Pedxing

Howdy. I had been looking for a project car because modding my daily is something I'm too old for and somehow got obsessed with Miatas. Small, cheap, lots of aftermarket support, perfect! Last December I finally pulled the trigger on one, a mechanically good, reasonably stock 1994 NA8 that looked crappy in a three-day bender kind of way, not a meth head gas station robbing sort of way. It had some chinesium headers, a straight pipe, and some volk replicas, but nothing major had been done to it. Crappy paint, shot soft top, and a CAS o-ring leak, but I'd seen worse. Came with a set of OEM wheels and tires, turned out to be the light hollow spoke ones.

The '94 was perfect for me because a) it's a 1.8 b) it's not OBD2 which makes running a full ECU setup easier (I have emission testing) as long as you tune it correctly, c) it has a working oil pressure gauge, d) it has a high pressure oil feed on the correct side of the block, e) cheapness.

Everyone: "What about the VVTs?"

Me: "Variable valve timing? I don't think they exist."

This is day 1:


No rust on the body but because of the soft top problems, I found this:



New(ish) panel next to the rusted out one, had to replace all of them and drill out several of the bolts. But everything cleaned up ok.

After some detailing and shooting some 2K clear on the quarter panel and both bumpers:



Got the RPF-1s from craiglist, like new.

Starting baselining the car, did the cooling system (rad, all hoses, flush), did timing belt/vcg/water pump, cas o-ring. Found intake timing was off by one tooth. Plugs, filters, etc. Got it inspected and passed emissions first time.

Did a little clean up on the interior: Ebay seat reupholstry (worked well for like $120), new soft top, console delete, radio delete, power window switch relocate, airbag delete, momo wheel and hub. Door card restore. Doing a retro thing.



I decided the paint was annoying so ended up plasti-dipping it (hunter green, 2 gallons plus 1 gal high gloss top coat).



August 2017:


Next step is I'm finally starting the turbo process. This is an experiment for me, I want to do e85 so I'm thinking I'll start with the ECU and wideband, learn some tuning basics. Switch to e85 while still NA. Then go for the trubo. Not allofit. This will be a street car only, thinking 200whp/200wtq ultimately. So researching small turbos now.

What say you veterans?

shuiend

iTrader: (24)

MKTurbo.com for your 200whp street setup. Skip the E85 as you don't need it on a stock motor.

Pedxing

Thank you sir. The MKTurbo is legend, I really do like that setup. My ambition right now is to do a 100% custom (piecemeal) build so I can work on my fabrication skills. But reality may smack me hard and you would be my first call!

For e85, I admit, that's a bit of a lark. I don't need it for power, was thinking just for safety when I play with timing plus it's plentiful around here. My injectors and fuel pump are old so was going to upgrade that anyway, replace some lines. Is the tuning of corn more trouble that it's worth? Main problems I hear is idle, cold start, etc type of issues.

concealer404

iTrader: (3)

Corn is worth almost nothing on a stock motor, is the stance that i take on things. You're limited by your rods, not your gas.

Engi-ninja

Hahaha, Princess Bride!

shuiend

iTrader: (24)

If you can weld then going the DIY route makes sense. You can find more then enough on here to copy my MKTurbo setups, and several users have done it successfully. If you mean to slowly acquire pieces one by one and DIY. You will probably end up spending within a few hundred of what my stuff costs, it will just take you a long time to acquire it all.

This. You can bend stock rods on Cali91 octane. No need to use corn to bend them for no advantage.

pdexta

iTrader: (17)

I'm a big fan of E85 and I can think of several reasons to switch. Every car I've done the math on it has showing to be more cost effective than 93 octane (costs ~40% less and loses ~20% fuel economy). Anything you're street tuning yourself it's much safer detonation wise. You'll make the same power on less boost, quicker spool from more advanced timing. If you don't run a cat it smells delicious instead of stinky.

To me if you're already planning a tuneable ecu, bigger injectors, a fuel pump, and there are plenty of stations in your area, there's no reason not to switch over.

shuiend

iTrader: (24)

All those points are true. To me though it all comes down to availability. And E85 is just not available anywhere near enough places to make me comfortable using it. Sure as long as I stay within 25miles of where I live I am fine. If I take the miata on a trip anywhere else though in the state I am just about out of luck finding E85. It is the same problem as an electric car to me. It might be good charge wise for 85% of my driving, but that last little bit is what keeps me from going.

Pedxing

Sweet. Hoping someone would get that.

Pedxing

Checking prices right now, it's looking like $1.80 for e85 vs 2.40 for 93. Though I paid 2.60 like yesterday, wth. But that's less of a concern (price/efficiency) than the safety thing. Also quick spool is big on my list -- have you seen good success with that? Also with my last emission text, it was my NOX numbers that were on the high side -- e85 is supposed to lower that due to lower temps. Basically i'd like a safe fast spooling street machine. Lots of torque from 2500 to say 5500.

Pedxing

Does the MS3 do the flex fuel sensor any good now? I know MS2 was not super awesome. That would fix the range concern right? Maybe not max power or efficiency when running a random blend but it should run ok hopefully.

Anybody running that with success right now? (I know: search noob.

pdexta

iTrader: (17)

I'm running a flex sensor and it seems to be working, but I can't ever bring myself to run 93 so I guess I can't say to confidently. I set the flex sensor up on the car n/a and it read ~7% ethanol. I switched to E85 with a couple gallons of 93 left and it read ~70%. Filled again with E85 and it's been consistent 85%, except for one tank I got that was 75% from a station in the area that's started to get a reputation for lower ethanol content.

I keep thinking about switching back to 93 to finish off my tune, but I'm confident it's good enough to get me around if I ever do get stuck somewhere without E85.

I just set it up 10% and 85% spark and timing maps and have linear adjustments between them, which if I recall, is essentially how MS2 handles it. After researching it seems like the ideal fuel map should be pretty well linear and the ideal spark map be more exponential as you drop from 85% down (hope that makes sense, I'm probably using all the wrong terms and not explaining it well). I just went linear on both so it's well on the safe side anytime ethanol drops below 85%.

Pedxing

Great info, thanks for that. I'm taking baby steps, so time to ponder. In TX we have emissions until the car is 25 years so next year (april) is my last year. I want to get the ECU and wideband going first. Fuel pump and injectors work now it seems but are old and I want to replace and tune prior to forced induction. Might as well pick new ones that are ethanol compatible since it's all about the same price and then decide.

Roll bar coming from Hard Dog this weekend. Assuming fed ex can make it through hurricane Harvey.

psyber_0ptix

iTrader: (4)

Stay safe! Hear it's going to be a hairy couple days.

psyber_0ptix

iTrader: (4)

Stay safe! Hear it's going to be a hairy couple days.

Pedxing

Thanks. 9 inches of rain Friday night and 9.5 more last night. But the Miata's still dry for now!

technicalninja

Heads up, the Texas Emission tests apply for vehicle 2-24 MODEL years old, As the 2018 model year starts 9/2017 you have exactly 5 more days that your car is covered under this law.
No more ASM (sniff tests) for you...

One of the reasons I moved from Tarrant to Hood county was to get away from "non-attainment" emissions regulations. (you cannot swap engines easily on OBD2)
My best friend is a technician/state inspector for a "Texas Recognized Emission Repair Facility" and is an emissions rules guru.
He stated that the "safety check" your car will now have to pass has NO emission component in it at all. This should mean you no longer need a cat to pass a visual inspection.

The ASM test requires a chassis dyno and only applies to pre OBD2 vehicles, 95 and earlier.
The dyno and 5 gas analyzer which my friends shop installed in the floor 15 years ago cost $42,000 new and had a maintenance contract of over $250 per month.
As they were doing less than 10 ASM inspections per month the shop owner decided to no longer offer ASM testing as he was making $10 and spending 25 per car on maintenance to the test machinery...
The state DEACTIVATED his 5 gas and dyno as all of the controlling software is through the DPS in Austin.
Now they have a useless dyno installed in the floor and a "broken" 5 gas that is taking up space in the shop.
As ASM testing will go away for everything September of next year ALL of the dynos and 5 gas analyzers will die.
Even the inspection stations got screwed in the end...

E85 can be tuned tightly enough to make a car "disappear" from a 5 gas. You can end up with readings beyond the capabilities of a standard 5 gas to detect, NO included.
E85 is the way to go if it is readily available.
Your injector/fuel pump sizing will be larger with E85.
You don't need it for 200 HP but If I was paying for a upgraded fuel delivery system I'd spec it for 50-100% more fuel than I needed for my power goals.
E85 can be the equivalent of 100-105 octane. As it burns cooler than gasoline it can reduce crown/combustion chamber temps which allows more timing or boost.
Flex-fuel sensor, 1000cc injectors, and modern ECU is the way to go IMO. Don't go cheap on the fuel system. Build a 350-400 HP capable fuel system FIRST and when you get the itch to build a forged motor you will not have to "rebuild" the fuel side.
Do a ****-ton of reading the build threads on this forum. Lots of good information exists...
Rick

pdexta

iTrader: (17)

Found this virtualdyno log I made a while back. I tuned for 93 octane and datalogged a pull on the way to the gas station. Filled with E85, loaded a E85 basemap that I made and datalogged another pull on the way home. Blue was going to the gas station on 93, Red was E85 coming home. You can see spool coming on ~200rpms earlier, as well as +35hp, +30tq at the same boost.

Pedxing

I REALLY hope you're right. The inspector who did mine back in April was saying they didn't care about model year months, to keep it easy it was just current year minus model year needs to be 25 or more for no emissions. For me that would be 2018 - 1994 = 24 = emission test. :( I wonder if there's some discretion by inspector.

Pedxing

Wow, that's awesome...[immediately looks for build thread]. Holy crap dude, turbo miata number five??? Ha, such amaze

OK I've got some reading material ahead of me, thanks for that info.