Does a 3.7:1 diff exist or can I not count?
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Ive counted so many times.. I even painted the tooth I started on.. Ill post the pics..
David
David
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From: SSO2003 2nd, SSO2005 1st, SSO2006 2nd, TACC Rd4 5th 4wd: In my car ;-)
David,
Just looked up the "Impreza" service manual, and they list two rear diff's wth 3.9's in.
1) 1600/1800cc "VA" type pt.no on case, or lable ends in "XF"
2) 2000cc non-turbo, "T1" on lable or case.
Apart from making sure what you have is as strong as the sport 3.9, 3.7 may just give you that "edge" you were looking for, for top speed
Mark.
Just looked up the "Impreza" service manual, and they list two rear diff's wth 3.9's in.
1) 1600/1800cc "VA" type pt.no on case, or lable ends in "XF"
2) 2000cc non-turbo, "T1" on lable or case.
Apart from making sure what you have is as strong as the sport 3.9, 3.7 may just give you that "edge" you were looking for, for top speed
Mark.
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Thread Starter
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Mark do you mean the 3.7 in you first sentence??
Will ring you to discuss tomorrow..
David
Will ring you to discuss tomorrow..
David
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From: @Junc 12, M40 Warwicksh; 01926 614522 CV33 9PL -Use 9GX for Satnav. South Mids Alcatek ECu dealer
Guys Don't forget that Uk cars have different ratio diffs front to rear because the step off from front to rear is at 1.1 : 1 rather than 1:1 like the JDM versions. SO I reckon that if the rear diff is 3.7:1 then the front will be 3.9:1
Don't even think about asking me WHY ???
David
Don't even think about asking me WHY ???
David
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From: SSO2003 2nd, SSO2005 1st, SSO2006 2nd, TACC Rd4 5th 4wd: In my car ;-)
David (API)
I think you'll find that the UK rear diff' is a 3.54.
Andy,
I guess we need to know what the diff' has come from. The "myths" are based on "Impreza" ratio's. If you want to include Legacy's, Justy's, Foresters, SVX's, + a few more, then I guess we find one, or two other ratio's we weren't aware of
Mark.
I think you'll find that the UK rear diff' is a 3.54.
Andy,
I guess we need to know what the diff' has come from. The "myths" are based on "Impreza" ratio's. If you want to include Legacy's, Justy's, Foresters, SVX's, + a few more, then I guess we find one, or two other ratio's we weren't aware of
Mark.
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From: @Junc 12, M40 Warwicksh; 01926 614522 CV33 9PL -Use 9GX for Satnav. South Mids Alcatek ECu dealer
Yeah Yeah Mark, I agree, but if the rear on a UK is 3.5 then the front will be 3.7 - don't you think?? Then you could have 3.7 front and rear if you used a JDM 1:1 step off.
David
David
Probably for sustained hi speed cruise temperature issues, particularly as it's not a 'UK' ratio but a 'Euro' model ratio...don't forget the official Skyline imports had oil coolers fitted on the transmission becasue of the higher sustained cruising speeds in Europe.
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From: SSO2003 2nd, SSO2005 1st, SSO2006 2nd, TACC Rd4 5th 4wd: In my car ;-)
David,
Just to put a spanner in the works, be it a very useful one, according to the latest service manual, the UK STi7 has 1.1:1 drop gears !!!! Whilst the Jap spec' have 1:1.
This would imply that you would actually need a 3.54 rear CW & P, but I would confirm this.
Mark.
Just to put a spanner in the works, be it a very useful one, according to the latest service manual, the UK STi7 has 1.1:1 drop gears !!!! Whilst the Jap spec' have 1:1.
This would imply that you would actually need a 3.54 rear CW & P, but I would confirm this.
Mark.
Although it doesnt go into much detail, the Subaru website only mentions a 3.9, even for the UK car.
UK sti 6speed
Still doesnt explain, where the 3.7 comes from ???
UK sti 6speed
Still doesnt explain, where the 3.7 comes from ???
Thread Starter
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
FFS ARGH..
Im off to park a car on my head
Why is nothing ever simple..
**** it may just run FWD.
Im off to park a car on my head
Why is nothing ever simple..
**** it may just run FWD.
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David, check the gearbox first, in any gear compare front drive shaft turns to rear output shaft turns.
If the drop gear is 1:1 then it should be a 3.9:1 ratio, if it's a 1.1:1 it should be 3.545 (not 4.29 which is backwards) I think, brain's a bit slow this morning
Paul
[Edited by Pavlo - 4/16/2003 10:59:16 AM]
If the drop gear is 1:1 then it should be a 3.9:1 ratio, if it's a 1.1:1 it should be 3.545 (not 4.29 which is backwards) I think, brain's a bit slow this morning
Paul
[Edited by Pavlo - 4/16/2003 10:59:16 AM]
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The 3.7:1 rear diff is indeed listed in the Impreza service manual, which kinda implies that it does exist and that it is fitted to the Impreza. It didn't list which Impreza it was fitted to, I guess that I'de need to look at the spec sheet for each model and see if I can find it.
David,
Finding a 3.545:1 rear diff is easy, it's a stock UK rear diff, and there's plenty of them about at breakers yards! With regard to figuring out if it's a 1:1 or a 1.1:1 drop gear in your transfer case, pop the box into a high-ish gear and take note of the positions of the front and rear outputs... it is useful to turn the two front shafts so that the holes are parallel, you'll see if there has been any relative motion in the front diff later... turn the input so that the fronts turn once. If the rear has turned 3.9 times then it's a 1:1, or if the rear has turned 3.545 times it's a 1.1:1
Cheers,
Pat.
David,
Finding a 3.545:1 rear diff is easy, it's a stock UK rear diff, and there's plenty of them about at breakers yards! With regard to figuring out if it's a 1:1 or a 1.1:1 drop gear in your transfer case, pop the box into a high-ish gear and take note of the positions of the front and rear outputs... it is useful to turn the two front shafts so that the holes are parallel, you'll see if there has been any relative motion in the front diff later... turn the input so that the fronts turn once. If the rear has turned 3.9 times then it's a 1:1, or if the rear has turned 3.545 times it's a 1.1:1
Cheers,
Pat.
Thread Starter
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From: Leeds - It was 562.4bhp@28psi on Optimax, How much closer to 600 with race fuel and a bigger turbo?
Forgot to post on here...
I have erm obtai... seen the my02/03 service manual and had a look at the information for the 6MT box.. and the uk cars run a 1.1:1 transfer.. the australian model runs a 1:1...
David
I have erm obtai... seen the my02/03 service manual and had a look at the information for the 6MT box.. and the uk cars run a 1.1:1 transfer.. the australian model runs a 1:1...
David
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From: Kent in a 396bhp Scoob/Now SOLD!
OMG 
, Im getting Deja Vue and thoughts of RWD Escorts from my youth with all these diff options being the same numbers.
3.54
3.77
3.90
all we need is a 4.12 and a 4.44 to complete the match
, Im getting Deja Vue and thoughts of RWD Escorts from my youth with all these diff options being the same numbers.3.54
3.77
3.90
all we need is a 4.12 and a 4.44 to complete the match