t2te50

I want to get an Xa falcon and put a 460 big block with a dual pattern .484/.510 though lift cam which is recommended for dual plane manifold applications and doesn't require stall converter (c6). The vehicle will weigh around 1600kg, what 1/4 times can I expect? With 3.00/1 gears for cruising.

I want a tough streeter that launches off the line like a demon but is inconspicuos in doing so. What I mean is you don't need to put the trans brake on and stall her up just to smoke someone.

Being discreet about your intentions and anticapating the other person is half the fun in a road race.

KILLERME

I have similar set up , 3.00 mini spool for drags , I was doing 14.8s still spin out of trap. Now I have .520 lift cam , 2500 stall , same 3.o mini spool with 205/50r15 at 15psi, spin hard still but now running 14.2 my best, Just cant get off the line. I run 2.75 for cruising,, better less revs 2400rpm at 100kph . Need lower gears 4.11s and slicks to do good times. and soft suspension to hook up.

t2te50

Thanks for the reply mate. Flat 14 is reasonably quick but as I feared wheelspin is the biggest killer.

TruBlu351

Some lower gears....4.11's.....would be scary in comparison to 3.0's. That's still a very high drag racing ratio.

KILLERME, what rpm & mph are you crossing the finish line at?

Mate, with slicks you'll be getting front air time

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XE Falcon
393 Tremec TKO 9"

KILLERME

about 5200rpm ad 161mph

KILLERME

lol ah 5200rpm 161kmh = 100mph

TruBlu351

yeah, you'd have to have about a 500hp nitrous hit half track to do a 14 and make 161mph!!

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XE Falcon
393 Tremec TKO 9"

TruBlu351

Something doesn't quite add up with those 3.0 diff numbers.

You sure you have a 50 profile on a 205 (23.1" diam)? That's quite a low diameter tyre. Normally they'd have around 60-65% profile making it a 24.5-25.5" diam.

Your 2.75 diff #'s work out OK, 2400rpm @ 100km/h with a 205/50x15, so my bet is that your other diff is lower than 3.0.

3.0 diff @ 5200 with 23.1" tyre = 190km/h (119mph)

To make it work (ie: 5200rpm = 160km/h) you'd need around a 3.5 diff ratio. A 3.0 would have you pulling 4400rpm across the line.

With the diff jacked up you can measure the driveshaft rotations (3) to make the rear wheels spin around once. Or divide the crown teeth # by the pinion teeth # if it's out of the car.

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XE Falcon
393 Tremec TKO 9"

KILLERME

Hey, I run down the drags 3.0 ratio with a 205/50 15 , on the street I run 2.75 ratio with 255/45 17 @ 100kph was 2400rpm

TruBlu351

Cool Don't want to go smokin' those 17" job$!!

That's OK, the real question I had was a 5200 trap rpm with 3.0 gears and 205/50x15 tyres = 190km/h, but you said your trap speed was 160.

So either you're only pulling about 4400rpm at the finish line or your 3.0 diff is really a 3.5 ratio.

Get those 4.11's into it

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XE Falcon
393 Tremec TKO 9"