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-   -   [NC] 7.5lbs per HP build thread / xpost from M.Net (https://www.miataturbo.net/build-threads-57/%5Bnc%5D-7-5lbs-per-hp-build-thread-xpost-m-net-86322/)

elijah_mckay 05-14-2016 02:19 AM


Originally Posted by Chilicharger665 (Post 1312072)
If 8 psi gets 250 whp, then what is the argument for a 6758? A 6258 should easily put the NC drivetrain into 350+ whp range and maybe be more responsive. Is the 6758 going to be more efficient over the majority of the operating range or something?

In soviet's build thread, his 6758 only spooled 300 rpms (given it wasn't an exact, definitive side by side) slower than the 62 and made better power as well. I want to do some more research myself but it seems like they are very comparable

Chilicharger665 05-16-2016 10:51 AM


Originally Posted by elijah_mckay (Post 1331442)
In soviet's build thread, his 6758 only spooled 300 rpms (given it wasn't an exact, definitive side by side) slower than the 62 and made better power as well. I want to do some more research myself but it seems like they are very comparable

Good info! I haven't read Soviet's thread in forever. Did he have a ported head? The 2.0 in alb's NC has both more displacement and way better flow than a BP, so I bet the spool will be practically the same.

albuquerquefx 05-26-2016 05:00 PM

I'm back from my travels, although I'm a bit underwater from being sick. A long weekend approaches, and I'll kick my own nutsack if I'm not able to drive this puppy to work on Tuesday (weather notwithstanding.)

albuquerquefx 06-07-2016 10:45 AM

Someone at the office gave me a gentle jab for not posting an update ;)

First and foremost, I'm driving the car. It went to work with me at the end of last week, and then came back to work with me today. My tuner has warned me (obviously) to avoid WOT for this initial tune, and overall the tune is very conservative. The long term fuel trims are pulling fuel at a moderate rate, you can feel the ignition timing is pretty tepid and throttle response off-idle isn't quite right but I've yet to log any knock. While not trying, I've seen positive manifold pressure several times in almost every gear, mostly moving through city traffic or on the freeway / onramps.

Despite the tepid tune and flimsy off-idle response, I'm pretty happy with the clutch feel. It's awfully close to stock pedal pressure and just a tad grabby -- I fully expect the grabby will wear down a touch as more miles pile on. The gears do exhibit a bit more chatter I think, although still only in the lowest gears at similarly low RPMs. The new poly engine mounts have also worn in a bit, the first rush of vibration helped me to find a few items in the engine bay and elsewhere which needed a bit of tightening or adjustment. Here's one which surprised me: the hood prop rod joint rattles like a little turd, and I haven't figured out how to fix it other than (for the moment) wrapping a shop rag around it. Nearly every other rattle has been easy to find and remedy.

Now for the niggling issues.

The vband clamp between the manifold and turbo has a slight leak. This isn't Fab9's fault, I swapped their provided vband clamp for my own Vibrant quick-release clamp. The sizing (diameter) is correct, however I'm guessing the mated flange thickness is actually thinner than my aftermarket clamp expects and thus a tiny bit of leak is permitted. I didn't even realize that was the leak until yesterday; I had previously assumed it was my upstream O2 sensor bung-plug at the top of the downpipe. My fault for not doing a better diagnosis; I could've fixed it over the weekend otherwise.

Finally, I have a tiny oil leak at the bottom of my block-tapped drain plug. I used permatex on the threads before installation, however believe I made the hole just a tad bit too high and now the hex head of the drain fitting stops at the gusset in the block. When I first installed the drain plug, it didn't look like a whole lot of thread was meeting the block at the bottom edge, and now it looks like my guess is correct. I'm still working on the solution to this; my first whack was to clean it off and build up a layer of liquid metal filler epoxy at the lower edge. After curing, I backed the drain out, re-applied permatex, and reinstalled. This slowed the leak to almost nothing, basically a drop overnight, but it's still a leak and it's going to bug me. I'll probably pull it back apart again, and try once more with additional epoxy buildup.

The oil leak is a bummer, the exhaust leak will be easy to fix, the rest seems to be good :)

Fun fact: I DID get the Innovate SCG-1 tapped into the turbo's integrated boost control solenoid. Innovate specs their unit up to 30Hz @ 12v switched ground, the BW EFR solenoid is rated to 33Hz @12v switched ground, so all is well the world. Can't really test it out yet until I get the tune dialed in, of course.

As soon as I get the exhaust leak sorted, I'll start sending off data logs to get the tune dialed up.

Leafy 06-07-2016 10:53 AM

Why not grind the block rib so you can turn the hex on the drain plug?

albuquerquefx 06-07-2016 10:55 AM


Originally Posted by Leafy (Post 1336945)
Why not grind the block rib so you can turn the hex on the drain plug?

I was actually thinking that next, to be honest. The leak was so small, I was going to see if I could simply seal it. Since that didn't work, and I need to pull the turbo loose anyway to fix the vband exhaust leak issue, I may just take the grinder to the block and fix that way :)

turbofan 06-10-2016 04:25 PM

congrats man. In for dyno graphs :)

albuquerquefx 06-20-2016 01:39 PM

I'm back from the annual family Florida trip, pulled into the garage around 6pm Saturday night. The '14 Mazda 6 GT daily driver picked up better than 35mpg on a single tank of gas from Seagrove, FL to our home outside of Memphis, TN while maintaining an average cruise speed (computer-indicated) of 74mph. That includes kiddo break stops and a large swath of 55mph zone too ;)

Anyway, Saturday was a wash and Sunday was mostly spent catching up on chores -- grocery store, washing clothes, unpacking the clean dishes, mowing the lawn (10 days between mowings, and our lawn care folks came and sprayed on Monday which made it grow even faster.) Had about 30 minutes to play with the Miata, tried like a mofo to get the stupid shallow vBand connected between manifold and turbo and simply couldn't get it.

I'm gonna have to disconnect pretty much the entire turbo (oil and water feed and drain lines, intake plumbing, exhaust plumbing) so I have enough room to work. I take back whatever else I said was the hardest part of the install; for me, getting the turbo attached to the manifold within the confines of the engine bay is the hardest part. Drilling the hole in the block was mentally taxing, but not physically difficult.

The timing is OK though, because Bryan sent along a picture and some simple instructions for his propsed modification to the oil drain NPT fitting as it connects to the lower side of the turbo. The update basically shortens the NPT fitting by half, removing a potential issue with oil backing up into the core under heavy usage.

albuquerquefx 07-05-2016 11:21 AM

2 Attachment(s)
Car is back on the road! I'm still on the very first tune, had to get the exhaust leak fixed and put some miles on it before sending it back for the next tune update -- it kept thinking it was lean, so the LTFT was something stupid like +30% for a while. Since this is the very first tune, I'm under orders to avoid anything over ~50% throttle and ~4krpm. As such, I made a little video of a 2nd / 3rd gear jaunt at 30% throttle and shifting at 4k. Data log showed 4.6psi at 32% throttle and 3700rpm in 3rd gear..


Fixed the self-induced exhaust leak by removing the vband I had opted to use instead of the one provided. Also removed the oil drain line and changed the fitting per Bryan's instructions. Also fixed another oil leak which was coming from the brass fitting above the oil filter which I had forgotten to re-Permatex after making some adjustments a few weeks ago.

Gave it a thorough cleaning of the exterior and interior; it was really nasty from sitting in the garage for 60 days. I actually need to re-wax it too, somehow it collected a new scratch on the front driver's fender (wager it was my 4yo daughter parking her bicycle. ) Just a thin wisp entirely within the clear coat, so a bit of wax and elbow grease will make it go away.

http://photos.napalm.net/clubsi/WP_2...50_35_Rich.jpg

Drove it to work again today. The goofy Miata grin now has braces, as well it should! (the visible handicap logo is actually painted over in gray, I'm not illegally parked in a real handicap spot I promise!)

http://photos.napalm.net/clubsi/WP_2...12_36_Rich.jpg

Need another 350 miles to properly break in the clutch. I'll need at least that much to get the tune completely dialed in.

turbofan 07-06-2016 03:06 PM

Nice little sleeper.

albuquerquefx 07-12-2016 10:55 PM

2 Attachment(s)
Two very small snippets of logs I took today.

First and foremost: these logs are performed on the SECOND flash program for the car: the first flash was intended primarily to get the car to even start correctly on the new gear. Any reasonable turbo setup will go through a dozen of these flash iterations, so we're VERY early in the process.

These runs are also on the stock 1.75" Mazda midpipe and exhaust. No 3" test pipe here, the downpipe connects a funnel-shaped compression flange to the stock Mazda resonators, midpipe, muffler and tips.First image: snippet showing transient response; 3rd gear light acceleration (slow roll into 35% throttle) which easily generates positive manifold pressure. Don't have to mash the gas to get the turbo to spool:
Attachment 176436

Second image: rolling into WOT in fourth gear around 2000 RPM. Mixture is still rich on this conservative tune and we get boost threshold in 7/10ths of a second / 400rpm.
Attachment 176437

Borg Warner's EFR series means serious business.

NBoost 07-13-2016 09:14 AM

It is also amazing what these EFRs do on an engine that flows worth a damn. They certainly do a great job at masking how shitty the BP head flow is.

I love these NC EFR builds, a serious contender for a fun daily driver.

18psi 07-13-2016 09:18 AM

to be honest that's not really amazing spool. most turbo's will dip into positive pressure, 1-1.5psi, upon throttle tip in (unless grossly oversized). the real kicker is when they actually dip into significant boost. 5+

however

I'm 100% sure this setup will be really awesome once you open up the exhaust and crank up the boost, so I am in no way shape or form doubting how nice it's going to be.

albuquerquefx 07-13-2016 10:36 AM

^^ Absolutely agree. I'm more surprised what the damned thing does choked up on the stock exhaust and the 2nd remote ECUTek tune. There's a TON of room here for improvement, and I'll be posting more logs after exhaust, after tune, et al. At least now I've published an example of where I started, so the delta between here and completely done should be easily visible.

I've hidden a bunch of the columns, as most of the ECUTek tuners consider the truly important data points (ignition timing, VVT angle, drive by wire throttle plate management) to be proprietary information. The current map is hardcore conservative on the ignition timing and throttle maps (plate position never truly gets fully open despite my 100% throttle input.) The load vs VVT angle map leaves much to be desired also.

This is all on purpose to keep me from blowing up shit like a dumbass and then blaming it on a bad tune. It will get better, quickly.

Leafy 07-13-2016 09:04 PM

"proprietary info" that literally anyone with more than 3 brain cells to rub together will come to the same numbers or relatively close depending on tuning style and aggression.

albuquerquefx 07-14-2016 09:49 AM

Went picking through about 18,000 lines of logging last night. There's something up with my radiator fan as it doesn't appear to be turning on. I was stopped in traffic for about three minutes on the highway portion of the commute home last night, thought I got a faint whiff of coolant right as traffic began to move. I was just reaching for the tablet when I needed to reach for the shifter instead.

Logging shows the ECT's were 109*c, which isn't "hot" but I know my fans weren't on and they should've been. Soon as i started moving, it rapidly dropped to around 85*c.

Hope I didn't break the dumb thing, replacing the factory fan is a PITA.

Girz0r 07-14-2016 10:03 AM

Let it idle in the driveway up to temp and see if it comes on eventually :dunno:

albuquerquefx 07-14-2016 10:38 AM

Yeah, I'll tinker with it either tonight or over the weekend. Previous logs suggest the fan kicks in around the 100* mark, give or take. It was stupid hot outside, but I had the top down and wasn't running the AC.

18psi 07-14-2016 10:40 AM

Are you able to do any tinkering w/ ecutec? or is it one of those locked mumbo jumbos that "only your tuner" (herp derp) can go into?

Cause if you can, just lower the temp threshold and voila

albuquerquefx 07-14-2016 10:55 AM

Sadly, ECUTek doesn't (yet) expose the fan enablement temp controls for the NC. You have to load the ROM into MazdaEdit and manage it there. It's on their radar, or at least reportedly so, since they already know the ROM offset location for the values.


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