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-   -   Boosted NB, where to start... (https://www.miataturbo.net/build-threads-57/boosted-nb-where-start-110228/)

Fireindc Apr 11, 2025 04:39 PM

Duuude, glad everyone is alright. Kinda crazy that an NB could flip an SUV from a side impact, kinda impressive...

I'd definitely snag the motor/trans/diff from that NB if it were me. Worst case it has a damaged head, but I'd bet the bottom end is fine. It's not an interference motor so shouldn't have internal damage in that regard.

boosted_na_2025 Apr 11, 2025 04:58 PM


Originally Posted by Fireindc (Post 1664018)
Duuude, glad everyone is alright. Kinda crazy that an NB could flip an SUV from a side impact, kinda impressive...

I'd definitely snag the motor/trans/diff from that NB if it were me. Worst case it has a damaged head, but I'd bet the bottom end is fine. It's not an interference motor so shouldn't have internal damage in that regard.

It was a Duramax. Honestly my daughter is very lucky the truck didn't land on her, first flip it didn't touch the ground.

The car is an auto so I don't have much interest in the trans but car was a 8.5-9/10 inside and out and everything but the front is intact. Someone would probably want the top interior wheels that have new tires.
https://cimg4.ibsrv.net/gimg/www.mia...51588769ac.jpg

sixshooter Apr 11, 2025 06:34 PM

I am really really glad that she was okay.

There's a huge amount of salvageable stuff on that car if you choose to get into it. They're getting very hard to find a junkyard compared to 10 years ago.

JohnnyOTS Apr 11, 2025 07:49 PM

Yowch! Thank Heavens the Kiddo is all right. Stuff - whatever it is - will eventually end up in the dumpster/junkyard anyway. The health and safety of loved ones is the important thing.

Z_WAAAAAZ Apr 11, 2025 08:52 PM

Damn dude, sorry to hear about the car, but super glad your daughter's ok! Man, this thread's been a bit of a rollercoaster.

boosted_na_2025 Apr 11, 2025 11:25 PM


Originally Posted by Z_WAAAAAZ (Post 1664031)
Damn dude, sorry to hear about the car, but super glad your daughter's ok! Man, this thread's been a bit of a rollercoaster.

Haha. Tryin to bring some action to MT...

All jokes aside I appreciate you guys comments. My daughter is 19 and this is the first car she bought with her own money. She's had it maybe 2 months. She shouldn't have even been where she was, she works for me and I had text her and told her to take the day off but she didn't see it until she showed up to work. Left probably excited for the day off (she's a hard worker with amazing work ethic) and just wasn't paying attention. I'm just glad nobody was hurt. As a dad getting the call and then pulling up to see the truck had rolled and the damage to her car but not seeing her. Definitely wasn't my strongest moment. A couple older ladies that witnessed the accident had her off the road in the grass consoling her. Grateful for them.

As far as the car goes, everything from the windshield and doors back is intact. Excluding the steering wheel obviously. I think the valve cover and exhaust cam gear will end up being the only issues with the engine. Gonna pull it and sell the rest cheap just to get it out of here.

It's really a bummer the car was 9/10 inside and out, didn't smoke or burn oil. Transmission was rock solid. Idk if there's much of a market for the trans but it was definitely good. The guy I bought the car from gave me a really thick folder of all the maintenance he'd done over the years it was very well maintained. Got it for a steal to he just wanted to get it out of his garage. She's probably going to want another Miata so hopefully I can find her one that is half as nice as the one she just lost.

sixshooter Apr 12, 2025 08:53 AM

I would pull every part and every nut and bolt and save them as spares, everything you have shelf/attic/shed space to save. Trunk lid, bumper cover, tail lights, differential, axles, control arms, interior bits, relays, errythang. You can always sell the parts later if you ever get out of Miatas. You can't always find the parts readily otherwise.

boosted_na_2025 Apr 12, 2025 10:29 AM


Originally Posted by sixshooter (Post 1664042)
I would pull every part and every nut and bolt and save them as spares, everything you have shelf/attic/shed space to save. Trunk lid, bumper cover, tail lights, differential, axles, control arms, interior bits, relays, errythang. You can always sell the parts later if you ever get out of Miatas. You can't always find the parts readily otherwise.

If the market near me wasn't so saturated with Miata's and parts, I would do this. I could probably store all the parts if I sell all my Honda stuff (ouch), I'm just not sure if my wife will love it lol.

boosted_na_2025 Apr 15, 2025 07:28 PM

I spent Saturday pulling the engine out of my daughter's car. Sunday someone took the rest of the car. I picked the head up from the machine shop today. Now, I'm at a crossroads. I have the bottom end I've been working on ready to go together, crank being kind of iffy. Machine shop guy gave it the ok, but I'm still a little paranoid lol. First time engine build and all. Or, I have the known good engine from my daughters car. No issues there. Use the crank and send the iffy one to be turned? Or send it with the one I'm unsure of and hold on to the known good engine?
https://cimg7.ibsrv.net/gimg/www.mia...15d5ebc93d.jpg

boosted_na_2025 Apr 16, 2025 10:39 PM

Nobody responded to me yesterday so I'm guessing everyone was probably thinking I'm an idiot lol. The thing is, I'm really curious if the crank I polished will work without being machined. Sounds like an expensive experiment, I know. But having another known good engine on hand makes me really want to send it. Plus, I'm picking up some Carillo forged pistons with forged rods this weekend. The good motor is getting built as well. I am learning on this first one and will make some mistakes. If it works out great, if not then I learn a valuable lesson and taking that crank to get turned and buying new bearings.

I gapped rings. Out of the box every single ring was gapped the same, .022 including the oil rings. I left the top rings and oil rings at .022 and gapped the second ring to .024. That's what I have to work with.

I planned on pulling the blown motor out of my car Saturday but I have to work then go to Tulsa to pick up those pistons and rods. Sunday is Easter so It's not happening til next weekend, unless something comes up :eek:



boosted_na_2025 Apr 19, 2025 10:59 PM

Progress. Got the oil pump, oil pan, water pump on. Hoping for no leaks lol. Looks good but you don't know til you know. Once I get the head, timing belt and pulleys on I'm pretty much at a standstill until I can pull my motor out of my car. Today would have been a great day except we were under severe thunderstorm warnings a good part of the day. Rain on and off. Tomorrow is Easter so it probably won't happen until next weekend.
https://cimg0.ibsrv.net/gimg/www.mia...c0472b3d78.jpg


I did make a mistake. I put the oil return at the front side of the oil pan, right where the AC compressor is. Who needs AC in a Miata anyway lol
https://cimg7.ibsrv.net/gimg/www.mia...69ea7954cc.jpg

​​

sixshooter Apr 20, 2025 06:38 AM

You might still make it work.

boosted_na_2025 Apr 21, 2025 10:59 PM


Originally Posted by sixshooter (Post 1664352)
You might still make it work.

I'm hoping I can. The angle I'm able to check the AC bracket at, it doesn't look promising. Maybe a 90° AN fitting will make it work.

I think I have the timing set. Everything lined up where it's supposed to be. I did just realize I need to order new lower timing cover. One that came off it was broken and the mid cover is missing the seals.
https://cimg5.ibsrv.net/gimg/www.mia...dde48db2f6.jpg
https://cimg7.ibsrv.net/gimg/www.mia...31accc829a.jpg

boosted_na_2025 Apr 22, 2025 12:14 AM

I realized I never posted the difference between the tunes, the one I was running vs the one I blew my car up with. Tonight is the first time I actually looked at them and man, they are way different. The one on the left the car idled like S but ran well everywhere else, the one on the right it idled perfectly but also blew up...
https://cimg9.ibsrv.net/gimg/www.mia...36632ab7f8.png

redursidae Apr 23, 2025 11:20 AM

The timing looks good. Pictures always make the cam marks look a little off because of parallax.

Regarding VEs, in the left table your lower MAP area being that lean tells me it was auto-tuned and not hand massaged. When you use VEAL make sure to lock the idle and deep vacuum cells.

Unless I’m missing something, the one on the right is richer everywhere, and somewhat closer to what I would expect for VE values.

Are there any other big differences between the two tunes? What about ignition advance, engine basics, injector settings, AFR and Stoich AFR?

boosted_na_2025 Apr 23, 2025 11:36 AM


Originally Posted by redursidae (Post 1664465)
The timing looks good. Pictures always make the cam marks look a little off because of parallax.

Regarding VEs, in the left table your lower MAP area being that lean tells me it was auto-tuned and not hand massaged. When you use VEAL make sure to lock the idle and deep vacuum cells.

Unless I’m missing something, the one on the right is richer everywhere, and somewhat closer to what I would expect for VE values.

Are there any other big differences between the two tunes? What about ignition advance, engine basics, injector settings, AFR and Stoich AFR?

The tunes were identical, other than the VE table. The one on the left was supposedly tuned by a shop for the car. Never idled right. When I loaded the table on the right it idled perfectly. I did do some auto tuning to the one on the left because it was running super rich initially. I got the overall afr pretty well dialed but idle was never right. Like I said, table on the right with richer values idled perfectly and probably did run better overall. I think the 12 psi I hit is what blew the motor up. It was a 147k motor and probably wasn't treated the best before me.

SimBa Apr 23, 2025 03:40 PM

IMO I doubt the tune killed the car if the VE table was the only difference. Like redusidae said, the VE table that was being run when the car blew up looks like it would've been way richer than the other table.

Did the car drive decently on the richer map? If it was running super rich I expect it would've stumbled a lot in boost once you got lower than ~11 AFR, but I don't think that would've killed the engine..

boosted_na_2025 Apr 23, 2025 03:50 PM


Originally Posted by SimBa (Post 1664483)
IMO I doubt the tune killed the car if the VE table was the only difference. Like redusidae said, the VE table that was being run when the car blew up looks like it would've been way richer than the other table.

Did the car drive decently on the richer map? If it was running super rich I expect it would've stumbled a lot in boost once you got lower than ~11 AFR, but I don't think that would've killed the engine..

Honestly SimBa, the car was running really well. Keep in mind I had just swapped from the yellow rx8 injectors to ff 640's. The upgrade was definitely noticeable. The car was smoother, less nvh and the exhaust sounded completely different. I really don't think the VE table caused the engine to fail and tbh I'll probably start with that table once I get the car running. What I think happened was I was running 12psi shooting for 10psi on the mbc and probably had a boost spike. Only thing that makes sense.

The way it failed was kind of weird imo. Came around a corner, 3rd gear pull to probably just short of 6k, shifted to 4th and didn't give it hardly any throttle as I was already at the speed limit, a few seconds later hell broke loose. I still haven't been able to pull the engine so I haven't been able to check out the actual failure.

sixshooter Apr 23, 2025 10:05 PM

Often times the damage occurs a bit before the actual catastrophic failure. Several on this forum have had the kablooey under light load and not in the heat of battle.

boosted_na_2025 Apr 26, 2025 01:07 PM

I knew this would happen. Unfortunately I don't have a big enough garage to pull the car all the way in and get the motor out.
https://cimg5.ibsrv.net/gimg/www.mia...afaf61d02b.jpg
https://cimg7.ibsrv.net/gimg/www.mia...ddc916f189.jpg


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