NAPARM

Hey all i have the car listed in my signature below. It goes okay now but still has nothing down low (ie. off the mark). From a standing start if i put my foot to the floor the wheels are no where near spinning. Because it doesn't make boost untill 2,000 rpm i guess it's basically a stocker below that rpm or worse.
Anyway i'm looking at ways of improving the acceleration off the mark, i was thinking either a higher stall converter or lower diff gears. What would you guys recommend? Do you have any other ideas?
(only reason i'm not liking the idea of getting lower diff gears, is that currently the car sits on about 1850 - 1900 rpm at 100km/h, so therefore isn't making any boost. But if i get lower diff gears it will mean the car will be making boost while i'm cruising at 100).
ps. what will my revs be at 100km/h in 4th gear with say 3.7 or 3.9 diff gears.

Cheers, Dave.

marcuss

Hi stall converter will do the trick. I wouldnt go above 2500rpm stall speed for a daily driver. Get a good trans cooler because hi stall speeds generate a lot of heat and will kill the tranny.

Converter manufacturer will need to engine peak horsepower and torque, gear ratios, tyre diameter amd car weight.

This will put you into the tyre melting range. Enjoy!

WBT56

To get your new rpm, divide by existing diff ratio and multiply by proposed diff ratio. If the car is a slug down low, you may find that increasing the cruising rpm up to where the engine is more efficient will actually use less fuel. I assume you have 3.08 diff gears. You may find the answer in say 3.27 or 3.45 and a stall increase of a couple of hundred rpm. Remember it is a package- don't expect magic by changing one thing.

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If you're not driving a manual you're really just steering.

sylox

The Xr's have the 345 ratio and i am going to change to 3.7.

Dave if your interested in buying my old diff gears (if they fit) Pehaps we could both go up when I get mine changed as we may get a discount on fitting etc... Just a though.

But definately a high stall and some lower gears will give it a noticable difference for sure......

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WILD6

y dont u convert it to a 5 speed manual that way u rev it to 2000 rpm or more and take off with it on boost should see you lighting up the rear tyres regularly then

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series3 xr8 5 speed manual, pacemaker extractors, hi flow cats, 3 inch exhaust, lowered cold air intake, k&n air filter, 3.9 diff gears
13.9584 @ 98.51 mph 1.9447 60 ft
188.9 rwkw 525 nm of torque

NAPARM

well the funds won't allow me to convert it to a manual at this point in time, and i don't know if a T5 would last that long if i was a bit rough on it...

Walkinshaw

a change to 3.45 should help you off the mark.

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Ive been described as a vault of usless random knowledge.

Ill take it as a complement i think.............