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-   Engine Performance (https://www.miataturbo.net/engine-performance-56/)
-   -   Can my stock ECU handle one more mod? (https://www.miataturbo.net/engine-performance-56/can-my-stock-ecu-handle-one-more-mod-85915/)

concealer404 09-16-2015 09:02 AM


Originally Posted by AlwaysBroken (Post 1266848)
I agree that the MSM was a slapped together pile from the factory, but what we do know about the stock miata ecu and sensors suggests that the stock air flow sensor is good up to about 5-6 psi of boost. It was good for it in the 1.6, the 1.8, etc. The old greddy kit was a little turbo pushing 6 psi of boost directly into a crossover tube that went into the throttle body. For a long time, people were running about 8 psi on a fuel pressure regulator and a timing box. Stock ecu and airflow sensor there too, no?

edit: I might be mis-remembering stuff from 15 years ago, but I thought the greddy was just sucking air through the stock airflow meter, no?

You should probably clarify exactly what you mean by "good," in this case, because i'm pretty sure my definition of the word is wildly different than yours.

Savington 09-16-2015 10:39 AM


Originally Posted by AlwaysBroken (Post 1266848)
I agree that the MSM was a slapped together pile from the factory, but what we do know about the stock miata ecu and sensors suggests that the stock air flow sensor is good up to about 5-6 psi of boost. It was good for it in the 1.6, the 1.8, etc. The old greddy kit was a little turbo pushing 6 psi of boost directly into a crossover tube that went into the throttle body. For a long time, people were running about 8 psi on a fuel pressure regulator and a timing box. Stock ecu and airflow sensor there too, no?

edit: I might be mis-remembering stuff from 15 years ago, but I thought the greddy was just sucking air through the stock airflow meter, no?

The GReddy kit was more like 4psi, and it used a rising rate fuel pressure regulator to handle extra fuel in boost, and you turned the timing down to 6 degrees base which killed low-end power. At 6psi, the car knocked anyway, so you had to run a Bipes to keep that under control, and transition into boost was lean unless you ran an O2 clamp.

concealer404 09-16-2015 10:41 AM


Originally Posted by Savington (Post 1267049)
The GReddy kit was more like 4psi, and it used a rising rate fuel pressure regulator to handle extra fuel in boost, and you turned the timing down to 6 degrees base which killed low-end power. At 6psi, the car knocked anyway, so you had to run a Bipes to keep that under control, and transition into boost was lean unless you ran an O2 clamp.

So what you're saying is that Mazda designed the car to handle 5-6psi "good," right?

Stealth97 09-16-2015 12:17 PM

None of the stock non mazdspeed ecus can handle boost without band aid mods.

In reference to OP .. My well built N/A Engine would run on the stock ecu, at a cost of 10hp/15 lb tq. A proper ECU will make more additional power than any other single mod, safely with better drivability. No brainer really.

AlwaysBroken 09-16-2015 03:38 PM

Whoa guys, I wasn't trying to talk him out of getting a programmable ECU. I thought he was asking whether or not his car would blow up with cams on the stock ecu.

Good in this situation = "not cause the car to explode."

OP has obviously spent a megasquirt worth of money on mods already. I don't see why he doesn't do things the right way, but it's none of my business.

asmasm 09-16-2015 04:39 PM


Originally Posted by TheNomad (Post 1266511)
Re:N/A 99 miata 1.8

If I have K&N CAI, Ported Flat top manifold, RB header, 3 inch exhaust , minus Cat, plus magnaflow muffler…..

Will my ECU be able to handle the addition of the BP05 cam?

Thank You!

Install a wideband if you are nervous. Install an ECU if you want a good $/hp addition to the car.

TheNomad 09-17-2015 07:01 PM

Thanks to everyone for the responses.

Due to my "Posts=1" status (now 2!) I derived a bit more benefit from the more direct responses (but an educational initiation nonetheless).

The car is a dedicated track day car. I was hoping to get a couple of more events in (with the cam installed) before the season is over. Once the season is over (during winter months), the plan is to get a 2.0 block from mccullyracingmotors.com with the 11:1 pistons, clean up the head and add the Megasquirt.

Meanwhile, I'm getting the AFR gauge installed just in case, and if there is a lean condition, I'll move up the Megasquirt install. I'm just trying to avoid having to take the car to the dyno/tuner twice @ 450.00 a pop…

Thanks again.

MD

AlwaysBroken 09-18-2015 11:34 AM

IMO, if you're actually driving this hard on the track instead of puttering around the street while you save up for a megasquirt, you need to install the megasquirt and wideband yesterday. Hard driving for long periods of time is going to be a lot less forgiving of a bad/nonexistant tune than hard street driving.

I don't think you're going to be getting much power gains from your setup without adding the ECU and the only way to properly get rid of worries about adequate fuel is to run a wideband. If you can afford a stroker motor next year, you can afford to install a megasquirt and wideband this year. Programmable ECU and wideband isn't an optional part in any serious build.

TheNomad 09-18-2015 08:43 PM


Originally Posted by AlwaysBroken (Post 1267798)
IMO, if you're actually driving this hard on the track instead of puttering around the street while you save up for a megasquirt, you need to install the megasquirt and wideband yesterday. Hard driving for long periods of time is going to be a lot less forgiving of a bad/nonexistant tune than hard street driving.

I don't think you're going to be getting much power gains from your setup without adding the ECU and the only way to properly get rid of worries about adequate fuel is to run a wideband. If you can afford a stroker motor next year, you can afford to install a megasquirt and wideband this year. Programmable ECU and wideband isn't an optional part in any serious build.

Makes a lot of sense on all counts. Thx

Doppelgänger 09-19-2015 05:42 PM


Originally Posted by TheNomad;
RB header, 3 inch exhaust , minus Cat, plus magnaflow muffler…..


My ears hurt just reading that....lol

TheNomad 09-19-2015 07:00 PM


Originally Posted by Doppelgänger (Post 1268104)
My ears hurt just reading that....lol

Hey, there is a resonator where the cat was :laugh:

Seriously though, It's a track day car, and I never drive it without earplugs...


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