3.73's in my supra.

[trappd-in-859]

Will putting 3.73 gears in my supra(replacing the 4.30 gears) make any noticeable difference in performance?

I asked this question on i-supra but didnt really get a clear answer.

Also, will an lsd make acceleration better over an open diff?

TIA for all answers.

 

[pugarex]

smaller gears= better fuel economy.
i dont know about performance though.

 

[97hatch]

it will make it slower i would put in a 4.88 for faster acceleration and 3.73s for lots of top end speed if you are toping your car out and need more gear

 

[Cashizslick]

With 3.73's ur car is gonna feel like death.

 

[reikoshea]

yup gas mileage will go up and your car definitely wont feel as fast (but youll have a better top speed).

 

[trappd-in-859]

Ok cool, so 3.73's are out. Would putting 4.88's in my car drop my top speed by alot?( top speed for me is like 130mph) Also, how hard is it to put in new gears? How much should a shop charge to put gears in?

I figure since I have this car I might as well try to make it as fast as I can without breaking the bank. Supras of any year are pretty rare around here so I want to keep this car.

(thinking of a turbo engine swap down the road with a metal head gasket to help curb the infamous blown HG associated with the 7mgte.)

 

[reikoshea]

why are you paying a shop to do it...its about a 2-3 hour install (if you dont know what youre doing...30 minutes assuming you do). Its one of the easier things to do.

Is your car electronically limited at 130 or gear limited. I dont know what the difference would be if its gear limited...id say youd top out at 110 but youd get there hella quick.

 

[Celerity]

<cracks knuckles>

LSD - not a problem. Most of the Supra rear ends you'll run into are LSD from the get-go. Factory, you have several choices, including Cressida gears, Soarer gears, and older Celica gears (If you're N/A, 7MGE)

Longer gears are nice. I wouldn't mind them, but consider what you're actually doing. You're building a car that will be in daily ranges (50-100 mph) not a OneLap car (160-180). The longer gears will be real nice on the highway, but think if this is really where the car is spending most of it's time.

The shorter gears will also be nice, but the turbo will get hot with spirited driving (I say this mostly from personal experience).

My stock 87 topped out at it's ranged 150 mph. It had the .. lemme think... 1:4.08 (? Clayton ?) in it.

Off the line wasn't too bad (welcome to real torque) but moving all of that mass wasn't helpful on the overall strain of the motor, the gas use, and driveability.

 

[trappd-in-859]

So basically what youre saying is that if I stay N/A, I could benefit from shorter gearing. But if I were to do a turbo swap, shorter gearing would heat the engine up too much, and the negatives would outweigh the benefits?

Would you say that the stock 3.93's that came in the 87-89 turbo would be ideal for that particular application(turbo)? Or, would keeping the N/A 4.30's with a turbo engine be the best?

 

[Celerity]

Quoted post[/post]]
So basically what youre saying is that if I stay N/A, I could benefit from shorter gearing. But if I were to do a turbo swap, shorter gearing would heat the engine up too much, and the negatives would outweigh the benefits?

Heat up the turbo. It also wouldn't stay in it's effective range long enough with shorter gears. Not long enough for sporty road driving. Drag racing and brackets - Sure.

Would you say that the stock 3.93's that came in the 87-89 turbo would be ideal for that particular application(turbo)? Or, would keeping the N/A 4.30's with a turbo engine be the best?

I'm sorry.. N/A turbo engine ? I'm confused. You said 7MGTE before - I assumed you have a turbo, with the 4.30 gears from the factory (Which sounds about right for the 6 speed cars). The Turbos have shorter gears in the transmission, but only slightly and the rear is the same as the others. If you want this long gearing in the back you'll need to consider the rear from the SC300.

 

[trappd-in-859]

Sorry about the confusion. I have a non turbo 7m. What Im asking now is if I were to swap the 7mgte engine and trans into my non turbo supra, would retaining the N/A gears be better than going with the 3.93's that come stock in the turbo car?

Thank you for all of your help and most of all, patience with my many questions.

 

[Celerity]

In my opinion, YES.

Make sure you have the LSD though.