Hello. I've been a lurker / learner for 5 years and recently bought my second Miata, which is my first turbo Miata. Miata #1 is a Shinsen, Miata #2 is a MSM with Little Enchilada, Rev ECU, and some non-stock injectors (need to sort out what they are but the car came with the original injectors in a bag, so I know they aren't in the car...).

I thought I'd finally introduce myself so that I can now ask the same questions that have been asked on this forum for millenia without the shield of anonymity.

Plans for the car are, ideally, just smoothing out the tune and enjoying it for a while. It dyno'd just below 200whp and just above 200wtq. I will likely do rods and such down the road and go for some bigger numbers.

Immediate steps are pulling the tune / logging and posting here for insights from those of you that are more experienced than I. Thanks in advance for any feedback, and thanks for reading.

 

Welcome, nice cars! Do tell us a little about the 'Shinsen' ....

I definitely recommend rods in the MSM, sooner rather than later for peace of mind.

 

It’s just a special edition NB2 that had blue trim / seats / soft top and only came in titanium grey metallic. They built around 1500 of them and they aren’t special in any way mechanically. Normal 1.8 VVT, normal 5 speed trans, normal non-torsen diff.

Any recommendation as far as rods for the MSM? Just the usual suspects? Thanks.

 

Thanks, all our NB8Bs were 3.6/6-speed, open diff as I recall, except for the SE (local designation of MSM) which has the Torsen. NB8As were 4.1/5-speed open except for one special edition IIRC.

My rods are Manley, but any forged rod will do the trick. Do a bit of reading before you commit, there are lots of build threads with good info, and the stickies in the turbo section are required reading, you must pass the test at the end or you can't turbo until you do Being a lurker you will have picked up a fair bit, but nothing sharpens the focus as starting on your parts list for your big rebuild.

 

Nice pair!

I'm just an hour up north of you. I haven't been to any events but it appears there's a fairly active facebook group for local Miata shenanigans, and of course we're not far from Miatas in Boone or MATG. Not sure how the recent storm will impact those events.

 

Welcome to the forum! Nice looking rides man. Looking forward to seeing the tune progress as members here get their filthy hands on it!

 

Thanks! I've been to couple of smaller events here in Charlotte but nothing major. Shooting for MATG 2025 though.

 

Thanks! Hoping to get some logs and / or screenshots up today / tomorrow.

 

It took me longer than I'd hoped but here is a log and some screenshots of idling / basic settings. I really appreciate anyone taking a gander and providing any feedback whatsoever. I tried to cram as many tables and fields into each screenshot as possible to minimize the number needed. I also had to zip the log file because it exceeded the forum's file size limit, which is 20mb apparently.

Above I stated that I wasn't sure what injectors were in the car, I've since sorted out that they are Denso 195500-4450 425cc fuel injectors (RX-8 injectors). Other than that the car is an MSM with FM LE kit running an old MSLabs / Rev ECU. I also have an AEM AFR gauge installed.

The only issue as far as feel / drive-ability is a heavy hesitation or cut when in high RPMs and mostly or fully open throttle when shifting up to 3rd. Does not feel like a clutch issue, car just kind of "sticks" for a second or two.

 

No need to post the screen shots, just attach a copy of the tune along with the log.

But looking at the screen shots, it's not too terrible. In the logs you're hitting your AFR target in boost, although a few of the full throttle pulls I looked at were a bit rich.

Only thing that jumps out at me is the tune's using warmup enrichment for a significant amount of fueling. Typically it's set at 100% (0 enrichment) once the car is warm, around 170 degrees coolant temp. Yours stays at 111%, so it's adding 11% on top of everything. If it runs well, there's no harm in leaving it like that, but it's a bit weird.

Boost is falling off as RPM goes up, so I wouldn't expect you to be able to make much more power. The MSM turbos are good for around 200, and that's it. You can increase lower end torque perhaps, but that'll come at a severe risk to your rods. They only make 200hp, but can make 230-240ft/lbs.

 

First of all, thanks a ton for taking the time to look the log and info above and provide some feedback. I truly appreciate it. Per your recommendation, my tune and log are attached to this post.

- Re: running rich under full throttle - it looks like AFR dips to around 10 at times, but dips into the mid-10's far more frequently. Is this low enough to worry about? I'm not concerned with fuel economy or anything just causing damage. Most likely culprit a leak, I assume? I see normal vacuum #'s, for what it's worth.

- Re: warmup enrichment, good note and something for me to experiment with. The previous owner had a tuner work specifically on idling issues and I suspect this may be related to that fiddling. I guess it's possible they just neglected to back out the enrichment once the car is warm? I'll slowly back this out over 170-180 degrees temp and go from there.

- Re: limitations of stock turbo & internals - I'm well aware and thanks for noting. Internals are likely in my future but I plan to enjoy the car as it is for a little while, and just get it as dialed in as possible.

- My coolant temps stay right around 200 and occasionally bubble up to 215, and this is in relatively cool weather. It gets quite hot here in the southeast in the summer. If I'm hitting those temps now, is this something I need to address? From what I've learned on this site those temps are not terribly high, but do skew on the north end of normal. That said, there is limited information on MSM LE setups relative to the "normal" route of turbo-ing an NA/NB Miata, so for all I know these temps are typical for what I've got. As always, any feedback appreciated.

Thanks again!