Hey everybody,

I'm rebuilding my 98 RKC over the winter and am looking for some input on a good 2-1 system. The engine will be running the 89" stroker kit from S&S along with .030 pistons.

I have been looking into a Supertrapp supermeg system because of the ability to tune it however you like. I would like something that's going to optimize my total hp/tq output, not something that is the loudest.

I was also told my S&S that a 561 cam and 580 lift valve spring kit would be coming with my flywheel, but later told that it wouldn't. So now I'm wondering if I should go with that set-up, or do something completely different. I'm not sure what the stock Evo heads are set up to handle in terms of lift, and I'm currently not doing any head work other than basic maintenance.

Any input or help would be awesome. Thanks.

-Ben

 

580 is a lot for stock heads n springs, depending on the compression either a w-6 that works very well at 10:1 or a w-8 that works real well for 10.8:1 but you will have to go to better springs and porting for the w-8. The w-6 Will work with stock heads but bigger valves and compression are the key to making it all work.

 

I have a Supermegs on my Evo, admittedly with an S&S 107" engine. The engine runs remarkably smooth since installing that exhaust and it is just great. I can recommend it. Not being American I don't like loud exhausts and mine is fine.

 

S&S claims with the 89 inch kit that compression will be at 9.25:1 with stock heads. The valve springs are getting changed out too, I should have mentioned that. Do you think 580 lift springs / 561 cam would be too much with the stock heads?

 

Not being loud is perfectly fine with me. Did you have a hard time tuning it in with the disks?

 

You will probably have to go beehives or similar with a rating of .600 I really don't think stock will cut it.. and yes you can get better performance but to optimize the cam a head job would be most beneficial not to mention the byproduct of more compression included in the head work.

 

D&D FatCat

 

As to the cam , many here know much more than me.
The exhaust D&D fatcats are hard to beat.
WP

 

Anybody have dyno sheets of before and after? I'm going for max output with this build, not necessarily the loudest or best looking.

 

if you want max output your going to need head work done. valves springs and at the very minimum a good street port job. and with any large cam you need compression
rule of thumb is 9.6:1 and that's corrected compression ratio. a stock 80" with a W-6 cam needs 10.43:1 static compression and a W-9 needs 10.99:1 to achieve the golden number of 9.6:1 CCR and that's as high as you want to go on pump gas.