Hi and thanks to all in advance,fingers crossed someone may know the figures i am looking for.The following is what i require for a MY98 Subaru impreza turbo:1 vehicle weight 2 hp min speed 3 hp max speed 4 hp drivetrain loss 5 rolling resistance 6 drag cda

 

Doing some maths then?

My 97UK car with me & full tank is 1380Kg (Kerb weight stated as 1235Kg)

I use 24% drive train loss (19% rear drive only 15% front drive only) as 'average' estimate from a few googled sources

211bhp at 5600rpm, I think it's 24.1mph/1000rpm so this is 135mph, but you would expect to go slightly quicker than this. I got to 5800rpm as standard, 140mph near as makes no difference and I think top speed is quoted as 144mph so 5975rpm. (I was a little nervious flat out )

cD I use 0.33 again only from googled sources, I've not see one stated by Subaru, but it's pretty brick shaped so can't imagine it's going to be that good and if you have wing on the back it's not going to help either.

Rolling resistance? If you have long enough hill, you can work it out by coasting at constant speed and work backwards as my Dad KEEPS telling me.

Personally I bought a road dyno.


Aftermy 1st set of mods my personal top speed increased from 140 to 150mph and the maths I did with the power figures I got from my road dyno matched very closely, so the figures I used must be within a few %