Is Racing on 93 "Safe"? Not really.

[BULL]

I'll play hell finding them, but I have logs of my car on 91 with .25STK kicking in rarely at peak rpm.

Then I ran 104 and still had it, although reduced a bit in the rare frequency.

I could never decide if it was actually STK or noise.

 

[Speedy!]

Would love to see those.

 

[BULL]

Would love to see those.

I'll see what I can find.

More than finding them, I didn't take much of any notes other than file names, so accurately deciphering them at this point five years later might be futile.

That point of not only virtually no STK but also no change in STK was what made me not worry about it too much.

Also, don't forget the DA I'm at with the corresponding small air charge.

 

[fumanchu182]

Foo Maan Chew, Hickstah here,
And speaking of lifters?? Have you never been around to hear a lifter knock?? Knot know the difference between the sound of an hydraulic or a solid lifter?? Knot knowing the age of the subject matter,, there is a very difference especially when one gets flat. Do weed need to discuss this further?? Bob??

What? I have lifters that are noisy but they dont trigger the knock sensors. I also have a very loud car, no resonators, no mufflers, solid motor mounts. A 2.72 that makes it scream and a JLT that whines louder than debbie did in dallas.

If you are a stock car and run 93 you can get away with a lot, caveat: good weather. As soon as it gets hot expect timing to be pulled. If you have a pullied car, just dont. Went through this with OST when trying to tune.

I will never run the car at the track without 104 mixed in. If they dont have that, Q16. No more than 1 to 2 gallons cause I have cats still. On the street its detuned to 10* of timing for 93.

 

[Citrus90]

What? I have lifters that are noisy but they dont trigger the knock sensors. I also have a very loud car, no resonators, no mufflers, solid motor mounts. A 2.72 that makes it scream and a JLT that whines louder than debbie did in dallas.

If you are a stock car and run 93 you can get away with a lot, caveat: good weather. As soon as it gets hot expect timing to be pulled. If you have a pullied car, just dont. Went through this with OST when trying to tune.

I will never run the car at the track without 104 mixed in. If they dont have that, Q16. No more than 1 to 2 gallons cause I have cats still. On the street its detuned to 10* of timing for 93.

Why would race fuel trip up your cats when mixed with regular gas? I’d think you’d need more than 1 or 2 gallons to get to octane mix up to around 100 with regular 93 in the tank, right?

 

[fumanchu182]

Why would race fuel trip up your cats when mixed with regular gas? I’d think you’d need more than 1 or 2 gallons to get to octane mix up to around 100 with regular 93 in the tank, right?

104 is unleaded, cats will not have an issue. Q16 is leaded and wouldnt want to use more than that as it will ruin the cats.

 

[Speedy!]

I'll see what I can find.

More than finding them, I didn't take much of any notes other than file names, so accurately deciphering them at this point five years later might be futile.

That point of not only virtually no STK but also no change in STK was what made me not worry about it too much.

Also, don't forget the DA I'm at with the corresponding small air charge.

That last point is important. Higher aircharge is more likely to give knock so that's a factor for sure. When testing my car bone stock in 500HP mode I had almost no knock. Flip it to 700HP mode and 4-5 deg.

I used to mix in a little leaded race gas a few seasons ago. After I did some testing and got more information I stopped doing that, but that's a story for another day.

 

[16GoManGoHC2]

I must of missed mention of a knock issue. In any case I think 11.66 afr is a sweet spot. I always shoot for 11.4 - 11.6 for a street tune. That's .83 lambda on the Hellcats 13.85 stoich. I go for .81 on E85. I'll bring in a tick more fuel above 6000 as a safety.

More of a OCD issue then a knock issue lol. On my Flex tune I refuse to go any higher then 1.600 volts on my knock sensors. @jonx96 made this graph for me and plotted average knock. For the knock sensor settings and on straight 93 no octane boosters (no more of them for me, I’m going to splash 12 gallons of 93 with 2-3 gallons of E85 for about a E25 mix and that’s going to be my octane booster!!) and making about 825 wheel and 6.26 second 60-130 times on these timing settings on 93 I should just leave it alone lol. My mystery is why sometimes it runs totally clean STKR wise and 10 minutes later on return 1/4 pass same bridge just opposite direction I’ll see STKR. But if I do a pull in 3rd gear alone or even a 3-4 pull for a 60-130 run no STKR but in a 1/4 pass same weather conditions I get a degree or so of STKR blips. That’s what I’m trying to solve.
These are my high and low knock sensors and timing at various aircharge. I know I could bump up the knock sensors a bit but trying to find other ways to quench it. I’ve even had thoughts my stock damper I used may be some to blame and harmonics might be coming into play. Putting a stock size ATI Superdamper on now and come hood roads see if that makes any difference at all first.

 

[jonx96]

More of a OCD issue then a knock issue lol. On my Flex tune I refuse to go any higher then 1.600 volts on my knock sensors. @jonx96 made this graph for me and plotted average knock. For the knock sensor settings and on straight 93 no octane boosters (no more of them for me, I’m going to splash 12 gallons of 93 with 2-3 gallons of E85 for about a E25 mix and that’s going to be my octane booster!!) and making about 825 wheel and 6.26 second 60-130 times on these timing settings on 93 I should just leave it alone lol. My mystery is why sometimes it runs totally clean STKR wise and 10 minutes later on return 1/4 pass same bridge just opposite direction I’ll see STKR. But if I do a pull in 3rd gear alone or even a 3-4 pull for a 60-130 run no STKR but in a 1/4 pass same weather conditions I get a degree or so of STKR blips. That’s what I’m trying to solve.
These are my high and low knock sensors and timing at various aircharge. I know I could bump up the knock sensors a bit but trying to find other ways to quench it. I’ve even had thoughts my stock damper I used may be some to blame and harmonics might be coming into play. Putting a stock size ATI Superdamper on now and come hood roads see if that makes any difference at all first.

View attachment 63639 View attachment 63640 View attachment 63641 View attachment 63642 View attachment 63643 View attachment 63644

You forgot the pic of the graph 😊

 

[jonx96]

We also talked about a few settings to make it so his alcohol% isn't searching around as much as it is. I think this log changed 10% or so during this drive back and forth. I don't have my percent changing that extreme during a drive.

 

[16GoManGoHC2]

You forgot the pic of the graph 😊

😂 Graph added lol, good catch !!

 

[jonx96]

For some reason couldn’t use “max” value

 

[Speedy!]

IMO that's just too much timing on the 93 timing map by several degrees. I'd pull 2 deg across the board from 1.48 aircharge and above and test to see what the logs show for knock at that point.

 

[jonx96]

IMO that's just too much timing on the 93 timing map by several degrees. I'd pull 2 deg across the board from 1.48 aircharge and above and test to see what the logs show for knock at that point.

I told him I wanted to rework both of his timing tables. The high end of his e85 is fine but the mid range could use a little work. I think there is power to be had just from reworking the tables.

 

[16GoManGoHC2]

IMO that's just too much timing on the 93 timing map by several degrees. I'd pull 2 deg across the board from 1.48 aircharge and above and test to see what the logs show for knock at that point.

I told him I wanted to rework both of his timing tables. The high end of his e85 is fine but the mid range could use a little work. I think there is power to be had just from reworking the tables.

I’m alway open for safe experimentation. The 93 portion is based off my original HHP tune that ran for 2 years on 93. I’ll find and post that timing map for comparison, it’s scaled only to 1.50 aircharge with 14 degrees of timing, so that meant everything above 1.50 aircharge got the same timing curve as 1.50 right? That’s why I scaled it to 1.90 aircharge and reduced timing in higher boost

 

[16GoManGoHC2]

Here’s my original 2.85 93 octane HHP tune WOT spark table, the knock sensors are even set higher in this tune then I’m running now. Car rocked on this tune for 2 years.

 

[Speedy!]

1.50g aircharge and 1.90g+ are different animals. You're seeing some STKR (not bad but still) in your log so first step is to back timing off to see if it goes away.

 

[16GoManGoHC2]

1.50g aircharge and 1.90g+ are different animals. You're seeing some STKR (not bad but still) in your log so first step is to back timing off to see if it goes away.

I agree, what I’m asking there is if a tune is only scaled to 1.50 aircharge and the aircharge exceed that scaling and is actually 1.90 the tune will still follow the 1.50 aircharge timing table or no?

I just adjusted the next tune I’ll run on by this amount

So looks like this now, that is the areas STKR was blipping up in the 1/4 pull log.
Wish the weather was better I’d go try it now but it snowed here today and roads are salted shitty again From 56F at 3 pm to 3” of snow by morning this AM, come on spring!!!!

 

[jonx96]

That was scaled way wrong for a 2.85. You’ll see 1.7 with a 2.85. That’s your stock timing scale

 

[16GoManGoHC2]

How’s this look? I took everything under 1.5 aircharge and copied it over into the appropriate rows
Why they go so negative at low rpm??