Sinner....(Sactown F1R) build

Sinner

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Ok I've been doing some math and I haven't measured the crank pulley but using stock size as a reference of 6.5 and 4.5" blower pulley im not spinning the blower but only 50k rpm. The max speed is 68k rpm so I'm thinking I'll go down to a 3.4" pulley. That should put the max impeller speed to 67k rpm at 6500 engine rpm.

I'm using this math:
Crank pulley 6.5" divided by blower pulley 3.4" = 1.9

Then multiple 1.9 to the trans set up up ratio of 5.4 = 10.26

Last multiple 10.26 to max engine rpm of 6500 = 66690 impeller max speed.
 

Department Of Boost

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Blah.... Seems the car has 8" crank and 4.5" blower pulley.

That is a BIG pulley/damper. Is it custom? ATI doesn't list them that big.

If it is maxed out there is something wrong.

-Inlet restriction. Remove everything off the inlet side of the blower and run it on the dyno. Does it make more power/boost?

-Bypass is bleeding boost off.

-Blower is junk.

That blower will make upwards 30psi on 400cu in motors. No way it's maxed out at 15psi on your 300cu in motor.
 

swflastang05

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My Procharger crank pulley is 7.5", I know its really difficult to measure due to the large lip on front but that's what I got, then called them to confirm and they agreed. I'm running that 7.5" crank pulley and will be switching to a 3.85" blower pulley that will spin 73,636 @ 7000rpm, as you know the max is 74,000 so that should be good. My F1A currently makes about 21-22 psi with a 4.25 blower pulley.

Edit: I just saw your F1R maxes out at 68,000,
 

Department Of Boost

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My Procharger crank pulley is 7.5", I know its really difficult to measure due to the large lip on front but that's what I got, then called them to confirm and they agreed. I'm running that 7.5" crank pulley and will be switching to a 3.85" blower pulley that will spin 73,636 @ 7000rpm, as you know the max is 74,000 so that should be good. My F1A currently makes about 21-22 psi with a 4.25 blower pulley.

Edit: I just saw your F1R maxes out at 68,000,

That's a little more like it in regards to boost. What sort of power are you making?

How do you calculate the step up RPM on the PC?
 

Sinner

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That's a little more like it in regards to boost. What sort of power are you making?



How do you calculate the step up RPM on the PC?


Crank pulley divided by blower pulley then multiple by blower trans (5.40 on F1) and multiple the max rpm.

Example:
7.5" (crank pulley) / 4.5" (blower pulley) = 1.66

1.66 x 5.40 (blower trans step up) = 8.96

8.96 x 6500 (max rpm) = 58,240 impeller sprees.
 

Sinner

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My Procharger crank pulley is 7.5", I know its really difficult to measure due to the large lip on front but that's what I got, then called them to confirm and they agreed. I'm running that 7.5" crank pulley and will be switching to a 3.85" blower pulley that will spin 73,636 @ 7000rpm, as you know the max is 74,000 so that should be good. My F1A currently makes about 21-22 psi with a 4.25 blower pulley.

Edit: I just saw your F1R maxes out at 68,000,


Sorry for not using multiple quote but I don't know how on cell.

I might have a 7.5" crank pulley, it's tough to measure in the car. I'll try to call Procharger or ask Sactown.
 

swflastang05

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That's a little more like it in regards to boost. What sort of power are you making?

How do you calculate the step up RPM on the PC?

Not sure on the power yet, new setup, no dyno or track time yet, I'm hoping for high 9's though in the 1/4 :) I used the calculator on JPC's site..

Sorry for not using multiple quote but I don't know how on cell.

I might have a 7.5" crank pulley, it's tough to measure in the car. I'll try to call Procharger or ask Sactown.

It is super difficult to measure on the car for sure, Luckily I bought a new crank pulley from procharger just a few months earlier so they were able to look up my order and confirm, 7.5" was in fact the size x 12 rib pulley,
 

Department Of Boost

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Crank pulley divided by blower pulley then multiple by blower trans (5.40 on F1) and multiple the max rpm.

Example:
7.5" (crank pulley) / 4.5" (blower pulley) = 1.66

1.66 x 5.40 (blower trans step up) = 8.96

8.96 x 6500 (max rpm) = 58,240 impeller sprees.
So you're short 10K RPM's from max?

By my calculation you need a 3.875" upper to spin max RPM's. That's a HUGE jump when it comes to blower pulleys.
 

Sinner

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My kit has an ATI crank blower pulley that replaces the stock Procharger crank pulley so I'm not sure if it's 7.5" like stock or the 8" we measured at the shop. With the blower brace on the car it's very difficult to really measure accurately so I'm not sure....

I might just say fuck it and assume it's 7.5" and put on a 4" pulley. That puts it at 67k roughly
 

Sinner

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Ohhhhhh...

New kink in the plan... It seems the cam I had designed by a company is failing out of power at 6250rpm, that's why I'm only spinning to 6500 when I wanted to run up to 7-7.5k.

My power band is shit right now so I'm going to call that shop next week and see if they will replace these cams because they seem to be falling short.

Here are the cam specs again they designed but I did ask for the lift to not be too aggressive and running lock outs.

@.050 duration intake 227 exhaust 243 with lift 525/525 LSA 114 CLA 110
 

Department Of Boost

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My kit has an ATI crank blower pulley that replaces the stock Procharger crank pulley so I'm not sure if it's 7.5" like stock or the 8" we measured at the shop. With the blower brace on the car it's very difficult to really measure accurately so I'm not sure....

I might just say fuck it and assume it's 7.5" and put on a 4" pulley. That puts it at 67k roughly

There is no way you will be able to pile that much boost on without needing race fuel or e85.

Ohhhhhh...

New kink in the plan... It seems the cam I had designed by a company is failing out of power at 6250rpm, that's why I'm only spinning to 6500 when I wanted to run up to 7-7.5k.

My power band is shit right now so I'm going to call that shop next week and see if they will replace these cams because they seem to be falling short.

Here are the cam specs again they designed but I did ask for the lift to not be too aggressive and running lock outs.

@.050 duration intake 227 exhaust 243 with lift 525/525 LSA 114 CLA 110

That cam should rev like mad. Especially with a centri. The 127350's I just took out are smaller in every way and my car would scream right by 7000rpms.
 

Sinner

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I have a wastegate to control boost so the smaller pulley will help boost come in sooner.

These cams are spinning for shit. I wouldn't think I have a restriction holding them back.
 

Sinner

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Jason, I'm just sending you the fucking car and you can get it right.
 

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