U7194 Tuning

[hd-tsmith]

I purchased a new U7194 for my 2007 Corvette with the LS7- 427 and was completely unsatisfied with the performace tuning. So much that I went back to the factory tuning as I lost a tremendous amount of power and torque wiht the Pedator program.

I have tried to update my programing but since I don't have the software to convert the program I can't get it downloqaded to the Predator unit.

What is it that I can do with this as I am concerned that this unit has so many different applications that it may not be specific enough for my vehicle??

[johan]

Thats odd, the LS7 has one of the highest gains of power of all the LS based motors. What type of fuel are you using, it is possible that by us leaning it out and running poor quality fuel would of caused the very sensitive knock strategy to kick in and pull timing thus causing a loss in power.
The updates for this unit did not change any of the LS7 tunes. I can assure you that if the predator installed the tune 100% and the vehicle started that the proper tune is in the vehicle as if anything would be compromised in that process your vehicle would either not start or run extremely poor.
Do you have any other mods done to your vehicle?

[hd-tsmith]

No other modifications. I am running 93 plus octane using Chevon, Shell and Valero fuels. I did make a few mistakes on some fules with 10% Ethanol but quickly found that to be unacceptable. I had installed the tune and it shows accepted and started the vehicle and it appears fine until you are out on the roads. At full throttle there seems to be a lack of overall power. I can try to tune again but after doing it twice I finally went back to the factory tune.

I have had other Pedators on vehicle and have been quite pleased so I am concerned with this one.

[johan]

Ah ha, i have had nothing but bad experiences with Shell and Chevron, never used Valero. Ex. I had a bone stock 06 C6, stock tune pulled 5 degrees of timing due to knock on dyno with Shell, I drained the tank and replaced fuel with Mobil, and on stock tune no knock and power was up 20hp over the Shell fuel, this is still stock tune, nothing done to it. I had very similar experiences with Chevron.
The knock strategy in the new C6's is extremely sensitive as it looks if GM maximized the timing for good 93 octane fuel and relied on the knock sensors to take care of poor quality fuel.
In the LS7 and LS2 tunes for the 06-07 vettes no timing is added to the tune.
What i would suggest to you would be to install the tune with the current fuel you are running, go to diagnostics and live data, look at your knock retard and spark parameters and record the values, I bet there will be alot of knock activity. Then put Mobil, Sunoco or Amoco/BP premium and look at the same things, I am certain there will be much less knock activity.

[hd-tsmith]

Thanks for the input. I will try this and I hope to get the results you outlined. I know fuel is critical so only the best will get it done. Thanks and I will get back to you on the results.

[mikel]

Thanks for the input. I will try this and I hope to get the results you outlined. I know fuel is critical so only the best will get it done. Thanks and I will get back to you on the results.

I'd call these some pretty impressive gains for an otherwise bone stock vehicle.
There is no reason that you should not be able to duplicate these gains on your car, as long as the fuel is up to the task. Remember, these cars have 11.1:1 compression ratio, so fuel quality is critical to performance.

Thanks

[Whiterock1]

Ah ha, i have had nothing but bad experiences with Shell and Chevron, never used Valero. Ex. I had a bone stock 06 C6, stock tune pulled 5 degrees of timing due to knock on dyno with Shell, I drained the tank and replaced fuel with Mobil, and on stock tune no knock and power was up 20hp over the Shell fuel, this is still stock tune, nothing done to it. I had very similar experiences with Chevron.
The knock strategy in the new C6's is extremely sensitive as it looks if GM maximized the timing for good 93 octane fuel and relied on the knock sensors to take care of poor quality fuel.
In the LS7 and LS2 tunes for the 06-07 vettes no timing is added to the tune.
What i would suggest to you would be to install the tune with the current fuel you are running, go to diagnostics and live data, look at your knock retard and spark parameters and record the values, I bet there will be alot of knock activity. Then put Mobil, Sunoco or Amoco/BP premium and look at the same things, I am certain there will be much less knock activity.

If you don't advance timing on the LS2 or LS7, how do you make the additional power?

[Spartus]

By leaning out the fuel mixture at WOT. GM sets their vehicles at an extremely rich AFR. Usually around 11:1, and lowering it to 12.8:1 can give you some impressive gains.

As an example, my 383 stroker in my Impala was at 11.5:1 when I first hooked up my wideband on a dyno. It made 330 rear wheel HP. At 12.8 I only gained 15 hp, so kept lowering it until I found the point where power started falling off again, and ended up at the magic 13.5:1 where I gained an impressive 35 RWHP, giving me a total of 365 at the wheels.. That's around to 465 hp at the engine when you figure in 20% drivetrain loss, plus an extra 5% due to my loose converter.

[Whiterock1]

Good info! So the Predator tune will actually lean the AFR to achieve the hp gain? That is what I need here in CO at 6700' altitude. I have greatly enhanced cold air to the intake with an Aircharger and opened shroud--only outside air thru the grill comes to the filter, so leaning the engine thru the ECM, plus colder, denser air, should improve the throttle feel and give some hp, not that I expect to feel 10-20 hp when the engine makes 425+ now.

[johan]

Yes you are correct, you being at that altitude could lean your tune out even more since those tunes where made at sea level.

[Whiterock1]

Is there a sticky or instructions on leaning beyond the Diablo 93 octane tune? I wonder, with my very free flowing intake mods, if in conjunction with your tune, I need to lean it out anymore. Spartus seems to have hit a great number for his application, but he's not at 7000'. I don't want to go too lean, that is bad news! but would like to get the maximum I can from my engine.

[mikel]

Is there a sticky or instructions on leaning beyond the Diablo 93 octane tune? I wonder, with my very free flowing intake mods, if in conjunction with your tune, I need to lean it out anymore. Spartus seems to have hit a great number for his application, but he's not at 7000'. I don't want to go too lean, that is bad news! but would like to get the maximum I can from my engine.

Check the LS2/4/7 tuning sticky at the top of this page.

Thanks