Leafy, Of course it is possible. First dyno in the spring was with same 99 intake manifold as with Garrett. Reason for trying this one was desire to reduce max torque at 4000 rpm to save transmission and increase above 6000.

Not much difference between the two dynos.

Vlad, yes it is JayL:s old setup.

Intake before dyno. The Blow off valve got it's seal kinked and was replaced by straight pipe and EFR:s own valve was used in dyno and race.
https://www.miataturbo.net/attachmen...ine=1411770747

Exhaust, for grins and giggles.
https://www.miataturbo.net/attachmen...ine=1411770747

Corrected hp?

12 psi gauge in the mani? Or 180 kPa MAP?

I'd really like to buy HRK's car but I don't have quite enough kidneys to sell. Not that he's selling it or anything, but that I want one like it so badly.

Thread deserves an update, it looks like the compromised power from EFR is due to rings leaking.

I pulled the can cover and measured valve clearances.
All close, there were two of exhaust valves with 0.015 gap while spec is 0.012. Not ideal, but I don't think it would be a real problem.

Measured cold leakdown with modified Harbor Freight gauge. It has two identical pressure gauges so it can be run at any feed psi.
Cold at 100 psi going in.
1. 20% (80 psi on second gauge, while feed one shows 100 psi)
2. 10%
3. 25%
4. 15%
All leak from rings (or into oil pan)

Hot
1. 14%
2. 12%
3. 25%
4. 24%

Compression hot
1. 169 psi
2. 165 psi
3. 162 psi
4. 163 psi.

Design compression ratio 8.6 per measured volumes.

Borescope shows few slight vertical scrapes on crosshatch in the cylinder walls. Does not look too bad through the display.

Motor has four hillclimbs three track weekends, three dyno sessions. Three to four hours of real usage.

A bit short life for rings as proven this time. Knowing the car fouled plugs few times, and having the target at 11.7, would there be a chance of fuel washing oil down the cylinder walls? How about leaning it to 12.5 range? I understand that there is higher risk of detonation, but I don't like to refresh the motor with new rings quite this often.
The other thing to shorten the life of those rings would be detonation.
We have the knock sensor installed, but not activated.

11.7:1 is not near enough to have a problem with cylinder wall washing.

At your power levels I would not consider going that lean, 11.7 is already leaner than a lot of people run at your power levels and no one would ever consider that super rich. You need to follow the power though. If you can stay that lean without dropping boost or reducing spark advance it will make more power. And even then, the motor might even more power power leaner at less boost and/or advance but I dont think anyone has ever seen that result on a miata engine.

Thank you, AFR well below 12 seems to be the consensus here.
The 750 cc injectors are at 80% duty cycle at these power levels.
With various calculator found on injector sites, that duty cycle should come at bit higher hp, say 370-400 range.
If there would be tramp or unburnt air entering the exhaust and the lambda sensors after the turbine, that would show as lean condition and would cause the tuner to add fuel to get to that lower AFR number, while the motor sees very rich mixture.

In any case, the motor was most likely hurt before EFR was installed, and in prime condition with Garrett installed. The rings were Wiseco 8450xx and should be ok, they were gapped and did seal well in the beginning. Now I am interested to find out why the wore down so quick.
Anything I need to check while the engine is still in the car?
Send an oil sample to Blackstone maybe?

Just curious what oil were you using and how often was it changed? Any kind of oil cooler used?

My tuner tuned me for around 11.3-11.5 AFR and said that's perfectly fine.

IIRC
Straight Castrol W30 dino oil for initial assembly and start, changed after checking that everything worked.
Castrol dino oil 10-30 for first dyno, 332 hp and first Hillclimb.
Shell Rotella T6 after that, Changed twice, every time the transmission gave up.
Last two hillclimbs on this same oil.
Oil cooler shown in front of exhaust few posts back.

Here is the log file from the last dyno I sent to Scott. It was around 14ish PSI at the top end and had a bad MBC spring. I swapped it out for EBC and am now around 24 PSI (No dyno yet). This run was on a Mustang dyno in El Paso, TX.

Scott plotted the data from the log file: https://www.miataturbo.net/build-thr...19/#post989087

Good lord... go update your build thread and get that thing on a set of rollers ;)

Meh. Paul's setup was pretty heavily optimized IIRC. Timmeh did quite a bit of work on the manifold and exhaust, and I believe there was a bunch of headwork as well as a custom intake manifold? Its been a while since I looked it all up. Sufficed to say, its not just an FM or BEGi 2560 kit running 14psi.

99mx5: Are you still on a stock BP4W head?

Smoothed intake and exhaust runners with ports smoothed and blended up to the valves and polished combustion chambers with de-shrouded valves and stock valve springs. Pics in my build thread.

EFR 6758 and my GT2871
Attachment 238548
Attachment 238549

I need to build a manifold for the EFR, then get on a dyno.

What hotside is on that 6758?

Should be .64AR on the hotside I believe. I picked the turbo up from here.

Shuiend that is awesome!

I am very interested in seeing the results of that comparison... Will you be trying out both the .64 and the .85 housings on the borg? or did you only get the .64 from Micah?

Why will the EFR not fit your current manifold?

Last I heard the EFR is longer than the Garrett Turbos and thus the turbo must be moved farther forward to fit. It will not fit on a standard BEGI/FM location manifold.

that is true of the IWG EFR. The non-wg Vband EFR looks shockingly similar to the garett vband exhaust housing.

Lars has a low mount. I'd assssume the EFR and TiAL vband flanges are different.

I thought EFR's had integral BOV's.

I was just thinking that, myself....