Engine Specs For Historic Road Rallying.
#1
Posted 17 September 2017 - 06:15 PM
I'm building a car for hrcr road events. I'm running a metro cam, which is perfect for low down revs which is what I need in the tight and twisty tests. However I'm struggling to stay in first, every other car I have watched seem to be able to stay in first all the way around a test, mine I would find I'm having to change into second because I'm running out of puff. I'm running a completley std box, with 3.4 diff. Any recommendations on what I can do to help this?
#2
Posted 17 September 2017 - 06:17 PM
what gearboxes and final drives are the others using?
any issue using second?
#3
Posted 17 September 2017 - 07:50 PM
What size wheels?
#4
Posted 17 September 2017 - 08:06 PM
#5
Posted 17 September 2017 - 08:08 PM
then change your final drive.
#6
Posted 17 September 2017 - 08:41 PM
What speed are you changing up?
What spec is your head and rocker gear? Engine lightened and balanced with main centre strap?
#7
Posted 17 September 2017 - 11:29 PM
The SC gear set used by most competitors has a very high 1st gear. With a 3.9:1 FDR and the use of 7000 rpm it is possible to stay in 1st for a lot of very tight tests.
However, with a standard box and an MG Metro cam the 3.44:1 FDR should be fine, so long as you use around 6500 rpm. If you go any higher with the FDR you will lose a bit of acceleration through all the gears.
One alternative would be to use a set of the original Cooper 'S' gears and a 3.44:1 or 3.76:1 FDR. They are slightly closer in ratio than the standard gear ratios.
0 user(s) are reading this topic
0 members, 0 guests, 0 anonymous users