High Rpms

That's about right. I think most tachs read a little bit lower than 4000, but not much.

Miatas are not like "most cars". ;)

Yes. As do 96s and 03s and all other years.

Nope.

Thank god! about 2 years ago i had to hollow the catalytic converter and she sounded like a pissed off bumble bee after that. does the 91 also have a rev limiter?

You can check (miata.net) to see what years have what rearend ratios, but the (US) 1.6's have "tractor gears" in them ! The newer Miatas have higher speed gears. At 60 MPH, my 2003 turns 2800 RPM. My 1991 at 60 MPH was 3200 RPM.

Yes, your '91 has a 7300 RPM (+ - 25) rev limiter. If you are on the gas "full on", it will shake the crap out of you and make you think you "broke" something when you hit that RPM. :-)

Bruce Bing '03 LS

Yes, all Miatas have rev limiters. The one on a '91 cuts the fuel at about 7300 rpm, far below the point of risk.

Errrr, my '91 miata does not have one. It redlines at 8,000 rpm right now, or anywhere else I set it up to

20,000 engine-destroying rpms.

Would that be all "unmodified" miatas? :-)

Pat

Pat, Your '91 must have it "bypassed" ! The stock factory '91 cuts off the fuel at 7300 ( + or - 25 RPM ) My '91 started out at just under

7300 on the tach, but then I started watching it closer and could see that the tach would bounce around above or below. Depending on if I was holding the power just below that point or just jamming it up there. I am sure the tach is not very dependable up around there anyhow. When you are racing, you just tend to glance at it anyhow. You can hear the engine getting into that range so you just use it as a refreance anyhow. The torque is on it's way down by then anyhow !

Bruce Bing '03 LS

My reply was tongue-in-cheek, of course they were talking about stock miatas, or at least ones that have not had their engine management system replaced.

This car has roughly twice the power that it did in 1991, more than double the original power if I increase the boost. It is very bypassed, this '91 has the 1.8 liter conversion with a '94 block, '99 head, lower compression ratio, a big 'ole Garret turbo and an intercooler that looks about twice as big as the one on the Mazdaspeed. The power is delivered to the wheels by a torsen diff. from a 2001 model miata. The fuel is running through a Vishnu fuel rail to 550CC injectors, the previous owner was not messing around. This is all running back through a 3" exhaust, including the catalytic converter, and it is controlled by a Tec-3 engine management computer that lets you adjust far more than I ever want to.

The rpm limit can be set anywhere from a point so low that it would not work with a miata to a point that will let the engine max itself out to destruction. I am assuming that the computer stops increasing the engine speed at

8,000 rpm, where I have it set now, but I have never felt a cutoff and have bounced the tach a number of times.

Pat

Hee, hee, hee, that sounds like a fun one to have. We had a guy in a Honda this summer with a turbo that bypassed the the rev limiter. He also "bypassed the side of the engine block about half way around the course. (Externally lubracated at that point) ! :-) Ya'all be careful now, hear ! :-)

Bruce Bing '03 LS

Yeah, that is why I keep it down closer to 10 psi. The pistons, connecting rods, etc. are not forged, but this is an engine that was designed to take a turbo originally.

A mechanic friend did his first forced induction installlation of a GT Mustang a while back. I don't know all of the details, only that it was a huge supercharger that made the JR unit look like it came out of a toy car. Anyway, it ran for about 1/8 mile before blowing up the engine. I am not sure that they even knew what boost they were running, and the engine was completely stock. It has a big dual exhaust with gutted catalytic converters.

Great guy, even a very good mechanic in most areas, but he does not/will not work on my miata.

These things really have to be researched and it is expensive to do it correctly. I will almost undoubtedly experience a shorter engine life, despite the regular Mobile 1 oil changes, but it would surprise me if it blew a rod with what I am doing with it now. I also might not have the car by then, but it has run trouble-free so far for almost 30,000 miles since I have owned it.

Pat

That's cool, lots of extra toys to play with. I'm probably going to get the Flyin Miata intercooler, intake, downpipe, and exhaust package

plus signal modifier oncethe factory warranty expires. I know these parts have been developedtogether and don't do anything too extreme to the engine.