LetItSnow's casual, emissions-oppressed build
#1
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I recently introduced you to this guy:
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I've done the brakes, suspension, timing belt and the top. It's time to go under the knife again! My intent is to just give the car some more guts. It's my daily, and I'll probably get back to autocross (ten years in, I took a break last season) knowing that I'll die in PAX. No track days planned. This build is more for the experience of doing it than for hitting a power goal - I'm shooting for a particular boost and an engine that I trust. I don't care how many horsepower come with it.
I've been reading the hell out of this forum, forming my build list, and following the FAQ.
I've owned Corky Bell's book for years. Check.
Because I need to retain OBD-II compliance in order to pass NYS inspection, I've opted for an eManage Ultimate. (Bashers, keep walking.) I've got an O2 clamp and the MAP sensor, and a Boomslang is on the way. I'm exploring my options in widebands. So, there's my EM and ignition control.
Fuel is where things start to escape me. From the FAQ:
I've seen a share of 305cc bashing around the forum. Maybe this just varies by application? I've also read that the stock ECU will play nice with injectors up to about this size. Naturally, that could be the same as saying that all-season tires with low tread will get you through a Syracuse winter just fine...
Keep this in mind: As addictive as boost may be, I plan on maxing out around 8psi. With the limitations of some of the hardware I'm using, it seems like a good cap.
So, my question to you: With the EMU and otherwise stock fuel system, on 8psi max boost, will 305cc Supra injectors fit my needs, and will I need to make the underhood fuel pump loop and alternate FPR?
Jumping ahead a bit, as well... Looking at their page, it seems that Weir-Tech isn't in the flange business anymore. Is there a new go-to company for good ones? I've seen a few names pop up, but Turbo-Flanges.com has particular appeal to me for their recessed ports and the availability of a Subaru TD04 flange.
<Head flange> <Subaru TD04 flange>
![](https://www.miataturbo.net/attachments/build-threads-57/135063-letitsnows-casual-emissions-oppressed-build-img_3108.jpg?dateline=1426099615)
I've done the brakes, suspension, timing belt and the top. It's time to go under the knife again! My intent is to just give the car some more guts. It's my daily, and I'll probably get back to autocross (ten years in, I took a break last season) knowing that I'll die in PAX. No track days planned. This build is more for the experience of doing it than for hitting a power goal - I'm shooting for a particular boost and an engine that I trust. I don't care how many horsepower come with it.
I've been reading the hell out of this forum, forming my build list, and following the FAQ.
I've owned Corky Bell's book for years. Check.
Because I need to retain OBD-II compliance in order to pass NYS inspection, I've opted for an eManage Ultimate. (Bashers, keep walking.) I've got an O2 clamp and the MAP sensor, and a Boomslang is on the way. I'm exploring my options in widebands. So, there's my EM and ignition control.
Fuel is where things start to escape me. From the FAQ:
Originally Posted by Braineack
If you are using a “piggyback” fuel management unit such as the E-manage, the popular injector to use is a 305cc injector from the Supra.
Keep this in mind: As addictive as boost may be, I plan on maxing out around 8psi. With the limitations of some of the hardware I'm using, it seems like a good cap.
So, my question to you: With the EMU and otherwise stock fuel system, on 8psi max boost, will 305cc Supra injectors fit my needs, and will I need to make the underhood fuel pump loop and alternate FPR?
Jumping ahead a bit, as well... Looking at their page, it seems that Weir-Tech isn't in the flange business anymore. Is there a new go-to company for good ones? I've seen a few names pop up, but Turbo-Flanges.com has particular appeal to me for their recessed ports and the availability of a Subaru TD04 flange.
<Head flange> <Subaru TD04 flange>
#2
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I also believe the voodoo box is the better bandaid solution if you want to retain OBD-II capabilities over an e-manage but I am not an expert on bandaid solutions so I can't be sure. However. It is easy enough to get a megasquirt PnP and use that to tune the car and just put the stock ecu back in for inspections. No permanent modifications required.
#3
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Let me share a little of my experience. And since you're really not that far away perhaps a meet up sometime will help, namely a local autox event. What is your time frame for the project?
I am currently running the Powercards fuel and timing... Let me just say it isn't great at all. But I understand your position of OBD 2 compliance in NY state. So moving forward I believe I am running the 330 cc/min injectors (I would have to look as they came with my used MP62 kit) It runs fine and the stock ECU keeps up pretty well. Some idle issues (more to do with Supercharger than Injectors and ECU however). Also have some transition into boost issues (0-2 psi) runs really rich like 10-11 A/F. But I am switching to Megasquirt and 460 cc/min injectors (RX7) and that should suffice for my goals.
I am currently running the Powercards fuel and timing... Let me just say it isn't great at all. But I understand your position of OBD 2 compliance in NY state. So moving forward I believe I am running the 330 cc/min injectors (I would have to look as they came with my used MP62 kit) It runs fine and the stock ECU keeps up pretty well. Some idle issues (more to do with Supercharger than Injectors and ECU however). Also have some transition into boost issues (0-2 psi) runs really rich like 10-11 A/F. But I am switching to Megasquirt and 460 cc/min injectors (RX7) and that should suffice for my goals.
#9
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If it was only that easy... Putting the stock ECU back in, or anytime the battery is disconnected, all of the monitors switch to Not Ready. I wouldn't be able to just jack the stock ECU in, drive to the shop, and drive back out with a clean bill of health. The drive cycle to get the monitors to switch to Ready could take quite a bit of driving (the EGR one is the worst).
I really have three good options here. One of them involves time travel and an OBD-I car, and another involves moving to a state that doesn't require an OBD-II plugin annually. Neither of those is currently possible. That leaves me stuck with the third option, which is to do the best I can with what I've got to work with, and I'm sure that (skipping any understood "that sucks, dude"s) the experience on this forum can help me find a good solution.
Wha'cha think?
#11
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If it was only that easy... Putting the stock ECU back in, or anytime the battery is disconnected, all of the monitors switch to Not Ready. I wouldn't be able to just jack the stock ECU in, drive to the shop, and drive back out with a clean bill of health. The drive cycle to get the monitors to switch to Ready could take quite a bit of driving (the EGR one is the worst).
cause I've done this at least a few dozen times and it never took more than about 30 min of driving and 1 cold start. so at the worst the car would be "back to stock" for 2 days vs 1
you should probably stop doing drugs
#12
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My experience... I ran the bandaid option for about 2 years. Then I wanted to be reliable, consistent, and get the most out of my set up.
Being that you have more than one car and I'm guessing what 5,000 miles a year on the Miata maybe? Get your car inspected in April so every year you can swap ECU at the end of season drive enough to get the monitors to reset store the car and then first trip in the spring is to the inspection shop. Or inspect in Nov at the end of season. This way you're changing the ECU is never in the middle of a season.
I bought a kit with Bandaids and it bothered me for so long that I honestly only drove the Miata to and from autox and a few times a year (3,000 or less miles a year). This year I am doing the full ECU and hope to have a more stable, safe, and reliable tune for driving around and autox.
Being that you have more than one car and I'm guessing what 5,000 miles a year on the Miata maybe? Get your car inspected in April so every year you can swap ECU at the end of season drive enough to get the monitors to reset store the car and then first trip in the spring is to the inspection shop. Or inspect in Nov at the end of season. This way you're changing the ECU is never in the middle of a season.
I bought a kit with Bandaids and it bothered me for so long that I honestly only drove the Miata to and from autox and a few times a year (3,000 or less miles a year). This year I am doing the full ECU and hope to have a more stable, safe, and reliable tune for driving around and autox.
#15
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If you run a different computer, you'd have to unhook it and go back to stock computer to pass emmissions. As said, you can tie the wastegate OPEN so it won't build any boost and drive it and get it to pass with the turbo hardware still in place, so long as the emissions equipment is installed and working correctly. I'm more or less doing this with my car, sorta. I'm gonna have to swap injectors as 305's are enough for my build. I'm actually doing a parallel setup so I won't have to swap computers, both stay in the car, I'll just swap injectors, and swap ignition coils, install TB in stock location, take belt of SC, drive and test.
#18
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Realistically to go back for emissions testing you would unplug the MS and plug in your stock ECU. Block the vacuum line to the MS so you don't have a leak. Then disconnect the wastegate and don't go WOT. If you have swapped in larger injectors you will have to swap back to stock. I don't know what manifold you are using, but you will probably need the EGR pipe hooked up.
#20
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The newer pnp units can be physically uninstalled in literally 5 minutes or less.
Yes, it is THAT easy.
Every time I've weighed the pros/cons of piggy vs standalone (and I have, MANY times, because CA) no matter how I spin it, it just doesn't make sense to go piggy/bandaids.
Yes, it is THAT easy.
Every time I've weighed the pros/cons of piggy vs standalone (and I have, MANY times, because CA) no matter how I spin it, it just doesn't make sense to go piggy/bandaids.
FWIW, I'm letting the stock computer in my setup do idle/AC/PS idle up, factory gauges, emissions equipment, alternator. Then let the MS do the important go-fast stuff. It's more weight/wiring/complexity, but the factory does these things perfectly, and I've messed with MS for years and they are not perfect all the time in my experience. s