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  #1  
Old 24th July 2010, 08:08 AM
Eternal Eternal is offline
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Default Quick reply needed about dif/max speed.

Hi guys! found a smashing deal on ebay for a lsd 7.5inch diff thats local to me. Only problem its a 3.64 rather than a 3.9. The Diff tag reads 91 GG ADA 3.64 its fron a granny cossworth im pretty sure its a lsd and has 100mm flanges.

16's with 55wall, 3.32, 1.9, 1.31, 1.0 and .838. Final drive is 3.64
6400 redline
1st/37.8mph
2nd/66.1,
3rd/95.9,
4th/125.6,
5th/149.9

Would normaly be this in donor car
17's with 55wall, 3.32, 1.9, 1.31, 1.0 and .838. Final drive is 4.1
6400
1st/34.9
2nd/61.0
3rd/88.5
4th/116.0
5th/138.4

I think thats kinda insane as thats pretty fast top end but not good on acceleration? would rather it the other way around really as acceleration does not get you speeding tickets.
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Old 24th July 2010, 08:34 AM
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Is that just computed speed or taking into account drag?

Acceleration is gr8 so long as you can put it on the ground, with all the power and light weight you may find 1st gear to be unusable.

I am using a 3.64 behind a 150BHP V6.

TT
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Old 24th July 2010, 08:37 AM
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Ps. the 7.5" LSD should be between 200-250 normally. with 7"'s about 80 less...

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Old 24th July 2010, 08:38 AM
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Two things,the higher the number of the diff ratio the more acceleration ie 4:1/5:1, the lower more top end less quick acceleration and in any case the car weighs many times less than the old Granny but then factor in the aerodynamics of of a 600kg brick and you will have you top speed.

you will get to 60mph quicker than most exoctics costing 100,000 and more for a lot less money and much more fun.

Edit: as TT says getting it on the ground is the problem with such a light car.
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Old 24th July 2010, 08:39 AM
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true true just have to add the weight of a 2.5l turbo straight as well. Putting that power down is going to be trouble on the iva i know it! 260bhp+ rofl insane.

Great in that case i guess lower is probably better. I have just done something stupid..........

ford scorpio cosworth complete rear axle diff etc.....100!!!!!!!!!! umm i hope i can use it? Maby i was a bit brash but i thought the scorpio has the same drive shafts as the sierra? Dont have a clue what ratio it is of if its lsd but its from a cossy so cant be that bad..... at the very least i have the dif i want and can probably use the discs calipers ect.
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Last edited by Eternal : 24th July 2010 at 08:43 AM.
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Old 24th July 2010, 08:42 AM
flyerncle flyerncle is offline
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If there is no tag just divide the pinion by the crown wheel teeth and this is the ratio to 1.
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Old 24th July 2010, 08:54 AM
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It's a scorpio one not a Granada one so it will be 3.64 open not LSD.

Track is slightly wider on the scorpio too so the shafts may be longer.

TT
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Old 24th July 2010, 08:55 AM
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Hubs are 4 stud though which is better than the 5 stud Granny ones.

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Old 24th July 2010, 09:06 AM
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Nice will get it through the iva at least. Will have to send the shafts off to get shortened i guess but still good buy i think. Yeah the 4stud helps as it matches the sierra uprights. Shame about the shaft length but hay for 100quid cant grumble gives me everything i need to get on at least.
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Old 24th July 2010, 09:11 AM
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well the diff will sell on for 60, and the rear calipers,hubs and carrirers for 60+ too.

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