[KingLT1]

Originally Posted by FoundNemo

Wrong. Ted Jannetty has dynos showing gains of 20-30rwhp on a bone stock car going from 93 to 100 octane.

That is because the ecu was likely pulling timing on 93. 100 octane helps keep the ecu from pulling timing.

Originally Posted by L78toLT1

No way 10% e is costing you 4 - 5 mpg vs non-e 93. E60 only costs me 2mpg compared to 10% e 93

Agree

[WhiteMale]

Pulling timing with 93...??? Shouldn't be happening, right?

[Z OH 6]

Originally Posted by WhiteMale

Pulling timing with 93...??? Shouldn't be happening, right?

Should be rare but could be a bad tank of gas, or really high temps. Bottom line is that a stock tuned ZL1 isn't going to GAIN any more power with 100 octane over 93 octane, so much as it might not LOSE any power over 93 octane under certain conditions.

[SJFGTO]

Originally Posted by Z OH 6

Should be rare but could be a bad tank of gas, or really high temps. Bottom line is that a stock tuned ZL1 isn't going to GAIN any more power with 100 octane over 93 octane, so much as it might not LOSE any power over 93 octane under certain conditions.

^Agreed^

[foshjowler]

Originally Posted by L78toLT1

No way 10% e is costing you 4 - 5 mpg vs non-e 93. E60 only costs me 2mpg compared to 10% e 93

I would agree. Full E85 should result in using about 30% more fuel. Going from e0 to e10 I would expect maybe a 5% difference.

[KingLT1]

Originally Posted by WhiteMale

Pulling timing with 93...??? Shouldn't be happening, right?

It happens especially during the summer. The timing map is pretty aggressive on the stock tune and the engine relies on the knock sensors to keep it in check.

[Heartbreaker]

Originally Posted by Camaro1973

There’s 0 gains going from 93 to 100 unless your timing was increased. Octane alone doesn’t create more power , octane +timing does because it’s more resistant to knock.

If your max Timing is 20 degrees it doesn’t magically increase itself for 100 octane.

ECT,IAT,MAT = yes

Ted Jannetty has proven on back to back Dyno runs that 100 octane vs 93 octane adds 25 hp. Look it up.

[CW3SF]

Originally Posted by Heartbreaker

Ted Jannetty has proven on back to back Dyno runs that 100 octane vs 93 octane adds 25 hp. Look it up.

Stock tune? Or when he tunes for the octane increase?

Two completely different circumstances.

[Joshinator99]

Originally Posted by CW3SF

Stock tune? Or when he tunes for the octane increase?

Two completely different circumstances.

Stock LT4 sees timing retard in very warm weather or extended heavy use, even on 93 octane. So the stock tune would easily lose 25 HP in that instance. Using 100 octane lets you “gain” that back, even on the stock tune.

[Camaro1973]

Originally Posted by Joshinator99

Stock LT4 sees timing retard in very warm weather or extended heavy use, even on 93 octane. So the stock tune would easily lose 25 HP in that instance. Using 100 octane lets you “gain” that back, even on the stock tune.

Your talking about losing timing to heat, ECT, IAT's etc. Regardless if it pulls a few degrees timing for the above adding 100 octane isn't going to change that, nor does it increase timing.


There's a Base timing table (high octane) which im sure you know of, and there are several other tables were timing is either increased or decreased based on several factors. As i mentioned, ECT, IAT, MAT etc will all increase/decrease base timing tables.


Point im trying to make is, there's no magic table for 100 octane, the car has no idea it has 100 octane in it, and there's nothing in any table that will raise timing if you have it in there.


Unless its always on the low octane table, which it shouldnt be, or timing when tested on 93 was simply pulled because of temps thats the only way 100 octane is going to show any difference.

[SFV1LE]

I always run a lot of VP 101 octane at the track, I start with 5 gallons in a full tank and keep adding more each session so by the end of the day I'm at 95 oct+. It's expensive but good insurance on warm days with inconsistent pump gas, and keeps the power up.

I was at ACS in Fontana back in October the guy in garage next to me with a 2019 ZR1 was having timing issues due to engine temps on a stock tune even with several gallons of 101 in the tank to make 93+, he had to add a lot to fix it. My ZLE on same octane outperformed (out-cooled) his ZR1 in that way, and a better lap time, that day.

[d15b7]

Hello. I almost bought a ‘19 ZR1 last summer but the deal fell through. So I’ve done a lot of reading and studying on the cars. The LT5 is different (in s bunch of ways) than the LT4; there is a supplemental instruction in the ZR1 owners manual that states if you were tracking the car it is highly recommended to use 100 octane. You’ll get the best performance on 100 octane. That’s what it says. I believe there is a totally different tuning and mapping for the LT5 engine, that has timing tables that can utilize the 100 octane.

[Z OH 6]

Originally Posted by Joshinator99

Stock LT4 sees timing retard in very warm weather or extended heavy use, even on 93 octane. So the stock tune would easily lose 25 HP in that instance. Using 100 octane lets you “gain” that back, even on the stock tune.

This I believe which is what I stated, its not so much that you're gaining 25hp over the stock power ratings, you're just preventing the power loss in extreme conditions.

[KingLT1]

Originally Posted by Camaro1973

Your talking about losing timing to heat, ECT, IAT's etc. Regardless if it pulls a few degrees timing for the above adding 100 octane isn't going to change that, nor does it increase timing.


There's a Base timing table (high octane) which im sure you know of, and there are several other tables were timing is either increased or decreased based on several factors. As i mentioned, ECT, IAT, MAT etc will all increase/decrease base timing tables.


Point im trying to make is, there's no magic table for 100 octane, the car has no idea it has 100 octane in it, and there's nothing in any table that will raise timing if you have it in there.


Unless its always on the low octane table, which it shouldnt be, or timing when tested on 93 was simply pulled because of temps thats the only way 100 octane is going to show any difference.

The LT4 engine is on the edge of knock even with 93 due to it's aggressive timing table. Even if ECT and MAT are within check they will still see some KR unless it's cool/cold out. The 100 octane helps prevent KR. ECU doesn't default to low timing tables if it sees some KR either. It has to see a specific amount at different loads for that to happen.

I agree if the MAT's are high then it will pull timing regardless, but that isn't what Josh or myself was talking about. GM tunes these engines to knock and rely on the knock sensors save them. They are fed a lot of timing and have the knock sensors set to be very sensitive. Yes that sounds stupid I know...not sure what the theory is behind that but that is what they have done. The LT1 does the same shit. I have seen it tuning a few different combinations myself a long with other reputable names in the business.