J-pipe mounted turbo on aspirated manifolds

jamesinc · 2015-06-25T05:50:41+00:00

Considering that both designs are pretty poor from a performance perspective can anyone shed some light on wether a J-pipe from a N/A manifold would flow bet...

calvintibia001

Nah, It doesn't really have to be equal length for Turbo Manifolds

deleted_user_160

spot on sam, thats where my thoughts come from, my brother built one for this defender, but then rolled it and killed the engine, so now is a LS1 powered 4x4.

but yeah we could make them in any shape easy enough, and the high mount flange should make things easier for the 2 series guys where steering column clearance issues are majors.

calvintibia001

blondejay;52619 wroteI've thought of making a simple manifold like this with the t3 flange at a 45deg up. :D

I like hanging my Turbo low hahahahaha

GingerNinja

calvintibia001;52649 wroteNah, It doesn't really have to be equal length for Turbo Manifolds

I thought it was the whole point of twin scroll?

calvintibia001

GingerNinja;52656 wrote
calvintibia001;52649 wroteNah, It doesn't really have to be equal length for Turbo Manifolds
I thought it was the whole point of twin scroll?

Maybe, I am not sure, cause stock Evo Manifolds are Twin scroll but they are not equal length. Not sure about that then

BradC

calvintibia001;52654 wrote
blondejay;52619 wroteI've thought of making a simple manifold like this with the t3 flange at a 45deg up. :D

I like hanging my Turbo low hahahahaha

Now *that* is a "log" manifold. No really... great for diesel and non-performance, but not that fantastic off boost.

deleted_user_160

What are the pros and cons of a simple tubular design like I posted above?

Note that if I was to go ahead with something like that, I would use single piece tubing for each exhaust runner. 2-3 maybe drop down in a U shape to match length of 1-4

jamesinc

The purpose of equal length headers is to ensure the exhaust pulses out of each cylinder are evenly separated when they go through the collector, maintaining very consistent back pressure. In some race cars where they just run very long straight pipes from each exhaust port straight to atmosphere, the length of the pipe is such that at a particular RPM the exhaust from the previous bang will create a partial vacuum and help to suck exhaust out of the outlet.

jamesinc

When you introduce a turbo, because you have put a restriction on flow, it's less important to keep it consistent as it becomes very turbulent in the manifold anyway.

calvintibia001

blondejay;52695 wroteWhat are the pros and cons of a simple tubular design like I posted above?

Note that if I was to go ahead with something like that, I would use single piece tubing for each exhaust runner. 2-3 maybe drop down in a U shape to match length of 1-4

That would work, but I doubt it will improve flow that much from stock ?

GingerNinja

blondejay;52695 wroteWhat are the pros and cons of a simple tubular design like I posted above?

Note that if I was to go ahead with something like that, I would use single piece tubing for each exhaust runner. 2-3 maybe drop down in a U shape to match length of 1-4

What are you trying to achieve? Trying to make room for a massive hi-mount turbo or just improving flow over the stock log manifold?

http://www.enginebasics.com/Advanced%20Engine%20Tuning/turbo%20manifold%20design.html

GingerNinja

This looks interesting. Wonder if it would fit a RHD car.

http://forums.turbobricks.com/showthread.php?t=275175

calvintibia001

GingerNinja;52727 wrote
blondejay;52695 wroteWhat are the pros and cons of a simple tubular design like I posted above?

Note that if I was to go ahead with something like that, I would use single piece tubing for each exhaust runner. 2-3 maybe drop down in a U shape to match length of 1-4
What are you trying to achieve? Trying to make room for a massive hi-mount turbo or just improving flow over the stock log manifold?

http://www.enginebasics.com/Advanced%20Engine%20Tuning/turbo%20manifold%20design.html

I doubt Log Style will give massive gains over the standard manifold, may give the turbo some more room, I am going for a half tubular design though

Philia_Bear

Log works good for holset

deleted_user_160

It's more for simplicity, positioning, and material.

But, by the time I'm finished with one it would prob closer resemble a beautiful notted mess of high mount turbo manifold.

Although in all seriousness, if we take the factory -89 and 90+ manifolds they are as simple as simple with odd length runners. So something similar to the above pictures I posted with a couple of U shaped longer 2-3 cylinder runners, should in theory (at least the way my brain is putting all this information together) be on a similar performance as say a ported 90+ but keep the exhaust pulses into the turbine consistent. (Something was already aware of)

So a slight decrease in initial spool time should be achieved, provided I keep the over all package a short length from exhaust port to turbine flange.

calvintibia001

blondejay;52794 wroteIt's more for simplicity, positioning, and material.

But, by the time I'm finished with one it would prob closer resemble a beautiful notted mess of high mount turbo manifold.

Although in all seriousness, if we take the factory -89 and 90+ manifolds they are as simple as simple with odd length runners. So something similar to the above pictures I posted with a couple of U shaped longer 2-3 cylinder runners, should in theory (at least the way my brain is putting all this information together) be on a similar performance as say a ported 90+ but keep the exhaust pulses into the turbine consistent. (Something was already aware of)

So a slight decrease in initial spool time should be achieved, provided I keep the over all package a short length from exhaust port to turbine flange.

I think it might flow a tad worst than stock tbh, won't the exhaust flow collides with each other ?

deleted_user_160

Isn't the whole point of the tubular type knotted fancy beautiful type manifolds? To keep all exhaust pulses running smooth at the collector?

The likes of the below images.

This one is the closest example I could find to what I was planning, it's pretty spot on. The only thin I would do, is add a external gate flange and blank it off, for future use.
So this style in theory should be tonnes better than a factory cast manifold no? (The only change is it would be TOP mount not bottom.

calvintibia001

blondejay;52805 wrote
This one is the closest example I could find to what I was planning, it's pretty spot on. The only thin I would do, is add a external gate flange and blank it off, for future use.
So this style in theory should be tonnes better than a factory cast manifold no? (The only change is it would be TOP mount not bottom.

This looks heaps good, I personally prefer bottom mount, is that I Don't hv to rotate the turbo and stuff.

carnut1100

Equal length good flow headers are just as relevant for boosted applications as for NA.....it's just that crap design has a bigger and more noticeable effect on NA than turbo.
Proper flow will make a turbo work better.

deleted_user_160

Which design?
We have put a few up.

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