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Sierra LSD Ratio
shane159 - 26/9/15 at 06:42 AM

Hi Guys,

I've been contemplating swapping my diff for a LSD for sometime but I have no idea what would be the best ratio to suit my car?

I have a MK Indy with a 954 Fireblade engine fitted, the diff fitted at the minute has push fit shafts and is 7". I'm wanting to use the car for fast road/trackdays.

If anyone has a similar setup an could give me any info any help would be much appreciated.


snapper - 26/9/15 at 07:03 AM

You can only get the Sierra viscous LSD in 3.9 & 3.6
However you can change crown wheel and pinion from any Sierra diff and put it on the viscous part, this gives 3.38 & 3.14 as an option
I believe that your engine will top out at 110mph with a 3.6.
Use a gear speed calculator to crunch the numbers


PAUL FISHER - 26/9/15 at 02:09 PM

You will be fine with a 7" 3.62 Lsd, I had one fitted in my 929cc injected fire blade Indy, same gear ratios as the 954cc.
Mine would do 120+mph.

[img] me giving demo rides at oulton kit car live
me giving demo rides at oulton kit car live
[/img]


Matt21 - 26/9/15 at 08:13 PM

919 blade here
3.94 lsd
115mph (120 bouncing off the limit)

nippy acceleration mind!

7k rpm at 70mph on a motorway is absolutely brutal though!
good for smaller roads though

its all a compromise, each has positives and negatives, its just which you can put up with easier


shane159 - 28/9/15 at 09:19 AM

Thanks for the info guys.


Andy D - 28/9/15 at 10:31 AM

quote:
Originally posted by PAUL FISHER
You will be fine with a 7" 3.62 Lsd, I had one fitted in my 929cc injected fire blade Indy, same gear ratios as the 954cc.
Mine would do 120+mph.

[img] me giving demo rides at oulton kit car live
me giving demo rides at oulton kit car live
[/img]


Did the passenger forget to do up his chin strap Paul?