347 s-trim question

Hey Guys,
This site has a ton of info !!!! I didn't even know about it until today. I have been searching this form as well as a few others and I can't seem to nail down the answer I am looking for.
I am setting up a car for my dad, the combo is as follows:
347
8.7:1 compression
573/560 224/232 cam
Ported TFS High Ports
80 mm t/b and spacer
TFS-R intake
13/4 bbk longtubes
anderson power pipe w/ 90mm mass air

I am shooting for 14 lbs of boost at about 6100 RPM. Can anyone tell me what pullies I should run ????? I have an 8"/3.15" combo but @ 6000 that puts me at about 54,xxx RPM and I am thinking that is going to be too high.

Any help/personal experience would be greatly appreciated,

Thanks,
Jason

Quote:

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Originally Posted by flyin '85

Hey Guys,
This site has a ton of info !!!! I didn't even know about it until today. I have been searching this form as well as a few others and I can't seem to nail down the answer I am looking for.
I am setting up a car for my dad, the combo is as follows:
347
8.7:1 compression
573/560 224/232 cam
Ported TFS High Ports
80 mm t/b and spacer
TFS-R intake
13/4 bbk longtubes
anderson power pipe w/ 90mm mass air

I am shooting for 14 lbs of boost at about 6100 RPM. Can anyone tell me what pullies I should run ????? I have an 8"/3.15" combo but @ 6000 that puts me at about 54,xxx RPM and I am thinking that is going to be too high.

Any help/personal experience would be greatly appreciated,

Thanks,
Jason

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Thats WAY too high, 45,000 is max efficient and 50,000 is max speed period. I would not go much past 45,000 since all you are doing is heating the air more with no real gains in power. It's hard to say what you are going to get for boost with that free breathing setup and 8.7:1 compression. I would just try and figure out your impeller speed to stay below.

Go here to figure it out, I think yo uare a little high on your figure:
http://www.vortechsuperchargers.com/...pspeedv-1.html

Yeah,
That is what I was thinking too.......The guy at Vortech recommended the 8/3.15 combo. When I started looking into though, I thought it was going to be too high myself and that is why I started looking into it........

I run 3" and 8" pullies with my S-trim. I am way over spinning it but it still makes power up there for sure.

I bet you could get 14#'s with the stock 3.33 pulley with the 8 inch crank pulley.

Thanks chuck,
I think that's what I am going to do. I ordered a 3.33 pulley which will put me right around 50,xxx RPM if I shift around 6-6200. I guess I better tell my old man to save up for an intercooler.

This boost is addictive, I have an 85 gt with a 347, it is carbureted and I am seriously considering going to a blow-thru setup.......

Yeah....just start w/ a 3.33.

Buddies 93 gt 347 has gone high 9's on an Strim this year ~ 16psi! Definitly not a drag only car too!

Good luck!

Thanks Blown by
I just got all the rest of the parts I was waiting for, including the 3.33 pulley. I would like to get this thing running and at least get some dyno #s before winter

3.15 / 8inch would be fine....

I was running a 3"/8" with my s-trim and saw 18 psi.

Thanks for all the replys guys,
As soon as I get it on the dyno I will post what it made for boost/ horsepower for everyone's reference......