Coopz
|
| posted on 25/3/09 at 09:16 AM |
|
|
Sierra Diff
Ok, so I'm building the Indy with an O6 R1 engine. I got a donor package from mk and was supplied with a 3.62 open diff with push in driveshafts
which I've cleaned up and look good.
But now i'm starting to think I want a 3.62 LSD which obviously uses different driveshafts too.
Having never driven a BEC or in fact a CEC kit i'm just wondering what people think. What the main driving differences between the two diffs,
why is lsd considered better? Should I change now before I build any further?
Any advice welcome thanks toby
|
|
|
|
|
adithorp
|
| posted on 25/3/09 at 09:32 AM |
|
|
I think your first choice might be whether to go for a 3.38 diff. 3.62 might be a bit low geared. Do a search for ChrisGamlins gear calculator and
check out your revs at crusing speed and max in top when you hit the limiter.
LSD will give you better traction, especially in the dry, but can make things a bit tail happy in the wet.
adrian
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
smart51
|
| posted on 25/3/09 at 09:45 AM |
|
|
I have a 3.62 LSD on my 98 R1 BEC. It is fine for the road but peak power is at 103 MPH in top gear so on the track people overtake me back on long
straights. The 04 onwards R1s have even closer gear ratios so a 3.38 might be a better option. A 3.62 might do though, best to work it out.
The sierra LSD acts as an open diff if both wheels have grip, which is good. In a 1 wheel slip situation, such as powering out of a fast corner or
full acceleration in 1st on a road with patchy grip, the LSD sorts things out and lets you accelerate rather than just spinning 1 wheel. On surfaces
with less than ideal grip, the LSD makes you spin both rear wheels, rather than just 1, which makes the car a bit tail happy.
In comparison, an open diff also acts like an open diff when there's good grip. If one wheel spins, it raises a white flag and lets the wheel
spin. You don't get the acceleration but neither do you get tail spin.
Donuts are easier with an LSD.
|
|
|
A1
|
| posted on 25/3/09 at 01:46 PM |
|
|
ive got a 3.9 lsd in my indy, its okay, but im thinking of getting a 3.1 that i saw, for the extra top speed.
it is quite tail happy in the wet, but you just have to learn restraint!
|
|
|
