guess what? another SC overdrive pulley question

wigglesrewind

Registered User
yeah i searched and found about 50 threads on this subject, read through the first page and didnt find the answer i was looking for so here whats going on:

i have a 5% overdrive right now on my bird and see around 12psi of boost at wot. ive also got the stock size jackshaft pulley installed as well. i have a custom exhaust setup thats a 2-1-2 design and is 2.5" all the way with a resonator at the Y and 2 turbo mufflers. i have stock exhaust manifolds right now but i got a pair of ported manifolds with the car when i bought it. my question is would a 10% pulley benefit my any? i think my motor can handle it with the exhaust that i have and if not then i would think that adding on the ported exhaust manifolds would allow me to run the 10% pulley. and since im only seeing 12psi i thought there would be room for a little more boost.

any opinions or comments are great. thanks in advance guys.

-josh-
 
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I have 10% pulley's on both of my SC's. One by choice, and the other because I got a different blower and only had a 10% pulley laying around to use on it (came w/ no pulley).

They are both early model non efficient M90's and they both pull hard down low and seem to lose power up top. I have stock intercoolers on both. I get about 13 psi on my auto and maybe 12 psi in the 5-speed although if the weather is cold it will hit about 14-15 in 3rd gear but I don't floor the cars much. Especially with the cost of gas now. If I started racing them at the track I'd get 5% pulleys. But for light throttle on the street its ok. I just don't redline the car. I usually keep it out of boost and if I need to get in front of someone 5-10 psi usually does the trick. So I'm not worried about pulling timing or detonating because plain and simple I drive like a little old lady unless I'm late for work.

The only way some of these guys are running 10% pulleys and getting away with it is because they have big dog exhaust, front mount ic's, and blowers that have been ported to increase efficiency which in turn lowers the boost, but flows more air. So then they overdrive the jackshaft pulley and the supercharger to bring the pressure back up to 14-15 psi which they are capable of cooling with the intercooler plus they add fuel via tuning (which cools the intake charge). So basically if you just want to slap a pulley on there and not upgrade the rest of the system to handle it, you will only gain a little torque but lose the power when the car gets up past the torque peak. If you drive like me you will be ok and it might even feel faster. But if you race the car or drive it hard, I'd wait till you get the supporting mods.
 
thanks for your input scott, i do race on the weekends, not competitively but just for fun, im on a quest for 14s with my daily driven SC with close to 170k on the clock. if the smaller SC pulley would rob some hp up top then i will probably stay with my 5% and worry about some other mods first, i just bought an 8" fan from summit to do the IC fan mod and i'll be getting 3.27s installed this week. underdrives are also on the list there somewhere.

any other members have different opinions?
 
Injectors & Fuel Pump

wigglesrewind said:
any other members have different opinions?
Have you upgraded your injectors and/or fuel pump? When you do the fuel pump, spend the extra $20 to upgrade from the 190 lph to the 255 lph. That way you won't ever have to drop the tank.

68COUGAR
 
yeah it has a 255lph fuel pump but i still have the stock injectors. i will probably top out this bird at 235-240 rwhp so i think the stock ones should be okay? what ar ethe stock ones rated, i know mustang injectors are 19lbs stock.
 
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