1st gen Turbo...safe PSI on BP-05 ECU

[Tweeaks]

well I was wondering what would be a safe PSI to run without any type of engine management I was thinking something like 3-4 PSI should be just fine untill I can get some sort of engine management. I know a few guys that are running over that (in other cars) with no management and aren't having problems...

[thunderb0lt]

The BP miata guys run upto 5-6psi before making any radical modifications. Honeslty, it'll depend a lot on your engine's current health.

[skr33t_rac3r]

dude ur cars getting to be one of my favorite pros out there

[Tweeaks]

The BP miata guys run upto 5-6psi before making any radical modifications. Honeslty, it'll depend a lot on your engine's current health.

allright well i'm gonna try and rebuild it soon anyways the rings are going...

thanks skreet...soon i'll finish the kit add a hood scoop and do a repaint

[bruce95fmla]

well I don't know what turbo your running.
but I know that it would depend on which turbo you run. A t25 or T28 at 5-6 psi is a good amount of boost. You would still need something to add some sort of fuel when you are under boost.

If you install the turbo, just make sure you have everything. I think the BP can handle way more than 5-6 psi with good tuning and stock internals.

[Mik]

In my GTX (N/A ECU), I'm running the stock 7psi with a RRFPR, stock N/A injectors (not GTX injectors) and not a single problem for about 10,000 km. I also have a MSD 6BTM boost activated timing retard but question the need as its set to a minimum setting with no pinging.

[bruce95fmla]

In my GTX (N/A ECU), I'm running the stock 7psi with a RRFPR, stock N/A injectors (not GTX injectors) and not a single problem for about 10,000 km. I also have a MSD 6BTM boost activated timing retard but question the need as its set to a minimum setting with no pinging.

how is your a/f throughout the rpm range.
bruce

[Mik]

how is your a/f throughout the rpm range.
bruce

It bounces back and forth between lean, stoick and the first bar of rich at anything less then WOT. At WOT it pins at about the third green (rich) light on my autometer gauge.

[thunderb0lt]

It bounces back and forth between lean, stoick and the first bar of rich at anything less then WOT. At WOT it pins at about the third green (rich) light on my autometer gauge.

You might wanna check your stuff there. O2 sensor output is supposed to go from full lean to full rich when at low RPMs without load.

[bruce95fmla]

It bounces back and forth between lean, stoick and the first bar of rich at anything less then WOT. At WOT it pins at about the third green (rich) light on my autometer gauge.

hense why I hate autometer O2 sensors. they bounce around to dang much ...

but for the most part your rich in wot.

[Mik]

I just double checked the Mazda service manual and at warm idle the oxygen sensor (which the gauge reads) should oscillate from 0.25V to 0.75V. The complete span of the guage is from 0V to 1V. So indeed mine is operating correctly. It should not be reaching full rich with no load.

[bruce95fmla]

hey Tweeaks I wouldn't run the turbo with no fpr and boost. I am not sure, but at highway speeds would there be a chance of running lean.. especially if your car is running like 2800 rpm at like 70 mph ..

anyway
Yeah MiK only thing I don't like about autometer o2 gauges is that they bounce all over the place. It does it in thegoldpro(ben)' car and my friends crx.
Bruce

[Mik]

hey Tweeaks I wouldn't run the turbo with no fpr and boost. I am not sure, but at highway speeds would there be a chance of running lean.. especially if your car is running like 2800 rpm at like 70 mph ..

anyway
Yeah MiK only thing I don't like about autometer o2 gauges is that they bounce all over the place. It does it in thegoldpro(ben)' car and my friends crx.
Bruce

Is there another meter that does not? I always understood that the fluctuations were how the ECU maintains an average a/f ratio.

[turboge]

Sounds about mid 12-13 on the A/F... i'd still check it with a wideband... you may need a bit more fuel.