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M90 housing vs manifold in a GTP turbo build

B

BlkNLow

New member
I know this newbie question is going to raise the ire of many on this site (yes, I've done searches) and I have my 'Flamesuit' on. But, this is supposed to be a community, so hopefully some of you guys can assist a Brotha.

So, here goes: What are the pros/cons of using a gutted M90 housing vs a turbo intake on an L67 turbo build? Engine is being completely rebuilt with a custom cam and forged pistons, appropriate rockers and springs, etc. I just want opinions on horsepower and performance loss or gain with one vs the other. I am aware of the cost advantages of the Blower housing. Thank you.
 
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A real turbo manifold will flow the best, but you'll be just fine with a gutted and opened up M90 case.

I'd stick with a M90 case for saving money unless you are wanting really high HP numbers, then it might hold you back.
 
M90 case doesn't have runners to direct airflow possibly causing some unnecessary higher boost numbers with no gain. A L36/L26 manifold is a better way to go as the air gets directed into its intake port easier.
 
An L26/36 with an HV3 or a Holden intake would be what I'd go for. They're relatively inexpensive compared to other parts. I'd prefer the L26 since it isn't plastic like the L36.
 
Lets be clear here.
Are you calling an N/A L36 or L26 upper/lower intake manifold a turbo manifold?
I swapped my gutted m90 case for a custom sheet metal intake and modded L32 lower but couldn't really tell you what if any difference it made being other mods were performed at the same time.
 
If you're looking to save money, don't bother building the bottom end. Kind of pointless unless you're trying to set some sort of world record. Even then I'd try a stock bottom end first.
The m90 case is inferior to a regular intake manifold.
 


231FUN said:
Lets be clear here.
Are you calling an N/A L36 or L26 upper/lower intake manifold a turbo manifold?
I swapped my gutted m90 case for a custom sheet metal intake and modded L32 lower but couldn't really tell you what if any difference it made being other mods were performed at the same time.
Click to expand...

I'm referring to the ZZP turbo 'intake' with the HV3 insert. Yes, I'm a bit of an idiot!

http://shop.zzperformance.com/store/p/502-L67-32-to-L36-26-Intake-Conversion.aspx?msg=variant



SnowFlake said:
If you're looking to save money, don't bother building the bottom end. Kind of pointless unless you're trying to set some sort of world record. Even then I'd try a stock bottom end first.
The m90 case is inferior to a regular intake manifold.
Click to expand...

I have to rebuild engine anyway....flattened a XP cam and made a mess of things internally.
 
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