Ok..im doing the turbo build as you all know(or should know from the posts) and im lookin for a cam. I have a GM847 and I want something smaller..more streetable. I get horrible cam surge but I deal with it cuz it goes really good and sounds bad-***. Since the turbo sound will outweigh the cam sound I want something smaller. Maybe get a lil better gas mileage "out of boost" Something in the low 220's. I dont plan on turning the car past 6000rpms(to attemp to prolong life of engine) so something in the power range of 1500-6000rpms instead of 3k+(like the 847)which is when my cam clears up and starts to pull. I have LE2 ported heads also. Its going to be a 355 with a t-76 and I plan on running 8-10psi on pump gas and 12-14psi on race gas(i care more about safety of the engine instead of making the most HP) and im hoping for 10's. Im keeping the 3.42's as well. Ok well I hope I gave enough info for a base for the cam. Thanks-Mark

 

I have a similar set-up and I am temporarily going to run a 221/221 .542/.542 114LSA from combination motorsports until I get my heads ported next year. Then I can get a custom grind made to match the head flow.

 

Oh..so I should go bigger since I have the ported heads? And will this cam sound different since the numbers match..unlike the gm847?

 

Cam choices are less important with turbo setups based on the dynocharts and reading I have done online. I'd say grab up 224/224 with a ~112-116 LSA(your choice). Should make good power.

 

Lift?

 

I believe the lobes have .560" lift w/ 1.6RR (they are comp cam lobes if you check heir lobe library).

FYI, I believe the 950rwhp LT1 with the PTK kit as running a 218/218 cam...

 

Where can I get this cam? And it will have better driveability than the gm847?

 

Any vendor that sells comp cam camshafts can custom order one for you. The driveability will be 10 times better. The cam only has 0 degrees of overlap if its ground on a 112LSA. The overlap decreases even more if you get a 113, or 114, or 115, or 116LSA... you see my point The more positive overlap, the lopier its gonna be and the less driveable. Here is the formula for caculating overlap:

intake dur. + exh. duration = A
A/4 = B
B - LSA = C
C x 2 = Overlap

Example: 224/224 114LSA

224 + 224 = 448
448/4 = 112
112-114 = -2
-2 x 2 = -4 degrees overlap (negative overlap)

Do the same for your GM847 and compare how much overlap it has compared to this cam.

 

Ok..thanks. So a 224/224 .560/.560 114 is good?Youd think someone would want the lift a lil higher for a blower cam. And I know I they did over 900 with 218/218 thats nuts..I still want it a little bigger..so I can go bigger in the future. What would something like that run me?..

 

Custom comp hydraulic roller cam will be the same price. This means it doesnt mattr what th specs are, it will be the ame price as if you spec'd a 244/244 or a 210/210. Expect to pay what a regular comp cam costs... $239 or so. Bigger isnt always better with turbos. If you want a 700rwhp car, then a cam even smaller than 218/218 would support it and still be driveable. The biggest I'd go personally is 224/224 114 ... but I am considering a 218/218 112 cam.

 

Oh..so 224/224 .560/.560 114 would be good?

 

I would do a seach for "cam" on ls1tech.com in the FI section and check out what the LS1 guys use. There are 100 times more turbo ls1's then LT1's.

 

Please drop us a PM or give us a call. We have done many forced induction LT1's and have several different custom cams that will work well for you.