Exhaust manifolds
Discussion
hi Gary, yes same size diameter as standard headers.
ChimpOnGas said:
spend said:
Cliff, weld in BIG bosses so that you can supply a pair of screw in adapters...? If they want narrow or Wideband you can just swap the adapters..
I've used similar method to convert your old manifolds to pretty much the same spec as you re-welded Fatsos (bored + cut back the 'long snouted' original boss, tapped, then threaded boss inserted that has internal thread for sensor IYSWIM)
I don't think Cliff is doing manifolds anymore, here he is demonstrating pipe size & how he prefers a tighter bore.I've used similar method to convert your old manifolds to pretty much the same spec as you re-welded Fatsos (bored + cut back the 'long snouted' original boss, tapped, then threaded boss inserted that has internal thread for sensor IYSWIM)
clive f said:
The new manifolds I am making are not intended to increase the performance, they are purely an option as a direct replacement for the existing manifolds, having no precats means the pipes only need to converge into a 3" pipe to help increase flow, and of course these manifolds will fit a catted or decatted or turbo y piece, I`ve had lots of people ask me over the last few years if I make standard manifolds as their standard ones have started cracking, or, just do not like the appearance of them, so this is my alternative.
Any photos / indication of cost?SILICONEKID345HP said:
You have to admit , American v8`s do sound nice ,its got to do with something to do with the exhaust .
In the past I've owned a '68 Camaro and a '71 Firebird so I do have some first hand experience Daz. I wish I kept the Camaro as it would now fetch serious money, but at the time I couldn't afford to keep running it as they were both my daily drivers (in succession).I still prefer my TVR and it may have escaped your notice but it does essentially have an American V8 motor in it, as does yours Daz. !
If you know anything about CFD (computerised fluid dynamics) you'll know that when considering back pressure, bends are more of an issue than tube length. I have seen some manifolds that maintain tube length by curling some of the tubes. This is highly likely to cause more back pressure variation than variable tube length manifolds.
This one is a good example of a nicely balanced system, the differences in length and turn radius are small so back pressure should be fairly balanced
This one is a good example of a nicely balanced system, the differences in length and turn radius are small so back pressure should be fairly balanced
SILICONEKID345HP said:
You have to admit , American v8`s do sound nice ,its got to do with something to do with the exhaust .
It's got something to do with the crankshaft / firing orders Daz 
A firing order that yours shares with (to the best of my knowledge) all recent (last 30 years+) GM V8s.
SILICONEKID345HP said:
You have to admit , American v8`s do sound nice ,its got to do with something to do with the exhaust .
What about this sound? https://www.youtube.com/watch?v=Ei-m96LQlXQ
Only 2x2.45" 316L SS exhaust pipes and 4 mufflers.. 2.5" collector. Next setup i will go for 2" collector. No reason to go any bigger than 2" if engine made +400hp. If go for 180deg manifold, then 2.5" would be more ideal.
You will need bigger RV8 engine to get similar sound like American V8. My SD1 5.2l Will make quite similar sound like American V8 see youtube..
Agressive cam and high compression ratio make more noise..
Three or four years ago there was a thread on here where a set of nicely fabricated equal length headers had been done for a Chim as a one-off; I think by Janspeed but I might be remembering that incorrectly. Just tried searching but not managed to turn it up; maybe someone else will remember it and find...
Kokkolanpoika said:
What about this sound?
https://www.youtube.com/watch?v=Ei-m96LQlXQ
Only 2x2.45" 316L SS exhaust pipes and 4 mufflers.. 2.5" collector. Next setup i will go for 2" collector. No reason to go any bigger than 2" if engine made +400hp. If go for 180deg manifold, then 2.5" would be more ideal.
You will need bigger RV8 engine to get similar sound like American V8. My SD1 5.2l Will make quite similar sound like American V8 see youtube..
Agressive cam and high compression ratio make more noise..
That does sound nicehttps://www.youtube.com/watch?v=Ei-m96LQlXQ
Only 2x2.45" 316L SS exhaust pipes and 4 mufflers.. 2.5" collector. Next setup i will go for 2" collector. No reason to go any bigger than 2" if engine made +400hp. If go for 180deg manifold, then 2.5" would be more ideal.
You will need bigger RV8 engine to get similar sound like American V8. My SD1 5.2l Will make quite similar sound like American V8 see youtube..
Agressive cam and high compression ratio make more noise..
I do not like idea to use TVR type collector.. Merge collector look´s mutch better. Or eaven STD type tubular manifold collector.. TVR collector diameter is huge. They flow easily +500hp each.. Gas speed is very poor.. If i will make new manifold´s for TVR, i will drop collector size to 2" diameter and then go for single 3" pipe..
And what about those 180deg manifold..
Are those reading´s measured using STD TVR manifold or some universal Hedman headers´s? Like those?
http://www.v8tuner.co.uk/product.php?id=476
I like idea to use some 180deg manifold. But 25hp ingreasing vs good 4-1 manifold is unbelievable
And what about those 180deg manifold..
Are those reading´s measured using STD TVR manifold or some universal Hedman headers´s? Like those?
http://www.v8tuner.co.uk/product.php?id=476
I like idea to use some 180deg manifold. But 25hp ingreasing vs good 4-1 manifold is unbelievable
Kokkolanpoika said:
I do not like idea to use TVR type collector.. Merge collector look´s mutch better. Or eaven STD type tubular manifold collector.. TVR collector diameter is huge. They flow easily +500hp each.. Gas speed is very poor.. If i will make new manifold´s for TVR, i will drop collector size to 2" diameter and then go for single 3" pipe..
And what about those 180deg manifold..
Are those reading´s measured using STD TVR manifold or some universal Hedman headers´s? Like those?
http://www.v8tuner.co.uk/product.php?id=476
I like idea to use some 180deg manifold. But 25hp ingreasing vs good 4-1 manifold is unbelievable
not so unbelieveable as you have answered why yourself , "tvr manifold collector is huge, gas speed very poor"And what about those 180deg manifold..
Are those reading´s measured using STD TVR manifold or some universal Hedman headers´s? Like those?
http://www.v8tuner.co.uk/product.php?id=476
I like idea to use some 180deg manifold. But 25hp ingreasing vs good 4-1 manifold is unbelievable
because they thought they needed cats inside the manifolds themselves as well as the big cat in the y piece, Don't know how true it is, but once heard a story of tvr attempting to get into the American market and precats were used to try to meet the strict emissions laws in the states, but if its true and it failed anyway, why still supply them on cars in the uk?
Isn't the gas speed concern a bit artificial in that the engine will see the terminations of the individual headers into the void of the huge collector 'as if' it were exiting to atmosphere? At least in standing wave terms, there will be a signal on each cylinder when its exhaust pulse crosses that threshold... seem to remember most 4-stroke engines like something like a 30" tuned distance between the chamber and 'atmosphere' (or harmonics of that distance) - hence drag headers being so short etc - and provided flow is not actually impeded, anything after that transition will not be that influential on performance. Yeah, I know exhaust design is way more involved than that but do recall that being the starting point... Anyhoo, the new manifolds look grand Cliff
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