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For comparison purposes k20a2's with stock motor, stock IM, I/H/E on our dyno have made between 185-191whp (tuned).

This setup belongs to Barnie from Hickory who brought his RSX-S earlier today for a complete partial throttle & WOT tune.

RSX-S - k20a2
Toruku - street cams (stock valve springs)
RBC Intake Manifold
DC Race Header (designed for mid-range)
3" exhaust > 2.25 or 2.5" exhaust towards the end (customer didn't necessarily enjoy the sound of the 3" all the way through)
K-pro
93 octane



3 Run comparison.



The light blue chart is Barnie's base run which was a tune from another shop.
The darker blue chart is the tune that we provided to him after adjusting cam angles and some ingnition.
The red chart is from lowering VTEC engagement point and adjusting the cam angle some more. While there isn't a peak power gain, the power under the curve is huge, and should make for an all around faster car.

For those who may not know, on the "k20a2, z1 & z3 motors", the intake cam can be adjusted up to 50 degrees electronically through Kpro tuning software.

Guys, the following quote is from the following thread on k20a.org.
RSX-S: Toruku Cams & Bolt on's - Pump Gas Dyno Tune - K20A.org .:. The K Series Source . Honda / Acura K20a k24a Engine Forum

Just thought it would be something some of you guys who may be getting into tuning may appreciate.


[quote=GT35RK20]

[quote=k20addict]still power missing and the curve should be very smooth. No dips but yours has a dip[/quote]


First, keep in mind we are dealing with i-vtec (adjustable cam angles) and not a standard vtec motor who's vtec engagement point is as straight forward to specify as anything else.


It's really quite simple if you knew how the different cam angles came into play with these particular cams and the characteristics of the DC header. DC headers show up as a "bump" in the midrange and then falls back in line. I know because I've seen this before on other K20's, including my own before I boosted.


The low cam likes the 30 degree cam angle for maximum power, the high cam likes 50 degrees right where vtec engages. A compromise has to be reached between how smooth the curve is vs power, etc... Keep in mind that it takes the cam angles .1 seconds for every 10 degrees of change and if you couple that with a vtec engagement where oil pressure is already a greater factor, can contribute to a harsh engagement/noticeable dip... Hence, a compromise has to be found.

Changing it to 40 degrees on the low cam right before vtec engaged with a 50 degree cam angle would cause a loss in power of 10-12whp but it would of had a smooth transition and vice versa.

We played around with transitioning the cam angles best to gain the most power but still have a smooth of an engagement as possible. What you see before you was the best compromise between practicality and power. Sure I could have made it even smoother but like I said before, doing so would of been at the expense of power due to how the cams respond at the different cam angles and thus a best case scenario compromise had to be met.[/quote]