40 replies to this topic

[Gingerjoe]

my new 1275 block is gonna be around 85bhp, ac.dodd build.




there my pistons

[jameswildcooper]

mine is about 5ish seconds to 60. 140ish bhp

[Massey]

mine is about 5ish seconds to 60. 140ish bhp

wow what have you done to that ................

[mini_mad69]

not saying this is 100% but if you put the weight of the car in and the amount of HP it roughly works out some figures. Used this for my supra and its about right....

http://www.letstorqu.../calculator.asp

Ive used that, was about right for my mates ST fiesta, and gave my 1380 around the same figures as the ST.

But it doesnt take into account, aero dynamic drag, how much traction/tyres, It's very basic calculator.

[womwom]

not saying this is 100% but if you put the weight of the car in and the amount of HP it roughly works out some figures. Used this for my supra and its about right....

http://www.letstorqu.../calculator.asp

Ive used that, was about right for my mates ST fiesta, and gave my 1380 around the same figures as the ST.

But it doesnt take into account, aero dynamic drag, how much traction/tyres, It's very basic calculator.

So how much roughly does a standard clubman weight then?

[Paul Wiginton]

They claim Miglias are under 4 seconds, I know my Sprint is quicker than a Miglia with over 340hp per ton

[jameswildcooper]

mine is about 5ish seconds to 60. 140ish bhp

wow what have you done to that ................

running a supercharger aswell. should be a little quicker once i get my 13x8 alley cats on as i struggle to get traction with my 10x6s also needs setting up again so a little more power to come...

Edited by jameswildcooper, 02 March 2009 - 09:17 PM.

[tomkidd]

I think 1275 mpi minis were quoted at being 9.95seconds to 60. They are geared quite 'tall' for making motorway cruising easier, so I reckon a 1380 should be roughly at least 1-2 seconds quicker than that?

[JetBLICK]

My 1.2 managed to keep up with a 3.2 Audi TT up till about 3rd gear, which is way past 60, and they do 0-60 in 6.2sec in the book - so id say in reality my 0-60 is somewhere between 6-7 seconds. No doubt thats achieveable then with a 1380.

[The_Mistro]

So this 3.2 Alfa Romeo Brera does 0-60 in ther same time as a 1380 mini..

yep, 10.6 seconds for that alpha isnt it? you got to think of it more as power to weight ratio, and final drives, its all very well a car having 3000 odd bhp, but if it weighs 10 tonne, thats 300 bhp/tonne, where as a car with 1000 bhp that only weighs 2 tonne, has 500bhp/tonne so it should shift quicker! also if the gearbox is set up for top end speed, and one is set up for acceleration, the top end car is going to accelerate slower, but its top speed is going to be higher, so it all depends what you want from a car, i would say that alpha is set up more for a higher top speed than just acceleration! where as the mini prob wont go half the speed of the alpha, but will get there quicker!

[mike.]

Standard pistons won't last long with more than about 70bhp.

MMM what about the 90bhp conversion kits you get using standard pistions? They have more than 70 and last fine?

Good point. All I can say is that its quite well known that very few of the JCW conversions achieved the 90bhp they were meant to bring. Can't remember where I've read it, but I'm sure I've seen something by either AC Dodd, or Calver that says you should use standard pistons up to about 70bhp, then 21251s for between 70 and 90, 21213s over that, and much over 100 you should be really looking at Mega and Omega pistons.

hmmm I was hoping to make about 90bhp with my MG engine. Haven't really got the budget for new pistons and rings as well as all the other bits!

[Mattlav]

this is all very interesting i really want to get one now

[mike.]

Since its been brought back up again. Any other opinions on if i'll need uprated pistons to make a reliable 85-95bhp?

[*DJH*]

Don't forget when calculating the cars weight doing power to weight ratios that you must include your own body and fuel weight too.

[Karl.G]

Don't forget when calculating the cars weight doing power to weight ratios that you must include your own body and fuel weight too.

Usualy these calculators ask for the kerb weight which doesnt include that mate

Edited by Karl.G, 18 April 2016 - 01:46 PM.