than they had the space for.
The F1 version isn't going to be of much use as it'll be expecting up to 18,000rpms or something, but it shows there is unlikely to be any 5/2/1 or 5/3/1 designs that are of any use.
Having an odd number of cyls does give that away, but you never know until it's fully modelled.
True but the stepped primaries of the F1 mani would be, should help alleviate reversion.The M5 pipes do go oval by the looks of it, so I guess their cross sectional area needed meant a larger diameter pipe than they had the space for.
The F1 version isn't going to be of much use as it'll be expecting up to 18,000rpms or something, but it shows there is unlikely to be any 5/2/1 or 5/3/1 designs that are of any use.
Having an odd number of cyls does give that away, but you never know until it's fully modelled.
Anyone know anyone that's used pipemax - and dyno proven the results?
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