Thunder

Ok My 6-spd GT is getting faster!!!!

I have 2000 km on it, and have noticed a few things that lend credibility to the missing HP issue being one of an ECU/PCM controlled break in period-

The first tanks of gas left nasty soot on the tailpipes. I have been cleaning them on a regular basis, and there is definately less soot- its running leaner. (same gas station, maybe not same gas). I've put the miles on fast (just got the car last week) and environmental conditions haven't changed that much.

There is MORE POWER than say the first 500 km. There is a definite and gradual increase in power.

The fuel economy is improving dramatically.

I wonder if there is a dyanmic map adjusting the A/F ratio (rather than a "switch" at a definite mileage) making it leaner the more you drive it.

I am SURE this car is leaning out and getting faster....gradually. I can't attribute this to anything but the ECU / PCM.
Bottom line.... I don't care about these dyno results....I am SURE this car is buliding power by gradually leaning out.

Thoughts?

P00Man

hmmmmmmmmmmmmmmmmmm

thats some good evidence...

keep the news coming
________
Vaaapp

B-Nez

Nice post count, pooman. Don't post anymore, and you'll be the man forever! Well, at least until you hit 8,888 posts...:D

akrx8

thunder,thanks for the insight.ive been hoping this might be the case.bombardier has a similar program on there hi-power skidoos that slowley increases ign timing between 5 and 10 hours to allow proper break in.just a side note that my car now has 300 miles only and pipes are very sooted allready,more than i could have amagined.also ive noticed every dyno has seemed to be a little higher each test(church autos was 189.7 hp i think)seems like that car is only down 14 or 15 hp.

neit_jnf

Maybe it's just the engine getting broken in with increasing miles... Or it could be that ECU thing :p

Jsuzuki

This is just pure speculation:

Maybe the RX-8 is "learning" it's environment. It firsts starts off in a safe mode and is programmed to only change variables in small increments. This might be the reason why it takes so long to get to full power.

I remember a discussion on Audi / VW 1.8t motors about having similar issues. When the ECU was flashed, reset, or powered down for long periods it took a while for the performance to come up.

In Sports Compact Car magazine, they were messing with a Subaru Impreza WRX. They reset the ECU and found it producing less power. SCC figured it learned to use the low octane SoCal fuel, and use a less aggressive setting. When they got higher octane fuel, they reset the ECU again and began making original power.

Now both of these are turbo motors, probably requiring a better computer with more programming. Maybe Mazda engineers specified a highly adaptable ECU? Or maybe a really intelligent ECU that can adapt to use fuels from any region to save on programming costs? So with higher octane fuels that are available in Japan, the RX-8's in Japan make the rated power. Maybe the US fuel is forcing the RX-8 to dump in more fuel to prevent detonation? Maybe cars in Arizona are making more power?

Elak

Thunder, assuming your driving habits haven't changed either, what % improvement are you seeing between say 1k miles, and now at 2k?

/Elak

TT2RX8

Just like Thunder, my Rx-8 (2300km - 1500 miles) seems to be gaining some power; just today, the DSC engaged twice:D and the soot seems to diminish.

As far as fuel economy goes, well I can't confirm any change, revving the motor more and more... playing with the car today (redline a few times, hi speed driving) I used a quarter of a tank for only 60 km (about 40 miles) Ouch!, that only 160 miles a tank!!!