Is Racing on 93 "Safe"? Not really.

[16GoManGoHC2]

That says discontinued ?

V2 is but V3 latest dual sensor unit isn’t, I couldn’t get a link for it though. The guy on HP Academy has a video on it, says it great tool.

 

[16GoManGoHC2]

That says discontinued ?

Here ya go, V3

https://www.plex-tuning.com/products/plex-knock-monitor-v3/

 

[Citrus90]

I just spent a considerable amount of time reading through each and every post in this thread. I normally wouldn’t, since I’ve always used 93 in my 392 and my old 5.0 Mustang, but I’ve got a Jailbreak on order and it will be my first foray into supercharged vehicle ownership.

I test ‘n tune occasionally at a few local tracks in the summer time, but otherwise daily drive my car and beat on it rarely, if ever. What I’ve gathered - despite not understanding some the Uber technical mumbo jumbo - is that I can damage my rods and catapult an engine on a stock 6.2 by sticking with regular premium fuel?? This’ll be the first I hear of it, although the data and anecdotal experiences in here seem to buttress this hypothesis well.

I’m on board. I think it’s safe to say that shelling out $100 or so and putting in some race fuel is the safest bet, rather than pinching a few pennies on some shelf-stocked booster, yes?

Doesn’t seem like too much of a sacrifice for a 90k car. Thanks for everyone’s advice, input, and experience. This place is great, even for relative novices like me.

 

[vortecd]

I just spent a considerable amount of time reading through each and every post in this thread. I normally wouldn’t, since I’ve always used 93 in my 392 and my old 5.0 Mustang, but I’ve got a Jailbreak on order and it will be my first foray into supercharged vehicle ownership.

I test ‘n tune occasionally at a few local tracks in the summer time, but otherwise daily drive my car and beat on it rarely, if ever. What I’ve gathered - despite not understanding some the Uber technical mumbo jumbo - is that I can damage my rods and catapult an engine on a stock 6.2 by sticking with regular premium fuel?? This’ll be the first I hear of it, although the data and anecdotal experiences in here seem to buttress this hypothesis well.

I’m on board. I think it’s safe to say that shelling out $100 or so and putting in some race fuel is the safest bet, rather than pinching a few pennies on some shelf-stocked booster, yes?

Doesn’t seem like too much of a sacrifice for a 90k car. Thanks for everyone’s advice, input, and experience. This place is great, even for relative novices like me.

Stock you should be fine. At worse it could pull some timing. The main thing is on a modified car with more boost to have a little extra in the tank. Could still help on a stock car depending on how good the gas is and the DA

 

[Speedy!]

Stock you should be fine. At worse it could pull some timing. The main thing is on a modified car with more boost to have a little extra in the tank. Could still help on a stock car depending on how good the gas is and the DA

You saw my first post in this thread correct? That was my car BONE STOCK. Definitely not fine. This thread is not about performance.

@Citrus90 based on my experience I highly recommend you add unleaded race gas to your pump gasoline in a ratio that's enough to equal 98 octane when racing.

 

[jonx96]

You saw my first post in this thread correct? That was my car BONE STOCK. Definitely not fine. This thread is not about performance.

@Citrus90 based on my experience I highly recommend you add unleaded race gas to your pump gasoline in a ratio that's enough to equal 98 octane when racing.

Did you log other days at the track as well or just the one day to see if race fuel would help?
Curious if you saw much of a difference with weather as far as KR is concerned.

 

[Speedy!]

Did you log other days at the track as well or just the one day to see if race fuel would help?
Curious if you saw much of a difference with weather as far as KR is concerned.

Those drag strip logs were in good air, like 50 or 60°F. I was getting a lot of knock as you saw. Race gas helped.

I have other logs, I can post screen shots if interested where I tested on the street the following summer. Same thing. On 93 I was getting a TON of STKR on 93. Like 3-4 deg throughout the RPM range. Started mixing in 109 unleaded race fuel and re-testing and the higher the octane went the lower the STKR was. On 93 I actually had LTKR logged which is bad.

 

[jonx96]

Those drag strip logs were in good air, like 50 or 60°F. I was getting a lot of knock as you saw. Race gas helped.

I have other logs, I can post screen shots if interested where I tested on the street the following summer. Same thing. On 93 I was getting a TON of STKR on 93. Like 3-4 deg throughout the RPM range. Started mixing in 109 unleaded race fuel and re-testing and the higher the octane went the lower the STKR was. On 93 I actually had LTKR logged which is bad.

Ya I was curious I know up here our 93 quality drops to a pretty unsafe number. But since these cars are meant for 91 you'd think it'd level out. I am almost more surprised by the knock in the summer logs.
The one bad things about knock sensors is they pick up knock after the event in hopes they caught it soon enough so the following knock events don't happen.

 

[vortecd]

You saw my first post in this thread correct? That was my car BONE STOCK. Definitely not fine. This thread is not about performance.

@Citrus90 based on my experience I highly recommend you add unleaded race gas to your pump gasoline in a ratio that's enough to equal 98 octane when racing.

Guess I never ran across a stock Hellcat throwing a rod just going down the track

 

[Hickster]

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??

 

[Speedy!]

Ya I was curious I know up here our 93 quality drops to a pretty unsafe number. But since these cars are meant for 91 you'd think it'd level out. I am almost more surprised by the knock in the summer logs.
The one bad things about knock sensors is they pick up knock after the event in hopes they caught it soon enough so the following knock events don't happen.

Bingo. I can tell you FOR SURE when tuning a car if we ever saw 3deg of STKR much less 5deg we'd have been pulling timing immediately and not letting that happen again. I'm not sure what Dodge was doing or what "91" octane fuel they were tuning these cars on but no way it's a good thing. Maybe they did some kind of torture test and figured it wouldn't break until the warranty was up and banked on most owners not going to the track or something, who knows.

I also tested 500hp mode as a comparison. No knock to speak of. Switch it back to 700HP mode and knock in the logs. It was just tuned too aggressive from the factory at least for the 93 octane I have access to.

Guess I never ran across a stock Hellcat throwing a rod just going down the track

I've gotten several emails personally from folks with stock cars that motors blew up. One was a Dodge dealer service manager curious what I could tell him. Data doesn't lie my friend.

 

[DavidKFla]

Here's my experience with 100 octane, ethanol free race gas.
I've had my car for about 3.5 years and taking it to the track about 2.5 years.
Anyway it's always had a high temperature problem even stock. It would fall on its face anywhere from half track to about 1000 feet.
I decided to try some race gas. Today was the first day that I was able to make it to the track. The car normally runs 10.60s-10.70s. It would always lay over.
Today with 2 passes it ran a 10.46 and a 10.58 hazing the tires about the 1st 100 ft. Car pulled hard all the way through at 131 mph.
I'm never going back to 93 pump.

 

[Speedy!]

I went and found these logs from some summer street testing back in the day. This was June in TN so figure 90 degrees and humid.

First log is on Shell 93. Knock all through the WOT pull in 3rd gear.


Added unleaded race fuel to bring the octane to about 100 and re-tested. Almost zero knock.

 

[vortecd]

Well just another reason to run e85

 

[jonx96]

Forced induction is more to dial in than people think. There’s a point where you have to much timing and more air charge will help. There’s a point where there is to much aircharge and timing would help. I almost wonder if dodge went up just a small amount in boost and pulled a degree or two of timing if that would have helped and could have made the same or similar power. Makes me wonder if the redeyes have the same issue ?
Obviously, there are many people who are running a 2.85 and even smaller pulleys on 93. As long as these aren’t max effort tunes 11 to 12 degrees of timing on the big end and you may not see any knock.
Just a thought. More air may have been the answer. But that would have made dodge step up Injectors and dual pumps in the hellcats to. Then you get into an emission issue. So that’s my thought. Dodge should have turned down timing and added more air.

 

[Speedy!]

Dodge wanted to claim a 700+HP car off the show room floor. That's what this is. If you look at the later year Hellcat tunes, and the Redeye tunes, you'll see they reduced timing a bit. It doesn't take much to dial in right on the edge of knock and stay below it. So that 4 deg of STKR I saw in my above log, taking out 1 degree of timing might have gotten rid of all of it. Once knock kicks off it can be contagious LOL.

Custom tunes and pulleys from reputable tuners you won't see as many problems these days as now they know where the timing and knock sensor limits are to avoid them.

If I were reviewing a log from my 2016 Hellcat bone stock and it was a modified car I was working with I would have pulled 3deg of timing and tested. If that worked I'd add one back and see what happened. I also would have never set the commanded PE fueling to 12.1 AFR, more like the 11.4 - 11.8 we talked about previously.

 

[jonx96]

Dodge wanted to claim a 700+HP car off the show room floor. That's what this is. If you look at the later year Hellcat tunes, and the Redeye tunes, you'll see they reduced timing a bit. It doesn't take much to dial in right on the edge of knock and stay below it. So that 4 deg of STKR I saw in my above log, taking out 1 degree of timing might have gotten rid of all of it. Once knock kicks off it can be contagious LOL.

Custom tunes and pulleys from reputable tuners you won't see as many problems these days as now they know where the timing and knock sensor limits are to avoid them.

If I were reviewing a log from my 2016 Hellcat bone stock and it was a modified car I was working with I would have pulled 3deg of timing and tested. If that worked I'd add one back and see what happened.

i do the same. See knock pull some and see what happens. If I am correct the 2018 had some small supercharger improvements and you had stated the 18 is a little less timing. So they could have had the same thought I had.

 

[Speedy!]

In any case they saw a problem and made changes, otherwise there wouldn't be the changes right?

Someone with a newer model could do the same testing I did and see what they see. Most people don't understand data logging and think hooking a computer to the car will void the warranty so it's better to just recommend putting race gas in the tank and let'r rip.

 

[Citrus90]

You saw my first post in this thread correct? That was my car BONE STOCK. Definitely not fine. This thread is not about performance.

@Citrus90 based on my experience I highly recommend you add unleaded race gas to your pump gasoline in a ratio that's enough to equal 98 octane when racing.

That’s what I gleaned from what you wrote, too. Really appreciate the advice, dude. After break-in, I’ll be picking up some high octane fuel when I hit the strip for the first time. Now, about those break-in oil changes… lol!

 

[jonx96]

you can’t be more right on the logging. There was a guy at the track this fall with a half race gas tune and 93 tune he said. He said the car didn’t feel like it was running right. I asked if he was logging he said he didn’t know anything about that and just knew how to load the tune. I offered to help him but he had a burn box so didn’t want to remove that to log……….