Thanks for the answer. Now a few more questions, so that I can better understand what all is being said in this thread.

Have you done this process on the customers car? If not, how can you claim a knock event or that it is going to knock in the future? Are you going on past experiences to think it does or will knock?

 

Cool, when you get back from working, could you talk about your AFR curve on this car with a dynoflash? Thanks!

 

Talk about the pot calling the kettle black.....

 

Al- I believe your answer is on this article http://www.innovatemotorsports.com/resources/rich.php
What I have understood from reading You choose to use the approach of more timing and richer AFR in the peak boost-midrange-peak tq to prevent knock.

Shiv uses the other approach with less timing or 0* and leaner AFRs in the peak boost-midrange-peak tq without knock.

Two methods both valid but if you read the article one is considered better than the other.

 

He would start by showing how close the measurement points are on the AFR scale, whereas the other dyno sheets from that same dyno day show an AFR scale with 2x-3x the delineation between measurement points. Basically, this tune goes from 11.4 to 10.8 and back to 11.4. I am not saying it's good or designed, but I do know that right at the 6k point, I usually have to add a touch of fuel. Anyway, I don't know if it's a mail-in flash or custom tune, but you can't let the illusion caused by the scaling get you too concerned. If you change the scale, the shape of the AFR curve would appear much less drastic.

 

The AFR points are still a point by point. Does that mean it's ok? This is from the 2nd dyno day not the one you linked up awhile back. here is my chart if you want to compare. 2400rpm to 7400rpm



and the dynoflash again:

 

Not wrong at all. Don't be so hasty when trying to disprove me like you always are trying to do it seems. I didn't say anything about the RPM scaling. I said the AFR SCALING. Here's the example of what that Dynoflash tune would look like on a typical Dynojet readings that scales from 10.0-14.0 AFR:



For example:

 

I realized my mistake before you posted this and edited it. Still doesn't mean the tune is right, why should it bounce all over the place like that? Look at my chart, it stays within .2 AFR the whole way. Al's changes .6 from 3800 to 6200 and again another .6 from 6300 to 7400rpm. Why is that?

The reason why the dynoflash AFR points scale that way on that graph is because the AFR is all over the place so the AFR scale changes accordingly. I believe the mustang dyno charts scale accordingly unlike Dynojets which just show the whole scale. If you notice my AFR chart the points scale is actually tighter. Wonder why?

I am glad we are finally actually having a discussion about tuning.

 

Hey Jorge, that's a great link. I never knew that someone actually addressed the advantages of one approach over the other. Good find

-shiv

 

Lean and retarded timing = high egts and thermnal stress on pistons

 

Are you back from working now? Can we discuss your AFR chart above?

 

The car when it had my tune was obviously not funtioning properly - my disgnosis was a boost leak

 

what???? This is a whole different car than the evo 9 we discussed earlier. So everytime we post up a dyno and AFR chart from a dynoflash car that doesn't seem right your answer is it has a boost leak?!?!?

You have got to be kidding me.

 

I don't know why. I already told you I wasn't saying the tune was good or bad. I was just keeping you from alarming everyone by constantly harping on that curve, which looks MUCH WORSE than it actually is. If you look at my Dynojet-like graph, it looks perfectly normal. Yes, the other tune you showed is very flast other than a .2 raise at the end for whatever reason, but it does LOOK good. If you go look at al's threads from his tuning sessions, he talks about just this very thing - how nice and smooth he is able to make the AFRs especially while road tuning. I don't know the history of this car, but the resulting curve isn't nearly as bad as it looks upon first glance. In fact, I am not certain that the exact same AFR at every RPM is always the best thing anyway. AFRs in a vaccuum do nothing and mean nothing. It depends on the boost and timing at a given RPM that determines what AFR is best, and that's probably different on every car.

Would you say that to consider something the "best" tune, you look just at how flat the AFR curve is? What if there is more fuel required right at 6k for whatever reason? Wouldn't you want to gradually add fuel as it reaches that point, then gradually remove fuel as you move away from that point? Again, not saying one or the other is the "best" just that pointing to the shape of the AFR curve with a non-standard scale is not the best way to form an argument.

Also, I think you have it backwards when explaining the different scaling. The scaling on the Dynoflash chart is the tighter one, because the max and min values are much closer together than the max/min values on the other chart. Notice the 10.8-12.3 vs 11.0-13.3. That's what determines the scaling, not the "quality" of the tune and/or its fluctuations...

 

You are trying SO HARD to find ammo, man. Can you please chill out with all the hasty remarks and take a second to realize how desperately you are looking for a way to disprove/discredit Al here? It is highly unlikely that he even bothered to look at the last few posts we've been discussing. It's pretty obvious he was referring to the original car in question, since that's the POINT OF THIS THREAD. Seriously, man, take a step back and gather yourself. It's like you're on a witch hunt or something.