im buidling ud a carbed 350 fer my 89 im gonn ab runnin 10:1 compression with lunati flat top pistons i kno thats kinda high fera supercharger how much boost could i put thru it would i be ok at 8psi? and ifso what gains could i expect from that

ps its a aluminum headed motor fully blue printed and balanced

 

I would be scared to put more than 3 to 5 psi through it--even at that low rate it maybe volital

later

rick

 

A friend of mine runs 14psi max (turboed though) on his VR6 golf which is also 10.1..no problem, any higher and it doesn' t like it. Could mean nothing but I wonder how that compares to a sbc and what it would like.
He puts down 305 to the front wheels...my GTA has no chance against it

 

hmmmmmmmmm ok thanks guys any other opnions?

 

the golf most likely has forged internals, not just a stock engine with a turbo straped to it. Forge your engine and you can run high amounts of boost. (but then you get into the tranny and rear end holding the power.)

 

ok heres my new scenario im going to rebuild my 305 with forged internals and run stok compression put on an intake and carb and supercharge it

now heres my questions
what should i run for heads?
what type or blower should i use
how much boost could i run

im more into the paint and body and am pretty new to motors so nethign will help thanks guys

 

hello
I would stongly recomend a aftermaket block with spayed main caps, or fing a rare 301 turbo block from the 80s. also stud the bottom end and use a stude gurdle. as for the 305 ditch it you would be better off destoking a 350 to a 302 put a 283 crank in a 350 or 327 block. I say this because the 305 has a small bore that effects the flow of air. You will have to knotch the top of the bores for any real performance heads to breath at a worth while flow, and it still will not be what you desire. trust me I have put a gn in the 10s for a buddy. we took third for our division in the buick nationals at the slow track (bolling greens Kentucky) I would not runn any highr that 8 to 1 pistions, and make sure they are turbo pistions. we run as high as 28 psi in boost very violent and dangeriouys
I would recomend that you start with 7 psi and work your way up to learn about the proper timing and fuel you will need as boost goes up les imming and more fuel is needed

GL

rick

 

one mistake in last post

pistons -make sure they are blower pistons

later

 

An alum headed 10:1 motor is sorta like a 9.20:1 iron motor. In reality, with enough fuel you could prolly get away with about 6-8psi of non intercooled boost, with around 20-23d timing.

If you add an intercooler, you could prolly get your full timing back, or run more boost..

I ran flat tops with iron heads for years with my blower, but running lean too many times (too small injector) and it finally blew up. Nows the time to consider things like: different pistons, quench area, intercooler, etc.

A good turbo piston has a very thick deck. I'm using a SRP reverse dome blower piston. It has a -16cc area, but also has a good size quench pad. The deck is extra thick,and uses 1/16 rings.

TRW makes a decent blower piston, but the dish is way too large IMO for a Centrifigul. (unless you milled the heads to around 60cc)

-- Joe

-- Joe