He's going the distance, he's going for SPEED

[kwhiteside]

Got some questions now that I think I have some basic understanding. Take a look at this pic and notice a few things about my tune when going WOT in 4'th gear.

1. I'm a bit rich. about .5 usually. I've recently read that running rich is a loss of power. So if this were a pro dyno guy tuning my car, what would he be thinking he could gleam out of my car power wise if the car actually hit the 12.85 pe mode setting?

2. Now I thought I was doing good with this tune when I saw the LT trims starting to kick in here. In my newby mind I figured to get rid of the extra trimming I would have to add gas, but I'm already rich. Being rich is better than being lean at 6200 rpm, right? Now I've been reading about LT trims and turns out they have some magical historical learning ability and I'm wondering if they are misleading me a bit due to previous readings where high LT trims were always recorded. When do you reset the LT Trim history, and how?

3. Now if I had it dialed in where AFR was what PE commanded 12.85 and there is zero knock, would the professional dyno tuner look at that and be obligated to try another degree of timing until that point where you start incuring knock?

__________________________________________________ ________

On a side note. How much work does a pro dyno tuner really have to do? His pulls are WOT, instant PE and MAF mode. Do they even bother with the main VE table? The goal us usally to get max hp/tq out of a WOT pull. I'm thinking they only mess with High Octane spark, B5001 MAF, and maybe the simple PE table if it's jacked up.

I've taken two of my Vettes to the pro tuners. First was 02 low mileage convertable. Ran perfect, just wanted to get the most I could out of it at the drag strip after headers and vararam. I'm figuring they did exactly what I described above. ( But I really don't know, I was totally ignorant to what he was doing )

The second is my current Z06 that was totally screwed up and you probably have read many of my posts along my learning with it. They did a couple runs and saw how far off it was and stopped the process, called me and said it needed too much work to be dyno ready. I'm sure they could have fixed it on the dyno, but the deviation from what I think is the normal process ( see above ) would have incurred way to much time and expense for me the customer to afford. However, now the tune is pretty solid and I'm sure the pro guy would be able to start gleaming the most out of it. So I'm trying to figure out what process the pro guy uses. (See my question 3 above) About the only thing I remember from watching my car be dyno tuned, was the pro turning to me and saying "it wont take any more timing".

[SSpdDmon]

Timing adjustments should be made on a dyno (to see if power is actually gained from increased timing) and then checked on the street to make sure there's no knock (loads on the dyno vs. street are always different).

As for AFR, it will affect HP slightly. But, not as much as timing when you're already in the 12's (IMO). So, shoot for 12.7:1 on your WBO2 @ WOT (this allows for some cusion) and call it good. You might be able to find 3 or 4 more hp @ 13:1. But, it's not worth risking higher cylinder temps IMO.

[mr.prick]

LTFTs are positive during PE?
If so you will be richer.
There seems to be a threshold where positive LTFTs will not be added to PE.

To reset LTFTs:
Scan Tool:> SHFT+CTRL+F2

[joecar]

Like Jeff said, for your extended WOT runs, keep the AFR and spark timing safe.

On your chart above, the LTFT's appear to me to be zero during WOT.

[kwhiteside]

Like Jeff said, for your extended WOT runs, keep the AFR and spark timing safe.

On your chart above, the LTFT's appear to me to be zero during WOT.

We're going for SPEED . I understand safe, how to get SPEED.

Scroll to the right, they are 0.8 and 2.3

[SSpdDmon]

We're going for SPEED . I understand safe, how to get SPEED.

Scroll to the right, they are 0.8 and 2.3

If you want to take it to the limits, you need to measure your changes with a tool (like a dyno). That's your best bet. Then, you can see what AFR and timing combo makes the best HP. The challenge is (as I mentioned above), the way the car performs on a dyno vs. on the street may be different. So, you'll need to validate your findings (look for knock retard and validate street AFR) on the street after you hop off the dyno.

I still maintain though...is an extra 5 or 6 HP worth potential engine damage? Honestly, you'd be better off pulling weight out of the car if you're that desperate.

[kwhiteside]

If you want to take it to the limits, you need to measure your changes with a tool (like a dyno). That's your best bet. Then, you can see what AFR and timing combo makes the best HP. The challenge is (as I mentioned above), the way the car performs on a dyno vs. on the street may be different. So, you'll need to validate your findings (look for knock retard and validate street AFR) on the street after you hop off the dyno.

I still maintain though...is an extra 5 or 6 HP worth potential engine damage? Honestly, you'd be better off pulling weight out of the car if you're that desperate.

I certainly always want to be safe, first off. That said, who pays a tuner $575 to get safe. Who pays $800 for EFILive to be just safe.

Next engine probably wont have A/C strapped to it.

Guys run a couple sessions on slicks, then sell them go guys like me.

Guys put fresh motors in mid season to get that extra 5hp they may have lost.

Your screen name is speed demon, I would have thought you would understand the topic as stated. I'm not saying I will go crazy and blow my car up. I do want to know how to push it to the max (safe) point.

You know how when you go to the drag strip and you want just 2/10'th more speed. Similar for track stuff, they time your laps and you look for ways to get those times down. Road racing turns are really important, but the straights are part of it too. Yes, its an obsession. Speed is my little crack pipe, and I'm asking you guys for handouts

[SSpdDmon]

Who pays $800 for EFILive to be just safe.

Me.

This guy and all of his loyal customers: www.alternativeauto.com

I'd rather have a strong running car making ~98% of it's power potential that I can drive aggressively and not have to worry about engine failure VS a car that pushes the ~102% threshold at the cost of longevity. I don't have money laying around to throw new internals in my engine just because the weather changed on the day I got froggy with the gas pedal. But hey...maybe that's just me.

You seem to have an aweful lot of enthusiasm for the peak of performance. I respect that. But what you're describing in the tune world is the equivalent of taking a drill, a big-ass drill bit, and "swiss cheesing" the chassis in the mechanical world. Yeah, it'll get ya down/around the track a little quicker. But when the shit hits the fan (or someone hits you), it's not where I want to be.

As for "max safe" - I think my pointers above are right about there. However, I can only give you rules of thumb. Every car is different. That's why we have measuring devices that help us understand the changes we make.

[WeathermanShawn]

You will have a greater performance gain getting rid of a spare tire or chunking your AC, or doing a race battery and relocate, or taking out all of your carpet and leather, than chasing down the road you are going.

I also run 'only' 22 degrees of timing at WOT. I put it up on the dyno and we saw no gain taking it up to 25-28 degrees. All it did was knock. As far as fueling, I like to think of it this way. Normally people can for a 'lean' WOT. But, if your combo is efficient, if it can 'burn' the extra fuel from being richer, then potentially you have more power. This is quite important after a dyno session. The load is different on the street, and most of the time you have to add .2-.3 on the WOT fueling to compensate for the extra load.

I understand your pursuit of power, but having the 'big picture' always helps in the end. You could win one race by 1/2 car length, and blow a piston on the 2 or 3rd race. There is more respect for people who win consistently, and normally those people due their homework.

Good luck in whatever avenue your pursue. I honestly mean it. Everybody has a different point of view.

[SSpdDmon]

..WeathermanShawn..

Just noticed your combo. You have any dyno sheet pics?