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Location:
Lost in the K hole
Registered:
May 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Fri, 10 September 2004 11:37
 
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unless it reacts like an 8L S/C V8 on methanol @ 1200rpm...
*meh*
im not even happy with my own car dude, youre not competing for my love with it!! 
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Registered:
June 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Fri, 10 September 2004 15:14
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Well, as much as I'm enjoying this, I should probably lay it to rest by stating that my intended use is:
1) a daily driver
2) a weekend runabout along the old pac highway
in that order.
Although I would love a track & sprint car, realistically I don't think I could put my baby through that kind of torture on a weekendly basis, and still expect her to keep plodding along doing 500 work kms per week, without incurring massive maintenance costs.
I reckon I'll save up till I can afford a dedicated track & sprint car (read: years away), and then outfit that girl with a lovely little dog-box & uber-tight 4.5:1 LSD 
-J-
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Location:
Brisbane
Registered:
July 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Sat, 11 September 2004 00:05
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i havent read all the other posts... but
ive got a 3.9 ma61 manual lsd in my soarer with an r154 box
2nd gear see's 95 km/h
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Registered:
June 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Sat, 11 September 2004 15:04
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That sounds about right to me.
My 7M comfortably goes to about 5,000 rpm, whereas the 1J comfortably goes to about 7,000+ rpm
Which is why I hit 70 in 2nd, instead of 95
-J-
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Location:
Brisbane
Registered:
July 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Sat, 11 September 2004 23:58
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| joorsh wrote on Sun, 12 September 2004 01:04 |
That sounds about right to me.
My 7M comfortably goes to about 5,000 rpm, whereas the 1J comfortably goes to about 7,000+ rpm
Which is why I hit 70 in 2nd, instead of 95
-J-
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hehehe
too many changes
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Location:
sunny coast, qld
Registered:
October 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Sun, 12 September 2004 01:36
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just to add a little to the topic: my car has a a 4.6:1 diff in it (1jz-gte & a340e). Obviously it will be different compared to all you manual guys but I have found it to be quite alright. Didn't rev all that much on the highway, got pretty good fuel economy and revs out extremely quick.
I don't know if it is because of the smaller non sequential turbos on my 1jz compared to Norbie's 2jz, but I really hadn't noticed anything like what he said regarding running out of revs before having to change gears. But I suppose the a340e would have a longer first being a 4 speed auto.
anyway, that is all
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Location:
Brisbane
Registered:
May 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Sun, 12 September 2004 07:32
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Autos are a totally different kettle of fish... they're much better at loading up the engine at low speeds.
They also have a much taller overdrive than the manuals, hence you can get away with short diff gears.
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Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Sun, 12 September 2004 08:21
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Ed - please follow your own rules with regards to posting ON TOPIC in the Tech & Conversions section. 
ESPECIALLY on such a topic as that 
FWIW - Pimpboy has a 4.11:1 diff centre and hits over 100KPH in 2nd easily. I think for the sake of the argument, a short diff is good for an NA engine, but not so much for a torque monster turbo engine - who needs gearing when you have turbine compression?
Any engineer will tell you that in terms of torque reproduction, lowering RPM and increasing gearing loads yeilds more benfits from a turbine than decreasing the gearing loads to increase RPM.
ed, quit being a dong and let it be man, not everyone has your tastes of diff usage. 
Now im walking away frolm this one....
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Location:
Adelaide
Registered:
September 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Sun, 12 September 2004 22:07
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| joorsh wrote on Fri, 10 September 2004 16:12 |
Well, after this gargantuan rambling diatribe, I think I'm going to look into a 3.5:1 diff. Is there a car out there I can pinch these ratio's from, or do you think I'm better off going for a new set? And what am I looking at price wise?
And Norbie - where did you pinch your diff from and how much did it cost you (If you don't mind me asking)? I presume it's LSD?
-J-
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Hi Josh,
I have a 3.58 that I bought off Blake, and following Norbs lead, will probably oput thgat behind my engine. I'll start off with the 4.1 that is in the car at the moment and see how it goes.
The 3.58:1 is from a Manual RA65 Celica if I am not mistaken. There is a post in the Tech section strated by CLG re what F Ratios came in what cars
Cheers
Michael B
PS I have an Excel sheet that you can plug in the numbers to, PM me an email address and I'll send it to you
Oh, and don't forget the impact of tyre size on the whole equation
[Updated on: Sun, 12 September 2004 22:14]
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Location:
Perth
Registered:
October 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 03:53
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OK, I don't really have anything 'original' to add to this thread - just confirmation of what is alreay above.
I have a 2JZGE W-58, F-series 4.11 diff and 1JZGTE MA61. 1st gear is almost redundant and I use 5th on backstreets regularly. I was on the freeway on the weekend doing 100knh and around 3,300rpm (at a guess - haven't got tacho booster yet).  Very loud, expensive and irritating!
Before chucking the Truetrak centre in, I will also be hunting for lower ratio gear.
Justin
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 08:30
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| Celia-Sue wrote on Mon, 13 September 2004 11:53 |
I was on the freeway on the weekend doing 100knh and around 3,300rpm (at a guess - haven't got tacho booster yet). Very loud, expensive and irritating!
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2750 actually.
Get a 3.727, it will drop to 2500 or there abouts.
Thats what I plan to do.
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Location:
Barossa valley SA
Registered:
January 2003
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Location:
Brisbane
Registered:
June 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 08:36
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most supras etc are designed to run @ 3000RPM @ 110KM/Hr is what ive observed. My ma70 auto does it, and my ma61 manual did it
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Location:
Perth
Registered:
October 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 08:45
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| CrUZsida wrote on Mon, 13 September 2004 18:30 |
| Celia-Sue wrote on Mon, 13 September 2004 11:53 |
I was on the freeway on the weekend doing 100knh and around 3,300rpm (at a guess - haven't got tacho booster yet). Very loud, expensive and irritating!
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2750 actually.
Get a 3.727, it will drop to 2500 or there abouts.
Thats what I plan to do.
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Me too! It sure sounded like more than 2,750 - and felt very very WRONG
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 08:53
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| Celia-Sue wrote on Mon, 13 September 2004 16:45 |
| CrUZsida wrote on Mon, 13 September 2004 18:30 |
| Celia-Sue wrote on Mon, 13 September 2004 11:53 |
I was on the freeway on the weekend doing 100knh and around 3,300rpm (at a guess - haven't got tacho booster yet). Very loud, expensive and irritating!
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2750 actually.
Get a 3.727, it will drop to 2500 or there abouts.
Thats what I plan to do.
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Me too! It sure sounded like more than 2,750 - and felt very very WRONG
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Well, by maths, using a w58 5th gear (0.783), diff of 4.1, and rotary tyre length of 627mm, you should be doing 2750ish at 100kph
My W57 (0.861) does 3000rpm at 100kph, with a 4.1 diff.
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Location:
Perth
Registered:
October 2002
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Re: 7M-GTE MA61 rear Diff choice?
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Mon, 13 September 2004 09:00
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Hmmm ... makes sense <scratches head> ... it just sounded and felt so very wrong.
Only other variable is the engine and it's ability/desire to rev. Do you know what Soarer's (ie 1UZ's and 1JZ's) 100kph cruise would be in RPMs?
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