[sqweaka]

could some maths expert work my gearing out for me?
got a mk2 ford consel rear end which is 4.11 i believe and i want to run 8.20 crossplys on the rear that are 28" tall i believe
i'm wanting to know what rev's the V4 will be pulling in top.... what other info do you need to work this out?

hope this makes sence

ian

 

[chevy2]

with that info, assuming the trans is 1-1 in top, not an overdrive trans,
not allowing for converter slip is 20.28 MPH per 1000rpm,
40.56 mph at 2000rpm,
60.84 mph at 3000rpm.
add 20.28 mph for every extra 1000rpm thereafter.

 

[30psi]

Just did it as well and made it 20.38mph per 1,000rpm with the same assumptions as chevy2

 

[sqweaka]

wow thats quick so thats 70.98mph at 3.500 revs
that sounds useable to me what do you guys think?

 

[30psi]

Thats not that bad I guess, assuming your engine can rev? Be annoying if it maxed out at 5,000rpm

For example, one of my cars 'Datsun No.2' revs at 4,800rpm at 80mph (max rpm is 6k). So for a fast cruise it's crap, but 'Datsun No.1' does 3,000rpm at 70mph, but revs up to 8k.

 

[chevy2]

honest opinion?
had 3.73 gears with 26" tyre on the Nova,
also did around 3000 @ 60mph,
fine for around town and dual carriageways, but on a longish run 3500 @ 70mph gets old real quick, keep wishing there was another gear,
not to mention hard on the motor and fuel:tdown:
never really found the benefit as my car is small tyred so ALWAYS blew the tyres away with the 3.73s, would only have found the gain on slicks or drag radials,
gone back to the original 3.08s now,
far more street friendly, around 2450 rpm @ 60mph,
it still ALWAYS blows the tyres away:tup:

 

[sqweaka]

just done some more googling on the tyres i want to use and have come up with a diffrant dia.... 29.5" that will change things
think i need to get someome to measure up and give me a correct tyre hight!
8.20 x 15 firestones

 

[chevy2]

just done some more googling on the tyres i want to use and have come up with a diffrant dia.... 29.5" that will change things
think i need to get someome to measure up and give me a correct tyre hight!
8.20 x 15 firestones

not a great difference,
29.5" tyre will be 21.36 MPH @ 1000 rpm.

 

[100ev8]

click this link and download the gearcalc zip at the bottom .

http://locost7.info/gearcalc.php

some usefull stuff at the side of the page as well

rob