Higgs Boson

It depends if the computer commited to memory the retard or just did a temporary pull.

If we are talking about one dyno pull there is a chance it didn't save the retard permanently or just bumped it down slightly where more runs would pull even more timing out. In this situation better fuel will stop it from pulling more but you wont get back any saved lost timing until you reset your knock learn.

Dabigsnake

Interesting. So, the knock retard has to be reset? Does it not reset/default back on its own at any time? Disconnecting battery or clearing codes w scan tool? Does that totally reset all parameters?

Higgs Boson

Disconnecting the battery has worked on previous cars so I would think it will still reset the knock learn.

Something I do on my personal car (that I do not do on customer cars) is set the Lo Spark table the same as the High Spark table so there is no learning down to lower values. Since I am always very in control and sort of **** about where I get gas and monitoring everything on my car, I am almost constantly in a state of tuning the car when I drive so if there is ever real knock I make adjustments on the spot. Of course, that gets ironed out pretty quickly so it's not really an issue.

My tune is also flex fuel enabled so alcohol in the tank will also allow it to raise spark under heavier loads.

If I were to run race gas like VP or whatever, I would need to raise spark in the main spark tables to take full advantage of it but I typically wouldn't use race gas since ethanol is so cheap.

dar02081961

No sir it does not have to be reset. Unless you want it done immediately.

The learn or re-learn takes place after a refuel.
I am not sure how this is determined, but I think it has to do with the fuel door being opened and some qty of fuel increase shown or observed by the PCM from the fuel gauge.

Its designed this way because the car can get hold of different fuel as it travels from region to region or state to state or the driver switches from brand to brand or quality (octane).

jbsblownc5

Yes, on the first pull with Torco, we pulled NO timing and made "stock" #s, 546 RWHP. On the next pull, I believe intake air temps already started to rise, so it did pull a little timing and a little HP...

I've now got the Granatelli Expansion tank, along with an additional radiator with Spall fans to help cool that extra fluid from the heat exhanger, and meth to boot! I went ahead and tuned on Torco/91, and we no longer pull timing for octane or intake air temps...

C7/Z06 Man

Question: I have read here that pulling fuse numbers, 4, 53 and 62 under the hood will do the same thing as disconnecting the battery for the computer. I ask because I think that would be quicker and easier.

davepl

I haven't checked the fuse map, but wouldn't pulling the ECM fuse accomplish it? I can't see a computer having multiple sources of power, and there are not (so far as I know) multiple modules that need to be cleared, so just the ECM should do it.

In theory, I've not tried it.

C7/Z06 Man

Whoever posted what I read seen to know what he was talking about and gave a reason for pulling the three fuses because I was thinking the same as you, just the ECM fuse #4= Engine Control Module.

53= Transmission Control Module/Engine Control Module
62= Engine Control Module

His Reasoning: I would hope it would just be #4 but why mess around when they are so easy to remove.

Higgs Boson

I really don't know the answer to that one guys because I never do it.

C7/Z06 Man

Edited post #548 above in bold print.

Alaska SS

Has anyone done a before and after tune dyno test yet?

Alaska SS

Well, I had my car to the track and have before and after numbers...nothing worth talking about though. The DA was almost 3k feet higher Friday night so the actual times won't tell the story. However, the car didn't fall over at the 1/8th like it did in the past, felt MUCH better!!!

Once the air cools and I can do an apples for apples comparison I'll post better data. Just a little food for thought...everyone else lost roughly 6-7mph on Friday as compared to previous outings, I only lost 2mph. The tune seems to be working.

I'm going to try to get the car on the Dyno Friday and I'll post better data that will truly be apples for apples as the last dyno pulls I did were with a 4200 DA...expected to be the same on Friday. Fingers crossed for good results but I'll keep everyone posted.

BEZ06

Thanks for the good info!!

Were you running an octane booster in pump 93, or do you have pump 100 available?

Alaska SS

We have 100 right at the pump.

patrick4588

is there a 100 octane tune for the 17-18s?

Mad Dog 24

I believe so, call your GM dealer I think it cost me 330.00. I've had it for all of 2017 in my 15 Z06. At the road courses with 100 oct the car pulls much harder under load. It is noticeable in seat of the pants and consistent track times. Glad i did it but man it gets expensive at 2 full tanks per day!

patrick4588

AzDave47

The GM 100 tune is for a stock setup.

Doing the other changes you listed should have a aftermarket tune done (void warranty) and you could use 100 octane and have the tuner set it up.

patrick4588

Mad Dog 24

I have a Haltech filter, Borla rear cat delete, oil catch can and no tune. The car is a beast. I will not tune to keep the warranty in place as its at WOT a lot! My dealer knows my car well and all is good with them. Sure if there was a problem they may try to use my mods as a way out but they also need to prove it.

Comparing my car to a bone stock one at the track we did notice that without 100 octane and my mods there is little difference. With 100 Octane there is. I hope this helps answer a few questions.