A long term 350hp/350ftlbs Transmission solution

[gooned]

Hi Realmers. I'm at the point where it's time to work on getting The Colt back on the track for road racing, (yes- it's not technically a 510 but it has the drivetrain from one), but I need to solve my long standing weak link - transmission.

Quick background on the setup, 2.4 LZ with SDS EFI and turbo running 15+ lbs boost on 115 octane, I never went more than two race weekends without shredding either a tranny or the roadster puck clutch. Was running the junkyard ZX 5 speeds with either .86 or .74 overdrive back when I could actually go buy one every month in the summer, set up with a pump & cooler to help keep the oil happy. Power is going through 25x14 slicks on a narrowed Toyota truck diff with torsen that'll pave in third coming off the fast corners

No I never dyno'd it but based on the stuff it breaks, injector duty cycle (and the competition it would out pull) we think it's good for 300-350 ftlbs and close on hp, the year it got parked for the new family commitments (talk about mixed emotions ) I had purchased the rare ZX turbo T5 but it's never been apart yet to start on a swap, I now doubt I will cut the car up to fit this monster bell housing when I really need a serious clutch anyway.

So what tranny to run

Love to hear any suggestions or

[bertvorgon]

Funny...James and I were talking about your transmission issues just yesterday.

I thought that the Supra tranny was the next step?!

[JordanTr]

30a trans will hold that all day. V6 Pathy and truck, Z31T, Z32, R32, and R33 could all be candidates for a tranny. Not sure what you'd do for a bell though.

Here's an adaptor for a Z33 6 speed trans to KA (and therefore L). I'm sure there are clutches that would hold 350 all day long for the Z33 box. The White Bunny clutch would probably do it as well and is super cheap.

http://collinsadapters.com/index.php/ad ... plate.html

[gooned]

Funny...James and I were talking about your transmission issues just yesterday.

I thought that the Supra tranny was the next step?!

Hey Keith, funny how life times these things eh?

Rob and I had talked years ago about w58 or R154 (think I ID'd those correct) as adapters are avail in Australia...they seem to adapt for everything over there. (I can bolt an LS motor to my 74 landcruiser...)
I'm also looking at the Gforce T5 with the upgraded gear set with syncros ( I'm convinced after talking to many that dog boxes have to open up frequently ) as it's rated for 400-500. But as Jordan has just pointed out there are many options that are not on my radar, hence the opinion taking & discussion.

Weight, parts availability, and strength are the big factors. Bell housing can be made or modified as it'd be a onetime cost.

One factor on my setup is that the motor & remote mount turbo with all the plumbing have to come out first to pull the tranny, it's a big job that wore us out years ago & I'm not getting any younger so I really want a robust solution.

[gooned]

30a trans will hold that all day. V6 Pathy and truck, Z31T, Z32, R32, and R33 could all be candidates for a tranny. Not sure what you'd do for a bell though.

Here's an adaptor for a Z33 6 speed trans to KA (and therefore L). I'm sure there are clutches that would hold 350 all day long for the Z33 box. The White Bunny clutch would probably do it as well and is super cheap.

http://collinsadapters.com/index.php/ad ... plate.html

Thanks Jordan,
Looks like big bell housing issue again, only it's part of the trans for what I can see, removable bell housing would make life easier...tough to see a firm comment on torque/hp rating after a quick google, you have any idea?

[OUTthere]

I like the idea AEM had in 2008 when they made a short run of bellhousings that mated a ka24de to a ford c4/c5. Wish I could find one it would solve half my problems.

[Byron510]

Jason, I know the Japanese and European transmissions generally have integral bell housings which may be an issue in your case due to their size. But what about North American made cars? There are some serious horse power OEM machines available today on the market at or over 500 hp, available with manual transmissions. In fact it's crazy what we can buy today off the shaft HP wise. These cars must have transmissions that would be suitable to your horsepower needs, but I don't know if they are geared correctly for your application. I know it's only an assumption and of no real use specifically. It used to be that the big three relied heavily on ZF and Getrag gearboxes for their manual transmission applications that did not have integral bell housings. But to be honest I have no idea who makes the current gear boxes available in cars today. Maybe calling around to local hot rod shops and strait line shops and ask these guys what they think of specific boxes and maybe get some applications to find them in.

Byron

[gooned]

Yeah I'm fairly certain I need a removable bell housing to make this fit, I'll chase down what the newer pony cars are running....thanks for chiming in Byron.
I did get a chance to talk to Jack at Mission about his setup, Ls powered rx7 with the viper six speed running aftermarket gears, he hasn't had it back out of the car since it went in. More tranny than I need for sure!

[Dave Patten]

Having started down the road of installing a G Force T5 gearbox, let me see if I can shed some light on what I found out.

The L28ET 280ZX used a T5 transmission. This Nissan T5 has a removable bell housing. The Transmission to bell housing bolt pattern on the ZX bell housing is the same as the Ford T5. So I mocked-up a World Class (WC) T5 from a Mustang to the 280ZX T5 bell housing with some minor modifications.

We needed to reduce the diameter of the front bearing retainer on the WC-T5 where it centers the transmission into the ZX bell housing. We also planned on using the complete Nissan T/O bearing system so we turned down the OD of the tube that the T/O bearing slides on so the Nissan T/O sleeve would work.

We did not get any further on the project. Where we were heading was to mate the ZX bell housing/T5 transmission with an adapter to an SR16VE engine, so further info might not be of much help anyway.

The clutch disc will not be a problem. Contact http://www.Clutchnet.com They can custom make a disc to match the outer fiction surface area of your flywheel/clutch to a spline that works on the Mustang T5 input shaft.

The pilot bushing will need to be addressed. I did not get to the point of figuring if the T5 input shaft length was correct or not, but the pilot bushing diameter will need to be adjusted. If you are going with a G Force T5, my suggestion would be to have them make the input shaft to your specification on length with a pilot bushing diameter to match the Nissan diameter.

[gooned]

Thanks Dave, very helpful info.

Still trying to identify other gearbox options with removable bell housings for options.

[gooned]

So another (smoking hot) day at the track, talked to a bunch more experienced racers running various gearboxes, took away a common suggestion from all - forget using a syncro box. I have been under the opinion that racing dog-drive boxes are to finicky to be reliable for a season, clearly any pro team IS using a specific race box when rules allow, mostly with reliable results, so I need to broaden my horizon.
I talked first hand to someone who has used up Gforce T5 box with a mild small block, he strongly suggested I have way to much tire & torque to bother going down that road. Of course I was recommended a Saenz or Weismann but also Gforces's own purpose built 5 speed or a Jerico 5 speed...then there are all the sequential boxes out nowadays.

Lots more reading. Then there is the whole Budget issue too. Main thing is to do this ONCE!

[loungin112]

30a trans will hold that all day. V6 Pathy and truck, Z31T, Z32, R32, and R33 could all be candidates for a tranny. Not sure what you'd do for a bell though.

Here's an adaptor for a Z33 6 speed trans to KA (and therefore L). I'm sure there are clutches that would hold 350 all day long for the Z33 box. The White Bunny clutch would probably do it as well and is super cheap.

http://collinsadapters.com/index.php/ad ... plate.html

GOLD!!

[Byron510]

30a trans will hold that all day. V6 Pathy and truck, Z31T, Z32, R32, and R33 could all be candidates for a tranny. Not sure what you'd do for a bell though.

Here's an adaptor for a Z33 6 speed trans to KA (and therefore L). I'm sure there are clutches that would hold 350 all day long for the Z33 box. The White Bunny clutch would probably do it as well and is super cheap.

http://collinsadapters.com/index.php/ad ... plate.html

GOLD!!

But would this work? Is the KA not mounted vertically like the NapsZ? The L sits at a 7-11 degree angle relative to perpendicular, leaning over to the RH side of the car.

Byron

[okayfine]

I put a KA trans behind my old L20BT. Trans was angled, but as far as using it from inside the cabin there was no indication of the angle once I bent the shifter lever and no problems underway.

[gooned]

I put a KA trans behind my old L20BT. Trans was angled, but as far as using it from inside the cabin there was no indication of the angle once I bent the shifter lever and no problems underway.

This^^^
I have my Lz24 mounted straight up, I always ran a 280 box (well a different 280box every 1-3 races) with the shifter bent to suit.

As I have a toyota PU diff in the colt I'm realizing how big a job it would be to run any one of several gearbox options that are 1:1 in 4th/5th as I'd need a 3.13 gear to reach my current top speed of 150, best I've found is my current 3.73. No idea how close a supra r&p would be to the PU diff but they come 3.13...