Duke SuperDork
Aug. 12, 2010 8:05 a.m.

Hey, Keith, gotta question for you.

I'm strongly considering buying a '96 Miatar. The PO has fitted it with what he described as an Ubercharger (haven't seen it up close yet). I note from FM's website that the Ubercharger "failed to live up to its full potential and has been discontinued".

So, what should I know about this piece of equipment? Will I regret the purchase?

The car has about 90,000 miles on it and he says it dynoed at 239 hp at teh wheels. I do not know what if any internal work has been done to the engine. It's got bigger injectors and an external ECM of some sort - he told me the brand but it slipped my mind, and lots of other goodies that should make it a reliable track day workhorse, including the airflow deflector to get better cooling to #2 and #3. He says it runs 180 degrees under track day conditions.

I know the owner and don't have any reason to suspect him of shenanigans since I am likely to run into him on a semiregular basis in the future. I just don't want to end up with a liability any worse than usual with a track car.


Raze Dork
Aug. 12, 2010 8:34 a.m.

cause running stock internals on 2+x stock power is cool for the first dyno pass...

If you know the guy, ask him about internals, seriously before you take the plunge, I don't know Miatas but building an N/A motor to FI specs can't be cheap if this one is stock and grenades the first time to the track...

Duke SuperDork
Aug. 12, 2010 8:42 a.m.

Your point is taken, but it's been run a lot, and moderately hard. If it was going to grenade it would have grenaded already. He's selling it because he just bought a 2010.

Junkyard_Dog HalfDork
Aug. 12, 2010 8:48 a.m.
Raze wrote: cause running stock internals on 2+x stock power is cool for the first 3 dozen dyno passes...

Fixed that for ya. You've obviously missed the bazzilion posts and articles on boosted Miatas.

miatame Reader
Aug. 12, 2010 9:06 a.m.

What are you trying to get at Junkyard? There are a ton of boosted Miatas running 240hp daily without trouble.

The Ubercharger had trouble with the twin screw unit not being reliable and not as flexible as there proven turbo systems.

I would buy an Ubercharged car, but only because I wrench myself and have had a supercharged Miata before. It isn't a change the oil and drive car anymore, it is going to need additional attention.

If you don't know cars and aren't wealthy enough to have a mechanic give it proper attention I would shy away.

Raze Dork
Aug. 12, 2010 9:23 a.m.
Junkyard_Dog wrote:
Raze wrote: cause running stock internals on 2+x stock power is cool for the first 3 dozen dyno passes...

Fixed that for ya. You've obviously missed the bazzilion posts and articles on boosted Miatas.

nope, I've read them, but since he said it's been run out, alot, I'd still have a word with him to see where it stands. If the alternative route is swapping motors when this dies for another stock motor and keep going I'm all for it, no need in putting big $$$ into a motor, unless the PO already did, in which case he'd have to decide to either rebuild it with more expensive parts, or just snag another cheap JY replacement, it's all about economics of time, money, and ability...

Tom Heath Webmaster
Aug. 12, 2010 9:33 a.m.

Chris Swearingen is using an Ubercharger (well, parts of one at least) on his nationals-contending SSM Miata. His is beyond 300 whp, and seems to work pretty well.

I'll stick with turbos, but the Ubercharger (and a few other systems) seem to be a viable alternative to those who prefer their boost to be belt driven.

Keith SuperDork
Aug. 12, 2010 10:09 a.m.

Ah, the Uber. It's a pretty cool setup. There were two major problems:

  • the company manufacturing the components had some serious quality control problems. Not a problem once you get the parts on the car, but there were a lot of difficulties getting to that point. It was also a particularly complex kit which added to the challenge. When we stopped using that manufacturer, the Ubercharger was discontinued.

  • the twin screw supercharger works better and better as the boost level goes up. But at 12 psi, you're getting close to the rev limit of the compressor. The reliability of the supercharger was good but not exceptional - certainly not in the same league as the turbos.

The ECU is most likely a Link. That particular unit has been discontinued but we're still supporting it as best we can. The "Obiwan" Link used for 1996-97 cars was the best of the breed. 239 rwhp is a very plausible and safe power level on stock internals for that setup, but you may want to figure out the blower speed and possibly limit the engine speed to 6500 or so on track.

If anything happens to the blower, it can be rebuilt by Whipple. We have a number of spare parts for the kits, but the custom fabricated stuff is limited to what's on hand. We do have a number of pulleys for adjusting boost level though.

A good Uber car is a lot of fun and makes that intoxicating scream. But the combination of the limitations of the compressor speed (and thus boost level) and the difficulty in obtaining consistent components killed it as a kit.

Junkyard_Dog HalfDork
Aug. 12, 2010 10:13 a.m.

I meant to say its totally safe. Damn early morning posts before caffeine can get garbled

Duke SuperDork
Aug. 12, 2010 10:20 a.m.

OK, thank you. Link sounds correct, but I do know he just put the ECU on this spring to replace a different unit in place before. This blower has been on the car a couple years and the whole package seems pretty well sorted. The once or twice I've driven it, he did ask me to keep it around 6,000, I assume for the reasons you mention. I don't know how much boost it's currently pushing but I have no plans for more.

I understand this car is going to need more care than a stock Miata, but I'm not trying to push the bleeding edge. I like the idea of a blower rather than a turbo because it would get used most frequently for autocross at a couple of relatively tight venues, with maybe 1 or 2 track days a year. I'm more concerned about grunt and instant response than I am about high sustained HP.

It also has an LSD (unknown), FM big brake kit (he mentioned Wilwood fronts, but not rear calipers?), the FM X-brace and frame rails, and a (I think) Hard Dog bar with diagonals. Koni Sports with unknown coilovers.

I'm taking the car to an autox this Saturday and will spend some quality time with it, getting to know the particulars better. Thanks again for the input - if I buy it I'm sure I'll pester the crap out of you.

Junkyard_Dog wrote: I meant to say its totally safe. Damn early morning posts before caffeine can get garbled

I got it the first time.

Keith SuperDork
Aug. 12, 2010 11:09 a.m.

The LSD is most likely the factory Torsen, but it could also be a clutch-pack from an RX-7 or possibly a high-dollar OS Geiken. The big brake kit uses the stock calipers in the back, but on a larger rotor. FYI.

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