[Ross]

What do you guys think would be the optimum diff ratio for a slightly modded 7M-GTE at the dragstrip?

And what about a more highly modified engine, with bigger turbo and probably a stand-alone computer?

Would you want to go to a higher (say 3.4 or 3.5:1) ratio with a more highly modified turbo engine?

 

[Supra Bob]

I would want to go with a higher ratio, though not too high. Higher ratio's are good because they place the motor under more load... which in turn makes it produce more heat... which makes more boost, sooner. However, go too low and your gonna end up hurting your acceleration... I'm planning on using either a 3.73 or a 3.90 on my 5M-GTE.

 

[williamb82]

well, i would go with at least a 3.727. i have broken 2 4.30's and have a 4.1 in the car now. at 10 psi i can break traction at the top of second gear on the street. imo the tires spin way too easy with even a 4.10. im going to install a 3.727 with my true trac when i can get to it. hth.
william

p.s. my mods are 3in exhaust no cats, hks smf air filter and 60 trim ct26. thats all thats done to the motor.

 

[MikeD]

I agree that 3.73 diff is good. BTW, I'm still using a 4.30 diff which is a joke. My 7mgte mk2 has too many mods to list, 1st gear is useless. Just about any car can hang with me on the street in 1st as I can't boost without spinning, but once in 2nd, I can control traction OK (still not wot) and blow away just about anyone. 3rd & up is where I can go wot.
I gotta get 3.73, too. Hopefully, this would make first 2 gears more useful.

 

[Junkie]

Once you go TURBO,I don't think 1st gear is ever useful again :wink:
Especialy a modded 7mgte,I still hate 1st in Ophir's with the 3.42's. With 3.73's you should launch very well,just have to shift immediately,2nd will be a bit short but livable,3rd pulls real good,4th should put you thru the traps,with LOTS to spare.We had a set in O's car ,just didn't put the car in the right power band for thr road course,drags should be sweet. my .02

 

[ITSUKI Drifter]

I have a 4.10 LSD on my 1985 MK2 equipped with a 6MGTE and with a set of Mickey's Indy Profile Street/Slick Tires I still have problems with tires spinning in first and second gears... and the slicks measures 255/60R14 on stock Supra 14x7 rims.... That is by launching the car in 3000 rpm

Before that I have problems with spin even I was still N/A before just launching the car at 2000 rpm with the Mickey's

 

[Joseph]

I still hate 1st in Ophir's with the 3.42's. With 3.73's you should launch very well,

Where did he get the 3.42 R&P? And what do you hate about it?

I was looking at final drive ratios in other cars, check this out:

MK4 TT 6spd : 3.133 :shock: Auto: 3.769
350Z 6spd : 3.54
Porsche 911 6spd : 3.44
Corvette Z06 6spd: 3.42
BMW M3 6spd: 3.62

 

[Junkie]

3.42 R+P from mid 80's toyota 2wd truck. My personal opinion is 1st gear is still too short :twisted: Let out the clutch,then push it back in to grab 2nd,good for the length of time it takes to shift is all The only taller option,3.07,is just too tall a gear,and would be harder on the rest of the car.3.42 or 3.58 are great for street and road course.I liked the 3.73 on the street while under 300rwhp,but with more than that,IMO they are drag gears only.

 

[Joseph]

Say I got a 3.42 R&P, would I be able to get a compatible speedo drive gear from the donor truck? Did they use a W58 tranny? I think I saw somewhere that these R&P sets were still available from Toyota, anyone ever price these?

Thanks,

 

[SilverMk2]

I think I saw somewhere that these R&P sets were still available from Toyota, anyone ever price these?

Not sure about the 3.42 R&P but the 3.73 set is a smidge over $500 from Jeff Watson. I'd imagine they are all in the same ball park price range.

 

[Avp23]

about a rear diff

im up here in kirkland just 5 or 10 miles east of seattle and i paid 280.00 for my 3.73 rear diff. and that was at a store. these people really check out ther products before they put stuff on the shelves.

 

[Ross]

Once you go TURBO,I don't think 1st gear is ever useful again :wink:
Especialy a modded 7mgte,I still hate 1st in Ophir's with the 3.42's. With 3.73's you should launch very well,just have to shift immediately,2nd will be a bit short but livable,3rd pulls real good,4th should put you thru the traps,with LOTS to spare.We had a set in O's car ,just didn't put the car in the right power band for thr road course,drags should be sweet. my .02

I have a 3.909 ratio at the moment.
Do you think a change to a 3.7 would be noticeable, or should I wait until I am putting out serious horsepower / torque and go for a 3.42?

 

[Supra Bob]

Re: about a rear diff

im up here in kirkland just 5 or 10 miles east of seattle and i paid 280.00 for my 3.73 rear diff. and that was at a store. these people really check out ther products before they put stuff on the shelves.

What store was this, and do they have any more available?

 

[Junkie]

Once you go TURBO,I don't think 1st gear is ever useful again :wink:
Especialy a modded 7mgte,I still hate 1st in Ophir's with the 3.42's. With 3.73's you should launch very well,just have to shift immediately,2nd will be a bit short but livable,3rd pulls real good,4th should put you thru the traps,with LOTS to spare.We had a set in O's car ,just didn't put the car in the right power band for thr road course,drags should be sweet. my .02

I have a 3.909 ratio at the moment.
Do you think a change to a 3.7 would be noticeable, or should I wait until I am putting out serious horsepower / torque and go for a 3.42?

Personaly,Id leave the 3.9's until you get more turbo,unless you are already unhappy.I think Wde T is still running 4.30's,and likes them.Really,the guy driving it is where it mattters,unless it's being driven for competition,then you find what gets the job done

 

[Junkie]

Re: about a rear diff

im up here in kirkland just 5 or 10 miles east of seattle and i paid 280.00 for my 3.73 rear diff. and that was at a store. these people really check out ther products before they put stuff on the shelves.

What store was this, and do they have any more available?

Bob--I'm the guilty party Nix 99 I'll double check the stock and see if we have one stashed :roll: I'm sure we have a non-lsd 3.73,not sure of about one with.

 

[Supra Bob]

Heh.. Cool Shawn. How much for just the R&P? I can get another housing complete for $50 local, which would save shipping... and I think I may go tru-trak..depending on Williams reports on it.

 

[Junkie]

I'll see if I can find one from a truck.I would have to charge the same for the r=p as the whole Supra carrier.The r+p are the only real value.But,the truck diffy couldbe priced better.I'll see what I can do,but not till Monday,we actually get the weekends off.Saturday retail was not a benefit to the business,so we don't do it

 

[Supra Bob]

Weekends off!?!? Wow... have your boss talk to my C.O. please... lol.

Cool about the price on the R&P...I kinda figured that would be the case. I am just thinking more of the savings on shipping.

 

[WadeT]

I'm starting to really hate the 4.30s. Once the blue car is done, if ever, the 85 red car will get some 3.73s. Considering I have a F303 tranny code I don't have much of a choice! :wink:

In all fairness to the 4.30s, stomping the gas in 3rd at 35mph I swear I could own anything though 4th gear. Well, at least it seems that way, lol.

 

[usul42]

I got the last of the posters in today from the printer.

I'll wrap up the last of them to send out in short order and post somewhere randomly within the board to let people know when they ship.

Oh and it looks like I will have roughly 10 extras to sell when this is done with.

An announcement for that will also be posted randomly in the annals of the board.

Thanks for playing,
Sten