Twerp's '91 Miazda

[starfox07]

Now, throw a rotary in it!!

[thedguy]

Originally Posted by starfox07

Now, throw a rotary in it!!

I've looked into it, it's actually easier to shove in a Chevy/Ford v8 under the hood than a rotary. Makes one wonder if Mazda just assumed that people would want to put other peoples engines in their kick ass chassis'

[LS2 V8 Miata]

V8s are easier, even than some V6s Ford SHO, 4.3 Vortec, like the mazda rotary all pose problems based on clearance issues and tranny / drive-train stuff.

[Twerp128]

So had the car for a month now, here's the report. The car is immensely fun to drive, very neutral a bit prone to over-steer, of course you can get the under-steer out of it too. Overall very grippy and nimble, (Good Bridgestones help). Braking is good, acceleration is something to be desired, but hey if I wanted that I woulda bought a Mustang GT. The ride is hard, but worth it. Usual convertible, chatters and creaks. Trunk is beyond worthless. Ergonomically it's good, and should be as easy as any small car to wrench on. Basically I'm very happy with the purchase.

I guess at first I was caught up in the whole, Jap cars don't have soul (Aside from the Skyline, NSX, and the Rx7 obviously.) You know what fuck soul and passion, the car is too much damn fun. Sure the 944 is faster, but God the MX-5 is so much more fun to drive. Plus when you read how the MX-5 came about, with Bob Hall and a bunch of noticeably shorter Japanese engineers who poured all their knowledge and enthusiasm into this car, it just makes you think. Just because the car looks like an anchovy doesn't mean it doesn't have soul. So that aside, I hope to be hanging onto this car for a while, and now that I love it I plan on improving it.

Short term mods
Daily driver - When the 944 is fixed or gone and/or after I get a raise. Keep the miles off it, having something for the rain/winter and when it's up on the jacks. Learned the importance of one of these the hard way with the Porsche.

Run Flat Tires - Clear up some trunk room and lose some weight, I think I can deal with the added road noise.

Clean the carpets - Have a bit of mold in the trunk, gotta clean the drains then get to that mold.

Patch the roof - yep, gotta get to that.

Cruise control - I don't need it but my poor right foot does. Plus it'll save a bit of gas.

Lose the AC - I haven't used AC in like three years. Probably will keep the Power Steering though.

Long term mods

Engine - New exhaust & intake, maybe get some sort of chip mod. I want to run this engine up in mileage then have it blueprinted and get the manifold ported and polished. That wont be for a while though. Basically I just want a little, like 20-40, more HP out of it. Then make the necessary changes to the cooling, electrical, and fuel systems to keep it reliable and running better then stock. Oh and new motor mounts!

Driveline - Better clutch and mildly sporty flywheel, hopefully get a LSD. Lighter rims and some sporty dry Michelins or Pirellis, maybe Hoosiers? Possibly wider tires, don't want to screw with the balance though.

Brakes - I need better brakes, I realize the Porsche spoiled me in this department. But I need more braking power, I have the tires for them but the little Miata brakes just don't have it in them. This will affect rim size possibly. Haven't looked into the upgrade possibility yet or even researched what others have done. I guess I'd like bigger rotors as well as more pistons, to reduce fade as the car may see much more track time (hopefully) in the future.

Interior - Momo steering wheel only after I have some Recaros and harnesses so the airbag is useless. May lose the carpeting in the trunk. Playing with the idea of a rollbar and a hardtop.

Suspension - Don't really know. Would like to install a strut brace up front. Maybe some additional chassis stiffening stuff. It's really the last thing this car needs.

[jayhawk]

Thank God you got those stupid ports off! I was about ready to hop in my car and drive East, equipped with only a gasket scraper and a vengeance!

And the more you drive it, I will think you will change your mind on it having a soul; or if anything, you will start to notice it's character. Hell, my car is only a year old, but it has a character I have never experienced in any car I have bought in the past 8 years.

[Twerp128]

So anyone know about the oil gauges on my car? Ever since I changed the oil it's been working kinda funny. At first it was all over the place, and now it works good when I start up the car, but as I drive it says I get less and less oil pressure, and is still kinda jittery which makes me think it's a gauge/sensor problem. Recently though I've heard the '90-'94s have oil pump issues I sure don't want to risk that.

Engine starts good, idles at 1,200 rpm for a few seconds before it drops to a steady 800 rpm. No funny noises, a tiny bit of valve train noise but nothing more then normal, at least for the few months I've had it. Runs at correct temp. The only thing I can think of, is when I changed the oil it was at the bottom of the acceptable limit, now it is at the maximum acceptable limit, at the full line on the dipstick, would that mess with the sensor?

[thedguy]

Miata's are notorious for grounding problems. http://forum.miata.net/vb/showthread.php?t=158890

found this digging around the other day



I cleaned out the connector underneath the brake booster and got my tach working again. Now if I can only figure out why it's 1200rpms off.

[Twerp128]

The oil sensor magically started working again today.

But then I was driving to work and I'm not sure what happened. I'll admit I was talking on the cell phone. I was trying to shift to fourth from third but may have got second. The car cut out, but, I didn't hear any grinding or anything like that, the revs didn't spike either though. Not sure if I actually got second gear engaged. I may have also bumped the ignition key off, I've done it before with my knee, then with the engine off I may have tried the gas and flooded it. But I waited a good half-hour and it's still not starting.

Coolant and oil levels are ok, I can move the shifter through all the gears with the car off like normal. Check engine light is on. Battery and gas are good. When I try to start the car the starter runs and seems like it is trying to start. I really hope I just flooded it.

EDIT: Could it be the timing belt broke?!
EDIT EDIT: Not familiar with this engine. If the timing chain did break is there any chance of the pistons and valves playing paddycake? I definitely don't hear anything out of the ordinary when I try to start the car. I know in my 944 and Porsche flat sixes a broken timing belt can destroy an engine. I thought this was due to high compression, but I can't see how a valve and piston don't collide without a timing belt?

[Twerp128]

^It's the timing chain, if you look through the oil fill you can see the cam and when you crank it there is no movement. Luckily there should be no damage to the valve train. And unlike the 944 it's like a $500 job with a new water pump and accessory belts unlike the Porsche that's $1500! And it needed it done anyway.

Plus I'll have them cut the AC belt too, then later this year I can get it decompressed, and pull the guts out and save some weight.

[Punisher Bass]

I did some looking around, and far as I can tell the miata doesn't have an interference engine, so everything inside should be fine.

[Twerp128]

I am so getting towing put on my insurance.

[thedguy]

Originally Posted by Twerp128

^It's the timing chain, if you look through the oil fill you can see the cam and when you crank it there is no movement. Luckily there should be no damage to the valve train. And unlike the 944 it's like a $500 job with a new water pump and accessory belts unlike the Porsche that's $1500! And it needed it done anyway.

Plus I'll have them cut the AC belt too, then later this year I can get it decompressed, and pull the guts out and save some weight.

Non-interference engines FTW. The timing belt pretty easy and I did it + water pump/Thermostat and new belts and hoses for less than $350.

[Twerp128]

So talked to my mechanic today. He says he is 90% sure the timing belt is the original, which makes me kind of pissed at the few previous owners. But that also means the car ran 130,000 miles without a timing belt or water pump breaking. Says something for Mazda's engineering.

[thedguy]

Originally Posted by Twerp128

So talked to my mechanic today. He says he is 90% sure the timing belt is the original, which makes me kind of pissed at the few previous owners. But that also means the car ran 130,000 miles without a timing belt or water pump breaking. Says something for Mazda's engineering.

Mazda says to do water pumps ever 120k miles so it works out.

A little interesting bit of info for ya. In the state of California law says all timing belts/chains are supposed to last 100k miles. Every manufacturer uses the same ones world wide and hopes they last the extra 40k.

[Twerp128]

^ Actually I joined that Mazda forum you posted a while ago, and some of the members mentioned that. Said they had to change all the manuals for California cars to read timing belt needs changed every 100,000 while the dealerships told them to come in at 60,000.

[Nocturnal]

Very nice little car! Just a couple of things that might help you...

-The brakes are actually pretty powerful, albeit very under servo'd. For track work theyre spot on, as you stamp on the pedal they really are very sharp. That said, for anything 200bhp and above, you really need the 1.8L brakes.

-If you want around 40bhp, its honestly easier and cheaper to just turbo it.

[Ottobon]

Originally Posted by Twerp128

Sure the 944 is faster, but God the MX-5 is so much more fun to drive.

I'd love to hear why the 944 isn't so great, might make a interesting read.

[thedguy]

Originally Posted by Nocturnal

Very nice little car! Just a couple of things that might help you...

-The brakes are actually pretty powerful, albeit very under servo'd. For track work theyre spot on, as you stamp on the pedal they really are very sharp. That said, for anything 200bhp and above, you really need the 1.8L brakes.

-If you want around 40bhp, its honestly easier and cheaper to just turbo it.

Greddy Turbo kit is $1600 MSRP. I haven't heard any complaints about it, especially for the price.

[Twerp128]

I'd look into it, but I have a hard time force-feeding an engine designed and intended to be naturally aspirated. Still worth a look though, think I'd have to make sure the engine is rock solid first.

Meanwhile, the car is sputtering and hesitating and I probably need new plug wires yay!