Decreasing 5th gear in a sj413 gearbox

For all Suzuki related topics
Post Reply
Bazooka
Driver/Navigator
Posts: 32
Joined: Sun Aug 23, 2009 8:03 pm

Decreasing 5th gear in a sj413 gearbox

Post by Bazooka »

Just brought a 1.5 diesel starlet, the future engine for my 87 413/Jimny1300. I was just doing some gear calculating, planning to go 33" tires (32 x 9.5 simex’s) and I will run them on 3.909 diffs and 4.15 transfer gears. Everything looks good gear and speed wise up until we hit top speed, because of the low red line of the diesel engine compared with the 1.3 at 3000rpm I am only doing 95kph, I would like to cruse at 100kph doing 2800rpm so I need the 5th gear to be around 0.700 not the stock 0.795 or any of the later ratios like 0.975 or 0.864. Anyone know the best thing to do, bigger tires :wink: or can I get my 5th gear lowered, is it possible to lower the 5th gear? The engine will be going in mid next year but I would like to have the transfer, diffs and gear box all ready by then. The engine when it is rebuilt turbo intercooled should run pretty close to 56kW (75hp) and 150 Nm (110 ft lbs) so it has the power to do the job, I just don’t want to run it with the rpm to high.

Anything I have missed? I am new at all this Suzuki modifying thing. :mrgreen:
User avatar
badnuz
Hard Yaka
Posts: 2367
Joined: Sat Aug 11, 2007 12:00 pm
Location: Melbourne
Contact:

Re: Decreasing 5th gear in a sj413 gearbox

Post by badnuz »

trailer it everywhere???? 8) :mrgreen: :lol: :roll:
i used to Cruise, now i PATROL
User avatar
IcedJohnno
Trailer Trash
Posts: 821
Joined: Tue Oct 11, 2005 12:00 pm
Location: Christchurch nr the hills

Re: Decreasing 5th gear in a sj413 gearbox

Post by IcedJohnno »

Give Don a call at
The Machine Shop in Christchurch.
He specialises in modifying gearboxes for close ratio, race and endurance rally applications.
He can also do wide ratio applications.
Some of his big Toyota boxes are now running upwards of 450hp through them. They have completely new innards in them with wider gears, stronger shafts and almost all gears are different ratios from stock.
He will make you any gears to suit, including lower transfer ratios or your wider ratio 5th.

He also is currently making bellhousings to suit various applications.

Call Don at The Machine Shop on 03 374 6184
or cell 0273 495 089.

I work with Don on projects regularly and thoroughly recommend him and his work.
Bazooka
Driver/Navigator
Posts: 32
Joined: Sun Aug 23, 2009 8:03 pm

Re: Decreasing 5th gear in a sj413 gearbox

Post by Bazooka »

Thanks IcedJohnno, just the reply I was after. Do you know if he has a waiting list? Will probably get it done early next year.
User avatar
IcedJohnno
Trailer Trash
Posts: 821
Joined: Tue Oct 11, 2005 12:00 pm
Location: Christchurch nr the hills

Re: Decreasing 5th gear in a sj413 gearbox

Post by IcedJohnno »

No Probs
Figured if you had gone to the trouble of working it all out, then you were probably interested in the result.

Give Don a call, I'm not sure what his wait time is.
Post Reply

Return to “Suzuki”