Low HP on Dyno

[superman07]

What's the knock on Torco?

The Brown is from MMT, Manufactures say its safe but there are also white papers on it degrading catalytic converters and clogging emission systems, so be careful. Its also illegal on the street in many areas. I don't like the idea of anything coating my plugs, or clogging my cats.

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[PositiveGMotorworks]

My UPR did the same thing, This car cannot stand a leak, it completely screws the fuel trims. Have you ran 50-100 miles since you fixed it? Have you filled up to trigger the fuel inference protocol? When mine went ape shit the inferred ALC percentage was way off. The car didn't properly command the correct AFR's. My car felt like it lost torque and felt sluggish. I had to fix the problem like you, but also made sure that the car had time to properly establish fuel trims before I beat on it. I used the NGuage to verify that the car had in fact inferred the proper fuel parameters.

Thanks for this information! I thought out of everything I did, the broken UPR clean side collector was likely the culprit. Good to know it was the smoking gun. I wasn't aware of the ALC percentage issue but I have filled up at least once since since I corrected the leak and driven a enough. What parameters should I look at on the nGauge to verify everything is good now just to be sure? Does your car still pull timing under wide open throttle and other times randomly? Mine also adds timing in the lower RPMs as well according to the nGauge.

 

[superman07]

look for alc learn, and alc percentage. Learn should be a red one, unless you have just filled up and t will then be a yellow zero. Once the ECU has inferred fuel the flag goes back to a red one.

The percentage should read as 10 percent or so for normal fuel.

what makes you believe its pulling timing, are you watching the timing adv and knock in real time or data logging?

Turn traction control completely off and data-log. You must hold the switch for 5 sec. I have seen advancetrac do some weird things when it thinks tires are slipping.

Try logs in second, third, and 4th gear at WOT.

 

[PositiveGMotorworks]

Thanks for the info.

KnockR shows 2,3, or 4 at times. I'm watching it real time but we also data logged while on the dyno and saw the timing being pulled.

 

[superman07]

Man, that's a lot of knock. I have not heard or seen of that even on 91. Stock ECU tune?

 

[PositiveGMotorworks]

Yep but I still made normal power this time so who knows? Do you see a 0.00 KnockR values all the time? Never - or + numbers?

 

[KenF]

Yep but I still made normal power this time so who knows? Do you see a 0.00 KnockR values all the time? Never - or + numbers?

I can tell you I've seen Knock numbers into the 5's on mine and my car put down 472 on a Lund tune with 93 and Lethal OR legs installed. It doesn't feel at all like it's falling down but it's still hitting numbers like that. About to finally install the JLT intake and FLexfuel tune so we'll see what happens after all that.

 

[KenF]

FYI the times I've seen KNOCK numbers that high was under WOT not just cruising around.

 

[PositiveGMotorworks]

FYI the times I've seen KNOCK numbers that high was under WOT not just cruising around.

Yes me too. At lower RPMs and less than full throttle I see timing being added sometimes.

 

[superman07]

Yep but I still made normal power this time so who knows? Do you see a 0.00 KnockR values all the time? Never - or + numbers?

I see negative values almost exclusively when I do watch the guage, but If I data-log I can see the car adding timing up to a point. In a log from time to time I can register very minimal events and watch the corresponding timing advances adjust. What I do not typically see in the logs are severe events where the car is retarding from the base map 4-5 degrees.

I saw this only twice, once with Lethal Off Road pipes which came off 2 days later and solved itself, and when I had a vacuum leak with corresponding shit fuel trim info.

As soon as I hit the throttle the number goes negative slowly getting back to a zero base.

 

[superman07]

I can tell you I've seen Knock numbers into the 5's on mine and my car put down 472 on a Lund tune with 93 and Lethal OR legs installed. It doesn't feel at all like it's falling down but it's still hitting numbers like that. About to finally install the JLT intake and FLexfuel tune so we'll see what happens after all that.

Not an expert but the Lund tune probably has more aggressive timing maps. 4 to 5 degrees of retard from a more aggressive advance map could be Apples to Oranges. Only Lund would know I suppose. I thought I read both the 93 and e85 map use a 30 degree max.

But if it drives fine and your happy that's all that matters.

 

[KenF]

Not an expert but the Lund tune probably has more aggressive timing maps. 4 to 5 degrees of retard from a more aggressive advance map could be Apples to Oranges. Only Lund would know I suppose. I thought I read both the 93 and e85 map use a 30 degree max.

But if it drives fine and your happy that's all that matters.

Yeah I haven't noticed anything that would concern me at this point. I posted mainly just to throw the information out there from what someone else has seen/experienced. I guess we shall see again what happens with new tune and intake.

So why did you remove your OR legs out of curiosity?

 

[superman07]

too loud for me, especially without resonators, I hated how loud it was even when not going fast. I also never solved the vibration issues. My car was slower due to the false knock. Probably could have got rid of it with some effort but the noise was a deal breaker.

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