Is there a lot of head room on a stock LS3 NPP 6MT running 93 pump? Enough to warrant buying a dyno tune to bump fuel economy and performance up?

 

I should add to this i had an 03' z51 6mt with an ati balancer, borla touring /w x pipe on stock manifolds with a z06 airbox and haltech honeycomb maf screen. It was getting around 20 in town and 32 hwy. I see 17 town and 25hwy with this base ls3 and it feels less responsive.

 

The ECM has two Octane tables, and if the car has problems with the high octane table (engine knock) it will kick over to the lower octane table with retarded engine timing instead.

Also, the car can be converted over to E-85, since the ECM has pervisions for that too.


So yes, you can tune the high octane table for the higher octane, but if you get fuel that is say that octane rating, but has a higher E rating instead, it's going to kick down to the lower octane table when it run into problems with engine knock instead.

So a better trick, is to just keep the octane rating higher than needed instead so the car will stay in the high octane table to begin with. Here, a meth kit is used to maintain the Higher than needed and the AIT down, and allow the car to run on the lower 91 octane rating with the high octane timing pushed instead.

Lets face it, the washer fluid converted over for dual purpose will hold enough 50/50 mix of Meth (about $6 a gallon if you make it yourself) for both the motor and windshield for weeks on end, and your burning the less expensive 91 octane for just crushing around.

 

This is something many people misunderstand. It doesn't just switch between the two timing tables all at once.

Here's how it works:

There is a knock learn factor variable that changes based on knock/lack of knock. It goes from 0.000 to 1.000

0.000 = 100% using the high octane table
1.000 = 100% using the low octane table

In the tune there is a setting that defines how much the knock learn value is increased based on how much knock is seen. 3* of knock may increase the knock learn factor by say 0.200. Then, under certain conditions (typically slightly more load than you'd see cruising down the interstate) the knock learn factor decreases by a small amount until it reaches 0 again or encounters more knock. The process then repeats.

Example:
With a knock learn value of 0.200, timing would work out to 0.8 x high octane table value + 0.2 x low octane table value.

At 0.500 it would split the difference basically

At 0.75 it would be 0.25 x high octane value + 0.75 x low octane table value

So.. that's how it works.

If you have access to HP Tuners and go under spark-->retard, the section for knock learn is what defines all of this. You can also log the knock learn factor PID if you want and can see it move when knock is over a certain amount (also definable)

 

With above being said am I a suitable candidate for HP Tuners and buy a WB? Should I pay for dyno tune and leave it to the pros? I plan on keeping the car stock with the possibility of z06 headers and opening the airbox up but keeping it stock (rainproof)

 

How much is HP Tuners /w a WB? Can you guys walk me through eco tuning under 2.5k and lean race tuning over 3k after I get an ati balancer and z06 manifold installed?

 

HP Tuners Pro is $649 new, decent wideband is ~$150-200

What do you mean by "eco" tuning 3K?

 

I'd like to aggressively advance timing for part throttle to 25% under 3k rpm to maximize economy -- and compromise power.

At 3k I'd like to lean out to a lean race tune for 93. If that be more/less timing or fuel. I plan on getting the radiator to keep it all cool.

I'm coming from Kawasaki motorcycles, but LS Corvettes are on the same fundamentals.. right?! - Lean is mean.

 

I have to believe if you could get much better fuel economy just by advancing the timing a ton, I think GM would have done it already. Maybe you can get a little better out of it, but I doubt anything huge. I'd be interested in see what results you end up getting.

Advancing timing only helps to the extent that you end up with peak cylinder pressure at the right time.. peaking earlier by overly advancing the timing does nothing but put extra stress on the bottom end.

 

On the Yamaha Warrior 1900cc..While I was able to build the whole engine, account for static compression, I never had the ability to control timing on the engine.. The end result was a motor with a 95mi tank range or a **** load of spark knock in traffic.. I gave up on it and sold it. I feel like I can take complete control on the LS platform. I know my tuner did that for me on the LS1 but I don't know how he did it. He sure as hell read what my wants were, I paid like hell for it and it was totally awesome. (Mayhem Motorsports) It was all timing and lambda. Stock headers, borla x and touring back.

The new LS3 car is my everything car. I do everything but drag race. So I'd rather tune it for maximum part throttle performance than otherwise. Anything 50% up would be track profile. Mayhem really knocked it out when I added the honeycomb MAF screen. I gassed that car up once a week. The LS3 is guzzling twice the city mileage.

There are some gains to be had against "piston idiling" and they were able to zero it all out without additional cooling.
My ask is- am I seeing that on the LS3? Why? Is it timing or cooling or just a big *** block?

I am planning to run the stock heads/cam, add an aluminum radiator /w trans/oil, run more timing and tune it. I think this car can do better, but I'm not sure. I want to track it quarterly and I don't have a second car.. what would the stig do?

 

Fastest way to blow up a motor: Tune it wrong!!!!!!!!


Trust me, there a horror stories of tuner blowing motors up from a bad tune from the start.
http://ls1tech.com/forums/generation...-motors-3.html

And NO, it not just the C6's, since some tuners are still in the dark on the direct injection tuning on the C-7 motors as well.
http://bangshift.com/bangshift1320/b...ar-fun-profit/

 

You're very right, especially about the C7's. There are VERY few tuners that should be touching those and I hate to even think how many will be damaged over the next few years due to incompetence.

There's only one person I would trust with mine, if I had one.

 

I can't add much really but I've been told that these LS3 engines make more power when ran a bit rich. Unlike the majority of sport bikes that develop cleaner throttle response when leaned out.
My modified LS3 ( already tuned, cammed, etc) runs beautifully but really does get crap mpg. My scan gauge shows AF ratios in the range of 12.5 under most conditions.
I too had read the stories of 30+mpg out of manual Vettes but not mine! The 1200 mile road trip home resulted in about 25 mpg and every tank since has been about 14 mpg.
I bought mine exclusively for a play car so I figure the rich tuning is good for protecting the engine at the track.
Btw, when they talk about lean engines running hot they really mean in cylinder temps that can melt pistons which has little effect on coolant temps really. Don't plan on an oversized radiator protecting your engine from a lean condition.
Good luck.

 

Fuel is cooling,

Right up until you are running too rich instead, and the fuel is washing away the film of oil on the cylinder walls and you start going through piston rings faster instead.

 

You're better off buying a hand-held unit for what you want out of the car. Lew can steer you in the right direction.

 

Once again, the cooling effect is in the cylinder, not really the coolant.

The concern is burning up a cylinder from too much heat. You won't see that on your coolant temp gauge.

 

Getting a tune in any manner short of free, will cost you more than any savings you'll get through fuel economy. At $4/gallon and a 1 mpg increase over an average 25 mpg car, it'll take 66K miles to break even from a $400 tune. That's assuming you never use a heavier foot to play with the better performance of the tune. So the bottom line there, is to forget fuel economy as a part of a tune.