Izzy1000

I assume that the 100 Octane Calibration required GM to advance the timing in order to benefit from the fuel. I assume that the HP must also increase with advanced timing and 100 Octane fuel.

Can anyone confirm or dispel the statement

Thank you all

Higgs Boson

they did not add more spark lead, just reduced the reduction from intake temps.

hp increase or just hp decrease prevention, depends how you look at it. it's still a 650 hp car/tune, it just won't be reduced to 600 or 550, etc due to hot intake air.

The Yav

Higgs,
Please be patient with my question I do not understand how computer turning works. I know for best performance you need a knowledgable tuner and a tune is mandatory for best performance and success.

Can you use the GM 100 Octane Calibration with a HP tune in conjunction with a tune for CAI, lower pulley and meth?

BLUF: is the 100 Octane Calibration a complete new tune? Or does it just recalibrate intake temps so the computer does not pull timing to protect the engine = loss of power. Can you replicate the 100 Octane calibration with HP tuner. Thanks In Advance!
v/r
THEYAV

Mad Dog 24

Higgs i cant disagree with you on what GM did with our new calibrations because you know a lot more then i do technically speaking. BUT, last year in the middle of the summer i did my own unofficial 100 octane test. Day 1 we used 93 all day and the car was as it is always is normal consistency and i could feel a power loss although minor at the end of the sessions. Next day 2 again at Watkins Glen. We ran 100 oct race fuel out of the pump. The car had better pull everywhere and especially up hills. Hit the rev limiter on the back stretch much sooner if i didn't up shift and the times were consistently better. Again what ever it is the seat of the pants test is remarkable just wish the race gas was cheaper! Glad i did it and hope this helps others.

Bill Dearborn

I take it you have the 100 octane tune in your car. Can you say whether or not the performance with the 93 octane gas and 100 octane tune was any better than 93 octane gas with the stock tune?

What if we used 100 octane gas without the 100 octane tune? Would there be a change in performance?

At $8.25 per gallon and using 25 to 30 gallons of fuel per day a day at the track could get pretty expensive.

Bill

Higgs Boson

if you get an aftermarket tune you do not need the "100 octane tune." it would be redundant, there is nothing GM did that your tuner couldn't do in about 4 seconds.


I am not sure if you were on the 100 Octane Tune or just running 100 octane with a stock tune. The Z06 (along with pretty much all modern performance cars), without taking into account any IAT tables or temperatures, will knock on 93 even though they say to run 93. This is because manufacturers do not use pump gas to calibrate, they calibrate spark lead to MBT (maximum brake torque) and then allow the computer to learn and remove spark lead as needed just enough to prevent detonation (knock/ping) as sensed by the knock sensors.

So 93 is not enough octane to achieve MBT in the first place.
Knock sensors notoriously "hear" mechanical sounds it thinks is knock and the ECM pulls spark because it's scared. It could be injector noise, valvetrain noise, exhaust noise, supercharger noise, etc. Knock sensors are far from a perfect technology.

When you factor in all the variables, you will not achieve optimum potential on pump gas (93 or less). A bone stock Z06 will benefit from more octane, not necessarily 100, maybe 97 or whatever, but more than 93, of course depending on your altitude, etc.

With the 100 Octane tune, none of that changes at all. The only thing that changes is how much spark lead is removed due to intake air temperatures (nothing to do with actual knock/ping, etc). The ECM sees the air going into the engine is too hot (based on a preset table, not anything actively measuring other criteria and it is this preset table that is changed) and begins to reduce spark lead by a preset amount (again without actively measuring the results of this action) and power takes a drastic hit.

The reason it is called the 100 Octane tune is because GM doesn't want people to run this less aggressive spark retard table with 93 octane mixed with hot air and too much spark lead....whether it is truly a potential problem is another story/argument....on my car I kill the IAT spark retard up to a reasonable temp. I guess that's the nice thing about being able to monitor and edit these things whenever I want. Never any danger and if I get a little knock event then I can decide what to do with it.

Mad Dog 24

Bill, Yes i have the 100 octane tune all last year. When i just use 93 from the Citgo at the bottom of the hill i fell its no different than without the tune. Last year i would run just 93 when working on skills and new lines and 100 race fuel when seeing what those skills did! At WG i will take an educated guess that i pick up at least 1 to 2 sec per lap with race gas. The car pulls as strong too at the end of sessions as it does in the beginning.

I have used TORCO too. While its similar perf. results i think the 100 pump race fuel has an edge. Negotiating with my fuel sponsor soon so not sure if i will be using the 100 pump much this coming year.


Higgs, It all seems to be about IAT as i read your post. I will be pulling my SC off this spring for other reasons. Thought possibly about installing the Fastprom heat blockers gaskets that you install between the heads and SC. Your thoughts on this inexpensive easy mod and possible results?

BEZ06

I got the GM 100 octane tune about a year ago. I run 93 on the street with no noticeable problem at all - but I don't do a bunch of street racing!!

I haven't done any analytical evaluation of the difference, but like Mad Dog says, the SOTP dyno says the GM tune and 100 octane really feels good - and keeps the car running strong for a whole 30 minute session.

I've been using Boostane Professional (tried Premium but it didn't do as well, although I might not have used enough - the mixing ratios are different, and more Premium is required per gallon than Pro).

I get 93 pump gas for maybe $3 per gallon in FL and I think it's similar when I go up to VIR, Bowling Green, and elsewhere in the southeast.

The Boostane Pro costs maybe $30 per quart (32 ounces) - so let's say it's about $1 per ounce. I recently got a 5 gallon barrel of Boostane Pro and it's down in the $0.60/oz range in volume.

The mixing ratio for 93 to 100 octane for Boostane Pro is 1:138.9 - i.e., 1 oz of Boostane Pro for every 138.9 oz of 93 octane gas.

With a gallon of gas being 128 ounces, I need 0.92 oz of Boostane Pro in a gallon of 93 to get it to 100 octane. That comes out to 4.6 oz for my 5 gallon jugs - however I usually put in around 5.5 to 6 oz in each of my 5 gallon jugs just to make sure I've got enough.

When using the quart bottles at around $1.00/per oz of Boostane Pro, it essentially raised the price of each gallon of 93 by around $1.00, or up to $4.00/gallon of 100 octane. With the Boostane Pro out of my 5 gallon barrel, this year it will cost me cost me about $3.60 per gallon of 100 octane.

I used some Torco last summer and found it worked great. But I tried the Boostane Pro and found it's actually cheaper than the Torco. The Torco is cheaper per bottle, but I had to use more in each gallon of gas than I do the Boostane Pro, and the Boostane Pro won out. And the Torco left an orange color on my exhaust pipes, so it probably was getting more than that orange!!

I've run 100 octane race gas (which at Daytona is a little higher than your quote - I think paid about $8.80/gal in Dec).

I can't tell any difference between running the 100 octane race gas or the 93 with Boostane Pro, and the price of the Boostane Pro definitely is better!!

Bob
.

Izzy1000

If they just reduced how quickly the ECM pulled timing than why change it and call it 100 Octane Calibration? It could have stayed at 91 calibration with the same results. The ECM would not pull power.

I spoke to one of the engineers at Boostane. When you use the Boostane calculator it tells you how much Boostane to use for a specific number of gallons to get the Octane from 91 or 92 or whatever to 100. Calculator than shows HP will go from 650 to 740HP. They told me the spark must be advanced to get the most power out of the Boostane. Otherwise you are using it to stop the knock and not make additional power.

Izzy1000

After I had the 100 Octane Calibration installed and used 100 Octane gas the first thing I noticed was how quickly I reached 6500 RPM. At the beginning the limiter cut in a few times. I now use Boostane to reach 100 Octane but I also think the pump 100 Octane does work a little better.

Izzy1000

Why not just advance the spark and use a meth kit to keep the power up. I assume a Meth kit will cool the air down enough so the ECM does not pull spark. Yes or No. I can remember engines that just had a short block, a intake manifold, an exhaust manifold and a 750 Holly Double Pumper. No electronics. But we never made this much HP either.

Higgs Boson

read the last paragraph, first sentence of my previous post

many people use meth or e85, etc to cool down the combustion and/or iat.