Does anyone have any experience with RPW's stage 2 or 3 cams or ported heads for the 4g93 sohc?

Starke02

Member
Im installing a stage 3 RPW cam into my ported head with rpw valve springs, rpw cam gear & 275cc injectors and am just wondering what kind of power output I'd be getting. Other mods done so far are just ihe, tuned at LLT Racing making 113whp currently. To be installed with the cam is a 65mm tb and custom intake manifold.

If anyones done similar mods or even just bits and pieces of what im doing I would like to hear from you and see what kind of torque and power gains you guys had
 

Starke02

Member
I reckon I can net atleast 150whp with all of this, maybe even more who knows, but I think atleast a 37whp gain is not unreasonable to get with all the mods
 

donki

Administrator
Forum Administrator
At the wheels? Maybe net yourself around ~15-20kw atw if youre lucky. A new high performance cam is a great way to add power, but there are a tonne of factors that go into making that power. Duration of the cam, the lift, the compression, and how well tuned will impact maybe 50% of that gains
 

Starke02

Member
Yeah of course, so many factors to negate power. Guess I'll just have to wait and see next month when I've got everything installed!
 

DrB

Active Member
What are the cam specs and what was done to the head, any idea on head flow?
Is the plenum standard?
 

Starke02

Member
I've ordered the stage 3 NA cam. The head has ported and polished intake and exhaust, 3 angle valves with 63' exhaust valves, heavy duty stiffer valve springs. Head will be the slightest bit shaved, maybe by a few thou to ensure its flat.

Intake manifold is going to be custom made to fit a 65mm throttle body and will be port & gasket matched to the head
 

Spetz

Well-Known Member
The gains may be too high up in the revrange though.

Either way a very interesting project you have there, do keep us posted
 

Starke02

Member
The gains may be too high up in the revrange though.

Either way a very interesting project you have there, do keep us posted
Yeah it will make peak power towards redline but id like to see how mid range is affected.
Thank you, I will!
 

Spetz

Well-Known Member
The DOHC 4G93 revs to 7,500 and the bottom end is the same.
So with upgraded valve springs in the SOHC head I'd say you can raise the redline to 7,500rpm as well.
 

Starke02

Member
The cam could end up making power close to 7500rpm and its definetly safe enough to raise it there if need be. If it revs that high without any valve float thatd be mad
 

donki

Administrator
Forum Administrator
Its the stock bottom end you'll have issues with with massive power (think large turbo), the stock bearings dont tend to do well with torque (RPM+HP), but an NA build will be fine. Stock RPM can be raised like 500-800rpm without too much of an issue of float anyway
 
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