the afr verses horsepower test

[wayneschofield]

QUOTE (jinx44 @ Aug 23 2008, 02:17 PM) <{POST_SNAPBACK}>

Yes there is. Real world testing under a full load. You even said it yourself in regards to mixture at different RPMs. The acceleration rate of the piston and swirl in the chamber varies the air charge as well. A dyno can not offer a real world load so the acceleration rate is different. The exception to this would be Mustang brand dyno's can put a load on the tires based on weight and even wind resistance as RPMs increase. They are the only dynos that get close to real world.

BTW, don't get me wrong guys. I use dynos to initially tune everything, but that is not where tuning stops.

I use a Bosch dyno, all day every day. It's the same one as Mercedes, BMW and Porsche use, whos cars do tend to get used in the real world. It can do all that a Mustang dyno can but it does it with much better repeatability, which is why I use it and why it costs twice as much as just about all other similar dynos.

I use it to set up cars that go on to win championships, usually around fourteen championships a year are won using my setup expertees. I have been doing it since 1988 so I think I have half an idea what I speak of, thanks.

I also do ABS system setup to get the best performance from making cars go slower too :-)

[thedeatons]

Yeah, I googled Wayne's full name one time, and was impressed with the website I found. No wonder you are riding a Dale Wayne, you know all about full adjustibility!

[wistech]

Here are the last runs after the long session of map tweaking . I marked the widest variances in afr to see what effect they had on the numbers. Going extreme lean had a drop in torque .

[wayneschofield]

QUOTE (thedeatons @ Aug 24 2008, 03:58 PM) <{POST_SNAPBACK}>

Yeah, I googled Wayne's full name one time, and was impressed with the website I found. No wonder you are riding a Dale Wayne, you know all about full adjustibility!

My own website is pants really. I never get time to sort it out.

My company is called 'Chipwizards', if you google that you'll get some various forum feedback..... mostly people saying I never answer the 'phone.....

[wistech]

The answer to the question. The blue line was the power curve I were looking for. The red line is what we ended up with after focusing on straightening the afr line.

[cannondale27]

Well for one thing you never accomplished straightening AFR out and secondly if you lost power you either went the wrong direction, something is wrong with motor now or the dyno is wrong. My bet is something is wrong with motor since that has always been the case when power goes down after tuning. You should know that.

[wistech]

It's the data or the tuner.

[cannondale27]

Don't be to sure about that. For instance my last tune where I couldn't get motor up to normal temp I was fighting the backdoor programing of the ECU which compensates for coolant temp and losing power. By time it got up to temp or near it no gains were made at all. Best runs were when cool and tuned. Later come to find out valves were probably leaking a bit. I can also remember when I had the piston that ring broke through valve pocket. Highest hp runs were at begining but never beat them even with flat AFR. It was obvious something was wrong yet I never knew it while riding the thing. Dyno showed issue. When tuning is impossible or really frustrating something is wrong and best bet is to not waste time just get it off dyno and figure out problem. You give a example and a poor one but look through the charts there are way way more where power was gained.

[wistech]

Then there is this little baby. Our championship winning 467. An early run even at the extreme of down to 10 afr it still bested the final flat afr's in torque and hp.

[cannondale27]

Thats because the AFR at hp peak was right about where it belonged. Not 10:1. If ridden at less than wide open it probably would foul plugs!