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pop open the case and see what it's got inside.
DIY builds can have some funkyness to them, and chasing your tail thinking it's a normal build is really frustrating when you find that wonk jumper resistor someone installed.
before i can even start tuning, i have to figure out a few things, flex, boost, and o2 sensor connections. The speedy was pretty intuitive in the sense that the pin for flex was labeled flex, and the boost pin was labeled boost. I know on ms3pro pnps its defaulted to the narrowband o2 sensor path, but unsure on this board. I could really just forget the flex and crank up my ve table to account for it but id like to get this all done well so it can last.
i did end up updating the firmware to the latest version which went fine.
i have these nice diagrams on trubokitty, but im not entirely sure what board is what, daughterboard, expansion, so on. Im going to poke around it all tonight after work, hopefully i can get tuning tomorrow with not much wiring to do.
Didnt know id get cool stickers, made it even more worth it.
So it's got a 3.57 board that is SMD. likely not a DIY on that one, though there is a jumper on it... (yellow wire)
But you didn't pic the mainboard. You can KINDA see it on your first harness pic.
yeah i didnt take any boards apart from each other yet, i figured if this ran an nb before it shouldnt need much modification if any, getting my outputs swapped from speedy and then if issues arise ill try and find them. That jumper was d1 to the other end i couldnt tell. Only other pic i took
I got all of the outputs changed to what i needed, it ended up being less complicated than i anticipated, moved the ms3's o2 wire to the narrowband spot on the harness where my wideband was already connected, added a flex wire where there was none, and then swapped the boost output on the ms3 to output to the purge valve where my boost controller has been. Fired right up this morning and not trigger issues im dealing with yet. I am dealing with some odd vvt and injector characteristics. I have kraken 700cc's and no data, I got by on the speedy with a deadtime of 0.9 @ 14v, setting this ve table up, I had a ve value of 48 to idle and 51 at 4psi of boost wot, so I played with the deadtimes and changed it to 1,2ms, this was what i ended up with using the epicefi deadtime tuner before i figured out the trigger issues at 4k rpm happened. This paired with a smaller req fuel gave me a more traditional ve table spread, but still flat. I have incorporate afr turned on, I read a few posts on its function but my takeaway was just turn it on, it helps. idk.
I got some crazy bucking trying to iron out the ve table, I didnt have super crazy afrs, more like a misfire buck, I finally saw in the log that my vvt duty was going bananas. I dont really have much info on the vvt, i have a table ive been using on the speedy that worked well. If anyone feels like taking a look at my vvt settings, or even the tune and a log, that would be great. I think im doing well enough so far. My idle is decently stable and doesnt go crazy after i give it throttle or come to a stop. I have a good amount of tuning ahead for the ve table and corrections and such, but i need to fill up before i do that.
megasquirt has been good, got it all pretty dialed id say. Only consistent issue im having is with vvt not working and random hot start issues. It will start fine all day and then randomly hot start and die out, every attempt until i give it some throttle to keep it alive for a bit. Just odd, I havent looked into it much.
Last night I got the urge to wrench, the last time i blew out a turbo gasket, i noticed some small cracks forming going from the flange bolt holes to the inside of the manifold. Decided to tackle that and some other things. I used a carbide burr to dig into the cracks a bit and put the manifold in the oven at 500 degrees, took it out, welded it, burr'ed it, welded it again, put it back in the oven, turned the oven off and let it cool overnight.
I suppose that worked as I didnt see any cracks this morning. I also took the liberty of porting the hell out of the turbo at the manifold flange. I matched it to a gasket. I did this because the cheapo manifold had a t3 sized hole, just with t25 bolt holes, so it was basically hitting a huge lip. The manifold already doesnt flow super well, so I figured id give it some help where it could be had. I also made the most hideous wastegate bracket imaginable for the old t25 turbo's wastegate i had. I have issues holding high boost to redline with my 3 port mac valve. Even with duty at 100%, It can only muster 16psi by 7k rpm. I had thought that the 4lb 2560 wastegate was too light of a spring to hold the gate shut against the exhaust pressure. The old 7lb one let me hold about 16.7 psi to redline, but still not what i was looking for.
My spool has also been bothering me a ton, I dont exactly have any redeeming parts besides the ball bearing 2560, but with hitting 18psi at 5000rpm, I feel like I should have just opted for a t3 setup if was going to spool like **** anyway. My downpipe is my main suspect at the moment. Its this pocketed 2" hole deep flange, where the wastegate gasses just slam into a wall and have to get sucked down. A 2" hole, wall for wastegate gasses, and 2.5" downpipe. Cant exactly be the best for flow.
[img alt="not a spool curve youd expect out of a bb 2560r
"]https://cimg4.ibsrv.net/gimg/www.miataturbo.net-vbulletin/1120x531/image_2e64662b7c0c461fcdb71d964e34f4279336fe7a.png[/img] not a spool curve youd expect out of a bb 2560r
I got the chance today to test fit an fm manifold with the pulsar2860r gen2. Those parts are pretty top of the line for longevity and good power. I wonder who recommended those to a friend turboing his car
I live vicariously through the two people ive told to buy fm manifolds and psr turbos. That will change though. Ive already started squirreling away money for the pulsar turbo, depending on how fast my speedy sells I hope i can get it soon. I also listed my 2560 locally for 200$ and got tons of messages straight away, so i relisted it for 300$ I didnt think they were all that much being resold, but ill see what I can get.
The plan for parts goes as follows in order of first to last
PSR turbo, 3" downpipe, either kraken outlet with the vband (only 150$ so not bad) or a hastily made 3" downpipe Ill concoct. This will also be with a 3" full exhaust. Then return style fuel system with a referenced fpr. I dont think I can even hit 300whp with my setup atm, and if it does, itll be at 95% dc im sure. vd runs, red is before the manifold and turbo stuff, others are after.
If anyone has any recs or ideas on the spool or **** power im all ears.
Another thing i noticed! When pressurizing the pipes to find boost leaks, i had air leaking out of my mac valve vent. Im doubting thats supposed to happen.
Last edited by Bloopdog; Apr 14, 2026 at 01:27 AM.
Was doing some pulls today during work for some cl boost control logs. Did a third gear run and shifted into 5th to notice it was making an annoying little rattle noise from the shifter. Naturally i went to third again after slowing down to do another pull. After that it was definitely making more of a rattle and vibrating…
I had to stop at a light and upon taking off i noticed a rod knock noise after putting it in gear and moving… same noise in 2nd, 3rd, none in fourth, then noise in 5th. Interesting! Took it home and swapped cars, finished my shift and got home to obviously rip the trans out.
no noticeable issues i could find before pulling it. Fluid looked good, everything was sturdy. Guess trans was coming out.
Im out of practice, took about 2 hours including the newfound issue of having to take the manifold-turbo-downpipe out to get the trans out. This might seem a bit much, but the way the bolts on the downpipe and turbo are, along with room to get those things out, it saves a ton of time just taking it all out to remove the downpipe.
Trans out.
anyway now for the teardown. I spun the shaft and it definitely made the noise when spinning. I have my old 5 speed that had a crunchy 5th and noisy gears sitting in my parts room. So this one is never returning to working order. This made disassembly more fun.
Found these upon tail shaft removal.
That there is custom.
for something that reads so low on virtual dyno, i really do have some medium power issues. Im selling my 2560 for money towards a pulsar, but also buying a china 2871 from a member here, along with a spare better flowing downpipe and manifold. Once the 2560 and speedy sell ill buy the pulsar, but the 2871 is something i can run to get a feel for. In the meantime… guess the old nb 5 speed is going back in.
I love making updates solely because something broke…
this time Glad thats upside down
hot test!
i could hear a cylinder had low compression when starting the car. But i didnt really get misfires or odd issues. I did notice i would get puffs of smoke recently after ANY amount of decel/vacuum rev matching from 5th to 2nd through low rpm would still get oil smoke. I could rev it up in neutral and upon hitting the throttle again it would give me some smoke. I figured the stem seals i used were garbage so i was going to order a set of oem seals… i suppose i still will. Theyll just get done in the rebuild process.
i fear it may be time for a prim and proper rebuild, with all the fancy machining and measuring. This motor lasted 4300 miles, which makes me wonder what did go wrong. Any issue from the building process would have shown itself earlier and in a larger manner i would have assumed.
cylinder 3’s ring gap was 0.022 top 0.024 bottom. I wasnt happy with that but i figured more room for expansion wouldnt hurt. The others were slightly tighter than that. Im not sure if that has anything to do with it. Oh well! Im excited to get this done “right” though.
i ended up modifying my compression tester to put air into the cylinder, like a pseudo leakdown tester. I got heaps of air from my catch can. That was disappointing, at first i had compression tested it and got 60 psi, then put a small amount of oil in the cyl. That netted 65psi. This lead me to believe i had a head issue which i was happy with. I ended up trying that again later (warm) and put a good bit of oil in the cylinder. That bumped it up to 120psi. Not good but not far from the other cyls. Regardless it needed a rebuild. I have the motor prepped to come out. Im waiting on an engine puller to use, and im not exactly in a rush this time.
I still have not gotten the motor out to teardown and find the culprit. Im very curious, but it has to wait until I get another cherry picker to use. It is ready to be hooked up and yanked out though.
In the meantime I had been figuring out my options. I cannot remember how, but at some point I had decided to research what vehicles had BP motors used in them. I wanted to find a spare motor I could rebuild properly, and having a spare crank would be cool. I decided to check my local junkyard's inventory of the BP powered alternates just on the off chance I found something cool. I had no luck with the ford escorts, mercuries, or protege's. Bummer. I even checked statewide for any of those cars and couldnt find any examples that had the BP.
The last car I saw had the bp was the older kia sephias. I searched statewide on the junkyard inventory and lo and behold... There is a 1997 Kia Sephia at my local yard, that was just put there a month ago.
Naturally I went to scope out the scene. It could be a shell for all I know, high miles, blown up. Nope.
It was in fantastic shape, the only thing missing was the coolant neck at the back (front?) of the head. I checked under the valve cover, it was pretty varnished, but nothing crazy out of the ordinary. The cams looked fine. All of the spark plugs were in the head holding an inch of water above them. I spun the motor over a few times and it felt like it had great compression. Took out the plug that didnt have water in it, checked the bores with a borescope. They looked great. The piston had tons of carbon built up on it. I noticed the windshield had the usual things written on it. Eng - good , Trans- good blah blah blah. This was pretty cool. ODO read 112xxx miles, and it had a third pedal which was sweet.
I left the junkyard with plans to return and pull the motor the day before a wheelbarrow sale, in which you get anything you can fit in a wheelbarrow and under a jig without touching the jig for 150$
I got the text regarding the sale and headed straight there. I had the motor sitting under the car on tires and was gone within 2 hours. My Milwaukee stubby had died halfway through, and I was left to unbolt the transmission and a lot of little things with a breaker bar and electric ratchet. I should have checked the battery on it before I left. I took the head off of the motor, but kept the oil pan on. I also took off everything but the water pump and oil pump, because they didnt contribute any addition to the dimensions of the block laying on its side.
The next day I went back with my roommate to load the engine into the wheelbarrow, along with whatever other goodies I could add in for "free" I ended up fitting both cams and the gears, whatever bolts I could find from the process, the throttlebody which was the exact same as the stock nb tb, 2 fan motors for a chevy, the odd looking kia valve cover. And a 112k mile bp shortblock. Grand total out the door $138.24 I think there was also a time based sale which contributed to lowering it below 150$. I definitely could have fit more, but I was under the impression that the jig was very close to the height of the wheelbarrow, and not much could be sticking out. I should have ran it under before I filled it up, but I was took eager to go grab my motor. And I was definitely NOT walking back to grab random items.
Im pretty happy with my haul. I toredown the kia motor bp later that day and got it on the stand. The oil pan is garbage, but they do use a main bearing support plate like the 01-05 miatas, which was a worry. The bores were absolutely beautiful upon inspection. Virtually no vertical scoring, crosshatching still very much there, piston skirts have some vertical marks, but none I can feel. The rod bearings were like new. along with the crank journals. The crank spins very freely like butter. Bonus, the crank gear, keyway, and boss were all perfect. Which I hope will help me fix the small wobble that was developing on my pulley.
The block needs some (a ton) of cleaning. I think im going to get it checked. roundness, if it needs boring, taper, all of the things. Im also going to get it cleaned. I dont imagine it needs much at all in machining, but it wont hurt to have it known. I'm still waiting to decided if forged pistons are on the menu. Part of me wants to take this and run if it checks out fine. The pistons are known good with the motor, ie: they're not out of spec and causing wall damage.
One of my main concerns is the oil pump. I know mine has lead a long life, I was looking into billet gears, or trying to decide whether to just replace it. I am not a huge fan of boundary, ive heard of too many relief valve issues, and seen one first hand in a friends built coyote. Oem pumps arent exactly cheap though. I did get the pump off of the kia motor. It wasnt a vvt motor however, and I doubt its ideal to run a non vvt pump on a boosted vvt car. If anyone has done that please lmk how its gone.
This one is a little dirty. But it didnt seem to be leaking, the seal feels rubber as it should.
I also get a nice little drop in compression, which im happy with. I love my ethanol, but it seems like going slightly lower might not be a bad idea on the off chance I need to run gas at some point. Though its not a huge drop in compression.
I also think I found a good reason for at least some of the carbon build up on the pistons. ALL of the oil control rings on every piston were stuck closed. This thing probably smoked like a chimney.
I have this kia cover if anyone wants to grind off the kia part and have a minimalistic cover as well. Its kind of hideous, but might be someone elses cup of tea.
along with the nice kia casting mark. I couldnt find a bp mark on the motor, though its caked in dirt. I did see bp on the head, cams, and the rods. And my blown transmissions bellhousing bolted up to the block fine.
I ordered oem seals last night for this build, and my acl race bearings I had been getting off of amazon for 15$ a set jumped up to 65$ bummer.
I did order a spare "oem" thrust washer set when I last rebuilt the motor ( call it a premonition) so I dont have to get a dealer thrust washer set for 40$
If anyone wants the valve cover, throttlebody with iac, or stock cams, let me know. I have no need for them.
And finally, the last thing im unsure of. The oil filter stud. This one has no cooler, and no nut on the stud. Do I just need to get another nut and double nut the stud out, and replace it with mine?
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