Superchatged Fox and rear gear info.

Dfg88Saleen

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Aug 23, 2018
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3.55 is usually the best all around option . Boost from 4K and up ? I’d say it’s linear with the centri blowers from my experience . I’m not sure whwtxpulley setup you have . Sounds to me like a 3.33 /6.87 deal . A real pulley would give it a kick in the ass .

Linear with better gears and rpm range yes lol. I was just looking at what the general go to was for people. Especially those that drive far. Not sure on settling for 3.55's or 3.73's. Whats everyones top speed with 3.08's and 3.73's?


I'm a n/a guy right now :rolleyes: .
you have a small window of boost opportunity, and only 4-5 pounds.
i agree with toolow91, you need to pulley that thing up, with 10 lbs and a gear around 320 something to 355 max you'll need stock in a tire store. I think you need to get the boost to come on a little lower in the rpms then a 308 or 323 gear will work. Most fox convertible 5.0 cars came with a 320 something gear in them, thats what I would shoot for.
disclaimer: the advice given is not based on any real world experience, just the rantings of a guy that hangs out on a mustang forum with members that are WAY smarter than he is.

Definitely doing pulley change, getting it tuned on meth as well with a devilsown kit and new injectors, maf and aeromotive fuel system. But since i am going through it all i know im going to want a gear change, so i might as well do it at the same time.. my svo had 3.73s but ran out of top end due to the crappy 1984 5.0 carbed intake, and edelbrock 600 which was junk. Headers and cam, and work done to stock heads. Loved the low end of the 3.73 gears though.
 
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General karthief

wonder how much it would cost to ship you a pair
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It's gonna be a trade off, I'd say keep the gear and do a pulley change.
you can't compare n/a to blower cars, from what I understand if you have more power you need less gear, you just need to get your blower to come on a little more lower in the rpms, so if your cruising at say 2100 rpms in high gear get you boost to start building at say 2500 to 2800, that will keep you out of boost at cruise and your combo should live long time on the highway, am I right @TOOLOW91 ?
 
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Dfg88Saleen

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Aug 23, 2018
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It's gonna be a trade off, I'd say keep the gear and do a pulley change.
you can't compare n/a to blower cars, from what I understand if you have more power you need less gear, you just need to get your blower to come on a little more lower in the rpms, so if your cruising at say 2100 rpms in high gear get you boost to start building at say 2500 to 2800, that will keep you out of boost at cruise and your combo should live long time on the highway, am I right @TOOLOW91 ?

Yes its a trade off, but difference between the different types of blowers is like an eaton is a positive displacement blower,its like adding cubic inches and boost is there when you want it. Centri makes boost with rpms as you go so if i have airplane gears it will have to go a bit in order to make rpms where my boost window starts, which is why i have that small window lol . Turbos like a load, reason why gearing for turbos is usually around 3.23, 3.27, and on up to around 3.50's. But with the centri being belt driven it makes boost off of rpms. Gearing gives you a better rpm range.
I just dont want semi gears in my mustang lol, but i also know at some point i dont want 3.08s. My sn95 with an eaton had 3.08s and was fun, but with 3.73's, suspension and a tire it was another animal. I think I'll go for the tune and parts now, and see how it feels, i like the fact i can drive across 3 states with decent fuel mileage.
 

a91what

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Changing to a higher numerical rear gear is going to hurt mileage. A pulley change on the blower is not going to have it making boost at cruise speeds.
 
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TOOLOW91

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I have a touch of experience with the centri blower stuff ;) - my little heat machine a trim at 7.5 psi would boil the tires off from 30-40 mph roll with 3.55s forget about now with the ysi . I agree the blower makes more pressure as rpm rises but if you pulley it and get it to turn it will make way more boos in the lower rpm as you get on it like you’re looking for .

Your top speed with whatever gear is going to be based on the rear tire height . With 3.55s and a 26 inch tire I was seeing 133.8 mph at 6200 rpm at the stripe . Oh and at 640 plus at the tire it still avg 18-20 in 5 th gEar cruising with a lot of Highway fun pulls.
 
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