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10% pulley?
- Thread starter Treys92
- Start date
Looks like your exhaust will support it.Treys92 said:I'm thinking of stepping up to a 10% pulley. I currently have an early pulley on my home ported 94/95. What do you guys think i should do?? -Trey
You might also consider keeping your original SC pulley & getting the SCI 10% Jackshaft pulley.
68COUGAR
X
xThunderbirdSCx
Guest
port your heads like i did, then you can run something like 20% overdrive with an S-port
I had an early style blower with a 10% and "classic" exhaust and made leaps and bounds in horsepower gains.
I had an early style blower with a 10% and "classic" exhaust and made leaps and bounds in horsepower gains.
10% + OEM exhaust
68COUGAR
I had the 1st. 10% avail. back in about '90. Everything stock, except the SC pulley. I could feel a difference. Course 2 yrs later I pd. the local German Ford garage $7,500. to put new head gaskets in my engine.xThunderbirdSCx said:I had an early style blower with a 10% and "classic" exhaust and made leaps and bounds in horsepower gains.
68COUGAR
Numbers Game
The OD ratios are figured using the early pulley. The later M90 had a bigger SC pulley, which means that it moved slower than the earlier small pulley model. I think the late pulley is -3% from the early pulley. So with a SC 10% pulley on your late model blower, you'd be +13% from the late pulley.
The Stock arrangement overdrives the SC by 250%.
68COUGAR
Nope, you got it backwards. The additional overdrive would be slightly LESS than 10%.Treys92 said:I had considered that also, but wouldn't my total overdrive be greater than 10% if i went that route? -Trey
The OD ratios are figured using the early pulley. The later M90 had a bigger SC pulley, which means that it moved slower than the earlier small pulley model. I think the late pulley is -3% from the early pulley. So with a SC 10% pulley on your late model blower, you'd be +13% from the late pulley.
The Stock arrangement overdrives the SC by 250%.
68COUGAR
Supporting Mods
68COUGAR
It all depends on what supporting mods you have to go with the sc pulley. Every application is different. Maybe you didn't have the supporting mods on your late model, to go with a 10%. Other do have the supporting mods. So a blanket statment about what can & can't be run, is really misleading.JStudrawa said:I opened my exhaust with the age old 2.5-3-2.5 and was advised to run a 10% on my early model blower, but only a 5% on a late model or S-port.
68COUGAR
68COUGAR said:Nope, you got it backwards. The additional overdrive would be slightly LESS than 10%.
The OD ratios are figured using the early pulley. The later M90 had a bigger SC pulley, which means that it moved slower than the earlier small pulley model. I think the late pulley is -3% from the early pulley. So with a SC 10% pulley on your late model blower, you'd be +13% from the late pulley.
The Stock arrangement overdrives the SC by 250%.
68COUGAR
Thanks for clearing that up for me Cougar. I've heard both sides to the story, and can't come to a conclusion...Maybe Dave will chime in. I know that it puts me at higher risk for blowing headgaskets due to detonation, but that is something that has to be delt with on almost all SCs.
-Trey
Randy N Connie
Registered User
I have ran a little over 20% over drive on a MPII for
a short time ,with a stock long block motor with no problems.
I am now running over 20% on the same motor a MPIII
with no problems.Daily driver,except when it is raining out.
I just let up on the gas peddle when my boost guage gets
close to 15lbs.Unless I am racing some one.
I havent had any head gasket problems yet.The only problem
is wearing out my back tires.I use FEL-PRO gaskets. I do
plan to switch to Stainless gaskets this spring though.
I am thinking about going up to 30% OD in a couple weeks
for a dyno pull. I hoping to pull a 320 RWHP.I pulled
280.8 RWHP with a boost leak.So Since I found and fix this
leak.I am sure I am close to 300RWHP right now .
I don't know if this INFO is of any help for your goals of running
a different size overdrive pulley .But this should give you an idea
of the max over drive that can be done safely with a stock motor
with most all bolt-on running with pump gas only.
My opinion is you can run as much overdrive as you want.
As long as you can control the extra heat of the air.And
you have enough fuel.
a short time ,with a stock long block motor with no problems.
I am now running over 20% on the same motor a MPIII
with no problems.Daily driver,except when it is raining out.
I just let up on the gas peddle when my boost guage gets
close to 15lbs.Unless I am racing some one.
I havent had any head gasket problems yet.The only problem
is wearing out my back tires.I use FEL-PRO gaskets. I do
plan to switch to Stainless gaskets this spring though.
I am thinking about going up to 30% OD in a couple weeks
for a dyno pull. I hoping to pull a 320 RWHP.I pulled
280.8 RWHP with a boost leak.So Since I found and fix this
leak.I am sure I am close to 300RWHP right now .
I don't know if this INFO is of any help for your goals of running
a different size overdrive pulley .But this should give you an idea
of the max over drive that can be done safely with a stock motor
with most all bolt-on running with pump gas only.
My opinion is you can run as much overdrive as you want.
As long as you can control the extra heat of the air.And
you have enough fuel.
Last edited:
Randy, thanks for all the info. It is useful in making a decision. After exchanging email with Dave D. I've decided to hold off on any more overdriving until I get a double IC this spring, and will most likely end up going with a 10% JS pulley...along with a tune that i so desperately need. That, 42 # injectors, some 3.73s and maybe a break into 13s...
-Trey
-Trey
68COUGAR said:It all depends on what supporting mods you have to go with the sc pulley. Every application is different. Maybe you didn't have the supporting mods on your late model, to go with a 10%. Other do have the supporting mods. So a blanket statment about what can & can't be run, is really misleading.
68COUGAR
Right, this statement was concerning advice given to me and my situation. I guess it could seem like a blanket statement from an outsider's PoV.