How strong is a RX7 gearbox?

[OldNathan]

Any info on the strength of a series 5 13B turbo gearbox?

Reason I ask is I have one sitting in my shed and I found this the other day on the interweb...

The guy says he got it in the car how it was, and that the builder had the same setup in a race car for 9 years!

Wondering if its worth getting an adapter and making it work if it is strong as I have seen the adapters on ebay believe it or not. So must be a little bit common? If its no different to a W55 I'd rather do that. But if it is say about as strong as a W58 then might be worth it.

Please remember I have this box in my shed. Im not going out to buy one.

Nathan

[fuel]

strength difference between W55 and W58 isn't that much different - it's just that the W58 will more likely have the steel sandwich plate as opposed to the alloy plate.

The S5 RX-7 box is commonly used as conversions on Mitsubishi Starions and seems to hold up fine behind 300-400+hp DOHC 4G63s. Judging by the size I would say they are probably on par or slightly stronger than W55/58. I would probably use a W55/W58 and keep it all Toyota if possible.

I guess it all comes down to which ratios of each gearbox you like the most.

[OldNathan]

Thats true I didnt think about the ratios. I might look into that and see what the difference is between the toyota boxs.

It does look a decent size compared to my current W50 behind my 1UZ haha

[Dell'orto]

Synchros dont appear to be that flash in them though. My one was shagged after not huge amounts of k's...no idea on its history though

[oldmatedan]

just smash it in an try it its all ok

[Sorensin]

this strong |_______________|

sorry back to your actual helpful posts now!

[nothingsfree]

Dont bother. You can buy aftermarket bellhousings for 1uz to W gboxes.

Having had both gboxes, I would much prefer a W.

With new shifter bushes, the W is quite a nice shifting box, rx7 gboxes can handle similar power, but the syncros are shit.

[shizzl]

they are as strong as your driving ability and whether or not you actually give a crap about your car..

if you spent 99% of the time hammering it into gear and dumping the clutch,then any gearbox will die eventually.

s5 boxes can tolerate alot of power through them....

i know a guy who has a 13bpp and went through 2 w series boxes in a week..so he went back to a s5 box and still going sweet after 2 years..

[OldNathan]

Thanks for the inputs. I do know the ins and outs of bellhousings and adapters and the ease of getting them, so it only comes down to the strength of the box compared to a W. There are obviously cons, as adapter, redoing driveshaft yoke and shifter points. But if all that came to cheaper then a W58 and a $600 bellhousing then I would look at the RX7 box.

[danger]

Meant to be pretty damn strong I've seen them take a lot of abuse.

Think they were modelled on the old ribbed rotary 4 speeds which were pretty tough too

The turbo boxes are supposedly significantly better than the NA ones as well.

[morkster]

Seen a few stripped gears (hooking 3rd on boost burnout mostly). Depends how you treat them, you can ruin almost anything if you try hard enough.

[OldNathan]

Thanks Danger. Good piece of info there. I might continue to look into using and take some measurements over the pit.

I could make a W50 last longer then a R154, all with how I treated it. But its well know the R154 is stronger. All relative really.

[sentra]

s4/5/6 gearboxes are gay to rebuild compared to toyota stuff.

[OldNathan]

Thats a good point. If I look into the far future and blow whatever I have in the car I have to take rebuilding into consideration. Would be harder to find parts to I would imagine. Noted.

[Bombsquad]

Personally id go W series, ive had heaps of rx boxs and agree with the comments posted above, power wise they handle well but the synchros do wear out. I havnt rebuilt a w box but have done a heap with the rx and found then pretty easy and most parts are interchangable with other mazda boxs of the same year (eg s1/2/3, 626, 323, bongo etc. s4/5 rx and mx5. Also rx8 6 speed boxs are aparently the same as altezza)

If you want a w55 I have one ill be selling at some stage as I need a 58 for the remote shift tailhousing setup

[OldNathan]

Thanks for the info mate. How much for your 55? Im still deciding that if I am going to do a box change from W50 to 55/58 I might hold out for a 58. All depends on what a 55 comes up for though.

[Bombsquad]

afaik the only difference between 55 and 58 is the ratios/gear lever position and the price tag, which seems to be $600 bux extra for no reason. If you do end up buying a 58 and for some odd reason you need to change the shifter position id love to buy the 58s remote shift setup. Otherwise make an offer for my 55 i guess

[Requiemk]

rotaries = higher revs = increased synchro wear.

[brind0g]

Well its probably a bit late! But thats MY SETUP!! haha yeah the gearbox has lasted about 15 years behind the 1uz.. finally went last night, and im pretty sure its the syncro's that went too.

So on the hunt for a new box... Considering I did give it a hard life for the 5 years I had it.. Not surprised that it finally went...

Gear ratios are meant for a rotor, so maybe a W series would be better?? Im going to stick with another S5 box only cause its easier and i just put in a new clutch lol

[SHGWAG]

Well its probably a bit late! But thats MY SETUP!! haha yeah the gearbox has lasted about 15 years behind the 1uz.. finally went last night, and im pretty sure its the syncro's that went too.

So on the hunt for a new box... Considering I did give it a hard life for the 5 years I had it.. Not surprised that it finally went...

Gear ratios are meant for a rotor, so maybe a W series would be better?? Im going to stick with another S5 box only cause its easier and i just put in a new clutch lol

I have a S5 turbo box sitting in my garage that my brother's trying to get rid of.

He was trying do sell it with the engine, but may let it go separately fi your're interested?

PM me if you want it and I'll get in touch with him.