John_xr6

hey guys, im thinking of putting 3.7 diff gears in my car and remember reading that the auto wont change gears at the right RPM. i couldnt find any info on it so does anyone know? or has 3.7's behind an auto? any probs with it?

thanks.

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1994 COBALT BLUE ED FAIRMONT GHIA
Next Mod - T5 Manual Conversion
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zbenga

if you get your speedo calibrated it should be OK, but hell i hope you got deep pockets for the extra fuel consumption on the open road :)

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EF Futura, XR6 spec head, lowered, T5 conversion, 2.5" catback, AU XR8 snorkle w/ K&N

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This cat, is cat, a cat, good cat, way cat, to cat, keep cat, a cat, idiot cat, busy cat, for cat, 20 cat, seconds cat! Now read it all without the word cat!

John_xr6

LOL i barely travel on the highway and 3.7's wont increase the rpm to no worse than a 3 speed EA anyway.

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1994 COBALT BLUE ED FAIRMONT GHIA
Next Mod - T5 Manual Conversion
Pics Here

Mike Gayner

Fuel consumption isn't that much worse with a big ratio diff. I used to run 4.11s in my EA and noticed only a very slight increase in fuel consumption.

MadManz

is your car rev limited? my ba gt-p when i changed the gearing from 3.46 to 3.73 being an auto actually hits the rev limiter before it changes gears now!!! if only i had another 500rpm!!!

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NZ

i wonder if your car could be fixed byt that new edit thing for the BA's they have now Madmanz

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NZ

john if you leave the sender thats for the original diff ratio your shifts will be fine. Your speedo will be incorrect

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MadManz

ok will check, but so far once we purchased the car new, ford really dont have the time of day for us so i spose thats wot the ford company motto should be, "We'll blow wind up ur ass all DaY!!!

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John_xr6

Karl, should i run a 3.45 sender for the trans seeing as it has the XR Ecu and is programed for 3.45 or just leave it?

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1994 COBALT BLUE ED FAIRMONT GHIA
Next Mod - T5 Manual Conversion
Pics Here

NZ

yes a 3.45 gear will make it shift at the right rpm. yours will be shifting early at the momment if it has a taller than 3.45 diff

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