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Turbo exhaust manifold advice
jonno - 17/8/09 at 07:33 PM

Hi, i'm thinking of using a turbo on my project and spotted THIS on ebay...Its not what i want as i'm using a different engine, but looks like a easy design to make !!, how do you people think it flow, problems etc.
Any advice welcome please

Guinness - 17/8/09 at 07:45 PM

Dunno, but what is the exhaust port spacing and diameter of a GSXR compared to the ZZR?

Mike

twybrow - 17/8/09 at 08:12 PM

I thought for a turbo, the manifold design is far less important than a NA manifold. It will sure as hell work better than no turbo/manifold!

blakep82 - 17/8/09 at 08:21 PM

looks alright, and easy enough to copy probably doesn't flow very well, but probably not an issue for a turbo

madteg - 17/8/09 at 08:44 PM

What engine are you using ?

Antnicuk - 17/8/09 at 08:56 PM

that will work fine, its exactly the same design i used when i turbo charged my bike.

jonno - 17/8/09 at 09:13 PM

quote:
Originally posted by madteg
What engine are you using ?


Suzuki swift gti (G13b) with Sj413 gearbox.
Hoping for about 150bhp ish with a turbo

Davey D - 18/8/09 at 10:21 AM

that is just like a log style manifold. if making one for a car that bolts to the block with a flange they are usually made with 2x T pices, and 2x elbows. Simple, cheap, yet effective

liam.mccaffrey - 18/8/09 at 12:13 PM

Corky Bells book on turbos will tell you that manifold is ok iirc.

Cracking book even if you're no going forced induction

jonno - 18/8/09 at 05:27 PM

quote:
Originally posted by Davey D
Simple, cheap, yet effective


Sounds like the way forward then.

Thanks people

Antnicuk - 19/8/09 at 08:35 PM

i didnt realise it was on a car engine, you may want to put it the other way up so the turbo is pointing up, if you dont get the lowest point of the turbo higher than the highest point in the sump you can get problems with not draining the oil back into the sump.

Volvorsport - 19/8/09 at 09:41 PM

put the turbo flange on the side - thats how most are , ssac manifolds have a habit of falling apart tho if not braced properly .

if you can weld and are making your own - use weldable bends from plumb center schedule 10 or schedule 40 .

MikeRJ - 19/8/09 at 10:55 PM

quote:
Originally posted by Volvorsport
ssac manifolds have a habit of falling apart tho if not braced properly


So do their turbos, or at least the ones they used to supply. The compressor housing was made in two halves and epoxied together!

NS Dev - 20/8/09 at 06:24 AM

ssac?

Is that the same as XS Power?

Don't know, but my mate's kadett used an XS Power manifold to start with and we've got rid now, kept cracking. Was very cheap though so yer pays yer money, I wouldn't have wanted to make one for the price he paid for it!!!

He's got an XS Power hybrid t3/t4 9 i think) turbo though and that was £140 brand new and just flatly refuses to blow up after 3 years drag racing and road use!

jpindy3 - 20/8/09 at 09:22 PM

quote:
Originally posted by twybrow
I thought for a turbo, the manifold design is far less important than a NA manifold. It will sure as hell work better than no turbo/manifold!


its just as inportant,all depends on what power you want.a simple log manifold like in the pic is subjected to high polse's around the outlet,like with mine if i could use a 2wd cosworth manifold i would as the runs to the turbo are split in two witch flows better.but like all kitcars there are space problemsu

iti_uk - 21/8/09 at 01:34 PM

quote:
Originally posted by jpindy3
its just as inportant,all depends on what power you want.a simple log manifold like in the pic is subjected to high polse's around the outlet,like with mine if i could use a 2wd cosworth manifold i would as the runs to the turbo are split in two witch flows better.but like all kitcars there are space problemsu


jpindy3 is right, exhaust manifold design is just as important for a turbo application as it is for a naturally aspirated application. The problem is that, since your new turbo will be forcing more mmix into the cylinders than stock regardless of flow quality, you will see a jump in power over stock and think "wow, that's excellent", when in fact you could be dropping a whole load of potential by having a poorly designed manifold.

The manifold pictured on ebay looks a bit pants to me - just by looking at it you can see that you've got two flow-paths opposing each other right before the turbine flange. Of course, the gas will flow out through the turbo, but it will have lost a whole load of energy having to turn against an opposing flow, escaping radially from the "cross-pipe". A far better design would direct the flow towards the flange, not past it, and would probably look more like a short version of a good NA manifold.

Something like this would be good;
http://media.photobucket.com/image/shorty%20turbo%20manifold/SLSfabrication/Turbo%20Manifolds/HPIM3309.jpg

Of course, wastegate placement is also very important, but that's for another thread.

If you have space to do it, make something like the one in the above pic. Packaging issues may force you to make a not-so-good manifold, but if you can it will pay to do it properly.

Chris