4 Spd Jerico w/ '99 Motor
 

I searched for Jerico and didn't come up with any good threads. Trying to find info about bolt up aluminum bell housings. I know Quick Time makes one, but I don't want a heavy steel one.

Does anyone know where to get an aluminum bell housing that bolts up?

I'm not really interested in welding up an adapter plate.

Any help would be great and there has to be someone out there that makes them for road racers etc.

Thx.

There's an adapter plate available for TII trans. TII bellhousing is aluminum. Voila.

So the TII rear bellhousing is the same bolt pattern as the front of the Jerico 4 spd?

Oh.

Sounded like you were just concerned with motor side. My bad.

no worries. Thx for trying to help.

I saw a steel one on Jegs or Summit but have never seen an aluminum one for BP to Jerico.

Yeah I've seen that one by QuickTime, if I can't find something else this winter. Then I guess I'll have to go that route, but I prefer not to.

they make them steel so that a fly wheel doesn't take your legs off at high rpm. I doubt your gonna save a shit ton of weight, thin steel vs thick aluminum. I would assume your making good power with and want the 4 speed for either drag or drift.

I'm going to run a twin disc tilton 7.25 setup and only spinning to 7800ish rpm, so I'm not to worried about blowing up a flywhl. Power is handled, yes. The 4 spd is for my autox car to be honest and only going to use the first three gears since fourth is obviously 1:1

I just want to min the weight on the front half of the car, so that's why I'm after an aluminum bellhousing.

I have had aluminum bellhousings that were SFI certified. You are going to have to accept the fact that you are likely to have something like that fabricated. It is not the end of the world.

I know that a member here, Turns101, had a Jerico behind an MZR motor. I have not seen one behind a BP motor.

that is Jeff Abbott's Formula D car. All i can say is, is it worth all the headaches to save 3lbs?

How much is the weight difference? Truthfully many parts can be made the same weight between steel and aluminum unless the required geometry to make the part fit requires more material than is required for the strength and stiffness of the part. And I like having feet, I think having feet is one of the best things ever, so I'd stick with the steel lakewood/quicktime bell housing. I think TNTTuba has a magnesium case jerico that is going to be going into his auto-x car over the winter. And I'm also considering one, with the 3.63 rear end the 1:1 gear would be completely tolerable on the highway.

^Yeah that's my exact thoughts on the gearing to be honest.

Do you know the weight savings on the mag case vs. alum? Maybe with the mag case and steel BH it would be a wash, maybe?

I have heard that the mag case isn't as strong as the alum and could need replaced after a few year depending on use in the car. Thoughts?

I haven't looked that hard to be honest, my car needs ABS, an NB subframe, power steering, more front downforce and control arms before I really need to add power. TNTtuba should know more, I think he picked his up hella cheap from a hobby stock guy or something like that with already more or less the correct ratios.

In for transmission info.

domestic 4 speed with a plethora of options.

Basically you get the steel bellhousing meant for the old domestics and get one of their transmissions and add a custom clutch disc, throw out bearing and input shaft bearing to match the input shaft.

there are more options that fit that bell than just a jerico too. plenty of 4 speeds out there with hundreds of ratios and several different spline and length inputs with a few different shifter options depending on the use.

used they can go from $1,200 up for the transmission and you will have a 500hp capable transmission (on the low end) with straight cut gears and possibly dog engagement.

Also the 5 speed TKO500 fits that bell housing.

I wish I knew about this bello housing last year

However, you will have around $3k invested into the project even buying a used tranny for $1200 and a whole heap of work.

Custom clutch set up
Factory hydraulic assist to deal with
Custom cross member
Custom driveshaft
Custom rear diff support
Custom shifter set up to relocate rearward depending on bellhousing depth

Did I miss anything?

Custom clutch? I would just call up speedsport and tell them I need a new friction disk with a different spline.
It looks like it works with the factory hydros.
Crossmember? I'm making a PPF adapter, clamp on if need be.
~$150 at your local drive shaft shop to get your stocker cut down or lengthened and the front spline changed and rebalanced.
Diff support? See crossmember.
Custom shifter shouldnt be too hard. The Jerico and most T10/T101a variants are side loaders so they already uses a series of adjustable length linkages outside the trans to connect to the shifter. So at most its a few hours with the welder to move the spot the shifter connects to.

I truly think that's on the short side of how much it'll cost even buying a used trans and doing the work yourself.

I think 3k is probably a good estimate to do what I said, assuming you can fabricate. You're into almost 2 grand between a used tranny and the bell housing. If you follow gutted's list you'd be looking at more like 4-6k and you would be able to keep the PPF.

Well to put it into prospective I've figured $10k for a new setup with top shifting and I'm not far off with the est from Taylor Eng. Think the alum trans, top shifter, tilton twin, misc parts, bellhousing are just about $9k +or- and still need drive shaft/crossmember/mount/etc.

How fast do you want to go? It's a number that starts with a dollar sign.

At least my plan doesn't include duct tape. :bowrofl: Oh wait, you said clamp not duct tape. I'm pretty sure with 12" slicks on all four corners my end result would be the same either way. Broken. :sad2:

I just put one and one together. I had a spare gear box with me at Nationals. I wish I had known you all broke. We could have swapped the gearbox out in a couple hours on the Wooten's lift.

Thanks! However, it broke on my first run on day two so swapping it out wasn't an option.

Not sure how. The clamp would actually end up spreading the load on more area than making a bracket that bolted to the tranny mountin holes on the tranny would. Of course with delrin diff mounts and AWR or delrin engine mount there's really not going to be an serious forces on the PPF anyways.

And I would use safety wire and zip ties, duct tape is for barbarians.

:bigtu:

Subscribed. This subject should not require reinvention of the wheel, there's GOT to be NA/NB Miata's w/Jerico Dog boxes out there.

I'm sure they exist in prod racing.

So what would guys do with the PPF brace? Just weld up a bracket and bolt it together? Totally remove it and weld up a diff mount/support and tranny mnt? Any ideas out there?

With my T5 swap, I bolted the PPF to the new transmission cross member. I assume something simple like that would work with a Jerico.

This is an old picture but you get the idea. Now I have the mount on the back side of the crossmember which gives me more room to adjust pinion angle, and there's some urethane foam spacers (hacked up NB front spring stopper) between the PFF & crossmember instead of being rigidly mounted.
https://www.miataturbo.net/attachmen...ine=1381339334

You will need an accurately balanced driveshaft...the PPF does buzzzzzzzzzz like a giant tuning fork.

http://www.absurdflow.com/miata/klde/transcross2.jpg

Thx for the pics and that's basically what I imagined. Does that give the PPF enough strength mounted that way?

I would hope so, when its mounted like that basically all its doing is holding the nose of the diff up, especially if you have stiffer diff mounts.

Yeah I just don't know how much twist 350hp would put on the diff and carrier with 275/15 slicks on the car?

Do the math. Figure out how much max wheel torque you put down in first gear. (miata 5 speed is 3.163 first) Assume that PPF is 4 feet long or so.

Summin' like 1000lbs. :dunno:

But you dont know how much of the rotating force the diff mounts are taking, probably almost all of it. Which is why the diff arm with the notch cracks on cars making a lot of torque. The tranny mount and not connecting the PPF to the tranny mount rather than the subframe basically turns the ppf into an overly heavy diff mount. So you'd save some weight nixing it completely and just putting a mount near the nose of the diff.

The way I see it, and I could be wrong, is that the miata diff housing sees 2 loads.

1. The twist from the driveshaft trying to rotate the diff housing along the direction of driveshaft rotation. That's taken up mostly by the ears. This should be the driveshaft torque divided by the distance to the ear (divided by two, cause there's two ears).

2. The pinion gear trying to climb the ring gear. that load taken up by the PPF.

I'm not confident on how to calculate #2 but both ways I can imagine it bring me around 1000lbs at the end of a 4 foot PPF pole, using 300ftlbs engine, miata first gear, and ~4:1 diff.

Right, there is #2, but if you are already mounting the tranny and not using the PPF to mount the tranny, why does it need to go so far forward.

It just keeps all the angles in check

Well, I know it's been a while, but I figured I would share some pictures with you guys. I'm still waiting on some parts for the install. I almost feel bad putting the tranny under the car where no one will see it, because it looks really nice on my shop floor. I'm just hoping after the install, it' won't have anymore time on my shop floor!

sick. Keep posting pictures. Please.

What ratios did you go with?

Damn those things are pretty. It looks so tiny and you would think it would only weigh about 50 pounds. But those gears are heavy duty.

I bet it is strong and light. A buddy of mine is running a Jerico competitor with a fairly tall rear gear and a tall first gear. He coasts through the pits pretty quickly at idle and uses a winch to load the car on the trailer, but first gear is a very usable gear on the track for him (turn 7 at Road Atlanta) and he can still reach 160+ in top gear regularly on the back straight. It's a SBC engine though.

Well my gear ratios are really strange and prob useless for you since it's an autocross only car.

I'll work on posting pics as the progress continues.

No it is pretty applicable. Andrew seems adamant that it wont work for the track snobs so this is pretty much an auto-x only tranny choice on this site. The 3.63 rear gear would make 4th almost like a 1.6's 5th, and you can work back from there on the ratios. And run the car in 2nd at auto-x.

Yeah, the track snobs can either change their diff to run around the 1:1 4th gear. or run ALLOFIT with a gearvendors overdrive. Cause if you're spending a few grand, why not spend a few grand more. 8 gears should make them happy. There's an incredible amount of ratios looking at Jerico's 4speed gear ratio chart.

Another option would be to run a 7.7:1 rear gear (speedway quick change) and make 4th (1:1) as the first gear and install the rest of the gears on the opposite shaft as intended. You could re-jigger that shift linkage to even make the gears in the right spots.

The overdrive is interesting. Is it also side shifted so possible to build an insane shifter that automatically shifts it as you move and moves back to 1st gear. (yay for complex as shit linkages).

umm... yeah my gearing isn't convential lol. There is a HUGE rpm drop from 3rd to 4th in my box.

You can make this box work on the track of course, but a five speed would be better for the track.

Hey I actually looked at these overdrives. Its a planetary gear set so I'm assuming that shifting into it you're just applying a brake to the planetary gear or releasing the brake. Which would be why no lift and no clutch is required. And yeah it give you a gear between every gear. Not sure if the road course guys are going to have to remember to pull a lever/push a button to get another gear though. Also not sure how heavy they are.

Any more info on this Raucky

Nope not yet....I'm stilll waiting on some parts to be made, but I'm hoping to have everything in a wk or two.

You get that thing in there yet or what

Ok so after an extremely long pause on building my car. I've got the ball rolling again and here are some pictures guys.

Damn this is the first time I've seen actual pictures of this bell housing. They aint fucking around with making it explosion proof. That plate that replaces the "gasket" is thick as fuck.

Sexxxyyy! If I end up with all of the horsepower one day and nobody has come up with a good five speed solution then I may be following you right down this path.

Christ almighty, what does that thing weigh? Just the bellhousing itself

godddamnnn on that bellhousing, shit. Very nice.

Yeah I don't think I'll have to worry about it breaking huh?

The weight of the stock 5spd compared to the "complete" Jerico/Bell Housing is basically the same.