perhaps a log / tune would help, ive seen your posts and u certainly know alot more about tuning than myself. Setup seems alot like underdogs IIRC. Recall someone saying the Plat plugs not being great, maybe try some cheapo ones of those. Interested to see an out come. Hopefully its just something minor / oversight.

being in 3rd or 4th on a dynojet doesnt matter. hell run in 2nd and it will still output the same.

22psi and the same power as Brain with half that boost.....There's more than something small wrong with your setup. Is 22psi not just a lot of hot air from spinning the turbo to fast?

Maybe the MAF is a restriction :giggle:

I also fail to see how you expect to fuel an actual 22psi with 460cc injectors? Maybe your MAP sensor is just not reading properly, 85%-95%DC at 13-14 psi sounds about right, but 22psi?!?

Wait, you're not miss calculating KPa are you?

yeah I'm on 460cc injectors and hitting 90% DC at around 240rwhp.

that compressor wheel is good for 27 lb/min and the turbine shouldn't choke up like that...there's gotta be something choking it or something. Even my smaller 50 trim T3 is outputting better up top:

https://www.miataturbo.net/attachmen...ine=1340028058

The map sensor is reading properly.
Yeah I'm gonna move the point where the wastegate comes off to pre TB\post IC instead of the manifold. I will also try making a dual port wastegate out of my current wastegate.
doubtful the maf is a restriction.

I took off the exhaust and went from 80% duty cycle to 95% duty cycle to compenstate for the extra airflow, still had boost drop out so its not a restrictive exhaust causing boost drop out.

If I was smart I would of noticed it sooner and would of tried to fix it

The turbo you are usomg look to be the specs of a 83/84 Ford Thunderbird Turbo Coupe

There was another guy asking if he should use that turbo on the miata, he may have had the .63 ar hot side...

have you checked for boost leaks???//

BTW... I run 22psi on the .63 hot with 35 lb/hr injectors... no issues on my Ford like that..
One day I will install the wide band and see how lean I have been running.....

I would suggest using the .48 ar turbine housing to that guy if he can find one.

I know there was a few boost leaks before I haven't checked recently.

at 10-11 psi it holds boost pressure to red line and made 180whp at the end of the rev range.
probably now its near 190whp at 10-11 psi without exhaust and just downpipe.

I'm trying to figure out the issue and fix it. I know my next setup after this will be something newer, twin scroll, maybe Variable vane if possible.

Run a BLT... that should help with the taper on the upper end.

Blt?

bacon lettuce and tomato :D

run the same $150 chinacharger as me instead, enjoy torque :)

close....

Boost Leak Test


Since you run 22 psi check the system at about 35 psi...

Do you know how to make (or buy ) a Boost leak tester?

I have tq just as you do.

Probably just go to home depot buy some pvc and match the ends I need with soem caps and make a hole to thread a fitting into and pressurize the piping.

nope, its very different in the different gears for a turbo setup when boost comes on and power\tq are made. peak output maybe the same, but initial output is weak on lower gears.
So in lower gears peak tq output will be pushed further back and you can ramp in more timing compared to higher gears.

ive dyoned my car maybe 20 times now on a dynojet; ive done it in 3rd and 4th and had the exact same output each time. youre pushing a concrete cylinder and the software determines the gear ratio. the output wont change.

when on a loaded dyno, if you don't set it up right it WILL screw up the output. I've seen this when the operator used 4th instead of 5th on a 6-sp.


anyways, look at the above plot comparing my chinacharger and my t3 super 60 again...

And I can still take it out on the streets and show you that gearing still effects power output, you will not make the same tq at 4000 rpms in 2nd gear that you make in 4th gear. I've done my own dynoing with my AQ-1, just watch the accelerometers, they will tell you the dirty secerts of the car. A turbo requires load to get it making power.

I've seen the plot, its cool expect for when it goes from nothing to hell broke lose. around 3700 rpms

yeah sure, the turbo doesn't spool quite as fast, but your final numbers wont change outside a huge margin.

yeah I said the final output numbers won't change but it will move the point of tq\hp buildup far over.
iirc in first gear I didn't make peak tq output until 5.5k~ rpms

Anyways I'm just gonna buy two more map sensors to datalog the complete intake piping setup as well.

I honestly think that you will end up spending more money on this setup than a proper setup would have cost you, and end up with a bucket of crap.

But I guess you're doing it for the challenge of pulling it off for next to nothing, in which case I can respect that (but will still give you crap about it, sorry:giggle:)

I made ~240whp with a t3 60 trim at ~15 psi on 1.8. Over 20psi should be close to 300whp on this turbo, I don't get it?

My car had a cheap build, DIY log mani, DIY 2.5->3" exhaust, cheap crappy restrictive muffler, etc. etc. and I had no problem making the same power and torque with much less boost. I think you definitely need to check for a boost leak.