Need tuning help

[Telco]

2002 Camaro Z28, 4L60E trans, LS1 5.7L engine

This is my brother's car. When he bought it the car came with a Predator tuner, and he decided he wanted it to be tuned with EFI Live. And, here's where the problem came in.

Before I messed with it, the car shifted perfectly with the Predator program. I took a copy of the Predator, then put the factory program back in. Then I started fiddling with it.

Now here's the problem. At WOT, the car will not shift. 95 percent throttle, no problem. When I put the factory program back in, it still refuses to shift at WOT. I tried fiddling with the program according to some of the posts I searched out, no change. When you go WOT it pulls like a mother to the shift point, then it acts like it's hitting the fuel limiter. WAHaWAHaWAHaWAHa. You let off the gas, it shifts, then you ease back into it, and it pulls like a mother in the next gear. Jam the gas back down, it downshifts, and right back to the same problem.

I've included the last program I put in, if someone can look at it and tell me where I went wrong I'd appreciate it. But, I'm wondering if it's not some artifact from the Predator since the supposed factory program also has this problem. Thanks for any help on this. I'm at my wit's end.Telco 2002 Camaro.tun

[Taz]

Hello Telco,

For a WOT shift to occur both RPM and vehicle speed values must be met for that particular shift. You can have RPM or vehicle speed control the shift execution – I prefer to use RPM.

You have the WOT shift RPM set to 5000 for all shifts (D0940-2, D0945-7, D0950-2). The problem appears to be your vehicle speed parameters.

1>2 is set to 58 Km/h = 5383 RPM (D0910, D0911, D0912)
2>3 is set to 129 Km/h = 6355 RPM (D0915, D0916, D0917)
3>4 is set to 410 Km/h = 9999 RPM (0920, D0921, D0922).

Given the above, the only WOT shift that will actually occur is the 1>2.

I would set the desired shift RPM, then set the shift speeds to a value that occurs at least 250 RPM prior to this.

As an example if you want 1>2 shift to occur at 5500 RPM set D0940-2 to 5500 RPM. If 5250 RPM in first gear is equal to 55 Km/h, then set D0910-2 to no more than 55 Km/h.

Good luck …..


Regards,
Taz

[ChipsByAl]

Log the gear commanded, Engine RPM and injector pulse width. It may show the shift happening long before the rev limiter coming in, that would be smoked 3-4 clutches in the trans. Very typical.
Al

[joecar]

What mods does the car have...?

Can you also post the Predator file...?

The WOT MPH shift points seem to be set to give rpm's that execeed the rev limiters as Taz said.

How many miles on the car/engine/trans...?

Post some logs so we can see what is going on as Al said.

[ScarabEpic22]

Make sure the 100% shift patterns are setup to mirror the WOT shift speed values.

[Telco]

Sorry it took so long to get back. The car doesn't really have any mods beyond a muffler, they haven't had it long enough to do anything yet. Attached find the Predator file I copied before I did anything.

I've modified the RPM and MPH files of the next program to try and I'll be giving it a try this Friday. I'll advise later on how it goes, but it won't be quick.

[Telco]

Dammit, I think I just found the problem. In the original tune, as well as my other vehicles with working tunes, the upshift speeds (D0901) are higher than the downshift speeds (D0906). In the failed tune, the upshift speeds (D0901) are lower than the downshift speeds (D0906). So what's going on is I hit the 1-2 shift speed, it shifts, then I hit the 2-1 speed, and it shifts back down. I've adjusted this as well, using my other programs as a guide and adjusted according to the parameters listed in this post. Here's hoping. Thanks guys.

[Telco]

Hey folks, wanted to report back that the programming fault was the problem. I still have some tweaking to do, but now it'll run hard to the shift points and shifts hard as it should. Thanks for the help with this.

[joecar]

Cool, good deal

[Sid447]

That Predator tune,

Is not too bad at all.