Dynamometer Results & Comparisons - CMS C5 454ci build

Just finished up this build. We experimented with this cam and intake combo. We will be backing the cam down a little bit since the customer wants to start road racing.


Specs---

1999 C5 6 speed


LSX 454 ci

13.1 compression

WCCH Brodix Stage 2 Ls7 heads with CHE modded Ls7 rockers

25x 26x custom cam

Ported Fast 102 intake manifold and 102 TB

Halltech CF112 intake

1 7/8 AR headers no cats

CMS custom 3" catback

RPS street twin clutch

CMS custom 1 bar speed density tune


This was on 91 octane + some torco, customer will be switching to E85 in the near future once we swap the cam, which will significantly raise Dynamic Compression.
Graphs:
http://i294.photobucket.com/albums/mm82/cmswork/vettechrisvert454tq.jpg

http://i294.photobucket.com/albums/mm82/cmswork/vettechrisvert454af.jpg

video:
http://youtu.be/jcuobqlqSQs

I can't believe you got that big of a motor to carry power that high with a fast style intake. That to me is insane. Who did the porting?

I can't believe you got that big of a motor to carry power that high with a fast style intake. That to me is insane. Who did the porting?

the heads have a lot to do also WCCH makes amazing heads

Great work as always CMS! I hope my 418 with a new fast 102 and ryne s tune can be as impressive as that 454

Sounds like Chris's car..Great numbers!

I can't believe you got that big of a motor to carry power that high with a fast style intake. That to me is insane. Who did the porting?

it is a combination of two people...initially we had shortened the runners to what would happen, it was kind of a flop, it lost power from 4k on and didnt pick up on the top end. then we re-installed a new set of un-altered runners from fast and we just match ported the runner opening to the existing lightly ported fast base... the car picked 25 rwhp and 20 rwtq swapping back to the unaltered longer fast runners, in addition didnt lose power up top.... it carries the power pretty far likely because its got a fair amount of duration on a not so tight lsa, really widens the curve. we are going to be putting in a smaller cam (roughly 10-12 degrees smaller) for road racing, and switching to e85

I have had 3 different cams in my ls7 build and finally arrived at something in the same range as what you have. 254/265ish range. And I know it wont carry that high. Going to try playin with the fast. If a ported fast gets me 20 or 25 rwhp. I'm looking at power similar to what you have with a 427 and more compression

That thing is a damn monster. Great numbers for sure.

I have had 3 different cams in my ls7 build and finally arrived at something in the same range as what you have. 254/265ish range. And I know it wont carry that high. Going to try playin with the fast. If a ported fast gets me 20 or 25 rwhp. I'm looking at power similar to what you have with a 427 and more compression

i doubt the porting will give you 20-25 rwhp.... what gave us the gain was re-installing the factory length Fast runners.... the design of the fast is pretty much as good as it gets in terms of under the curve and topend power... any variation in either direction causes substantial losses in eitther low-end or high end.... i guess we arent smarter then the guys at fast lol... the best thing i can recommend is port matching the fast base to the heads themselves, then blending the base to the runners....

Great work. Finally some one who sees the importance of DCR. What is the DCR of the current combo? I knew 13.1 would run fine with the right cam on the street.

Great work. Finally some one who sees the importance of DCR. What is the DCR of the current combo? I knew 13.1 would run fine with the right cam on the street.

I think most of us know the importance of DCR, this cam was spec'd over 5 years ago for a different project, I figured we would try it since I kept seeing it sitting in the corner of my garage. lol

Next cam should really pump up the low and mid range without sacraficing much on the top end. E85 maybe next week, just to see how the big cam likes it for a glory pass.

Great work. Finally some one who sees the importance of DCR. What is the DCR of the current combo? I knew 13.1 would run fine with the right cam on the street.

yes the tons of overlap definitely helps make this liveable on pump and torco... when we go to the smaller cam that may change... but this build was intended for e85 from the get go..

A lot of people may understand it but still don't use it. Most of the builds are still in the low 11's on SCR with large cams. I am glad you guys are experimenting and posting results. Great work. My next project is going to be a large cube NA motor. Lots of great stuff coming out now. I am excited to see what you all end up with.