How low? I had/have that issue as well. there wasnt anything I could do at the time, So I have just let it be. I only had the issue at idle just like yourself.

I can see the pressure rise and fall when the relief opens and closes. Sometimes it just sticks and doesn't close when I come off the throttle. When stuck open it gets as low as 8-10psi at 1050 rpm (yes, my hot idle is set that high) which is too low. When the relief closes it idles at ~15-20psi. I may need to add some thicker oil for the next track day until I can pull the engine and swap the pump. I removed the oil filter sandwich plate in hopes that the pressure drop would lessen without the length of lines and the cooler. It will be cold in Atlanta for my trackday this coming weekend so I don't anticipate needing the extra cooling. The pressure achieves factory specs, which are listed as 45-56psi at 3000 RPM hot. It can achieve 130psi+ when cold and revved up a little.

Wow, Mine wasnt quite that bad. Although I have never seen cold pressures that high before on mine either.

Zero oil pressure on startup Wednesday. Ordered new Boundary pump but unable to finish replacement in time. I'm riding shotgun in a friend's truck up to Road Atlanta and will be renting something to drive. I'll hopefully have a nice time anyway.

When the gauge reads below about six lbs the engine starts to rattle as it runs. Unfortunately, I'm pretty sure it is actually getting no oil pressure.

It's the Road Atlanta curse... I swear. I'd probably be there drinking beers with ya if I didn't have a wedding to attend... gotta drink beer there instead :)

Well, I figured out what happened to my oil pump. Does anyone remember when my dipstick was cooked by radiant heat from being close to my manifold/turbo?

https://www.miataturbo.net/attachmen...ine=1358085735

https://www.miataturbo.net/attachmen...ine=1358085735

Yeah, tiny plastic bits are light enough to be sucked into the pickup screen and partially clog it. Some were small enough to go through it and get trapped between the oil pump relief and its bore. This caused the relief to bind up and eventually seize in its bore. It took significant force to push the relief valve out of its bore, revealing a plastic piece flattened against the bore wall. So much fun.

There was no metal apparent from the oil pan tapping procedure in case anyone was wondering. I was very slow and careful when I did that, so I'm happy nothing from that process was involved. If it did, metal should tend to stay on the floor of the pan since it is heavier.

New Boundary Engineering street/strip pump assembly is now in place. Engine will be reinstalled once my Mazda Comp motor mounts arrive from Good-Win Racing.

OK, car is going to the dyno in the morning. Prepare for fairly average turbo Miata plots. I figured it would be nice to have some idea what the car was putting down at this point before continuing onward. I will datalog as well, so I'll hope to be able to correlate some data in a nice graph.

I have a spare short block on the floor in my garage that will be filled with forged goodies at some point.

I am going to make my official guess as to what the car will dyno.

214 WHP.

Now I am going to have to go back and re-read this thread to see what all is on the car. :D

Good luck on some clean runs tomorrow.

'96 stock 1.8, 130k miles, FM log manifold, MS1, chinese 2870, 3 inch exhaust turbo back, rx7 460cc injectors, ebay intercooler, GReddy EBC, overboost protection kicks in at ~10.5psi. Like I said, average Miata dyno numbers are expected. I expect 210 but am hopeful for 220whp.

Well, I went to get a baseline. I had a couple of issues with the test, but that is pretty standard. The first one was the car did well in a couple of run ups on the interstate on the way there but had an idle that was a couple hundred rpm higher than normal when I got there. I found a vacuum line off that was not secured when I reinstalled the engine. It helped bring down the idle a little but there is something else off that I can't locate. After a few minutes I gave up looking and pushed onward. We were in a hurry for an appointment shortly afterward. The operator made three pulls but the boost was low, probably because of a vacuum/boost leak. So I was compensating after each of the first two runs by turning the EBC up a couple of clicks. The third run was still a little lower pressure than I would have liked to see tested. But there will be other days.

As usual, the dyno operator did a less than stellar job of getting the full operating range in the pull. The factory tach is was reading high compared to the datalog. I found out after it was over that he only pulled to 6400 and stopped when it was still climbing upward?!?!

We ended up with a ~165kpa upper limit which is about 9.2 psi, which is sad because I had been able to adjust the EBC to bounce off of the 10.5psi boost cut on the way over.

Anyway, numbers -
204whp @ 6400 at 9.2psi
194wtq @ 4800

EDIT: Dynojet, sea level plus 20ft, 60*F

I datalogged the events and transferred the data from the dyno plot and the data from the log into an excel spreadsheet to better compare the info.

https://www.miataturbo.net/attachmen...ine=1362275275
https://www.miataturbo.net/attachmen...ine=1362275275

I can not believe I did not notice the lack of a dip at the end of the graph. That old 1990s screen made it difficult to read. I do not recall seeing rpms on the screen either.

I will know what to look for next time.

So whats next?

At least in this thread for sure! Thanks buddy!


Mah spark map used for the dyno session:
https://www.miataturbo.net/attachmen...ine=1362424326

Masterful!

After looking at your map and comparing it to other maps I have seen, it seems like most of those cells needs more timing. I suspect the low timing may be causing some of your excessive heat from your turbo.

I think you will see a pretty good improvement in power once you have that map sorted out.

Possibly. I have to be careful when looking at the maps of others because some of those guys have built motors with lower than stock compression ratios, B6 engines, or NB engines. All are not equal and I've almost copied the wrong guy a few times. I am cautious with my timing, though. I am sure of that.


Announcement: I have signed up with NASA-SE for Roebling Road Raceway, Savannah, GA, April 13-14. I have also signed up for NASA-FL at Homestead Miami Speedway, May 12-13. Plan to come out and run, or just visit awhile.

Will there be any changes to your car before the next outing?

One or both of those might work for me. Kind of crazy that they are almost the same distance away. Any advice for someone that's never run a NASA event before?

Have you run with anybody before? Who and what level/classing?