Flyin' Miata kit on a Duratec 2.3???

I'm not ready to cut a check or anything, but just wondering if anybody's ever tried it?



The MX5 shares the Duratec platform, so the manifold should bolt up, and the previous owner got rid of that pesky smog-pump for me, but it looks like the steering shaft may be in the way - not sure about that.



I'm hoping that someone's had this idea before. Aside from needing a custom tune, is there any reason why it wouldn't work?

What kind of numbers do the Miata guys get with that kit?

There was a discussion on another forum that I saw, where they considered this kit. Nothing ever came of it. You could probably get more power out of a remote turbo setup for less money.

I agree that it would probably interfere with the steering shaft, and maybe the power steering pump, or even the brake booster.

As far as what's needed to run that kit, you'd need to find some air intake tubing, larger injectors, the tune, and a decent way to route the belt. Also not sure about throttle bodies, and what would be compatible with the Ranger.

According to the site, a stock Miata turned out 146HP/135lb.-ft. and the addition of their S/C kit produced 253HP/219lb.-ft; all said, a significant gain of 73% HP and (more importantly to me) a 62% increase in torque.

A turbo was my initial idea when I started thinking about boosting the 4-banger. It's cheaper and more efficient than a roots or a screw-type, but not without draw-backs. For one, a S/C has a nice & flat torque curve across the RPM band whereas a turbo has a "sweet-spot" that doesn't work well when towing a load at lower RPM's. I also read where folks are drilling into the side of their engine block to feed oil to a turbo, and admittedly, that idea scares me; a supercharger doesn't require lube oil from the engine, so no drilling into the block would be required. The easy answer is to drop in a V8, but then you loose all the awesome gas-mileage that you can only get with running a 4-cyl. and a six simply isn't an option for me personally.

I just ran across a thread talking about the very similar Cosworth S/C kit on another forum while I was tracking down pics of the Duratec drive belt system. I read through it, and the general consensus was that it would be too expensive to consider as a real viable option, but I didn't see much about actual application aside from one of the predominant members had the same reservations I did about the steering shaft. I didn't even consider the brake booster, but that's exactly why I like to bounce these ideas around the forums long before I ever get tempted into doing something rash.

As far as what's needed: Intake tubing = diesel exhaust shop, larger injectors = same stuff the turbo guys are using (Focus???), a tune = Bill @ Power Hungry Performance, and as far as routing the belt goes, it appears that the MX5 and the Ranger variety share a similar accessories set-up, and even share the same replacement drive belt.

Ranger


Miata/MX5



Throttle bodies also share the same gasket, so aside from the angle of the TB possibly fudging the mix (which I see as unlikely, but I'm no expert either), it looks like it all boils down to if it will physically fit without the steering shaft and brake booster possibly being in the way.

I bet we looked at the same thread on that other forum. I may even have a post or two in that thread.

I checked the FM website, and looking at their install pic on an MX5, I'm guessing the power steering pump will be fine. Also good info about the throttle body and accessory drives being pretty much the same. Like you said, it all comes down to the steering shaft/brake booster.

While I was looking at the kit, I noticed it comes with larger injectors, so you should be able to check those off of the list of needed items. No specifics about what size the injectors are though, or what boost levels they might allow.

If the steering shaft is in the way, you could always make up some new motormounts and set it up as a slant 4.

I don't know how slanting the engine would effect oiling, and if the Ranger is anything like the F150, there are floorboard clearance issues when considering moving the engine up, but a body-lift might cure that.

The S/C package looks like it's angled, but it actually fits nice & tight to the engine, so there's a (very) slight chance at having just enough clearance.





As far as boost levels, I found a reference to a Cosworth review and found that it comes with a 3.3" pulley good for 8psi @ 7500RPM, and the max is 12psi with a 2.6" pulley. My 2¢ says the 3" pulley would be the way to go in order to keep the S/C from spinning like crazy, and still making decent boost at minimum parasitic loss.

Sad news is that it looks like at one point these kits were carried by about a half-dozen companies, but FM appears to be the "last man standing", so come time for me to make a move (and granted, it costs nearly as much as my truck) they may not even be available anyway.