Thread: * * * * DC Performance Generation 4 Viper PORTED HEADS (30RWHP) * * * *

DC Performance does it again! Over the past year we have been looking very closely at the Gen 4 Viper engine. With superchargers, turbochargers and big engine builds not practical or economical for most customers with this new engine, we were looking for another 100hp without major internal modifications.

The production bottom end on these Gen 4's has proven very stout with good tri-metal bearings, ARP rod bolts and decent rods. The only limiting factor has been the pistons, so we did not want to increase the piston speed or compression. Another big consideration is the sensitive engine computer, the Venom engine controller is very sensitive to mechanical engines changes and we did not want any check engine lights or "limp" in conditions.

Our performance gains with exhaust and intake modifications have worked really well, the final step for the 100hp gains would need to be in the heads.

With changes to the VVT, cam and compression not viable options, we focused on the cylinder. There has been quite a bit of technology in cylinder head testing with wet flow benches and injector spray pattern analysis, so we thought a good look at the heads would yield some big power gains.

Our big focus on a head modification was to maximize air-velocity through the primary choke area of the intake and exhaust ports. Engines runs on velocity and not just cfm numbers. The area under the seat is critical and can be improved dramatically.



With our ported heads done and ready to test, our next concern was clamp load on the head and block. We wanted to do everything possible to keep the bore straight. The production head bolts are inexpensive and are borrowed from the passenger car line, so we opted for an ARP bolt set to finish off our package.



Our last concern was oil pull through in to the intake manifold from the PCV system. These engines are very sensitive to knock. On many engines that we tested, we have data-logged the knock control and found the computer retarding timing. This hurts power and can lead to piston issues. Oil in the intake and related carbon deposits increase knock (detonation). Our solution was a air-oil canister that does not allow the oil to migrate into the manifold.

Our testing was done on a 2008 Viper with Belanger headers and exhaust, Arrow intake and Mopar controller. Gains were 30-32rwhp in an AB test. Futher testing with our intake and better fuel added another 7rwhp. Air fuel was very safe and no check engine lights or "limp in" conditions were encountered.

For those of you who want the most from your Gen 4 Viper engine with good reliabilty, this is THE option! I will be posting dyno sheets, videos and pricing this week!

Here are the details on our new Generation 4 Head package. First off, this head package was developed to be a simple no-nonsense bolt on upgrade that will increase power and torque across the power band without additional mechanical modifications or calibration changes. These are direct replacement heads that will work with your production rocker arms, pushrods, valve covers and engine controller.

These heads can be used with or without exhaust and intake modifications, but will produce best peak power with headers and ported intake. We offer complete installed packages or parts only. We are there for you 100% after the sale with full technical support.

We developed this package with several goals in mind...

Best average power and torque across the powerband
No changes to driveabilty
No check engine lights and reasonable pricing.

Our heads are offered on exchange or we can do yours. Each head is fully ported on intake and exhaust, bowl area radiused, ports volume matched, multi-angle valve job, combustion chamber reshaped and volume matched, gasket surface is machined for MLS gaskets and correct compression ratio. All new seals are installed and all components machined or replaced as needed.


Here are the results of our testing. Again, this car was a 2008 Coupe with Belanger headers, high flow cats, side exhaust and Mopar controller. Initial test were done with Torco fuel additive to bring the Octane level to 93 as required for the Mopar computer.



Our criteria for testing was very controlled, each test was performed at the same engine coolant temp and heat soak.

Our initial test was a before and after test of the heads. The only variables other than the head change was the removal of carbon from the piston tops, new plugs and an oil-air separator for the PCV system.

34hp and 26trq

Next test was to remove the Arrow intake and install our ported intake.

5hp and 6trq

Our final test was to raise the octane level to about 95

3hp and 7trq

Please feel free to call us with any questions you may have. I am always available via PM.

We are taking orders!

Aaron, VP.
DC Performance Inc.
800.841.8979.

Thank you for a detailed right up. This is truly amazing. Love it.

Nice, Aaron!

love reading stuff like this. one q: most factory heads flow pretty poorly - why? why don't they go for these (seemingly) easy gains?

- chuck

Way to go.

Good job DCP, so there where gains with your ported intake and thats what I wanted to hear.

do you have a full price pakage on this 600rwhp gain?

Headers
Exhaust
Mopar PCM
DC ported intake
Ported heads

and anything else I missed please PM me for further info, Im very intersted.

That was my question exactly. Sometimes I think they purposely leave power gains on the table for their race team, after market divisions and tuners.

Originally Posted by carendt242

love reading stuff like this. one q: most factory heads flow pretty poorly - why? why don't they go for these (seemingly) easy gains?

- chuck

Originally Posted by carendt242

love reading stuff like this. one q: most factory heads flow pretty poorly - why? why don't they go for these (seemingly) easy gains?

- chuck

I'm going with cost, easier to cast rough heads and put them on a car than it is to CNC those same cast heads then put them on.

There is probably some truth to the idea of leaving some power on the table for factory race teams.

great work!

Nick