Bristol

iTrader: (1)

Looking for a cam better suited for my car as the one in it now appears to be a poor choice based on may opinions (( previously recomended cam which isnt working so well is a 08-305-8 )).

Heres a quick run down on the motor which was intended to be street driven so good braking ((vacuum)) etc. is a must. This is in my 91 Z28 1LE SD

355 CID SBC 9.8:1
64CC Edelbrock aluminum heads
Holley Stealth Ram
Holley AFPR
58mm Accel throttle body
24lb Accel injecotrs
Crane Gold 1.6 roller rockers
Edelbrock TES headers
MSD 6AL, Blaster coil and Billet distributor
currently a 700-R4 ---> T56 soon
currently 3.23s----> 3.73s soon

Not sure what else is needed to be known. Have access to a mint local tuner so tuning isnt too big of an issue. Current cam is a Comp Cams 08-305-8 which I love the loaping etc but have lower vacuum causing some break woes which seems to be better now with the SSBC electric vacuum pump but Id rather not use a pump. Any suggestions would be awesome. And opinions on the "Thumper" series cams

Thanks

Kris

plumminfool

Cam manufacturers are a wealth of info. They can tell you exactly what cam to use based on car, engine, use, etc.

86LG4Bird

iTrader: (1)

Comp 502 (218/224/112) or Comp 503 (224/230/112).
Both of these use the XE lobes which have faster ramps than that junk CC305. More area under the curve and less overlap. Either will give you more low end and midrange power than the CC305. If you get it tuned correctly to make the power your combo is capable of, you'll probably run out of fuel at the top end with the 503 and the 24 lb injectors, so I'd go with the 502.

Sonix

iTrader: (1)

You have the CS276HR then? 220/230-114? And you DON'T like it?? huh...
Thumpers are exactly the opposite of what you want

My carbed 224/230-110 had plenty of vacuum, you must be doing something wrong...?

Sounds like you want to "nancy it up". Cam it down. Look at the LT4 HOT cam perhaps?

Bristol

iTrader: (1)

Thanks for your opinions!!

F-BIRD'88

Are you using the stock GM torque converter? What is the base spark timing at idle?
What is the manifold vacuum and rpm at idle?
Is your power brake vacuum booster leaking?

Isky #211265/272 hyd roller (late model block)

www.iskycams.com

http://www.converter.cc/

Bristol

iTrader: (1)

2800rpm stall

timing is stock and no real tuning yet as tranny is slipping so gonna wait until T56 is in

vacuum is 13"-14" at 800 rpm idle

How do you check if booster is leaking? Has a new 1 way check valve, pumped the brake pedal with car off and goes hard in 3 to 4 pumps and held it derpressed and when I fire the car up the pedal sinks a bit.

F-BIRD'88

Compare the manifold vacuum with the power brake attached and with it disconnected. (hold your thumb over the vacuum hose)
Should read the same. What is your idle timing? "Stock" is not an answer.
A motor with a larger (duration and overlap) than a stock cam in it will want increased idle timing.
it will idle nicer and the manifold vacuum should be higher with increased idle timing.
The spark advanced timing tables in the puter will need to be modified ( remapped).
Similar to recurving a distributor on a carbed motor.
You want increased timing at idle (18-24deg) yet the same max power WOT timing 32 to 36deg BTDC
This will optimize the idle quality and manifold vacuum at idle, as well as the throttle response.
How much manifold vacuum do you have while idleing in gear?
What is the spark timing while idleing in gear? read from a timing light.