Miata Turbo Forum - Boost cars, acquire cats.

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-   DIY Turbo Discussion (https://www.miataturbo.net/diy-turbo-discussion-14/)
-   -   Build Thread: An Exercise in Heat Mangement (https://www.miataturbo.net/diy-turbo-discussion-14/build-thread-exercise-heat-mangement-91285/)

aidandj 03-05-2017 02:53 AM

150 is really cold for oil. You want your oil to warm up enough to get any sort of condensation out of it. Do you have a thermostatic sandwich plate?

Bronson M 03-05-2017 07:12 AM

Agreed 150 is the bottom end, 200 is better. Interestingly enough the Audi 2.7t I have has an oil temp guage in it, it rarely gets above 160 deg and it takes the better part of 20min of driving to get there.

I do not have a thermostatic plate, wasn't going to chance running an eBay piece with moving parts and the quality pieces cost more than my whole cooler setup. If the temps don't come up when I get the water temps in the right range I'll consider adding it.

Bronson M 03-05-2017 09:13 PM

Got 6 PSI tuned enough to beat on it........things are going to get interesting quickly as I wratchet this thing up to full boogie.


ahawks9er 03-12-2017 06:45 PM

Fun read - keep up the good work!

Bronson M 03-12-2017 07:45 PM

Finished up a few things and have been working out the bugs......and there have been a lot of them.

Just to name a few:
Blew coolant line off of turbo....water shot out of my hood vent all over the windshield blinding me and nearly crashing. Spent an hour looking for a leak in the radiator because it was soaked only to find the line on the turbo
Pulled a pin out of the TPS sensor
Found a wiring issue with the IAC (forgot to hook one wire to 12v)
Realized I forgot bias resistor on oil temp.....so that's why it hasn't been moving around
Replaced thermostat since the two holes I drilled were enough cool the car to 120 degrees
Adjusted the oil cooler and radiator ducting to get the nose piece to fit better

Then I could get back to finishing up the small things. The air filter was just hanging out in the fender.
https://cimg9.ibsrv.net/gimg/www.mia...81befcaafe.jpg
Broke out the first class template materials again
https://cimg0.ibsrv.net/gimg/www.mia...e086fc75af.jpg

Transfered it to the HDPE sheet
https://cimg3.ibsrv.net/gimg/www.mia...b1d7933552.jpg
No more soaked air filter
https://cimg7.ibsrv.net/gimg/www.mia...1f7b5021f5.jpg
This is what it looks like from the front with the nose piece off, the fog light feeds this area, while it's not sealed to build pressure I'm guaranteed to get ambient temperature air into the turbo.
https://cimg1.ibsrv.net/gimg/www.mia...da78499a5c.jpg

I HATE body work, but it turned out pretty decent. The whole car is due for a vinyl wrap, flat black or gloss?
https://cimg0.ibsrv.net/gimg/www.mia...ee77635d8b.jpg
https://cimg4.ibsrv.net/gimg/www.mia...bbbd9c0c27.jpg


As a little side project I ordered up some parts to make a CO2 powered trackside tire filler.

https://cimg7.ibsrv.net/gimg/www.mia...d8c6e0447e.jpg

Bronson M 03-12-2017 10:41 PM

Something to note if you're wanting to use HPDE sheeting like I have with it touching metal that is ~200 degrees. It does expand with heat and using rivets won't allow for this expansion so you get some buckling like you see here. It goes away as it cools. It still does it's job and it's not as noticeable as this picture makes it appear.
https://cimg6.ibsrv.net/gimg/www.mia...a46200ecaf.jpg

Few more gratuitous shots in various states of undress
https://cimg7.ibsrv.net/gimg/www.mia...f7551fc1ca.jpg
https://cimg8.ibsrv.net/gimg/www.mia...6dde6d5800.jpg
https://cimg0.ibsrv.net/gimg/www.mia...05a8ab623d.jpg

Zaphod 03-14-2017 06:58 AM

That is some impressive work...

Bronson M 03-17-2017 04:14 PM

The sad reality is that these bad boys will probably drop more time on an Auto-X course than all this fab work. I'm hoping I can actually use 1st gear again instead of just turning the tires into smoke.
https://cimg0.ibsrv.net/gimg/www.mia...363d819c3c.jpg

Bronson M 03-19-2017 10:47 PM

Two steps forward and one back this weekend.

Finished up the exit ducting finally, ended up being more complicated than I thought with a relieve for the crank pulley, and some stiffening ribs.

https://cimg1.ibsrv.net/gimg/www.mia...79487c5f00.jpg

Finished product.....
https://cimg1.ibsrv.net/gimg/www.mia...8a1c0c3360.jpg
https://cimg5.ibsrv.net/gimg/www.mia...65cc76abaa.jpg
I know this looks like it's choking off flow but you want to accelerate the air as you introduce it back into the air flowing over the car. It still follows the opening to heat exchanger rule of thumb.

Also took the time to make the switch panel for launch control, boost table select, traction control enable, and data log.
https://cimg5.ibsrv.net/gimg/www.mia...a39b83be46.jpg


Then took a couple of steps back ........Had a small oil leak coming from the fittings on the egay sandwich plate and found the o-ring squished out from around the fitting. So I took the time to make some delrin washers on the lathe and when I went to tighten the fittings I twisted off the threads in the plate $^%&$*%. Out comes the aluminum glue gun.

https://cimg6.ibsrv.net/gimg/www.mia...675c46b804.jpg

In china's defense I did enlarge the passages to 1/2" to allow for better flow which is what weakened the fitting.......but they should have had them full port with a larger diameter thread. For all the modifications I needed to make to the plate this was still probably the best route for me to take.

I got the oil temp working and was able to verity that I got up to 170 degrees in around 15 min of driving, I think it'll be ok in the long run but take a while to warm up.

I got the EBC plumbed correctly and it's now trying to control the boost......lots of tuning to do here yet but I got to see 12 psi for a pull or two and that's going to be fun.

TPS is on the fritz again......starting to think this connector is junk.

The coolant line I fixed once already decided to tear right under the worm gear clamp I installed to fix it the first time so I get to fix that again and burp the air out of the system for like the 5th time.

miataman04 03-20-2017 09:35 PM

I'm loving all the pics, this has been fun to read.

Bronson M 03-20-2017 10:46 PM

Thanks for the encouragement!

patsmx5 03-20-2017 11:09 PM

Looking good! As much as I refuse to modify the look of the body of my car, you got me wanting to tube out the front of my car to redo my heat exchangers and do a setup similar to what you have done. I love the hood vent even though it does not look stock, it screams function.

Der_Idiot 03-21-2017 07:49 PM

Are you using a heat gun to mold that stuff? It looks pretty easy to work with (never touched the stuff before).

Bronson M 03-21-2017 08:51 PM

Propane torch, for long bends I'm using a harbor freight sheet metal brake. You can somewhat weld the stuff by heating a piece of metal and using it to smear the two pieces together. It's ugly but it works.

Bronson M 03-25-2017 06:35 PM

Yahtzeeeee!!!!

All the pieces have finally came together, TPS is fixed, all the coolant lines are fixed, fuel pump replaced and EBC is now functioning in a way I can actually control. It's made it over 25 miles now without shitting the bed.


Fuel pump.....boy did I get thrown for a loop. So I popped what I thought was a stock pump out of the tank and noticed the walbro stamp and part number on the old pump. A quick google of the part number reveals the little shit is a walbro 255 L/hr pump. The car had a jackson supercharger setup on it when I got it along with some janky band-aids so i guess this shouldn't surprise me I never put much stock in the 72 psi pressure readings I was getting with my fuel pressure sending unit. It's an el-cheapo ebay unit and I was really just looking for pressure drop at WOT, which was in the order of 12 psi to 60 psi. With the new 190 L/hr pump pressure settled in at 62 psi at idle and now only drops ~4 psi at full boogie, and is much more stable so I'm not getting wild swings when I punch the throttle like I was getting. This verifies to me that the 255 is in deed too much pump for the stock regulator while it may seem temping to just tune around the high pressure at low loads I can tell you the car is much more stable and throttle response is much crisper now that the pressure isn't taking a huge dive every time the injectors open up.. To cure the 4 psi drop I'm seeing I think a return style fuel system will be needed. I have a return style fuel rail off the JDM intake I may put into service if I feel frisky.
https://cimg9.ibsrv.net/gimg/www.mia...5a5449baf9.jpg

I have no idea why the EBC has been giving me so much trouble but I just about ran out of talent with this. Finally figured out somewhere in the poke and hope of trying to adjust things I had set it up as inverted so once I got that fixed I started cranking up initial value tables until boost levels went above the 160kpa the wastegate was capable of. I have seen a few threads where guys end up with their PID settings in the 20/20/40 range or some times less at 15/10/30...... I'm up to 60/40/80 and it's still way too laggy to hold my desired kpa. At least now it's actually responding and I'm sure in another tuning session I'll get it nailed. 175kpa (11.5psi) feels really good, can't wait to hold that all the way to redline.

Now that the temperature has warmed up the worn out rivals are hooking better so I was able to get a clean 0-60 run in at 8psi with a somewhat crappy launch it was right at 5.0 seconds. That should be good for high 13's to low 14's in the quarter. I expect to see mid to low 4 second runs to 60 with the 245's and 12psi of boost. I'll probably need to get the traction control working to see those numbers though.

Another item of worry was the used clutch I had installed was slipping a bit on 3rd and 4th gear shifts, now that it's got some miles to break in it's holding much better and drags the RPM's down on a flat shift like my stock clutch did only with double the power. I kinda hope it doesn't get any grabier as I think it'll help the drivetrain live a longer life. It's a spec stg. 3 (sprung 6 puck) and other than a narrow engagement window it's very stock like.

I'll post another video once I get the boost dialed in.....then it's race time, first auto-x and then a track day when I have enough confidence that all the bugs are worked out.

miataman04 03-25-2017 10:11 PM


Originally Posted by Bronson M (Post 1401282)
Another item of worry was the used clutch I had installed was slipping a bit on 3rd and 4th gear shifts, now that it's got some miles to break in it's holding much better and drags the RPM's down on a flat shift like my stock clutch did only with double the power. I kinda hope it doesn't get any grabier as I think it'll help the drivetrain live a longer life. It's a spec stg. 3 (sprung 6 puck) and other than a narrow engagement window it's very stock like.

That stinks. I HATE pulling the trans out to replace those.

Bronson M 03-26-2017 08:56 AM

I knew I was taking a gamble with used parts, but the cost savings were substantial, 250$ vs 700$ so it made it worth the risk. Like I said it seems to be coming around and gripping well so it may have worked out in my favor.

If the car survives the racing season a substantial rebuild including a new to me 6 speed (mine has a whine in 1st), forged bottom end and all new hubs/bearings is in order for preventative maintenance before I crank the knob up to 300+ whp numbers.

miataman04 03-26-2017 10:30 PM

I'm hoping to end up the 300 range. FM says to get the 01 up 6spd and to be ready to replace transmissions as they don't hold up very well of course a 5spd is weaker according to them. Do you know if that is the norm on here?

Bronson M 03-26-2017 10:36 PM

Above 225 ft/lbs and the 6 speed is a necessity, 6 speeds stand up to 250 to 350 ft/lbs depending on how badly you abuse it.

A trans that's truly 300 HP+ capable is still an issue. There are folks trying to fit a T5 as well as another effort to make upgraded internals Neither option will be cheap

Bronson M 03-27-2017 01:21 PM

Did some tuning at lunch, and I've discovered some things...... not sure if they are unexpected or par for the course.
https://cimg8.ibsrv.net/gimg/www.mia...ab674f5304.png

Observation 1:
So I finally got the EBC reacting how I would want it to, you can see the map peak out at 175kpa then slowly taper to 160kpa at redline. This is with the wastegate commanded full shut. This could be a few things, one I've maxed out the turbo......can I do that with a 2560 without scattering rods? I have boost leaks or the wastegate leaks. I am still running a 2.5" exhaust so this could be holding me back as well. I guess it could simply be that the intake restriction is so low on this motor that 10 psi equals more power than a lot of builds see.

Observation 2:
As you can see the Duty cycle is high, it's in the 95% range at redline but AFR's are good. You can also see the fuel pressure drops off to 56 psi which is still 46 once you account for the boost. The AFR's are fat and happy so this isn't really a concern other than I'm using all these injectors have to offer. Using calculators from here: Fuel Injector Calculator from WitchHunter Performance it shows the injectors are around 450cc at my pressure and that's good for 275 crank HP with a BSFC of .6 Am I really making that kind of power with "only" 10 psi up top? Yes a dyno will tell.

Observation 3:
Intake temps seem to be really laggy, you can see the steady climb to 90 degrees in this snapshot. It takes them about the same amount of time to come back down to ambient 70 degree temps. I have no real basis of experience to tell if this is "good" or "bad". 20 degrees over ambient after a 0-100 sprint doesn't seem bad but it'll be interesting to see what it does on a road course where I'll be on it much more frequently but the speeds are higher.


I guess my fear is that with the huge intake piping, decent intercooler and honda intake that I might actually be making quite a bit of power. Possibly over the limits of what the bottom end can take long term. I hate to back it off since it's intoxicating as it is, and I will most likely be racing it before I can get it on a dyno. Would the capacity of the RX8 injectors be a good limit to stay under to save the rods?


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