Billet 5sp gearset
 

I was bored and searching around and found something interesting. I know I will be making enough power eventually to kill stock 5 speeds, and I WILL NOT run a 6-speed because the feel like poo. The quaife ratios suck, like a lot, so I was seeing what a 1 off gear set would cost, and also seeing how much the proper milling cutters cost to see if I could cut them in house. I ran across these, and a quick search on here shows no results. Mazda MX5/Miata/Roadster 5MT Synchromesh engagement gearset

They have dog and syncro engagement with straight cut and helical options. Also make rx7 and 6 speed gear sets, and some other mazda boxes I don't recognize (and honda, ford, and mitsu). Looks like they're made to order so I would guess minimum lead time is 3 weeks if they have no other work, and I know that could easily stretch out to 3 times that.

Best thing, no extra cost custom ratios. 3100 bucks gets you helical or straight cut synchro engagement and whatever the ---- ratios you want. They make no claims as to power holding, but they're billet steel, they need to be case hardened at a minimum if they expect them to last any amount of time irregardless of power, so at a bare minimum they should be able to hold 300 hp. figure better grade of steel and different heat treat, and whatever the heck else you want to pay for and you could easily make them strong enough to find when the tranny case start breaking.

yeah I have known about these guys for a while but the problem here is cost.
for the few of us making 300+ hp the 6 speed is still semi reliable and if it grenades you just buy another one. Seeing that you can buy a used 6 speed for an average of 7-800 and sometimes as little as 500 you can blow up 4-6 of them for the price of one gear set.(of course I am not factoring in the 800-1000 for the transmission rebuild to install the gear set).
And the most important factor, Miata people are not porsche/ferrari people, they are F_____G! cheap(poor) bastards.

While it is cool, I doubt anyone would justify the price without knowing what sort of power these things can handle.

4 grand (assuming 800 dollar install) is a ---- ton of money to spend on a gamble, especially when we have a member on here about to sell RX7 TII transmission adapter plates for under 500 bucks. And we know the RX7 trans is good for 450-500hp~. Add in the cost of buying a trans, fabbing PPF/cross member adapters and you'd still be WAY under the cost of the mystery gears.

Don't get me wrong, this is cool as hell and I LOVE the miata 5 spd box, but my love isn't worth 4 grand :giggle:

Trouble with the rx7 tranny is the gear ratios suck too. I need to hit 70 ish comfortably in 2nd, and then maybe have about 4 more mph head room before the limiter. I dont want to have to be shifting between 2nd and 3rd all day.

TII ratios are worse then the Miata 5sp. Only benefit is they can hold more power

A friend of mine had work done by CP Boost in the past and had them install their gears in a FWD G-series transmission in his 400whp Mazda3. It blew 3rd six months later. Now this was 5 years ago and G series transmissions are known for case flex issues and to still blow billet gears. So take it for what it's worth.

If they tell me what the steel alloy is and what treatments they have done to them, I can just do the damn math myself. Or if they'll sell untreated gears for less you oculd do whatever treatments you wanted. Even a cheap low carbon steel gear with a proper heat treat, shot peening and carbon case hardening will take a significant amount of abuse, like more than practically any car on this site with a bp engine could give.

That's pretty much it: its un-proven, and 3100 bux. People around here are not willing to experiment with that kinda money to see if its good or bad.

Why do you need 70mph out of 2nd gear?

Because with the power, grip, and downforce I plan to achieve being over 70 in multiple sections of an scca course would not be unexpected. And shifting to 3rd takes time and adds in one more element to make a mistake. When you've only got 3 tries to get it perfect at a national level competition you want to minimize anything that you could possibly ---- up that you can.

You better have a 600+whp motor in there

It'd probably be easier to gear your differential down a little bit and just use 3rd. First time you shift into it, stay in it.

Well considering the nationals level 240sx with a 400something hp engine and 600 pounds higher minimum weight is hitting those speeds on the same courses and I need to be 2 seconds faster on a 60 second course to podium at nationals I would hope that its dooable with 300something hp in a 2040lb car that handls much better.

Well, you gotta pay to play and for national level autocross trying to squeeze out the last tenths and not just track days then maybe it makes sense for you.
You can be the first and let us know about the quality and metallurgy. If the quality is there then some of us might be willing to risk that kind of money.

I can go 74.3mph in second gear on the limiter. At the Blytheville tour a few weeks ago on one section of the course we were on and off the limiter for a few seconds. You don't need anywhere near 600hp to do 70+ in second gear in a autocross situation.

The Quaife set works fine in my autocross car. I get 75mph GPS at 8000 RPMs with the 275 goodyears on 15x10 6ULs.

Here's all the available options for gearsets and some speed calcs based on them:
Drivetrain - DestinationSSM

creative performance have a few stupid fast (10's and lower iirc) 323's under there belt with these gears. while not specifically the miata gears sets, the FWD boxes are equally weak and if they can keep them together I would say its a safe bet these are decent.

I've emailed them asking for some more info. Would be good to have an alternative in case I get unlucky and explode my Quaife set...

Don't expect any kind of warranty from that piece of ---- company. I broke a diff the first day I had it and they refused to warranty it. This is back when I was dirt-poor and $900 for a diff was like buying a Ferrari.

Did you hear back from them? I cant get a working email address, and they dont list any info on their site. It's like they don't like making money.

BTW I had to submit an order to get their contact info, so far this email address hasn't been spat back at me.
Phone: 787-760-3046
FAX:
E-mail: info@cpboost.com
Website: www.CPBOOST.COM