Custom manifold - loooooong runners!
#41
That collector kills an otherwise sweet manifold. That manifold is going to perform very similarly to a "flowy log" manifold. With different off boost characteristics and a different location of the torque peak. But should still make the same peak power and torque. The collector is the most important part of the manifold. That thing has a "collector" at best, in essence what they did it take a "flowy log" and make the runners really long.
#44
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Not that I have a great understanding of engineering, but bracing it from below does seem to make sense. I'll put that to the guy doing the work when he looks at the manifold.
I've put a similar thread on my local forum, and while there isn't the depth of knowledge found on here (I got mostly "oooohhhh" and "aaaaaaaahhh" and "what does that do then"), a few seem to know a bit... one of them has similar thoughts to most of you, and also wants me to get a shift on and dyno it, so he's donated me a "GT28 replica" turbo, it apparently made about 300bhp on his last car (not an MX5) and "its a ball bearing one" ... thats all I know so far but it looks like this will move faster than I'd thought, I just need to get a 38mm wastegate (tial was recommended).
If the post hasn't been too delayed by all the christmas stuff, I may well get the manifold tomorrow... if so I'm taking a drive to C1-r and chucking it straight at Chris (the guy doing the prep work for me) so he can get started!!
Russell.
I've put a similar thread on my local forum, and while there isn't the depth of knowledge found on here (I got mostly "oooohhhh" and "aaaaaaaahhh" and "what does that do then"), a few seem to know a bit... one of them has similar thoughts to most of you, and also wants me to get a shift on and dyno it, so he's donated me a "GT28 replica" turbo, it apparently made about 300bhp on his last car (not an MX5) and "its a ball bearing one" ... thats all I know so far but it looks like this will move faster than I'd thought, I just need to get a 38mm wastegate (tial was recommended).
If the post hasn't been too delayed by all the christmas stuff, I may well get the manifold tomorrow... if so I'm taking a drive to C1-r and chucking it straight at Chris (the guy doing the prep work for me) so he can get started!!
Russell.
#45
And yet log manifolds are 100% acceptable when running at or below 80% of the flow of the turbo..
I bet this manifold makes more power than the FM or begi ones, and at least as much as the standard absurdflow deisgn.
The runners aren't paired any more of less than any of the following manifolds in practice.
Etc,
Dann
I bet this manifold makes more power than the FM or begi ones, and at least as much as the standard absurdflow deisgn.
The runners aren't paired any more of less than any of the following manifolds in practice.
Etc,
Dann
There's some very blatant differences between those two manifolds and the manifold in question.
I'll let you figure it out.
#50
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Manifold arrived this morning so I should be able to do a test fit on friday. We'll use the donated turbo for the mock up and maybe a basic test run but will start looking for something a bit nicer ... so far so good anyway, it looks as well made as the pics suggested and the runners don't look quite as long as I thought they would be. There is a small brace on the inside by the wastegate that wasn't visible from the pictures but it only braces 2 runners. It looks about the right place so possibly replacing it with a bigger one and duplicating it on the other side could work ... as long as the wastegate isn't in the way.
I'll add some pics when I test fit it with the turbo.
Russell
I'll add some pics when I test fit it with the turbo.
Russell
#53
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People saying it'll be rubbish because that's what they percieve it to be doesn't make it true.
It's similar to the MS devs being adamant the ideal gas law was perfect for air temp corrections.
We all know how true that turned out don't we
#56
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Basically yes, its cheap and its my first go at a turbo, so why not see how it goes. Fingers crossed it'll do ok, but the guy doing the tuning knows his stuff so if its not up to scratch I'll sell the manifold (almost impossible not to make a profit) and go again with something better. Worst case scenario I have to spend extra time and money on more dyno time, but I'm learning as I go so its all worth it I think
Russell.
Russell.
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