Scout2232

Quick question before I tell you why. I have a pulley for my s/c that is 2.95. Guy says its supposed to give me 12psi. I'm looking for 8-10psi, what size pulley would I need? 3.33?

Man I'm so excited. I bought all this new stuff and am so close to getting all of it so I can put it on.
This is what I've bought in the past 2-3 weeks:

Vortech V-1 S-Trim s/c with 12psi pulley
42# FRPP injectors
42# Sample tube
255lph fuel pump
Strange 10 way's for the rear
Urethane upper and lower spring isolators
New ford axel housing bushing for upper control arms

jtmustang

sorry i dont have an answer for the pulley question.. but i was curious are u going to run that setup with a intercooler or methanol? with that compression ratio. i started one of those threads the other day about cr and boost . i am just about to pull my motor and redo it with the same heads,cam and other similiar stuff. i just am wondering because after i do the motor and then some suspension and 3.73 gears i want to put on a blower? thanks jason

when are u puttin all this stuff on?didn't u just get your car tuned and dynoed,so u knew that u will have to get it tuned again?

Scout2232

Yea, the compression ratio I'm not worried about. It's something like 9.3, or around there since the cam overlap takes some off the top. If you are worried about it you can get a cam that can bleed off the compression a little rather than pull the motor to change pistons.

Check this out, its pretty helpful:
http://www.rbracing-rsr.com/comprAdvHD.htm

Yea I know I'm gonna have to have it tuned again, that's ok I'm not worried about it, for adding the s/c its worth it.
Hopefully I can get all this put on within the next couple weeks. Really depends on how motivated my brother is. He's getting excited about my car now, since he just splattered his 454... So could be soon, could be end of summer and into winter.

only90s

I found this on the Vortech site for you...[/align][/align]Please Note:
A change in one pulley size will usually effect boost 1-2 PSIG... down in diameter, up in boost and vice versa.[/align]






PART #
DESCRIPTION
PRICE
SELECT


2A038-275
8-Rib Supercharger Pulley (2.75")
$87.95/ea





2A038-295
8-Rib Supercharger Pulley (2.95")
$87.95/ea





2A038-312
8-Rib Supercharger Pulley (3.12")
$87.95/ea





2A038-333
8-Rib Supercharger Pulley (3.33")
$87.95/ea

Scout2232

Thanks man, I appreciate the help.

jtmustang

hey scout what was your cr off this formula? i have the same cam and heads as u ,stock crank/rods dss pistons at 9.7,i want to run 8 lbs or so when done with it

Scout2232

Those DSS Pistons that compression ratio is based off of 61cc combustion chamber right cause that's the size of the TFS heads.

Ok, so yours would be like this:
4.030, if you are 30 over right?
3.000 stroke
5.090 rod length
9.7 compression ratio, there's a calculator for that also (static compression)
inlet closes @ 38 degrees (mine cam was installed 'straight up' not sure if that effects it)
@ sea level.


Camshaft, Rod Length, Boost and Altitude Correction to Compression

Your engine summary is as follows: Bore 4.030 inches, stroke 3.000 inches, rod c-c length 5.090 inches, with a static compression ratio of 9.7 :1. Your camshaft specifications call for an inlet valve closing of 38 degrees ABDC (after bottom dead center).
Your chamber volume is 72.08 cc's. With this camshaft your dynamic, or effective stroke is 2.77 inches. Your dynamic compression ratio is 9.03 :1 corrected for cam timing, altitude, and rod length. Your dynamic cranking pressure, corrected for cam timing, rod length and altitude is 185.84 PSI. Your dynamic boost compression ratio, reflecting static c.r., cam timing, altitude, and 8 PSI is 13.94 :1.
Knowledge is power.

jtmustang

okay i see so the dynamic cr is more like realistic?what does the dynamic boost cr mean?

so i should be fine runnin a supercharger without intercooling or methanol right??????

thanks man!!!

Scout2232

Yea, exactly.
I'm thinking dynamic boost cr is what your CR is with the psi of boost added on top. The number will lower as you go up in altitude, I just used sea level because I don't know what the alt. is at your place. I also assumed you were running a 306 with stock lengthrods. But yea, if its too high for you, maybe a different/custom cam is in the works for you.

Scout2232

As for methanol or a intercooler, I'm not sure. I am going toTRY and not run any kind of methanol or intercooling on 92 octane with mine, but won't REALLY know for sure untill I take it to the tuner and see what they have to say about it. I don't thinkI will have a problem running with that setup, but they might have to pull some timing to keep it runningright ya know?