Skidude builds a turbo miata. Again.
 

I built my first turbo miata a little over 3 years ago and I drove it for a couple years and then sold it last September. I went very cheap on that build, and it was more of a learning experience than anything else. I learned a lot and now I am building another. It is going much more smoothly.

The car (before):
-2002, white, black cloth interior
-5-Speed, Open diff
-Koni Sports with Koni Coilovers
-15x8 6ULs (silver first-gen)
-Bald Dunlop Star Specs
-Biggest Racing Beat Sway Bar

The project (after):
-GT2560 à la S15 Silvia
-AbsurdFlow Begi Replacement manifold version 2
-AbsurdFlow 3" Downpipe
-Enthuza 3" exhaust with 18" magnaflow
-Ebay intercooler kit with 2.25" pipes and a 22x5x2.5"
-FM Stage 1 Clutch
-3.9 Torsen rear end
-Megasquirt 3 and 3x (home-build)

Megasquirt
 

I would like to say the megasquirt build went smoothly, but then I would be a liar.

I bought the kit and followed the instructions Brainiak posted up, but I missed a couple steps and forgot all of the input circuits. I didn't think much of why the inputs weren't registering in megatune when I was on the stim, and started building the alternator control circuit. That went alright, and I tested it on the board, but I forgot to test the actual connections on the DB37 connector. I fixed the input circuits and installed the megasquirt and completely forgot to verify the alternator voltage in the car, and started driving. I got about half hour away (so many things wrong with that, I know) and the car died. I figured out the problem almost immediately, but I had to have the car towed home so I could fix it.

I eventually fixed the alternator circuit problem and the car ran well and I started tuning. Had some hiccups, but with the help of some awesome forum members here, they remained just small hiccups. The cooling fans, AC, and VSS don't seem to work, but I am slowly working on fixing those while installing and tuning the car, since it will drive fine in this weather without cooling fans.

Clutch
 

Sorry guys, still no pictures in this post, but the next one will have some I promise!

The first hardware upgrade for this build was a clutch. I bought the FM Stage 1 clutch. My last car had a cheap Ebay 6-puck and I hated it because it would chatter all the time, so I spent a little more and went with a full face unit this time. A great decision.

The shop I work in here is a perk of working for the military (civilian DOD). It's pretty much a 6 bay garage where two bays are a service shop and the other 4 can be rented by the hour (or day if you're friends with the techs :giggle:). They have a lift in every bay, and every tool you could want in a service station, except an alignment machine and a leak down tester (those are the only things in the last 18 months I've asked for and they didn't have). It's wicked awesome. The only down-side is that I have to conform to their hours, and those aren't that great.

Anyway, the clutch. I went to the shop after work on a Friday, and started taking things apart. I rounded off one nut where the exhaust manifold connects to the downpipe and then I spent a lot of time trying to get the transmission out with the exhaust still in. That added at least two hours to the project. Eventually got the transmission out and replaced the clutch, and of course, had some trouble getting it back in past the exhaust. Eventually got it, but the whole job took about 6 hours longer than it should have for a total of about 8 hours over two days. Not my proudest moment, but the new clutch drives better than the stock one, and I'm very happy with it.

Turbo and Downpipe
 

Ok, now there will be some pictures... if I can remember how to properly load them in.

I took some days off from work to take advantage of the open hours of the garage. Starting yesterday I took 6 days off for a total of a 10 day vacation. I won't need the whole thing (I really hope) but I needed a vacation anyway.

Yesterday was the first day of the major build, and it was mostly used for pulling the car apart and installing the turbo and manifold.

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Here's the magic power adder. Pretty standard, really.

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Here's the car before. I'm going for an 18psi-esque look if you hadn't noticed. I'm going for a stealthy look on the outside, so it should look exactly the same when I'm finished.

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Here's the car an hour later. I've never taken a car apart this far before, so hopefully I can remember how to put it all back together.

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Look at that beautiful tubular manifold! It's almost a shame to rip it out and sell it.

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Look at all that space now that the air box and exhaust are out of the way! Just begging for a turbo. I think I'll give it one.

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Here is that beautiful exhaust manifold. Every time I look at it I get a little tingly in my no-no region. You can see the massive downpipe as well, though I forgot to take any good pictures of it out of the car.

I had to cut a notch in the shelf to fit the downpipe, but it didn't require much. A couple of the bolts were pretty obnoxious to tighten, but with some help from a friend, we got them all nice and tight for the manifold and downpipe.

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And here's the turbo in the car. Fills that space nicely I think.

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Now that the turbo is mounted, I closed the hood and went for a drive like this. Didn't really, I haven't even hooked up the oil lines yet.

Day Two: Intercooler
 

The shop hours on Saturdays are limited, so I didn't get to start until around 11, and they closed at 6, so it was a sort of short day. I got the intercooler mounted and the pipes all cut though.

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I'm going with the awesome NB intercooler piping option that you suckers with NAs can't use. I had some trouble with the power steering cooling loop getting in the way, but I bent them up out of the way and I think it will work. I forgot to take pictures of that part, I'll try to remember to do that on Monday (garage is closed on Sundays).

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Here's the awesome and not-at-all-ghetto intercooler mount I made. It pretty much just hangs there. I had some more stable mounts but they wouldn't play nice with the bent-up power steering loop.

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The intercooler is mounted. Can you see it? Stealthy, eh? I think it will be all but invisible once the bumper is back on. The only indication of mods from the outside will be a slightly larger exhaust tip. And the 6ULs.

I forgot to take any pictures of my routing, so sorry for that, but I will try to take a bunch more pictures on Monday when I go back for Day 3.

I'll be interested to hear what you guys think of my build so far.

ARE YOU TRYING TO MAKE A CLONE OF MY CAR????!!!!


Cause it looks that way. And I like it:D

I'm more using yours as inspiration. I don't have the budget or skills to build my motor, and the white things on top of your headlights aren't on my car, but I see your confusion.

Wheres the other 4 cylinders?

Car looks good! White NB's are sex.

Very nice. For future if needed, mount the turbo to the manifold off the car. It makes reaching the little nuts on the bottom of the T2 flange so much easier. After the turbo/manifold is bolted to the head, the downpipe comes up from the bottom with a twist with the car on jack stands. Install the one lower downpipe bolt first and hang the downpipe on it while you climb out from under the car (the bolt that is used on that slot in the flange). It's a 1 person job cause...I'm one person and have to make the stuff install and remove that way :)

Lookin' good! You will *love* that setup.

Truth!

Looks like a solid build, and it's always nice to have a lift and endless supply of tools. I'm jealous of the absurdflow goodies every time I see someone else with that setup *sigh*

And I can totally relate to that sentiment. I just pulled my car apart last week and had the same thought.

Day 3 and 4
 

I worked about 12 hours yesterday and about 8 today, and the car looks not a lot different than before except it has a bumper now. I did a lot though, just nothing that felt quite as substantial as actually installing the turbo.

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Fitting up some intercooler pipes, here's the warm side coming through the void in the bumper.

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Here's the cold side doing a similar thing, though it leaves through the back instead of the top of the void. This one also has clamps and an IAT sensor in this picture.

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Here is the front of the car, all put together on the inside, but missing the bumper. I put the driver's side headlight back in also. I think this is about when I noticed that my warm side intercooler pipe didn't play nice with my fog light. I ended up trimming that pipe a little, and then putting a small dent in it so I could put the bumper back on.

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Here's the engine bay as it sits right now.

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I got the front clip back on, and that intercooler is amazingly stealthy. I'm very excited about it. With the hood closed nobody will know what they're messing with.

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We can see here the massive racing beat sway bar and koyo radiator. I'm not a fan of the long screw ends on all the T-Bolt clamps, but I'm not sure what to do about it.

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This is the tip on the Enthuza exhaust that showed up today. I love the tip! I'm not sure how I'll make the rest fit with the downpipe, but I'll figure that out tomorrow. The downpipe from Tim is pretty long and just ends, and the enthuza exhaust begins with a flange about 12 inches forward. I am thinking I will just cut off the last 6 inches of the downpipe and then cut off the first 6 inches of the midpipe just in front of the cat and they'll go together nicely. It does make me nervous to start hacking into my shiny new exhaust before a single breath of exhaust has gone through it, but I have to make it fit somehow.

Thanks for the advice, I sort of figured that out most of the way through mounting the whole thing up. I also should have hooked the water and oil fittings up to the turbo before I mounted it also.

I got the enthuza exhaust today and the downpipe ends right in the middle of where the cat is so I know I have to cut a little bit off the end of the downpipe.

I couldn't find a garage to do the project in, since I can't rent the one I'm using for months at a time. I am sort of glad, too, since I don't think I actually had enough money saved up for the V8 swap.

Nice build, I just did mine last week and ran the same ic piping route. Mine was 2.5 though, looks like I had to cut out a crapload more than you did behind the drivers headlight. idk maybe the 01+ headlights are different. Anyway good looking build, what about the bov?

I don't have a BOV yet. I bought one and I bought a pipe-mounted flange for it but when it showed up it was 2.5" instead of 2.25" so it doesn't fit and they don't have any of the right size. I'm not sure what to do. I can't weld aluminum and I don't really know anybody who can, but I may see if I can get a flange welded into a real pipe sometime soon anyway. I'm only going to run 6psi for the first couple weeks until I get it all tuned anyway so I'll just have to deal with some compressor surge until my weld-flange shows up and I find somebody who can attach it for me.

Is that the muffler hanging down below the bumper? WTF?

Yeah, it's only just hanging there right now. The car is also about 4 feet up in the air, so with the perspective the muffler looks a lot lower than it really is. It will be better when I get the whole exhaust all fitted together.

i know some local people who can weld aluminum..heres what my IC piping look like if you dont remember

http://sphotos.ak.fbcdn.net/hphotos-..._1030338_n.jpg

I didn't remember that piping, the welds look fantastic. There are some really awesome welders at work but I will have to see if I can get them to take on a small personal project for me. If I can't then I will definitely ask for your help finding somebody who can stick that in there.

Looks like someone knows where to find a skilled welder and doesn't know where to find tight R mandrel bends.

np man.. if you want his info just shoot me a pm.. i know he will do even the smallest of jobs. which reminds me, my subaru is there now with its blown engine and i need to go pick it up asap lol

Huh what? I don't know where to find either one if you mean me... So far I have just been finding people who build the best stuff in general I guess.

Sweet build. What are your power goals?

235-240 at the wheels. It should be capable of that without sweating much, but I don't want to kill my motor. I have no idea how close they can tune things like that, but we'll see.

it cut down costs alot. his shop is a tad bit too crowded for a mandrel bender. when i was there last tuesday he had 11 cars inside his shop, has an in-house powdercoater, only 2 lifts, tons of spare engines, and most of the time is working by himself. lol

I hear ya on space and overhead costs. But you can buy prebent mandrel bends in various bend radii. It would cut down on those pie cuts and number of welds. unless that's the JDM custom look you were going after in which case...nice.

Final Long Day
 

Today I installed the new differential and the rest of the exhaust. In case anybody forgot, the exhaust is a 3" Enthuza stainless piece with a cat. The diff is a 3.9 Torsen from a guy in Atlanta.

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Here's the axle-back section of the exhaust. It's pretty and the tip is nice and centered in the cutout in the bumper. My last car always had a tip that was off center and it would rub and melt the bumper and it always bothered me. No problem here. Here is also the half-shafts hanging where the diff used to be.

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You can see here the excellent bends of the exhaust, and the output of the transmission. This is about when I noticed I'd dumped about a half-quart of transmission fluid on the floor through that very hole. Without the diff and PPF, the engine rocks backward and dumps the fluid.

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This is the downpipe I got from Tim, and it's kind of long so I had to trim it to get the rest of the exhaust to fit. I ended up cutting the front off the enthuza exhaust so it would butt up to the trimmed downpipe and I used a band clamp to attach them. It was painful to cut these two pieces, but they are on the car now and I'm happy. The exhaust is a little louder than I expected, but it's .5" bigger than my last car's so I'm not really surprised. I probably should have gone with a 22" muffler instead of the 18", but it will be great once I get used to it. I absolutely love the tone and look, and the fit seems perfect.

I went out tuning after I remembered to put fluid in the diff, and the tunerstudio autotune did a fantastic job. The idle is still a little annoying, since it seems to get stuck sometimes and idle at 2200rpm for a while (like an hour at a time), and then it will just go back to normal. Is it possible for the idle valve to get stuck open? I guess I'm just having a really hard time tuning the idle properly. None of the settings seem to change anything very much even when the valve isn't acting stuck. I will probably post something in the megasquirt section in a few minutes here.

I'll change the oil in the engine and diff tomorrow, and probably tune some more and try to iron out the rough spots. They don't act much like poor fuel conditions, but I'll see if I can figure it out tomorrow.

That's a nice, clean car you have there. Exhaust looks great. As for idle, the first thing I would do is work on the mixture. Set the MS to warmup mode so that your idle orifice and control valve are under manual control, and then tune your VE for highest vacuum (lowest kPa) or highest RPM. Now, make sure all your idle cells are using the same VE and ignition advance (something mild like 12-15° BTDC). At this point, you can start messing with closed loop.

Apologies if I'm overstepping with the basics here.

Your PID lockout settings are off.

How did you like it besides the idle issue?

My idle sometimes hovers around 2200rpm too, as my closed loop idle stops above like 2000. Normally when I first start my stuff up after a long winter.

this. You need to alter these for your car.

The rpmDOT threshold should be about 10 point sabove what you normally see at idle. So change one of the gauges to display rpmDOT, blip the throttle around and let it smooth out, then see what you get. if it's like 70, enter in 80 into your threshold for PID lockout detection.

Next for the max decel %, I find the number that works best is the MAP value a few points under where (haha i said underwear) you idle. For example, I idle at 32kPa and my max decel load % value is 29kPa. This means the PID code will trigger once you breach 29Kpa on decel..too great and it's possible you wont pull enough vacuum and the PID code wont try to idle and it gets hung up.

Another thing is the max RPM when idle valve is open value. I can shoo tmy idle up to 2500rpm or so easy, so that was the value I had in there. But what I found was (since I dont have VSS), was that when I was cruising below 2500 that PID code would enable. It would open the valve more and more and then once I hit the clutch the rpms would shoot up and I'd get locked out of PID. So I lowered that number down to like 1300, since I never cruise that low and I haven't had the issue since.

That should help you cure the issue.

That contradicts what Ken states about the max rpm with idle valve open/closed. He says that just effects the sensitivity of the PID code and the actual numbers don't actually matter that much.

He says it... but I have logs where PID enabled while I was cruising below that number. The day I lowered that value, it never happened again.

Ha, brilliant!

<goes out and adjusts max RPM setting>

I got the major part of the install finished. Changed the oil in the engine and diff, and closed the gap in the spark plugs to .040in. Re-gapping the plugs fixed the misfire I was getting.

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I've got some greasy marks on the hood and fenders from where I touched it with greasy hands. Does anybody have any suggestions on how to get the car white again?

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Another picture of the front of the car with the stealthy intercooler. Not sure why I like it so much.

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Here's the back with the end of the Enthuza exhaust. It's a subtle change from stock and I don't think many people will notice that the car is modified except that they will probably have ears. With ears, you can't miss the mods.

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Nice little cat, and the clamp that holds the center of the exhaust to the downpipe.

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A couple pictures of the underside of the car here.

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This is the only part of the charge piping you can see from the outside of the car (aside from the intercooler which you would have to notice).

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I think it might be time for some new tires. I'll order some RS3s when I'm over the shock of all this turbo money.

I got a chance to tune a little yesterday, but not a lot. My package from DIY hasn't showed up yet so my cooling fans still don't work so I can't sit and idle for very long, which makes it difficult to tune idle. Driving seems to be tuned alright, but warmup still needs some work. What happens at about 5500RPM? The car seems to just take off and run a lot smoother above there. I don't have VVT yet, and I haven't done anything on purpose to actuate the variable intake, but that variable intake thing is my biggest suspicion. Is it called VTCS? If yes, it is set to activate at 1800RPM, which is not even close to 5500.

I haven't gotten a chance to play with it too much yet, but I absolutely love it so far, thank you!!

Try a clay bar for the grease marks. Those things really work and are a lot easier to use than it sounds. Once you've clayed it, wax it and you're all set.

Nice car.

scott and i were discussing this at the gym while we were toning our thighs...

There is also a "leave valve closed above (rpm) XXXX" that may affect that.

Incidentally, the VTCS settings are correct for a turbo miata. You're thinking of VICS that activates at 5500. VTCS only affects warmup anyway. It doesn't affect idle speed (though it does affect idle stability when cold).

Just out of curiosity, what firmware version are you on?

So VICS is automatic, or did I set that up somehow without realizing it? I don't remember connecting it, but that doesn't mean I didn't.

I'm on firmware 3.0.1, waiting for the release that has VVT. BTW, do I have to do any hardware mods to make VVT work with the new firmware when it's released?

there is no ms3 3.0.1 firmware...you mean 1.0.1?
any of the 1.0.X releases are a safe place to be.

VICS was only on the 99-00 cars.
VTCS was only on the 01-04 cars.

i'm preparing a treat for your megasquirt thread.

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I added my boost gauge and AFR gauge. Took me a while to track down power for the light in the boost gauge that would dim with the rest of the dash, but I got it off the hazard light button when I realized it lit up (the button in my '94 never lit up so I never realized this one did). The USB port in the middle is attached to the megasquirt so I can hook to it without crawling under the dash or keeping a coiled up cable under a seat or something.

Yes, typo on the firmware version, it's 1.0.1.

So I don't have VICS, and VTCS is for warmup, so what makes my car shoot forward around 5500rpm?

I'm excited for the megasquirt treat! It's just what I need for a Friday night.

^ I'm digging the built in port for MS, any assembly pics?

Nope, completely forgot to get any pics before I installed it. I'd probably use a different port next time, since I'm not a huge fan of the shiny chrome on this one, or the fact that it sticks out so far. I'd also try to find something that would fit through a round hole since cutting the rectangular one was a PITA.

VTCS would do that "nothingnothingnothingZOOM" if it were set to a value where you're building boost. like 5500.

I have mine set up on xpander board pin 20 (inj H) and it activates when clt is < 60 AND rpm is < 1800.

Those are the settings I have on that output, so I still wonder why I get the zoom. It could be something as simple as my tune needing more work, but it's so consistant and predictable that I doubt that.

Ever since I replaced my stock injectors with some 570cc bosch ones I got from the classifieds here, the car hasn't run consistently. Now, I have no reason not to trust the seller, but I also have no proof that these were actually 570cc injectors, since they were used (cleaned and flow tested, they came in little sealed bags with new stuff)

This is my general settings page and my current fuel table. Do they look reasonable to you guys? Keep in mind the fuel table isn't tuned very well, but my AFRs are pretty near where they should be (today, anyway. They'll be way off tomorrow I'm sure)
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70s is high for idle cells. how'd you calculate your required fuel?

remember that 570 cc is at 43.5 psi. your fuel pressure is probably closer to 55-60. for the req fuel calculation, you should use 670.

you definitely need to smooth out some of that fuel map though. differences of 30% between adjacent cells is going to cause weirdness.

I just calculated it by clicking the button and putting 570 in for the injector size.

I know the tune needs some work, I'll get there. I just need to get the idle and stuff worked out first.

A little brake clean sprayed on a rag will get rid of that grease asap.

btw, did you spray paint the front of your IC black?

Yes.

My Megasquirt should be coming back to me on Monday (Thanks again y8s!!) and I will commence massive tunings.

How many pounds of boost should I run? I would like 240whp (give or take) so the car remains reliable, but I don't know what boost will give me that with this setup. I just really don't want to blow my shit up just yet.

I was there to witness the resurrection of your MS....

and about boost level: all of it.

And thank you as well, Brain. Was the resurrection dramatic, and involving lightning? I pictured you two in bloody white lab coats and goggles standing over a slab table with a soldering iron and multimeter.

About the all of it, how do I know when I'm using all of it? Just turn it up until I break something, then back off a quarter turn?

I was actually in my jammies, and it was very undramatic. but y8s did cheer when it finally synced and lit up.


and lol at all of it comment. its like finding MBT.



nice USB port, I did something simliar, but put it in my center console.

Thanks, I probably should have put it in the center console, but I had nothing else to put in that spot.

9-10psi should be about 240rwhp dynojet.

Dynojet, eh? That brings up a good question... if stuff starts breaking around 250whp, is that 250whp on a dynojet, or on a dyno-dynamics? I hear those are two very different power levels.

Either way, I am thinking I will street tune for 10psi and then get it dyno tuned as soon as I get everything ironed out.

I just got back from a little tuning with my awesome home-made electronic det cans, and it's amazing how you can actually hear detonation so clearly!

So anyway, I want to figure out what happens at around 5000rpm at WOT. Above there, the car runs a lot better and has quite a bit more power, and I'm stumped as to what would cause it. Please help!

I attached a log of a 1-3 pull and my current msq. Any help is appreciated, with this 5000rpm thing or anything else!

Did I actually stump miataturbo, or is nobody paying attention to my boring build thread anymore? The part where I don't have much power below 5k rpm is kind of annoying at autocross.