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Goodness, I've been running around the garage like a chicken with my head cut off. I have next to no photos, and really nothing exciting, but tons of work and stress involved nonetheless.
Got the new turbo on. I had to clock it and rob some hardware off the old turbo to get things working correctly. The compressor flanges on this turbo meant that a new intake setup was required. The new inlet flange is 2.5" vs 2" on the old turbo.
The compressor outlet also sits about 1-2" higher than the old setup, which required me to trim up the Intercooler piping a couple times. I'm not sure how much I've spent on silicone couplers/elbows recently, but it's more than I'd like. Admittedly I'm returning at least 2 of them. They didn't see too much, if any, use.
Basically, I've just been getting things working and rushing/slapping them together. Coupled with the bushings there's a lot that has changed lately with very little testing.
I also got to address the power steering return hose. I swear this stupid hose has cost me $100 at this point. After the engine build I bought a coolant hose that was mentioned on another thread as a replacement. When I trimmed that hose to fit, I screwed it up so I bought a second. Well, the power steering fluid has been sweating through the coolant hose. Lesson learned. I need to dig up that thread and leave a comment. I tried to get generic 5/8" PS hose but it kinked. At $8.99 a foot it was almost $20. Finally I broke down and got the OEM NA hose off eBay which apparently works with some trimming, $40. Just way more work and investment than this stupid hose is worth. Note the difference in color before and after the hose clamp.
So anyway, kinda hectic and stressful. I did get the car out with an eyeballed alignment. Definitely screwed up but it drove relatively straight. I'm not 100% confident in this turbo quite yet. It smoked when I first installed it, although I think that was due to a kinked drain line and the nose being raised a good amount. I also got some smoke on startup after the car sat in a parking lot yesterday. I've also had perfectly normal operation from it at times and my AFR's are nearly perfect without any adjustment to the tune (and open loop). There's definitely some oil in the IC Piping and intake, but I'm not sure that it's excessive.
Regardless, while it has been a whirlwind, hectic and stressful, the car has been driving fine. It's the hottest it's been this year, around 34 C (~94 F) for a high and I drove the car in traffic without issues. I even ran the AC for a bit and it idled fine aside from some issues on the tuning side by me. I'm only running wastegate (~7 PSI) but I haven't blown any IC pipes yet aside from one of the first drives after installing the new turbo.
The car's at the alignment shop overnight to get dialed in and I guess I'll try to break it this weekend at autocross. We have a guy who does the alignments for just about our entire SCCA club. He had one of our old club presidents in his D Prepared ND on the rack when I dropped my car off. Usually I'd sit in the car while it was aligned, but he asked for my weight so I figure he'll factor it in. I basically asked for the Supermiata dual duty alignment with a bit more camber up front.
I also smashed the bottom of the car a couple times and decided to raise the ride height. I'm guessing the lack of spring from the rubber bushings caused the car to drop way quicker. Time to start shopping coilovers and frame rails I guess
Love weeks like this! It's so easy to forget what you're spending all your time, money, and blood for! Seriously, I hope it all pays off and you get to enjoy the damn thing at autoX this weekend.
Sounds like the racing gods are beckoning you to remove your PS...
And if you decide you don't have enough going on with your car and want to add a set of frame rail braces, I happen to have a pair laying around that I'd send your way for cheap...
Alright, I get a second to breathe. The car held up over the weekend. We had a little more cooling trouble, but I'm guessing that was mainly caused by the factory belly pan being off the car, not being thorough enough when bleeding the coolant after the turbo replacement, and a course on Sunday that put me on limiter for multiple seconds. Overall though things went well. The turbo is doing turbo things, the intercooler piping modifications held together fine and the increased sized breather line seemed to be working.
I took 4th on Saturday and 1st on Sunday. Saturday I only got 2 runs without a passenger since a buddy showed up. I had 2 runs throughout the day that would've put me in 1st, but I coned them away. My last run I overcooked a slalom and ended up drifting most of the final sweeper. The rears must've been overheated after that because the car stepped out on a corner after that and I picked up a cone. That run was still under a tenth of a second from the winning time of the day. That's all talk though if you can't put it down.
There's about a month before the next event so I'm planning to tidy up a few things. The OEM PS hose showed up the day after I put the temporary hose in. Frustrating but the temporary hose allowed me to get the car aligned before the weekend, so I guess it worked out.
The oil feed/restrictor is weeping a bit. I should've pulled this all apart and cleaned the fittings when the turbo showed up, but I was rushing and just wanted to get the car back together. No worries. It seems like it'll be a bit annoying to pull, but not a huge deal.
The enlarged breather hose seems to be doing something. I'm surprised how much the bottle picked up from the weekend. Previously I hadn't been getting much of anything. This weekend put around 100 ml in the bottle, although some of that is the volume of the kitchen scrubber that's in there as well.
I took an overall engine bay photo as well to add a checkpoint for the build thread.
Immediately after, I installed a different air filter. Hopefully this is the last one I buy. Because the compressor inlet on this turbo is slightly larger than my old turbo I had to change the elbow and filter.
I was using a filter off my KN intake from before the car was turbo'd, but I'm trying to sell that intake so I didn't want to keep using that filter. I got another KN with a 3" flange which should work going forward if/when a different turbo is on the car. At that point I'd just need to get a new 90 to suit the new turbo's inlet. I'm surprised at how heavy this filter is though, I think it's a couple pounds.
I'm still lacking a bit of confidence in the car/turbo, but don't have much reason to. The new turbo has a few sounds like my old one, which seems good and bad. There is a little chirp/whistle that I hear on spool down and I'm not sure if it's normal or not. My old turbo made the same noise, but it also died...
The tune is getting a few changes too. The car starts pretty well at autocross, but for a few seconds after it fires up it bogs like it wants to die. I think this is a combination of too much fuel (trying to combat injector heat soak) and low ignition timing. I realized the IATs are getting high enough after the car sits that it pulls timing as a protection. My idle advance has been set to kick on after 5 seconds, so there is a period after the car starts where the timing is being pulled down and no corrections are there to account for that. I set the idle advance to kick on after 2.5 seconds now, so we'll see if that fixes the problem.
Congrats on the weekend, dude! 4th place with passengers is pretty dang good. And you obviously did put it down Sunday taking that W!
I still lack confidence at times in my motor/turbo as well. It's nerve wracking abusing these things as much as we do. I still remind myself, though, that if something was going to nuke, it probably would've done so before now. Or at least I hope so
Looks like you got some work to do before the next one but it should be manageable. Sending positive vibes to you and that new turbo.
I'll post with more details later, but you really should open up the breather side of your valve cover. Both by drilling out the hole within the baffled portion, and enlarging the port that goes to the catch can.
Basically on boosted high rpm application like we do racing these things, especially on a built/rebuilt motor with looser tolerances, the blowby velocity ends up carrying oil with it. Opening up those ports allows more air to flow through at a lesser velocity, thus a lot less oil gets into the catch can.
I know somewhere back in my thread I documented what I did. My car literally went from overflowing a catch can in a single 3-lap T/A session, to being able to run all weekend with barely any accumulation.
Also, great work over the weekend! Looks like lots of guys on this forum were successful racing their turbo cars this weekend, I'm proud of us all.
Thanks Fire! I agree, a successful weekend for a lot of us on here.
I assume you mean the exhaust side of the valve cover. That's what I did recently which resulted in the extra oil accumulation. It's a ways back up in the thread, although I don't expect anyone to be following along that closely. https://www.miataturbo.net/build-thr...0/#post1650844
The PCV side is stock still. Someday soon I'll open up the blender bottle and see how much of it's contents are liquid vs kitchen scrubber.
[QUOTE=Fireindc;1651879Also, great work over the weekend! Looks like lots of guys on this forum were successful racing their turbo cars this weekend, I'm proud of us all. [/QUOTE]
[QUOTE=SimBa;1651883]Thanks Fire! I agree, a successful weekend for a lot of us on here.
I meant to make mention of this in at least one thread today, W's across the board for the boosted boys! Hahaha good stuff, always stoked to see your guys' hard work pay off.
I can confirm drilling out and opening up both my VC ports to atmosphere and drilling out the internal passages to ~9mm (I think?) slowed down the filling of my catch cans substantially. I still get a decent bit going into my exhaust-side can, though. Are you guys running scrubbers in your respective VCs? That's something I never did but think I should.
Congratulations on a successful weekend @SimBa ! Minor work left to do it seems. Regarding the restarts, there is no reason to have such a delay for your idle ignition to kick in. Try using the lowest delay possible and letting idle ignition correction do its thing. You will need some extra fuel to fight off the heatsoak as you know, but don't feel bad to let closed-loop pickup the slack for a minute or so.
@Z_WAAAAAZ I'm not running any scrubbers in my valve cover. Currently only the exhaust side is ported, but I'm getting a lot more liquid from it than I was before drilling it out.
@redursidae Believe it or not I'm still running open loop idle with some simple timing correction. It works really well for me and most of the time the car idles smoother than my stock Subaru. I do need to start playing with PID loops though. Everything on my car is running open loop or simple closed loop (IE, no PID values, just a sensitivity slider). I've been reducing the amount of fuel I'm dumping in for heat soak but leaving the time a bit longer. I think that's working better.
I will try reducing the idle advance delay though. I'm not sure why I had it set that high. Might have been something I set up early on and forgot about.
Doh! I totally read your VC mods when you did it and didn't realize that was you when I made my last comment. No scrubbers in the VC for me either. Make sure you sealed the baffle with silicone when you had it apart.
I've read conflicting stuff about using scrubbers, I.E. that the oil can stick to the scrubber and more easily be carried into the can if you run them (vs draining back into the head easily without them). But I've not seen any conclusive evidence on that, so keep us posted if you improve on what you have! So far I'm pretty happy with my setup, the can never fills but occasionally my breather filter gets saturated and starts spitting oil droplets if I don't clean it from time to time.
I didn't mention it in the original post, but I'm sure I sealed that baffle plate. I bought the easy cheese style can of Ultra Black when I rebuilt the engine. I don't know why, but I find it so enjoyable to use, so I'm always on the lookout for an excuse to use it. Possible that I missed a small section of it, but I'm pretty sure I got it sealed up properly.
Same thing here on the scrubbers. I've heard arguments both ways.
I want to design and 3d print a lid for the blender bottle that has a mounting tab and a small baffle around the VTA holes that I drilled. We'll see if I get around to that, but I think it would be a fun project. I've already found a 3d model of a basic lid that I could probably build on. Having said that I haven't noticed much, if any oil coming through the VTA holes, so it's pretty low priority.
It has been heating up around here lately and unfortunately, but unsurprisingly, the car is not loving the heat. I bled the cooling system again last Friday to try to get out any bubbles I might have missed. Some air was trapped in the system, so I'm glad I did that. However, I took the car into downtown afterward and the temp slowly climbed throughout the 30 minutes of driving. Ambient temp was around 34 C (93 F) which is pretty hot around here, but we'll be passing 38 C (100 F) regularly throughout the summer. Even with the ducting, upgraded radiator and reroute the cooling system couldn't shed the heat.
I should note that I've been fiddling with AC control in the tune. If I set the AC fan to be come on when AC is enabled I don't have a way to turn it on when AC is off. Previously I had the AC fan to kick on at 90 C, ignoring the status of AC. The trace below was only using the primary cooling fan, and not the AC fan, which I have now reverted. The current setup is for the main fan to kick on at 85 C and the AC fan to kick on at 90 C.
The trace below shows the coolant temperature climbing slowly. I was being pretty reserved with the car as well, so no way it would hold up to a day of autocross or even a road trip in this configuration. This was a mixture of highway and city driving with no AC use, except maybe a couple seconds to see how the AC settings in the tune behaved.
So at this point I'm starting to think about cutting up the hood. I'm fairly indifferent on it at this point, I just want the car to stay cool. Right now, with both fans running the car could probably maintain temps on all but the hottest days of summer, but that's with AC turned off. What's the point of having AC in the car if I can't use it without overheating?
I'm open to suggestions. It could be that the Mishimoto radiator isn't up to the task, which would be a bummer considering it wasn't that much cheaper than the Super Miata unit (maybe a $100 difference?). I liked the lifetime warranty Mishimoto boasted and figured it would work well enough.
Side note, I'm surprised none of the hood louver kits seem to offer a cover system. I figured someone would have a solution that involved rivnuts and some bent up sheet metal to cover the vents during rain or on colder days, but I suppose louvers are targeted at track cars that wouldn't be as worried about those corner cases.
I'll get the car out into the heat again soon to see how running the fans in parallel looks, but again, that's not going to do enough to allow me to race the car in July/August.
Ha! Welcome to the club. Turbo BPs are a thermal battle, and with A/C you are going to work that much harder to stay cool (even without the A/C on just the condenser being there makes it harder to keep a turbo track car cool).
I'd do all the things. Including the crossflow, I hate to say it, but I'm 100% sold on the crossflow design and it's worth every penny so you should probably consider an upgrade.
Of course hood vents will help as well, so I'd do them for sure. Just make sure you get the right kind with proper vent placement.
I'd also re-visit ducting and make sure every little gap is taped off.
IF the overheating is mostly happening at slower speeds with A/C on, look into the FM SPAL fan kit. They are PWM controlled, so not as simple of an on/off, but I've seen those brushless fans running in person and they are seriously impressive.
So it looks from the log like your highest CLT was at that spike right before the log ended, at 217*F? Was that during city driving or on the highway? I'm spitballing here but if that last spike was 217, that'd suggest your average CLT towards the end there was around 200-210*F? That doesn't seem too outrageously high for 90+* ambient. Given those temps, I'd say you should be easily covered for more aggro driving in the heat with a set of hood vents. Of course, a crossflow and more ducting are absolutely going to help further. Hood vents will increase the cooling capacity of your fan setup though, too, and may negate the need for aftermarket fans if you're overheating at stops/low speeds.
My current setup substantially overcools my car in cooler weather, but I'll still see coolant temps creep up close to 210*F in slow stop and go traffic if it's 90*+ out. I went out and did some tuning on Saturday while it was 85-90* out, freeway CLTs during and after some sporadic pulls were between 195-200*F but I got up to 205* or maybe a little higher while driving on surface streets and intermittently pulling over for a few minutes at a time to mess with the tune. Think I've got my fan (no AC or AC fan, just the single OEM cooling fan) set up to come on at 204* or somewhere around there.
Edit: Forgot you had A/C as well. Sorry I didn't acknowledge that in my post.
Keep your fan activation temps to be around thermostat temps. If you're turning them on earlier, you're literally trying to cool a radiator that's already cool. If you set them later, you're waiting for the car to over heat before turning the fans on.
OE fans are barely respectable for OE Miatas. Power = heat, and the OE fan is built around 120hp. If you're pushing 200+, you need literally twice the fan. The shittiest Spal 12" does ~850cfm, I'd be surprised if the OE fan does 600. The 13" I have does 1700, it's changed my opinion on what a fan should be capable of. It turns on at 194 (196 thermostat), and cools it to 190 before shutting off. Recently replaced it with a MSM fan wired to max speed, and it would turn on at 194, but allowed it to climb to 200*+ on a 90*+ day.
@Fireindc I definitely have room to improve with my ducting. My current setup is made of politician's signs and, while I'm pretty happy with it, is far from well engineered. It's held up well so far, but there is definitely room for improvement there.
@curly I have an 80C/180F thermostat in the car and turn the main fan on at 85C with a 3 degree hysteresis. I went with a lower temp thermostat because I had cooling issues prior to rebuilding the engine, which turned out to be a faulty thermostat. I figured if I threw a lower temp thermostat in the car I could use the fans to regulate the temp (unless it was overcooling).
@Z_WAAAAAZ I'd like to get the hood vents to relieve engine bay temps as well as coolant temps, but overcooling is something I'm wary of. Blocking the radiator in the winter probably wouldn't be too hard to figure out. That's why I'm surprised nobody has blockoff plates for their hood vents, seems like there would be some demand and they could be designed pretty simply. Maybe I need to hit up send-cut-send if I do hack my hood up.
That log was city driving in direct sunlight. There was a bit of highway in there as well, which is where the intake temps drop/stabilize.
Happy to update that I took the car to the gym - OK, it was the arcade, but I still got a workout playing DDR - in similar weather to that last log and the temps were way better. I didn't realize how much the AC fan was doing to keep temps in line.
I updated (backdated?) the tune to kick the AC fan on at 90C regardless of if the AC was engaged or not. This is a Speeduino oddity. There is an option for a standalone AC fan, but there is no option to kick it on at a certain coolant temp even if AC is off, it only ever runs when AC is on. I might have to create a request for this or write the code myself. I'm definitely considering moving to a more professional ECU at this point. If a good deal comes up on a Link G4x I would be very tempted to snag it. Speeduino is a really cool project, but I'm starting to feel the limitations of it.
In the datalog below the ambient temp was 34 C (~93 F). This was a lot of 55 MPH roads, but with some construction and a good amount of traffic. The AC fan was able to keep those temps right around 90 C. I guess this is a testimonial for wiring your fans in parallel (or doing it via the ECU). Programmable output 0 is the AC fan if that is of interest to anyone.
I don't think I'm out of the woods as far as cooling goes. This was a calm drive and far from the abuse the car would see at autocross, but I'm at least confident that I can putt around without it boiling over or warping the head.
Since the car is mechanically sound enough I've jumped back to the laptop. I'd been wanting to redo my boost control table for a while now, so I switched to open loop and have been stepping up the duty cycle each time I go for a drive.
I probably should have gone out and done all of the pulls at once. Who knows, maybe the varying temps/conditions will give me better coverage in changing conditions
2560 with a generic MAC boost control solenoid
I got a few other projects done around the car as well recently.
One of my 3d printed top latches broke when I was trying to close the top when it was cold (tight fit). I found one of the old metal ones that wouldn't latch and put a screw in it to extend it which seems to be working well enough. I've done this on another latch and haven't had issues. Not the most elegant, but it shouldn't break and it was free.
1/8 E clip from home depot works on the top latch pin. A bit tight, but the next largest size was too big.
I also noticed that my gas tank is magically able to be filled now. I attribute it to the cracked vaccum plug on the evap line in the engine bay. I figured, if I'm just venting to atmosphere through a cracked plug I might as well just run some line to the frame rail.
I took some scrap hose and routed it above the passenger tire through the fender to see how it worked. I just filled up today after getting the car warm and the tank filled like a normal car would. I'll probably leave that hose for a couple of fillups, confirm it fixes the issue and then figure out a more robust solution.
Temps have been manageable ever since I reenabled the AC fan to run anytime the car is 90C or hotter. Around 75 Ambient the car takes a while to hit thermostat temps if I'm just cruising. Hood vents are still being considered. Been a while since I did any 3d modeling (high school), but I was able to come up with this in about 30 minutes this morning.
06-14-2024, 12:54 AM
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