Do you know how much he the trans will hope without modifying it?

Hard to say .A lot would depend on the mileage and condition of what you have. Once you start adding power you will decrease the life of the clutch friction plates due to the slow/soft stock shifts but I would think roughly 200-225hp would be no problem for the jatco as used in the 91-97 miatas if its in good shape and you keep the transmissions fluid temps in check. They can easily handle much more with the proper mods, However, There is no aftermarket support for these transmissions in the states, so if you cant build it yourself it will not be cheap to have it built for power.

New best 1/8th mile test using dragy. This is on the street with nitto drag radials.
https://cimg3.ibsrv.net/gimg/www.mia...0c4e7453cd.png
https://cimg8.ibsrv.net/gimg/www.mia...4a6a04c73e.png

To answer a couple questions asked elsewhere. The solenoid valve I am using is an EHCOTECH B21V-3/4-CC-12VDC SOLENOID VALVE. It can be found on ebay for 25-30 bucks. The exhaust check valve BWD cv8 Secondary Air Injection Pump Check Valve. It can be found at oreillys. I am using a total of roughly 2 feet of 1/2" npt galvanized pipe connected to exhaust manifold to allow a little distance for cooling of pipe. The exhaust check valve is connected to the end of the galvanized pipe opposite the exhaust manifold. I then have about 18" of high temperature 5/8" id hose connected to that check valve and the solenoid valve. I did it this way to try and isolate the solenoid as much as possible from exhaust heat. You may be able to do it differently and have it work perfectly fine. This is just what I did. I used at a minimum 1/2" Id hose throughout entire system. It takes a surprisingly large blast of air to kick start spool process in a very rapid fashion if using a larger turbo, and thats in conjunction with full throttle exhaust gases since this system is only used at full throttle. Also just to reiterate, This setup is really best suited for use with an automatic transmission off the line or the occasional hits from a roll.

UPDATE....
Well I finally made it to the 1/8th mile dragstrip. I made two passes. One was a 7.08s and one was 6.91 both at 105mph. Without the spool shot these times would have been significantly slower. I also got dragy data on the 6.91 run. Im posting it as well so one can see the accuracy of that device. Its actually quite impressive how accurate. It proves to be valid for testing when a dragstrip is not available.

Keep in mind these runs were made with an ebay gtx3076 churbo, ebay cast log manifold, ebay intercooler, stock head, cams, coils and intake.


https://cimg5.ibsrv.net/gimg/www.mia...b7578117be.jpg
https://cimg9.ibsrv.net/gimg/www.mia...7e38e71d96.jpg
https://cimg2.ibsrv.net/gimg/www.mia...3dc2e99443.jpg


I also captured some 0-60 data and 0-100 data on the dragy. It reported a 6.38s to 100mph and 2.98 0-60mph, it is 2.76 seconds 0-60 mph if factoring a 1 foot rollout as do all the magazine testers and manufacturers.

https://cimg6.ibsrv.net/gimg/www.mia...b8dec670dc.jpg
https://cimg0.ibsrv.net/gimg/www.mia...f59b9c73fa.jpg

Update;
I went to track again last weekend and made a few tnt passes. I backed up my previous best 6.91 second @ 105 mph 1/8th mile time with a 6.95. Time for more power and some weight loss after a few safety items are addressed. I purchased an Alston 8 point weld in roll bar kit but not going to install it until my hardtop i've ordered comes in so I can build to fit.

The hardtop I ordered was the cheapest aftermarket I could find. Here is the link to one I ordered. https://exoticeuroparts.com/shop/maz...termarket-new/.. I got the 10% off so after shipping it was $418.33. I also ordered this window and seal kit. https://treasurecoastmiata.com/i-158...treet-kit.html. I sure hope window fits.. I have the window kit in hand but still waiting on top. Anyone on here ever use this top?

Hi
I am new, I think this would be great on a supra jza80 to pre-spool the second turbo. It would require less air pressure as the second turbo has no load at this stage.
Has anyone tried this?

Hi little boy, are you lost?

Jk..

Hello Snuf,

Are you drag racing this car? Manual or auto tranny? I will tell you from experience my spool shot setup is best used for drag racing, or those occasional street pulls, and with an automatic transmission. This wouldn't be my first choice if on a manual transmission. There are a couple of reasons for that, which I can detail if you want, but for drag race with an automatic and a larger turbo this works very well. You may also want to give some thought to a small nitrous shot.

I doubt you will find anyone who has tried this on a sequential turbo setup. Very likely you will find very few who have successfully done this period.. You would most likely be on your own getting this to work on your setup. You may want to reach out to Pat for his thoughts as he has done a lot of work on compound turbos' and may have some ideas on implementing a spool shot system into a sequential turbo configuration.

-Marshall

Question: Anyone on here try a gt3576 or gtx3576?

I know thats a little on the large side for most on this forum, but for my setup and what I'm doing it may work well.
First, little background as to why Im asking. I have tried a number of different chinese turbos. I am currently running a chinese gtx3076 with .82 a/r exhaust housing. I have also ran that turbo with a .63 a/r housing. Trap speed in the 1/8th mile is about 2 to 3 mph faster with the .82 housing so thats what I kept on it. I have also tried a regular chinese gt3582 with a .63 ar on the street for a while and felt it made decent power, but was a little too lazy on the street when not using the spool shot. I wanted to put that turbo back on again to try it at the track, but we moved about 7 months ago and unfortunately that turbo was lost in the move somehow. My goal for this year is to try and trap 110 mph in the 1/8th. My best 1/8th mile trap speed so far with the chinese gtx3076 .82 housing is 106.82 mph, so I need to pick up about 3 mph. Seeing that the larger .82 ar housing is worth as much as 3 mph over the .63 a/r housing that leads me to believe the turbine was a little restrictive. I'm considering a chinese gtx3576 with .82 ar housing. That's basically the same compressor side as i'm running now combined with a turbine that will flow about 4 lbs pr minute more that my current setup. According to garretts' turbine flow charts the difference between the gt30 .82 ar and .63 ar is about 3 lbs pr minute, which netted me about 3 mph, so I'm thinking an additional potential flow of 4 lbs pr minute may help me reach my goal. I may also change my downpipe from 3" to 3 1/2" to help with laziness when driving on the street when not using the spool shot system. Any thoughts from someone with experience using these size turbos?

Update:

Just swapped china gtx3076 with china gtx3576. Both turbos have the exact same billet compressor wheel, however the gtx3576 has a larger turbine wheel. I'm using .82ar housings for both. The initial spool testing shows very similar spool characteristics for my setup. Unfortunately the roads here are a little too cold for actual performance data testing on the street with the dragy. However it should be quicker now with this turbo. It is exhibiting less internal exhaust manifold back-pressure, which should translate to more power. Hoping this change will get me to trap 110 mph in the 1/8th mile when at the track.

Hey Newaza is that you showing up on the Dragy leaderboard with this setup? I just got one and spotted some crazy guy with a spooled turbo setup.

What 1/4mile times do you predict you could achieve with the gtx3576? Asking for a friend.

I'm #3 on the leaderboard for mazda in the 1/8th mile with a 7.35. However thats an older time as I've gone quite a bit quicker since, but I replaced my phone and cant seem to upload later tests to the leaderboard with new phone. (btw, thats not my picture on there. Thats stock image from the dragy.. lol. Also not actually in mexico of course. I just dont want to attract any unwanted attention from the local popo.)

https://cimg2.ibsrv.net/gimg/www.mia...1765f92e3a.png

As far as 1/4 mile times go my best to date et of 6.91 in 1/8th equates to roughly 10.8 in1/4 mile and 106 mph in 1/8th is roughly 133 or so mph in 1/4 mile for power adder car. These previous best were achieved with china gtx3076. Traction has been limiting me a bit, even at the track. I'm going to be further addressing that part of the equation soon.
Im hoping with this new turbo and better traction to get in the 6.70 range at 110mph at some point this year. That should be good in 1/4 mile for high 10.40 to low 10.50 range at just under 140 mph. We see if this crap pile will hold together lol..

Which ebay vendor have you had luck getting these gt30 series china turbos from? It seems to vary from seller to seller

Well I had to create a new profile in order to save to leaderboard the runs I did with dragy after the new phone. The 6.92 run was done at the track. The timeslip showed a 6.91 while drage said 6.92, so only off a hundredth of a second so very accurate I would say.
https://cimg0.ibsrv.net/gimg/www.mia...e9af6c51f8.jpg
You will like using the dragy. Most difficult part is getting validated runs. You will get a lot of invalid runs for various reasons.

https://www.ebay.com/itm/GT35-GTX357...oAAOSw1~JZUKRC

This is the gtx3576 I just got and from this vendor. I also got the previous gtx3076 from them as well.
I have also gotten a couple other turbos from an ebay vendor called " usturbosystem". Altogether I have used 6 or 7 different ebay turbos to test and have been satisfied with them all. I did fail the thrust bearing in two turbos but Im pushing them hard so I can't complain.

Update: So I swapped out engine a couple weeks ago to have a fresh engine going forward. I keep 2 identical engines and swap every other year or so to freshen with new bearings, rings, gaskets or other parts as needed. I just pulled apart engine that was in the car. Everything looked really nice with the exception of the coating on the skirts. It was mostly flaking off. I called wiseco since this is supposed to be a permanent coating. They said coating peeling off can be an issue with high alcohol content fuel. Funny they don't mention that anywhere in there literature. Also its strange that I have used these in the other engine I rotate and coating did not flake off that set. That particular set looked prestine last time after cleaning and are on there second go around. Maybe this set used a different coating formulation or prep? Any ways I will just clean off the remainder of the coating and re-use these in anther block with proper ptw clearance without the coating. Just wanted you guys to know if your using e85 with coated wiseco's the coating will eventually flake off.
https://cimg7.ibsrv.net/gimg/www.mia...6c2e75e827.jpg

Update:
Since I am using a gt35 frame turbo now I decided to re-work my exhaust. I have swapped my front half from 3" to 3 1/2" and an open wastegate pipe. Back half is still 3", but I may change that as well. The drag strip is supposed to open again the 3rd weekend in april, but don't know if that will happen now with the covid virus situation so I may just have to test with the dragy to compare with previous data with the 3" piping.

I am also planning on changing the transmission fluid to a higher viscosity fluid such as John Deere Hy-gard or equivalent in order to hopefully tighten the converter stall just a bit. I will also likely make a minor change in the transmission valve body to increase torque converter pressure a bit to possibly help tighten stall and lockup clutch apply pressure. I will let yall know how these changes work just in case anyone else out there is tinkering with a jatco automatic in a miata.

Update; I decided to re-coat the skirts on the wiseco pistons that were pictured a couple posts up. The coating was successful as best I could tell so I reused them for my spare engine. I used techlines dfl-1 for the coating.
https://cimg1.ibsrv.net/gimg/www.mia...1be6db5800.jpg
https://cimg8.ibsrv.net/gimg/www.mia...d9d37cc2d5.jpg
https://cimg9.ibsrv.net/gimg/www.mia...0e96ae3ced.jpg


Also a quick update on the transmission. Since its been boring due to covid lockdowns I decided to pull and autopsy the tranny I've been running. Its still working, I just figure its time to pull and freshen since not a lot going on atm.

It is showing a fair amount of friction surface wear in the intermediate band, front clutch pack, and rear clutch pack. Those are the friction surfaces primarily used on my full power runs, The remaining fiction surfaces looked nice. I built a fresh transmission to replace this one and am building the one I took out to use for a spare. Although some of the frictions showed significant wear, i am very pleased with how this transmission has held up and performed. Its been together for a number of years and beat on regularly, so it owes me nothing. The mods for anyone looking to duplicate follow: I added 2 extra friction discs to the front clutch pack by removing the cushion plate and sanding pressure plate on tempered glass and checking with a micrometer while doing the sanding for flatness and thickness. I had to sand that pressure plate for proper clearance in that pack.The front clutch pack originally had 3 frictions now has 5. The front clutch pack is engaged for third gear.
The rear clutch pack I added 1 additional friction, for a total of 6 frictions. I did this by removing the cushion plate in that pack and replacing with one thicker steel for proper pack clearance. The rear pack is used on all forward gears. The remaining friction packs and bands are stock counts but also not overly stressed other than the intermediate band. The intermediate band is used for second gear. I would like to run a larger intermediate apply piston but they are very difficult to source so Im adding more apply force by adding line pressure, which adds more to all clutch packs as well.
The valve body was modded by shimming the pressure regulator approximately .250", all the accumulators were pinned for no movement as was the pressure modifier valve. All the orifice plug openings were enlarged substantially. The vacuum modulator pin was replaced with one about .150" longer (which I cut out of a nail LOL) and modulator is left unplugged since I manually shift using a linkage selector signal from the inhibitor switch to control the shift solenoids with no automatic function. There may have been another minor mod or two, but thats all I can think of at the moment and covers the major changes to successfully hold the power level I'm at currently. Hope this info can help if anyone else out there is looking to build and early model miata jatco to hold any power.

https://cimg6.ibsrv.net/gimg/www.mia...7b5dc0aa07.jpg

Time to get greedy for a little more power!

Will be adding this soon but I have to get a few more jets to test 35, 50 and 75 hp levels on top of whatever I have now. I'm really curious to see how a 50 shot spools the turbo compared to my compressed air injection system. Although the kit is rated up to 150hp i will likely limit to 50 and occasionally 75hp.