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Complete Upgrade! Part Two. July 2010

In case you didn't get to see part one of the "Complete Upgrade" build, I was looking for an improvement over the old custom Greddy turbo setup that I had on the Miata. I wanted a simple setup with great flexibility in turbo selection, excellent performance, solid reliability and low cost.

Picking up where we left off, I got the downpipe bolted to the turbo, which was an absolute joy thanks to the easy V-Band connection. It looks like the pipe is touching the firewall shelf, but there is a good 1/2" or so at the closest point. Miata turbo and downpipe

For the rest of the exhaust, in the interest of time I'll be running my 2.5" setup that I had while running the Greddy. The only difference from this picture (from 2007) is that I've removed the two bolt flange up front and stuck a flex section with a slip fit for the downpipe. It's not the optimal 3" size for this setup, but it will get me running so I can get the baseline tune sorted out. I plan to do a nice 3" as close to the turbo exit as possible on out to a Magnaflow, but it's looking like our baby boy may be arriving sooner than we expected! That's the part of this build that I hadn't shared with y'all yet - I'm trying to get it running before the stork arrives! miata diy exhaust

As I mentioned above, we've got a baby on the way, so my time in the garage for this build is limited and precious. I really had to kick it into high gear and make the most of my time when tackling each item. I've got an older neighbor who I often watch just sorta tool around casually while he works on his car. Maybe I'll have that luxury someday. For now it's full speed ahead!

The intercooler arrived yesterday! It's from Ebay/CXRacing and measures 28x7x2.5 and has 2.5" inlets and outlets. Here's a few pictures of it. Ebay Intercooler 28x7x2.5

Ebay FMIC

I really wish I could've taken more pictures of the intercooler install for you guys, but I was flying through it. I still have A/C and this intercooler fits great. I did have to gently bend the A/C receiver/dryer up and out a bit, but nothing too extreme. Other than that, it fit great.Miata FMIC

Just for reference, here's the intercooler I was running with the old Greddy setup. I got a big old tooth in the grille now!

I also jumped on the hot side piping today. I had these in my old' pipe bin, but they are steel bends from Summit Racing. They are 2" OD. I'll be running 2.5" on the cold side. MIG welding

Here's the hot side piping all wrapped up and ready to be bolted on. As with most everything, I gave it a couple coats of Dupli-Color high heat Low Gloss Black. DIY intercooler piping

Whew! So what do I get after working my butt off in the garage all afternoon? A cold beer, shower and some time in front of the TV? Hell no, more like "Mow the yard chore-boy!"

The next day I was able to spend some more time working on the car and got lots done. Probably the biggest task was finishing the cold side piping. When I did my Greddy build, the pipe below was in two parts requiring a coupler. It just took a little more time and effort to make it a one piece pipe - and I'm very glad I did. As you can see I've also added a Tial blowoff valve. On my old Greddy setup I used a 1G DSM blowoff valve. The Tial was tricky to get in there just right, but I'm happy with how it turned out.

God, this is a great tool. I am happy inside when I can find a reason to use the sawzall. I love my chop saw for laser-straight cuts, but the sawzall is fast and makes nice clean cuts on steel pipe. sawzall

I also got my boost controller in the mail yesterday. I've used Hallmans for a long time and you just can't beat the quality, simplicity and low cost. Hallman boost controller

Besides finishing and installing all of the turbo/intercooler piping I tackled tons of other little things too. I re-installed my water injection setup today also, which is a bit of a task due to the extra vac and water lines needed for the rear mouning location. It's worth it for convenience though! Here's the tank and pump assembly installed. Sneaky, no?
trunk mount alcohol injection

I got the boost gauge installed, did all of my heat shielding and set the timing. I still have to finish the intake setup, my filter and elbow should be here by midweek. For now I have a temporary setup on there. Speaking of heat shielding, I have an old turbo blanket that I planned on using, but I wanted something simpler and that looked less "hacky". I'd seen folks on here using license plates and thought that was a pretty cool idea. Here's my spin on it:

Here are the raw materials that I used. Two TN license plates and some heat resistant cloth that I had leftover from another project. I put a piece of 3" exhaust pipe in the vise and used it to roll/shape the license plates.

Here's the shield with bolted up and waiting for the valve cover mounting holes to be drilled. turbo heat shield

The finished product! Our nice flat license plates makes for a clean look. It seems to be working great and there are no rattles, etc even though the spacing is tight. Turbo heat shield


Every build has it's "moment," a time when things don't go exactly as planned, no matter how good your plan you may be. My moment came when I started driving the car around a bit. For the first couple days I was putting around and running errands - you know, just to burn off all of the exhaust coating and make sure everything was functioning properly. After confirming that all was well, I began to lean on it a little and that's when I knew I went too big on the turbo. The overall responsiveness was just too lazy for me. I've known some folks who say they can "drive around" that, but not me, I need the low end punch, especially in a lively chassis like this little car has. This was feeling like deja vu.
turbo lag

I mostly expected this, as it is a big turbo for a stock 1.6 to spin up. I think it would be fine for a built 1.6 or larger 1.8, but I need a little more response. I was prepared for that letdown coming in, which was why the T3 frame is so great. To remedy this small setback, I ordered this smaller, T3 50 trim turbo from EBay. Normally, a turbo swap would be a major cost issue, but the affordably turbos on Ebay allow you to experiment a bit - but you are sacrificing quality. This ain't no Garrett. You just have to be aware of that risk going in. Since this is a car I don't drive everyday, it's a risk I'm willing to take.
Ebay T3 Turbo

You can definitely see the smaller exhaust housing here.

Here's something a little odd, the bigger turbo's wastegate flapper (top one) was much smaller than the new turbo. I figured they would be the same, so I pulled the one I modified off the old turbo only to find this. I ended up going with the bigger one and modified the housing so the lever could open all the way.

Here's the turbo bolted up before final clocking. Between the great turbo location and the V-band downpipe, swapping turbos is a breeze. The only thing I had to change between the two turbos was the intake and turbo outlet pipe. You could definitely have two turbos and easily swap them out for different track events/preferences.


All done, except for the boost controller. For now I'm going to leave it this way and see how it operates. The Ebay listing says 8psi, but we'll see. I clocked the wastegate diaphragm too, as the as-delivered location pointed the vacuum outlets straight up to the hood. turbo miata




Who here likes surprises?
For engine management this time around, I am running a 1G DSM 4G63 Turbo ECU. Some folks will be able to spot the DSM bits in the engine photos above. The most obvious is the throttle body and elbow, you can also see the injector resistor box on the passenger firewall. The cam angle sensor is the stock Miata unit, the power transistor is from a 1G DSM (almost identical to the stock Miata unit) and the coil packs are DSM units swapped into the Miata bracket. I'm using the factory DSM knock sensor screwed into the empty intake bracket hole in the block. I literally had all of this stuff in an old bin from a swap I planned on doing, but never did. So many of the Miata components were similar, I couldn't resist. I got the idea from the guys that running the DSM ECU on the KA24 240s. The car runs perfect, no stumbles, stalls or high idles and the DSM ECU doesn't seem to know/care what name is on the valve cover!

The ECU I'm running is a 1991 EPROM. The keen-eyed folk noticed right away that I don't have a DSM mass airflow sensor, this is only because I had a spare DSM HKS VPC and decided to use that until I get a new version of DSMlink. For those not into ancient DSM piggybacks, the VPC converts it to a MAP setup, allowing you to run without a MAS, etc. The EPROM chip in the ECU is a custom KeyDiver one that I had laying around from way back that is optimized for 550cc injectors and the VPC.

The knock correction is all built into the ECU and works beautifully. It really is how I've been able to go fast with such simple setups on 4G63 powered cars in the past. I've always just logged knock using Technomtive datalogger, which is a dead simple tool that's been around forever. I mean, I monitor other parameters, but when it comes down to it, the knock sensor tells you everything you need to know at WOT.

The McDonald's iced coffee was an important component to this project. I don't eat their food, but the coffee is pretty good. In this picture I'm swapping out the coil packs from the DSM bracket to the Miata bracket. I was also doing some other stuff, which explains the schematics. The internet has made the car hobby so much more fun and affordable.

Here's my "test bench" The laptop wasn't required, I was just monitoring all of the sensors. It fired up and ran great like this, I just couldn't drive too far!



So, with that little tidbit out of the way, after getting everything together on the smaller turbo setup, I went out datalogging and am very happy with the results so far. I was running 10-11psi and although it is hot as heck here, it was pulling very nicely. I am really loving the midrange in this setup, it is plentiful and always right there when needed. It makes buzzing up and down the hills here a dream.

The datalog image below is from a dead stop 1st-4th gear pull, with sloppy shifts and all. As you can see, there is only the slightest blip of knock, and the 550cc injectors aren't even trying. Lots of timing too so there is tons of room here! Let the fun begin!



Thanks for reading and look for some videos of the new setup in action soon!

Thanks for reading!

-Tom