Hey guys I got a 1985 305 shortblock with 1988 L98 heads (64cc). The heads are bowl blended and ported. Intake is ported stock base with SLP runners. Compression ratio is somewhere around 8.3:1.

Running a T61 turbo 7-8PSI, more at the track. Meth injected/chemically intercooled.

Looking for cam recommendations? The (very bored sounding) guy at comp cams said to go with this:

Camshaft Specifications

Its backed by a 700R, mid 2k's stall, 3.27 gears.

 

That's just an Xe268 with a 114 LSA.

I'd use one of their turbo cams, with the shorter exhaust duration. That's got a split pattern, with longer exhaust compared to intake duration. Also, a bit smaller then that, since it's on a 305.
Or a straight pattern cam would work, maybe put 1.6 rockers on the intake only.
114 LSA is a good idea though.

 

Can you explain why i want lower exhaust duration.

Also, Ironically enough the heads have mixed roller rockers. 1.6 intake, 1.5 exhaust.

 

Perfect setup on the heads then. I'd recommend a straight pattern, or turbo cam then.

lower exhaust duration - Your exhaust is now more pressurized, because of the turbo right? So you don't need a long valve timing lobe to get more out.

Now I thought the exact opposite way before - more exhaust timing gets more gas out there, more gas out = more turbo spooling = more power. That thought is good for superchargers, or nitrous. However, turbos seem to like less timing. Look at "turbo cams" from comp, crane, lunati, whoever actually makes one that specs it's use as "for turbo cars".

This is somewhat debateable though, and i'm not sure it'll make that huge of a difference anyway, but that school of thought is pretty popular.

 

So you thinking like a 220/220 duration .470 or so lift with 114 Lobe sep?

Hows this look:

Summit Cam and Lifter Kits: SUM-K1104 - summitracing.com

 

ugh. It's ok for most of it's respects I guess, the LSA and duration are good.
But the 224->280 means a slow ramp rate.
The comp was 224->268. That's a fast ramp rate.

It's a good price for $70 with lifters and all, but remember your cam is the cheapest part that makes the most difference in how the car runs, price it as such.
Look at the CCA-12-253-4
if this link will work; COMP Cams Xtreme Energy Camshafts: CCA-12-253-4 - summitracing.com

That's 218/218 @.050" - 262-269 advertised, 2200-6400 powerband (in a 350 I imagine.) .462/.455" lift

 

So why does that cam have such a higher RPM range compared to the summit cam when its a shorter duration and lower lift, is it because its a faster ramp? Im assuming the ramp rate is relative to the difference between advertised and .050 lift?

Other then that, that looks like a good cam and still wallet friendly.

But im not sure what powerband i should be going for with the TPI and the turbo, the turbo should extend the TPI band a bit but how much?

 

whoa tiger, I didn't know you were doing TPI. Then again, I coulda guessed that...

Yea, ramp rate is easily "guesstimated" by doing the math on advertised-duration@.050"
I say guesstimated, since comp uses "advertised" at .006" tappet lift, crane is .004" etc etc. That's going to show a difference. Either way, that summit cam is pretty lame that way.

I wouldn't put a huge amount of trust in the recommended RPM range. But yes, the comp's range will be broader, due to the "superior" cam grinding abilities.

Now knowing it's a 305 TPI, I might say this one;
CCA-12-400-4
COMP Cams Blower and Turbo Camshafts: CCA-12-400-4 - summitracing.com

Would work. I don't want to recommend the smaller (smallest) turbo cam, as it wouldn't be much better than stock. You're not using a bone stock TPI top, so that's good.

 

Yeah ive got 350 heads which dropped me a point of compression or so, ported heads and intake. I dont wanna rev the sucker to the sky, its just a stock rebuild with mildy better then stock valvesprings.

 

Because of the low stall speed I would go with a lot less duration. Let the turbo make the power. Look in the Erson Cams catalog or the Engle Cams catalog or the Isky catalog for a "Turbo Cam" with about 208 to 214 @.050 intake duration, wide LSA and a equal or shorter exhaust duration. Each of these cam companies were making good turbo cams before Comp Cams was even thought of. the cam the phone tech speced for you is a supercharger cam.

Engle Cams #1002H turbo cam is as big as I'd go.

216/210 @.050 .458"/.440" 116LSA.

Again keep the duration mild. Let the turbo boost make the power. (trust me, it will) This cam or one real simular is Just right for your Turboed 305.

Engle Racing Cams