Plus I had to buy the following to make everything work:
-1.25" x 20" flex radiator hose
-2" to 2.5" 90 degree silicone reducing elbow to adapt to my 2" turbo outlet
-3/8" NPT bung for IAT sensor
-1" OD tube to weld on a bung for BOV
-.75" OD tube to weld on a bung for IACV
All totaled, DIY intercooler should be $206
The only problem is I sold my TIG welder to buy a new one and shipping is delayed. Install is delayed until next weekend.
Pics of the intercooler and piping:
I'm surprised by the quality. Everything looks pretty decent. Welding isn't perfect, but nothing terrible.
The piping is as expected. Powder coating looks good, but is has small scuffs from shipping.
Update on the project: the intercooler is installed, but not really.
Using the piping kit, I fabbed the intercooler pipes. I opted to weld what I could over using the silicone couplings.
I also fabbed some brackets for mounting the intercooler. It's mounted to the same mounting point as the A/C condenser.
Everything looked good and it was time for a test drive. On the first trip out I was having trouble getting boost pressure. I couldn't get over 0psi.
I came back and reconfigured some things, but the problem persisted.
I injured my thumb, had vacation, and became otherwise busy for the next few weeks. Today I revisited the miata with a new idea: the intercooler is restricting flow. I simply replaced the intercooler with a straight piece of pipe and it was like magic. I suddenly had boost again.
Made some good progress tonight. I got my new intercooler in. CXracing item number 0049. Had to make a few modifications for it to go in place of the DPT brand intercooler. By the way, DPT is working with me to give me a refund. It's currently in the mail back to DPT. We'll see if they actually give me a refund without any hastle.
The CXracing intercooler has 2 inch inlet/outlet, but I wanted 2.5". They didn't have one on their site that was the same core size with 2.5 inch in/out, so I just cut the 2 inch nipples off, and welded on some of the scrap ends I had from the intercooler piping kit. I also bent up some new brackets and welded those on as well. I took a page from the BEGi book for the new mounting location.
CXracing item number IC0049
Cut the 2 inch inlet/outlet off
Welded on some left over 2.5 inch intercooler piping to work with the piping already on the car
New brackets made to bolt to baby teeth mounting location. Much more appropriate than my previous setup.
Mounted up and ready for a test ride
New intercooler works beautifully. I finally got the chance to tune my EBC. I've attached my current tune, and the data log from my final 3rd gear pull when tuning EBC. Keep in mind that I still have stock exhaust, so my spool is a little slow compared to other T25 equipped miatas. My spark table is the stock table from DIYautotune, and the fuel table is stock with about an hour and a half of autotune this evening after I got the ebc tuned.
Please feel free to take a look at my tune and give me any pointers. I'm a very novice tuner, and look forward to smoothing some things out in the near future like throttle tip in.
Last edited by pshgomiata; 07-25-2015 at 12:26 AM.
Thanks. The MIG aluminum works pretty well, but by the time you buy a spool gun and argon bottle then you might as well have spent that money on a TIG setup. And I'd highly recommend an Everlast brand machine like I have.
If you've ever got something you need welded that you can ship easily, give me a shout. I really enjoy this kind of work. That goes for anyone.
In the past couple weeks I built and installed a 3 inch exhaust from the downpipe back to get rid of the stock exhaust, tuned OLEBC/CLEBC for 13 psi, and made a few pulls for some virtual dyno plots.
The exhaust is all stainless with one exception: I started with a flange I stole from the stock mid pipe. Bored that out to 2-1/2" to match the down pipe outlet, then made a reducer to bring the diameter up to 3". The midpipe is from the down pipe back to the axle where I have a v-band flange that connects the midpipe to the muffler. Muffler is the 22" Magnaflow 12578. Then it's 3 inch out the tail pipe.
For bends I used a 360 degree mandrel bent donut. The large muffler needed the tightest bends I could find to work without a 180 loop on the muffler inlet. Several things are required to fit this muffler without the 180 loop:
- 3 inch radius bends
- Rotate muffler 10 degrees
- Trim the muffler in/out to weld bends closer to the muffler case
I enjoyed having something round to weld, finally. I'm a pipe welder by trade, but now I have an office job. Felt nice to get back into walking the cup around some elbows and flanges.
I trimmed the stock exhaust hangers down and reused them on the magnaflow muffler
The muffler has about 1/2 inch clearance between the lower subframe brace and the sway bar above it. With the stock hangers, it bangs around a bit. Poly hangers will be installed soon to reduce movement.
You can see that the outlet did not need to be trimmed flush with the muffler. If I had to do it again, I would move the muffler closer to the tail pipe to allow more clearance around the subframe on the inlet side.
Last edited by pshgomiata; 08-15-2015 at 03:51 PM.
Once I got the EBC tuned I finally got some decently clean 3rd gear pulls to plot some virtual dyno graphs. I'm not sure how accurate the high HP numbers are, but I like what I'm seeing with the torque. Hopefully I can get a professional tune soon and see what it looks like on a dyno.
10psi at 3400rpm
13psi at 3700rpm
First clean pull
Clean pull after reducing kpa spike at 3700rpm. Same road, opposite direction.
Last edited by pshgomiata; 08-15-2015 at 03:36 PM.
The intake I started with was a simple, carbon steel flange and neck to mount a filter right on the front of the compressor housing. I wanted to source intake air from not directly behind the radiator and I wanted something I can plumb the BOV into at some point. A homemade flange and some ebay mandrel bent 2-1/4" tubing worked nicely.