Very good explanation. Thank you.

I think the MSM turbine housing is just too small for the td05 turbine, even once machined, unless you significantly hogged out the inlet to the turbine. And if you did that its pretty likely that you messed up the airflow anyways. You're probably better off turning the boost down and turning the timing up until you can get a different set of hotside parts in the car.

I'm not saying you're wrong, but I think you'd be surprised at how well the MSM tubine is designed compared to the Mitsubishi and how similar in size the turbine wheels actually are.

MSM (IHI) Turbine Wheel .49A/R
Exducer 43.65mm = 1.719”
Inducer 57.20mm = 2.252”

16G (MHI) Turbine Wheel .60A/R
Exducer 49.022 = 1.930”
Inducer 55.880 = 2.200”

Stock MSM housing before I cleaned it up.
https://www.miataturbo.net/attachmen...ine=1396844889

Someone elses ported MHI housing.
https://www.miataturbo.net/attachmen...ine=1396844889

The only large difference I've noticed in the 16G turbine housing, besides the fact that it is much physically larger and heavier, is that the inlet on my ported 16G housing is 2.25" where as the MSM housing is only 1.75". That said, the 16G housing immediately closes up and by the time the throat reaches the wastegate ports they're pretty much even.

Ahh, what the heck. Here's couple more for anyone who's interested.

https://www.miataturbo.net/attachmen...ine=1396844889

https://www.miataturbo.net/attachmen...ine=1396844889

StratoBlue, That was the best explanation of knock I have ever read thank you, im going to save that post and reference it whenever I have questions myself.

Thanks! Glad I could provide some insight. I tune cars everyday, so it's something I deal with regularly.

Hi Shane,

I have a very similar setup, only real difference is the inlet size on the compressor housing cover:

https://www.miataturbo.net/attachmen...ine=1383704955

My car was making 232 whp / 220 lbft @ 6,330 rpm at 16 psi. On a very slow ramp speed (250rpm/sec) it would get an occasional ping so we backed it off another degree and it lost 10 whp.

The engine was using lots of oil so we pulled it down again and found it had a #1 bore issue and an inlet valve issue on either #3 or #4. It now has new rings and bearings so I am still putting mileage on things before hitting the dyno again.

I'll keep you posted with how I go just so we can compare notes.

Cheers

Also I am running 9:1 +1mm CP pistons (SC7542). I'm already running less timing than you by the looks of it:

https://www.miataturbo.net/attachmen...7&d=1403052954

Are you running a standard exhaust? Mine is standard except for the dump pipe.

You said it's better but .49 ar is tiny for a 4cyl shooting for 300hp. That's probably why your not making what you wish cause you cant get the flow you need.

Tim,

I would love to see what you end up with .

And yes you're running quite a bit less timing than I am. Hopefully you can get some of that back with your rebuilt motor.

I currently have the small 99-00 solid lifter intake cam in but I'm getting a set of mild 264 cams made from Delta Cams. I'll get those put in soonish and see what I come up with.

I've also been tempted a few times to go down to this one gas station that has 100 octane fuel and see what I can do as far as timing and power. I'm sure I've got a lot of power left on the table with timing.

Long day though. Just finished replacing my rear main seal and I'm half way through a strong beer. Also got my flywheel resurfaced "while I was in there" That definitely feels like it's helping the FM2 clutch grab stronger. It had a few noticable hot spots.

And this is what I'm running for exhaust. Full 3" ARTech exhaust. With my complete stock exhaust bolted up to the turbo, it reaches 20psi by 6500rom instead of 4500.

Keep me posted on your findings.
https://www.miataturbo.net/attachmen...ine=1403060702

Just a little update in case anyone was or ever is interested.

Something that I'd been wanting to do for a while now is go get some good (higher octane) gas and see what I could do as far as tuning and making some more power.

Luckily for us in San Diego, there's at least one gas station I know of that sells 100 octane out of the pump (not requiring separate gas canisters) and doesn't require a special credit card.

I ran the tank down to about 1/3 and pumped in about 8 gallons of this stuff.
https://www.miataturbo.net/attachmen...ine=1405297329

Yes it's ridiculously expensive, but this was for testing/experimenting purposes.

The first thing I did was put put over to my usual testing street as to not waste much of this expensive refined prehistoric forest matter, but still get the 91 outta the lines and mix up the tank as best as I could. Once there I did a base run and then started turning up the timing. I did about 10 full 3rd gear pulls with varying timing and boost levels.

It was quickly apparent that the first 3 degrees of added timing made the most impact. I now have first hand experience of what everyone talks about when they say that after a point, added timing doesn't make much a difference.

I ended up with this as my final timing map which is about 5deg advanced through boost from my regular street/safe 91 octane map.

https://www.miataturbo.net/attachmen...ine=1405297329

And the results via Virtual Dyno look like this. 91 vs ~97 both at 21psi.

https://www.miataturbo.net/attachmen...ine=1405297329

I have to think that this is just another testament to what good gas offers. And California 91 is not that great. I'd imagine that I could get pretty close to this with decent 93.

So after I was done beating on the car, I decided to pull the #1 plug just for shits n giggles. I'm running bkr7e plugs and it looks like I can probably go even another step colder.

https://lh4.googleusercontent.com/vY...M=w846-h693-no

That's all really. Just wanted to share with everyone. I'll do my best to enjoy the rest of my tank.

And one more comparing the run from the beginning of this thread, to what I ended up with yesterday.

https://www.miataturbo.net/attachmen...ine=1405298327

Also it looks like I lost a couple hundred RPM in spool from the Virtual Dyno data. I gotta check and see if I can find out what that's about.

I've learned a lot in the past few months and especially this weekend about timing. There's probably more to be had. But I'm good for now...

Until these go in =D
https://www.miataturbo.net/attachmen...ine=1405298327

That plug, so much knock.

With the det cans, I only heard it knock a couple of times. And I tuned it out. I know it sorta looks like knock, but I think it's just hot. Will be pulling the head in a few weeks when the cams go in to check on things just in case.

Maybe its the camera flash making it look like its covered with sparkely knock crystals.

Are the cams expensive? I have flirted with the idea of a VVT head swap but I figure it doesn't buy anything above 4,000 rpm which is where the car spends most of its life anyway.

Pretty substantial difference in power with the fuel allowing extra timing! Wish I had easy access to E85 here!

You might try retarding the timing in the area where your spool is slow. That will leave some additional heat in the exhaust to spin the turbine. All else being equal, that's probably where your spool went. With the timing change, more heat goes to pushing the piston and creating torque vs. pushing the turbine. Another factor is that the race fuel probably burns faster -- with basically the same effect.

Props for the data!

More spark advance = more spool unless you're so far retarded that a significant amount of fuel is burning in the exhaust, even still you'll be lacking power durning spoolup.

That plug looks terrible. You REALLY need to back the boost down on this thing and have a professional tune it before you smoke it.

its really hard to say imo, but if those dimples are from knock...well you're gonna have a bad time.

keep in mind 100oct doesn't make you invincible, it just helps

The deposits on the plug are from burning of oil and fuel additives. They appear to be ash primarily. You might be burning a little oil or you may be running a little rich, which is safe but may end up fouling your plugs and generating too many deposits in the combustion chamber. Run a large bottle of Techron in your next tank of fuel to clean up the combustion chamber and run Rotella T6 if you aren't already.

I don't see any evidence of detonation. Detonation leaves little specs of aluminum or rust on the insulator in minor cases.

EDIT: And, double checking my thoughts I browsed gurgle images:
http://www.mts1200.info/motorcyclein..._condition.jpg

https://www.miataturbo.net/attachmen...ine=1405434157

http://www.ek9.org/forum/attachments...ug-reading.jpg