306ci YS-trim 450fhp?

**gt40_5.0** · 06-11-2004, 10:55 AM

what should my c/r be?

**BLOWNBY** · 06-11-2004, 11:49 AM

8.5-9.0:1

**gt40_5.0** · 06-11-2004, 02:33 PM

how much hp will 14-16psi make? estimate

**regattacoupe** · 06-11-2004, 03:47 PM

put it on and find out! Start low and work your way up. There's so many variables it's immposible to say how much you'll make.

**gt40_5.0** · 06-11-2004, 03:54 PM

well i dont want to put on too much or it will go boom :( i think like 8-10 is all i need but i dont think u can get it to put out that low a ys-trim can u?

**BLOWNBY** · 06-14-2004, 08:18 AM

I would say 14 -16 psi on your motor tuned with 93 and easy on the timing should put you at 525-550 ish rwhp.

**BLOWNBY** · 06-14-2004, 08:20 AM

If you want lower boost 6.87 and 3.15 pulley or 8" and 3.33 pulley will do it. Also no belt slippage issues with the big SC pulley.

**mustan5069** · 06-16-2004, 02:03 PM

Originally Posted by BLOWNBY

DUDE you will be good to go with the extra power. I have a sportsman motor with all stock internals except for the Lunati cam. Hyper pistons and two bolt main. I am maiking 670's rwhp, made 530'srwhp on the s-trim for 3 years before. All is good.

I just put my BTM at 3 on the street and turn it up at the track. I have a conservative tune so as not to squeze every last drop of power out and detonate a piston. If you have forged pistons, run the 3" pulley get hi 500's rwhp with a conservative tune and you will be making the power for a long time to come on the motor.

I cant remember but i thought it was 501 with the s trim on that big 351 not 530

**mustan5069** · 06-16-2004, 02:05 PM

Originally Posted by BLOWNBY

I would say 14 -16 psi on your motor tuned with 93 and easy on the timing should put you at 525-550 ish rwhp.

how do you expect someone to make that kind of horse power on 93 if you cant do it on 104 with 13 pounds of boost with a 351

**BLOWNBY** · 06-16-2004, 02:27 PM

The 501 rwhp was on a MD. and S-trim. These usually read lower than a dyno jet. GT40 is looking to run a YS which should make those numbers.

I am making 670's rwhp at 20 psi (630's @16psi) with mine so 525-550rwhp should be do-able with 12-14 psi on his motor and a YS with a conservative tune. (Dyno Jet) Se my images I uploaded them.

Anyway, also it is possible to do it with an s-trim. Some of my past post for s-trim questions I gave info on my buddies setup that I sold my s-trim to (8 rib belt no cog either). He has a 302 holley intake and heads tune on 110 and made 530 rwhp on a dyno jet with no inner/after cooler. Put a cooler on there and a degree or more of timing and 550+rwhp should happen.

The main advantage of the 351 is usually torque though not necassarily HP.

**mustan5069** · 06-16-2004, 03:11 PM

Originally Posted by BLOWNBY

It will work, but may not be producing the best numbers compared to a smaller blower. usually your low end will suffer. I ran the 8" and 3" pullies the YSI came with on a 351 and made 16 psi at 6,000RPM. You could use a 3.33 pulley to slow it down. It will work just not the best. But if you have it use it.
Plus the YS is less agressive than the YSI. GO FOR IT.

I have hyper pistons and two bolt main and am running 20 psi with a conservative tune and thus far all seems well. Not i have a good fuel system. All weldon, 60 injectors and ss lines.

You should be fine with your setup and 14-16 psi with 3.33 pulley.

Personally both the ys is to big for his combo hell the ysi is to big for your combo. he will make much better power with the s or t

**BLOWNBY** · 06-16-2004, 03:22 PM

Totally agree, but if you got it why try to sell it and replace with something smaller. Maybe not better power--top end, but definitly low end. This is why I am looking to see some T-trim dyno sheets on 302 or 351. So I know, maybe it is worth me trading a YSI for a T if the low end is better, but I don't think it is that much better. Want to see.

http://www.superchargerhelp.com/showthread.php?t=5323

It will work for what he wants. Not the most effecient way.

I on the other hand was going to go with the T-trim, however, to buy the T-trim in pieces (head unit, braket, distube, bypass elbow etc.) don't need all the ignition and fuel since I already had an s-trim, would have spent more to get the T-trim. And i didn't want to go throuth the headache of selling all the misc parts if I bought the T-trim kit. I could by the YSi reengade kit and get the exact parts I needed for less money that peicing the T-trim together. Also I was able to sell my S-trim to a buddy and heonly needed the head unit, bracket , dis and bypass. Worked out.