I have found this calculator to be accurate on my car, a few others I have plugged in seem to be quite close too :)

As it is based on an Auto trans car, the ET needs adjusted for manual boxes (time lost gear shifting) I have found that you need to add 8% to the ET for a syncro box and 5% for a dog box.

http://www.turbofast.com.au/drag.html

Andy

Andy,

Are you using wheel hp or flywheel hp,

As it seem when i put 8% on top mine with 336fwhp will go 13,01sek


Skassa

Using flywheel hp. I find the +8% ET works ok with my shabby slow (save the box) gear shifts, maybe try only +6% if you are really slicing it through the box ?

What weight is your car in race trim ? How did the MPH work out ? as that is closer related to power output and less disrupted by gear shift speed.

Andy

My car weight is 2976lbs(1350kg) with me in it :D

The speed is about right 113mph.

But i have done a 1/4mile at 12,67sek184km/t with a start were the car bogged

Skassa

Doesnt work too well with a rwd car though.

For mine, just asking for weight, and ET it estimates 348bhp, with a 12.54, and 3476lbs

Yet, when I ask for terminal speed, it estimates 470bhp for that to produce a terminal of 120mph, at 3476lbs.

I think its kind of assuming a perfect launch, with traction all the way, in an ideal world.
That doesnt really happen. Would work better for Subarus I guess.

Yes Steve, it assumes good traction so a rwd on road tyres will not fit too well. Get youself some drag slicks and get to santa pod though !!

Need a stronger rear end for that first. Rear CV joints have a habit of breaking.
Lookin forward to Crrail though. Hopefully it will stay dry. Still on road tyres though.

See you at Crail Stevie :)

Here are a few cars that seem to tie up closely with this calculator.

Car................Mass/BHP........Calc ET/MPH....Actual ET/MPH


My bike eng kitcar..580/140...........12.8/112........12.9/113

P20SPD.............1320/360est?.......12.6/117........12.6/118

My Scoob(last yr)..1240/390..........12.0/121........11.8/119

My Scoob(this yr)..1240/440..........11.5/127........11.6/127

Keiths Skyline.....1400/800.............9.6/149..........9.9/152

My V8 kit car...... 820/430.............9.5/145..........9.4/144

Riggoli Scoob......1200/650.............9.2/147..........9.1/147

All pretty close using the +8% ET for manual cars :) So what can we expect at Scooby shootout ;)

Mr X Scoob.........1320/500...........11.3/130

Mr Y Scoob.........1320/550...........10.9/134

Mr Z Scoob.........1320/600...........10.5/139


I can't wait :D

Andy

[Edited by Andy.F - 9/23/2003 8:27:47 PM]

[Edited by Andy.F - 9/23/2003 8:29:06 PM]