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

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

Andy

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

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