Strengthening a Starion gearbox?

[Lummy]

Hi guys. I'm pretty new around here and also new to Starion parts. My car however is well known: I have Ashly's old Scorpion, the Improved Production car.

My problem is the gearbox. Ashly ripped 3rd gear out of one and I blew all but 4th gear out of another one recently.

I have another one in it now, but it's clearly a weak point for the car.

What are my options for ensuring this doesn't keep happening? Are there any after-market gearsets? Is a custom dog-box the only option?

Any help would be appreciated.

Lummy

[Mick]

hey mate good score on the car!

apparently 3rd gear is the big issue and the guy that used to run coltspeed said he got sick a breaking them so he machined the area out and added a way oversized bearing to third because it vibrates heavily under big loads.

anyway thats one theory.

if you have a twin cam a w58 supra gearbox can be adapted with a custom bell housing.

cheers

[www.18u]

First of all congrats on buying such a nice car :D
The three things i could suggest would be:
1. Try the b2600 bellhousing and rx7 gearbox conversion,
2. Try and fit a late model pajero gearset with wider gears and bigger bearings.
3. Switch to a Supra 5 speed.

Im sure there will be more people who can help on here but they are the the first things that come to mind.

Goodluck.

[FST4RD]

I'd go the B2600 bell housing and RX7 series 4/5 box conversion.
Straight bolt up apart from the driveshaft from memory, although JAS knows way more about it, he's attempting it at the moment slowley!
Plus there's a few 10sec RX7's running the factory box...

[MainstreaM]

Lots of good info on the mazda box here.

http://www.projectzerog.com/rx7transmissions.shtml

Kane

[WANTSOM]

I'm running the W58 box in the track car and not having any issues. Gearbox is rated to 300hp. The other plus wth the W58 is PPG make a close ratio gear set which gives you a 1:1 final drive. Expensive though at approx $8K for the gear set.

But who ever said racing was cheap LOL

[iXNAY]

has anyone on here actually put a late set of pajero internals into a gearbox?

and what sort of filthy price are we talking?

[cheaterparts]

My problem is the gearbox. Ashly ripped 3rd gear out of one and I blew all but 4th gear out of another one recently.
I have another one in it now, but it's clearly a weak point for the car.
Lummy

the joys of IPRA turbo cars - the restrictor in the front of the turbo tends to lend its self to producing HP low in the rev range and that mean super high torque loads
ie 1 Hp @ 5252 revs = 1 ft lb torque / 1 HP @ 2626 revs = 2 ft lb torque so I'm guessing that your engine is putting out around 300 Hp @ around 4000 = around 394 ft lb and that will go higher at max torque
prob at about 2000-2500 that could be another 100 ft lb
as with most of the larger turbo engines under IPRA ,gearboxs suffer big time

has anyone on here actually put a late set of pajero internals into a gearbox?
and what sort of filthy price are we talking?

I thought pajero and starion used the same gears
I could be wrong but its what I had been told

an adapted stronger gear box may be the way to go

[redzone]

RX7 box for sure, if thats a wideblock which it should be if its running starion boxes, then its an easy conversion

[www.18u]

Early pajero boxes are the same as starions but with narrower gears. Later pajero boxes use double syncros on 1st,2nd and 3rd and alot bigger bearings.

[cheaterparts]

RX7 box for sure, if thats a wideblock which it should be if its running starion boxes, then its an easy conversion

ash made up conversion plate to run a wide pattern on the small pattern block - thats from memory so could be wrong

[Lummy]

It's the engine from a VR4 Galant, so I believe it's not the wide block, and yes, it has a conversion plate to run the starion gearbox.

Does this make the RX7 gearbox idea a bigger hassle?

[redzone]

shouldnt be a drama if u use the adaptor plate, hard to say without being there and seeing it obviously though. if u can find a dellow bellhousing or modify a 2lt sigma borgwarner detachable one u might be able to go the supra option instead, without the adaptor plate.

[cheaterparts]

if u can find a dellow bellhousing or modify a 2lt sigma borgwarner detachable one u might be able to go the supra option instead, without the adaptor plate.

of cause if you use the small pattern you will need to change the flywheel and clutch presure plate to the smaller size
that could be a problem holding the torque

just as running a sigma or dellow use cable clutch ( these things can be got around ) but worth thinking about

[redzone]

true so the RX7 option would appear to be a winner then...