Need Help 6.0 s400 cam selection...
05-12-2010, 09:15 PM
#1
Staging Lane
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Need Help 6.0 s400 cam selection... I am ditching my L92 build and just using the good old 317 heads in order to free up some money. Down the road will shell out the cash for something with a thicker deck.
The cam I have currently (was going into the WCCH L92 Heads) is a Comp LSR (239/255 .624/.624) 114 LSA I am afraid this would not be ideal in a turbo application so I am in search of a new cam grind. (unless you suggest otherwise)
Specs on the build will be:
Lq4 Block
Stock 3.622" crank
Eagle rods
Diamond Pistons (flycut for .700" lift cam for previous L92 build)
Freshened up 317 heads
ARP head bolts with either Titan SCS Headgaskets or Oring'd with copper gaskets
(may even step it up to 1/2 studs.)
Target static compression ratio will be approx. 9.5-9.0
For what its worth the car will be running a 4l80e.
Turbo is a Borg Warner S400sx3 75mm compressor wheel, 83.5 inducer, 74mm exducer, 1.10 T4 housing.
Manifolds will be based off the flipped truck manifolds with a TRUE divided setup to take advantage of the twin scroll turbine.
I am not scared to push the envelop with the cam but "word on the street" is that if you overcam a turbo car your results may suffer...
Options I had in mind were a Speed Inc TU1 or TU2 turbo grind or EPP's turbo grind....
Appropriate valve springs will be purchased after the cam is decided.
Car will be a weekend warrior type, will see the street as well as the track.
Please chime in turbo gurus!
The cam I have currently (was going into the WCCH L92 Heads) is a Comp LSR (239/255 .624/.624) 114 LSA I am afraid this would not be ideal in a turbo application so I am in search of a new cam grind. (unless you suggest otherwise)
Specs on the build will be:
Lq4 Block
Stock 3.622" crank
Eagle rods
Diamond Pistons (flycut for .700" lift cam for previous L92 build)
Freshened up 317 heads
ARP head bolts with either Titan SCS Headgaskets or Oring'd with copper gaskets
(may even step it up to 1/2 studs.)
Target static compression ratio will be approx. 9.5-9.0
For what its worth the car will be running a 4l80e.
Turbo is a Borg Warner S400sx3 75mm compressor wheel, 83.5 inducer, 74mm exducer, 1.10 T4 housing.
Manifolds will be based off the flipped truck manifolds with a TRUE divided setup to take advantage of the twin scroll turbine.
I am not scared to push the envelop with the cam but "word on the street" is that if you overcam a turbo car your results may suffer...
Options I had in mind were a Speed Inc TU1 or TU2 turbo grind or EPP's turbo grind....
Appropriate valve springs will be purchased after the cam is decided.
Car will be a weekend warrior type, will see the street as well as the track.
Please chime in turbo gurus!
05-13-2010, 01:23 PM
#5
He will just compound his back pressure issues. A cam that likes to pull to 6400 on those heads would be a waste with that turbine wheel. When running a 83mm turbine wheel on a 350+ci engine at 800-900hp you will be in the 3:1 range for back pressure. No reason to hang the exhaust valve open for a long time and let all of exhaust back in. It will make it hard to get the proper amount of ignition advance.
05-13-2010, 01:46 PM
#6
Staging Lane
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That sounds like some good info, So you are saying that the heads will be the limiting factor for me or the turbine wheel?
I know I picked the smaller wheel in hopes of a more street-able combo. I figure the less I rev the car the longer it will live fore the most part. That might be why alot of people have better luck with smaller cams in their turbo cars. I am trying most likely going to try to log back pressure for the hell of it.
I hope the heads are the limiting factor though because they will be swapped out down the road.
Thanks guys so far for the insight
I know I picked the smaller wheel in hopes of a more street-able combo. I figure the less I rev the car the longer it will live fore the most part. That might be why alot of people have better luck with smaller cams in their turbo cars. I am trying most likely going to try to log back pressure for the hell of it.
I hope the heads are the limiting factor though because they will be swapped out down the road.
Thanks guys so far for the insight
05-13-2010, 01:55 PM
#7
The turbine wheel will limit you to around 900hp, which is what the heads are good for anyhow. If you want a good strong street combo stay away from any cams with more the 228* of duration. It will get down the track much faster too.
We have made over 800whp with a similar turbo and an LS6 cam.
We have made over 800whp with a similar turbo and an LS6 cam.
