H22 + turbo = bad?
buh_buh
02-25-2002, 07:22 PM
That is what I have read. I don't know if this is true or not. I read this is true because it had something to do with the VTEC and turbo not working well together. What's the real deal? I have a H22 and I eventually want to go turbo route. So what are the downfalls?
drift
02-25-2002, 08:23 PM
mine works just fine.
phattycrx
02-25-2002, 11:13 PM
you want to know what will happen????
you will have a very fast car....
you will have a very fast car....
VTECseoul
02-26-2002, 06:10 AM
the theory is that the normally aspirated cam is designed to have what is called crossover; when both intake & exhaust valves are pushed open to help clean out the chamber of the spent combustion. when adding forced induction, the boosted air is "believed" to be wasted when this happens, thus losing "true" boost.
a cam designed for turbo is cut to eliminate having this, or has it (crossover) in a shorter amount of time. Don't believe the hype, a friend has a GS-R turbo running 300+ hp w/ stock block; & advancing the exhaust cam only gained 2-3 hp.
a cam designed for turbo is cut to eliminate having this, or has it (crossover) in a shorter amount of time. Don't believe the hype, a friend has a GS-R turbo running 300+ hp w/ stock block; & advancing the exhaust cam only gained 2-3 hp.
fritz_269
02-28-2002, 03:00 PM
What VTECseoul is calling "crossover" is usually called "overlap". And yes, high-RPM NA engines want more overlap than FI engines.
BUT - since the H22A is a DOHC engine, with the simple addition of adjustable cam gears you can dial the overlap to any figure you want. How cool is that? :) Advance the intake cam and retard the exaust cam to remove overlap, or vice versa to add overlap.
I'm also under the impression that the stock amount of overlap in the cams really isn't too bad for a low pressure ~6psi turbo. You might only adjust it a couple of degrees for peak power.
H22As do great with boost. Where did you read otherwise?
:cool:
BUT - since the H22A is a DOHC engine, with the simple addition of adjustable cam gears you can dial the overlap to any figure you want. How cool is that? :) Advance the intake cam and retard the exaust cam to remove overlap, or vice versa to add overlap.
I'm also under the impression that the stock amount of overlap in the cams really isn't too bad for a low pressure ~6psi turbo. You might only adjust it a couple of degrees for peak power.
H22As do great with boost. Where did you read otherwise?
:cool:
fritz_269
02-28-2002, 03:11 PM
Originally posted by VTECseoul
Don't believe the hype, a friend has a GS-R turbo running 300+ hp w/ stock block; & advancing the exhaust cam only gained 2-3 hp. Uh, just curious if this is what you meant to say... advancing the exhaust will increase overlap.
:cool:
Don't believe the hype, a friend has a GS-R turbo running 300+ hp w/ stock block; & advancing the exhaust cam only gained 2-3 hp. Uh, just curious if this is what you meant to say... advancing the exhaust will increase overlap.
:cool:
drift
03-02-2002, 12:47 PM
Originally posted by fritz_269
Uh, just curious if this is what you meant to say... advancing the exhaust will increase overlap.
:cool:
and advancing the the intake slightly will also decrease overlap
Uh, just curious if this is what you meant to say... advancing the exhaust will increase overlap.
:cool:
and advancing the the intake slightly will also decrease overlap
VTECseoul
03-02-2002, 11:00 PM
that's it...advancing/retarding, something. i'm probably just used to the idea of advancing OHV/SOHC cams.
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