ty_ty13

iTrader: (42)

I am most certainly trying to stay within the fueling needs of 60lb motron injectors... the rest of the fuel system is very strong (nasty cell, -8, custom fuel rails..etc)

so im trying to figure out what pulley i should run on a D1 SC for a 408...

it has a single plane gmpp intake , stock 241 heads (work on the exhaust side) 220/224 cam, and reving to 6500 rpms.

i dont want to over-do it and have to upgrade injectors..

im guessing a max of 780 fwhp is what i want...


so all in all what size blower pulley do i need.

Thanks,


Tyler

ty_ty13

iTrader: (42)

cant believe no one has chimed in

TrakDay

iTrader: (7)

What size crank pulley are you running? I would go ahead and max out the impellar RPM of the blower if I was you. So if you give us your crank pulley size we can figure out what size blower pulley you need to do that!

ty_ty13

iTrader: (42)

7.25 crank.. sorry about that...


also what if i used a 7.5 crank pulley... i'd like to keep the blower pulley large enough to not encounter a huge amount of slippage...


what would a 7.5 crank and a 4'' blower pulley net me at the crank reving to 6700 rpm max?

LSs1Power

iTrader: (5)

I would go with a 3.4 pulley if you are running a 7.25 SC pulley. This will put u around 56800 RPM on the blower. That should be enough to put you between to 650-700rwhp with your setup. Your 60lbs injectors and higher fuel pressure should be good for 750rwhp easy. The 60lbs injectors can flor 85lbs at 87psi of FP. Just get an adjustable FPR and increase the FP 1:1 and start with a 62psi base fuel pressure and you should be good.

When does your cam peak? If you need more boost i suggest getting a cam that peaks around 6800 RPM so you can take the car to 7100 RPM and max out the blower with the 3.4 and 7.25 pullies. That should make an interesting setup. Thats what im doing anyways

ty_ty13

iTrader: (42)

i'd like to use a 7.5 crank and a larger "richard racing" blower pulley to keep from having to use the sdce tensioner... but i may have to

LSs1Power

iTrader: (5)

I get it you are running the SDCE setup since you have a 7.25" crank pulley. If u are running the SDCE setup i wouldnt worry about belt slippage. If you want to go with a larger crank pulley get at least an 8" crank pulley to make the change worth it.

Going from 7.25 to 7.5 crank pulley wont increase much in term of blower speed. 49800 RPM can be had with 7.25 and 4" at 6700 RPM while 51500 RPM with the 7.5 crank pulley. that is only 1500 RPM on the blower which is not much increase in term of boost (Maybe 1- 1.5psi).

If you dont want to go to 7100 rpm to max the blower with the 7.25 crank pulley and 3.4 blower pulley then i suggest getting a custom 8" crank pulley and keep running the 4" blower you have now. That should put u around 64000 RPM at 6700 RPM. Im sure with your current cam u wont need to take it that high and shift around 6500 RPM and u will be fine.

Good luck

LSs1Power

iTrader: (5)

If you really want to use the blower to its max efficiency i suggest getting the SDCE setup. My car made 2 more psi with the SDCE setup even though im running the blower at the same speed. This shows how efficient is their setup.

As i said above... If you want a custom crank pulley go with a 8" instead of 7.5".

Good luck

EPP

iTrader: (22)

Get rid of the stock inlet hat and go with a 4" aluminum elbow to a larger filter, if you haven't already. We recently picked up 2 pounds of boost, and apparently ended our belt slippage problems when we eliminated the restriction. The bottom of the radiator had to be moved forward when we did this. Bob

Slowhawk

iTrader: (12)

Sounds familier

For the power out of a D1,run a good compression like 9.5-1 if you aren't already with a Cam that has alittle overlap to cut out low rpm TQ/cylinder pressure. The D1 ussually is only good for 700-750rwhp max due to the air it can flow. We've done 800+ through a C4 before but the compression was through the roof