DCP Stage 3 Gen4 Viper Coupe **(Video)**

[Dan Cragin]

Excuse the error in my last post, we do not raise the compression. Combustion chamber volume on the stock heads can vary from chamber to chamber. This seems to be the norm for production parts.

 

[Boxer12]

Dan, for track, what do you feel about a swap to the ACRX forged pistons, and delete the PCV system? Wouldn't that be an easy job since you already have the heads off? and allow you to raise the compression without fear of knock and develop more power? This is the route I am thinking of going, and expect the heads could be redone to take advantage of this change and push the power up further. Your expertise would be appreciated.

 

[evomind]

Dan, for track, what do you feel about a swap to the ACRX forged pistons, and delete the PCV system? Wouldn't that be an easy job since you already have the heads off? and allow you to raise the compression without fear of knock and develop more power? This is the route I am thinking of going, and expect the heads could be redone to take advantage of this change and push the power up further. Your expertise would be appreciated.

um.....u need a little more than the heads off to change the pistons.
with the heads off you can mill the heads to gain some CR, is that what you meant?
id be careful with milling the heads. how abt going with a good port job?

 

[Dan Cragin]

Thanks for all the comments.

We do feel the weak link in the engine for competition use is the piston. With our heads, manifold, colder plugs, oil separator and proper fuel I really do not see any issues for you club racers out there. The production piston is light, can be fitted with close tolerances and makes good power. The only drawback is that the upper ring is close to the top of the piston for emissions (hydrocarbons get trapped in the space below the piston top and the ring). This makes the top edge of the piston weak and can break during detonation.

For those of you who track your cars, run wheel to wheel or really push it to the limit. We have two engine options. One is a piston upgrade and the other is a rod and piston upgrade. These options require a blueprinted and balanced short block (so we cannot just change the pistons). There are numerous things you can do to improve the oiling system and gain more power as well. Some changes to cam timing and rocker ratios can really help.

Our goal with these engine packages is to build reasonably priced reliable power that will work with the production engine control system. Dodge did a great job on this engine, with a little more investment we can improve this.

We will have results on another project car shortly, we will see how repeatable the numbers are from car to car with our high velocity head package.

For questions and comments, feel free to call our Tech line at 310-841-6996/ ask for Dan or Lyle.