XEDE + RX-7 turbo 550s startup / idle video
 

The car: 1997 1.8 with BEGI GT2860RS turbo kit, XEDE, cleaned and flow-tested RX-7 550s, stock cat (until next week,) 2.25" NA style exhaust (for now,) relatively new plug wires, brand new NGK plugs.

I've been playing around with the settings to try to get the idle sorted out. Here's a hot re-start video that shows the slight lumpiness that I'm experiencing at idle. There was no noticeable lumpiness when I was running the BEGI AFPR. The car drives well under all other conditions. The video is a bit blurry, but the car typically idles at 26-27 vacuum.

Is your idle better, about the same, or worse? I've never ridden in anyone else's turbo Miata, so your comments are welcomed. Thanks...

http://www.youtube.com/watch?v=0NWQzSZcbE4

mine idle better than that but i only get 20-21 inHg vac

how and the world are you idling at 30~hg.

I also idle around 28. I thought that was normal.

badly

I think something is up if you are getting that kind of vacuum at idle. I'd expect to see that during deceleration not idle.

28kPa or 28~hg.?

FWIW, I was pulling that much vacuum at idle with the AFPR and the idle was solid. When I first installed the XEDE and 550s (Witchhunter cleaned and flowtested them for me), the idle and hot re-start situation was much worse (wouldn't crank when hot without giving it some throttle.) I discovered that the output scaling on the XMAP (provided as a base tune by BEGI) was lower than recommended in the BEGI XEDE tuning tips manual, so I corrected that (thereby increasing fuel across the board.) That is what you see in the video. I further increased fuel somewhat in the cells around idle, but it made things worse and I returned to the previous (current) settings.

there's no way you are pulling 30~hg.

what does the Xede say? if it's correct, then your cam timing is probably off (advanced)

Kpa.

that gauge is a vacuum/boost gauge so its inHg. Plus he said 26-27 vacuum, not 26-27 actual pressure.

that's normal.

but his gauge looks like 27-28 ~hg. which is like 20-19kPa.

Oh that makes sense.

What are the chances of his gauge being inaccurate?

I swapped it out with my VDO 0-25psi in my Talon and at least the boost part of both gauges were within 1 psi of each other.

Healthy vacuum reading is between 17-22. That's going to vary a bit depending on altitude. Are you currently under the sea?

These two things are related I'm sure. The XEDE is fueling based on MAP, with a funktastic reading like that I'm not surprised it isn't idling properly. I bet you are lean at idle. Have an WB02?

The AFPR would be effected nearly as much, if at all.

what does the thing read when the car is off?

I just had Begi replace that exact gauge because it was reading less than zero when the car was off. At idle it was also around 30 Hg. With the new gauge I'm at about 22Hg at idle. Make sure it reads zero when the car is off.

No wideband yet (5 psi until then,) the gauge reads about -10 to -11 when the car is off. I do plan on borrowing a wideband very soon.

is this a fucking joke? you would think someone would fucking mention that IN THE BEGINNING! I need ban powers.

I believe the Xede Fuels based on MAF Voltage and therefore Air Flow and not MAP. I'd recommend give Stephanie at BEGi a buzz. She was very helpful when I had mine, but I never got around to install it :)