Dyno questions

[talltxguy]

Hey ya all,
Went to the dyno and did some tweaking on my 20050_2 tune by adjusting some of the F tables because I changed from the underseat K&N to the undertank K&N. I'm running TORs with a cat/bypass.
So the operator ended up putting the exhaust probe in the one exhaust on the side of the oil tank. Is that what ya all have him do on yours?
And for those of you with Jardines (since I'll be getting those in the future), which side do you have him use?
Also, the operator told me that I was somewhat lean at 13.9 / 13.8. He told me that I should strive for 13.
I was always under the impression that 14.7 was the magic number, that anything higher than 14.7 was lean such as 15.5, etc. while anything lower than 14.7, such as 13.9 was rich. Anybody help me out on that one?
Have a Happy New Year's!
Tall Tx Guy

 

[Toystoretom]

14.7 is the theoretical optimum point for emissions control, you should get the most complete burn with the smallest amount of nasty byproducts. Sometimes the real world is different and 14.7 may not have the best "runnability" or make the most horsepower. So in the real world of V Rod eaters your dyno guy is probably right, to hell with emissions, let's make some ponies!!!

 

[Pig9r]

14.7 is what is known as stoichiometric or what is theoretically needed to burn fuel completely. That doesn't necessarily mean that is what will make the best power though. Most performance tuners shoot for the 12 to 13:1 a/f range. At higher RPMs running lean will cause detonation and heat related engine damage.

Most engines, the rocket included, run lean to meet emission standards. The O2 sensor on the Rocket is narrowband and operates at 14.57 to 14.7. You can "turn off" the O2 sensor by lowering values over 14.57 to less than that to prevent the ECU from going into open loop. If you look at the a/f tables of a map in tuneboy you will see a large portion of the lower end of the map is at 14.57. There is even higher numbers in the range where emission testing is done. One of the things I have done on most of the maps I use is lower the a/f ratio in those areas. I have lowered the a/f at near idle and would not recommend doing that again. The term that was used to described how it ran was pounded dog ****.

I would think putting the EGA in the left pipe would do since all of the exhaust ports dump into the same collector pipe and the left pipe appears to be pointed more toward it.

So talltxguy you left out one big thing in your post.......What did it dyno at? Give us numbers and graphs that are pretty.

 

[talltxguy]

When I had the underseat K&N, I pulled 131/141 with an A/F curve around 13. I switched to the undertank K&N and was worrried that the same tune was running lean, which as it turns out, it was. Unfortunately, I couldn't go to the dyno guy that did the underseat K&N, which wasn't a big deal because I just wanted to get the A/F line fixed. Anyway the dude didn't have a printer, so I have no graph. So far as my numbers, they're kind of relative because I didn't do a run there with the K&N underseat. But I ended up pulling 137/146. I will go back to my original dyno guy as soon as he gets back from vacation, and I'll have a graph. He and I are gonna add some fuel to the F tables and see what we can do.
Tall Tx Guy

 

[talltxguy]

Well I called my original dyno guy today. There'll be no going back to him. LoL He's moving out of Texas and heading up to Oklahoma. And the nearest dyno guy doesn't have a freakin' printer, so I called a dude up 2 1/2 hours away. Turns out he's a nice guy who charges $80 an hour on the dyno and will work with me & Tuneboy. Not once did he slam Tuneboy and try to sell me Power Commander, Racelink, etc. In fact, he wanted the Tuneboy website so that he could get familiar with it before I visit. And yes he has a printer. Only thing is that my buddy wants to go with me but doesn't wanna go til February, so I won't have pretty charts and numbers until then.