Im looking to twin turbo my 88 firebird formula
The engine
SBC 406 2 bolt main
4340 Eagle crank and H-Beam rods
SRP forged dish pistions
World Product heads 70cc chambers (put me around 9.0:1 or 9.3:1)
750 CSU carb and looking at a victor intake

I was wondering what cam i should get i want the lopy cam sound but somthing that would work with the turbos as well. Looking to start light with this one and find all the weak links and upgrade them then upgrade the engine some more well you know how it works im sure

 

I would say a solid roller in 245@.050 range about .720" lift range or just call comp cams or cammotion. also get rid of the carb.

 

The biggest issue is that what causes lope more or less works against efficiently building boost in a turbocharged engine. A 110 lobe separation will lope like crazy but turbo cars are happier around 114. Perhaps you could make something in the 112 degree range work and get the sound you are looking for.

Sounds like a killer engine combination to put boost on. I don't think you'll be worried about lope (or lack there-of) once you hear the turbos spool up the first time!

 

lobe seperation by itself says nothing about the cam. Stock 87 GN had less than 110 lobe separation.

 

just go custom http://www.bulletcams.com/

 

I was thinking of typical v8 cam durations (in the 220-240 @ .050 range) that he would likely select. The Buicks if I remember correctly had a sub 200 degree duration that makes TPI cams seem not so small! So a 108 deg separation cam with a duration of 195 degrees would have less overlap than a 112 degree cam with a 220 degree duration.

Another way I could have put it is as the duration increases, the LSA needs to increase to keep the overlap in check. The more overlap, the more lope and the less efficient it will be for a turbocharged application.

 

Wow thanks for the help guys. Right im sure i wont care for the lope as soon as i hear the turbos spool. I just like the sounds of that idle i had a chevy 400 with a isky 292 great engine, Thanks for the ideas and the input

 

So what about a cam like this one http://www.summitracing.com/parts/SUM-K1106/
My vavle springs are good to 550 lift and i have 1.6 ratio crane cams gold roller rockers and stud girdles

 

Correct; 192/196 .384/.408 @ 107 LSA w/38 degrees Overlap....

 

what about a lt1 cam ?

 

I went and ordered my cam thanks for the help, heres the specs
Cam Style Hydraulic flat tappet
Basic Operating RPM Range 2,800-6,300

Intake Duration at 050 inch Lift 234

Exhaust Duration at 050 inch Lift 234

Duration at 050 inch Lift 234 int./234 exh.

Advertised Intake Duration 292

Advertised Exhaust Duration 292

Advertised Duration 292 int./292 exh.

Valve Lift with Factory Rocker Arm Ratio 0.488 int./0.488 exh

Lobe Separation (degrees) 114

But i have 1.6 rockers and my uncle said id be closer to .520 lift so im still good with the valve springs at .550

 

Your overlap is 64º with that camshaft....

 

Im new to the boosted world im going to assume thats not a good one, but what kinda affects will it have for power levels and effecency of the turbos

 

High overlap has a negative effect on supercharged engines because the added boost will blow straight through the exhaust valve prior to quench. On turbo's, however, high overlap creates reversion. You will be fine, as your supposed to try new things as a beginner, then later dial in what you want. Give it a try, and tell us how it works out for you....

 

OK thanks for the info helps out alot

 

Those heads aluminum or iron? Cam looks fine. Similar in duration, overlap and LSA to my hyd. roller cam in my 401.

Single pattern with LSA in the 112-114 range is not a bad place to start with a turbo cam.