HPtuners Question and Answer Thread

[Speedy!]

Perhaps my question is the subject for new thread but, what are the advantages of an e85 vs. 93 vs flex tune on a street car?

A tune for a specific fuel (93 or E85) is not relying on any external variables to determine what fuel the car is actually running. It's more static so less to worry about from a variability perspective.

A flex tune is reading various sensors, injector pulse width, and even the fuel tank level at times to determine when to calculate and how the fuel in
the tank is determined to be what it is.

I've gotten to where I mostly run my straight E85 tune. It works fine for the E85 I get around here which ranges from E70 in the winter to E89 in the summer. I personally like to run a half a tank or so of 93 through the car about once a month just for peace of mind on keeping the fuel system cleaned out. When I wanna do this I run the car down to near empty of E85 and load my flex fuel tune to make the switch to 93 run the 93 out, switch back to E85 and leave the flex tune in until I'm back to around E80. Then I go back to my E85 tune.

My flex fuel tune works just about perfect but I'd never suggest someone race on one etc. I did learn through LOTS of testing that flex fuel tunes are meant for a fuel swap for the most part. Like going from almost empty on 93 to a full tank of E85 or vice versa. Adding a few gallons here or there trying to go back and forth also works, but takes the car longer to figure out. A good compromise might be to get it stabilized around E60 or so to get some fuel mileage if you're gonna drive a lot and still want a decent octane in the tank.

 

[DavidKFla]

A tune for a specific fuel (93 or E85) is not relying on any external variables to determine what fuel the car is actually running. It's more static so less to worry about from a variability perspective.

A flex tune is reading various sensors, injector pulse width, and even the fuel tank level at times to determine when to calculate and how the fuel in
the tank is determined to be what it is.

I've gotten to where I mostly run my straight E85 tune. It works fine for the E85 I get around here which ranges from E70 in the winter to E89 in the summer. I personally like to run a half a tank or so of 93 through the car about once a month just for peace of mind on keeping the fuel system cleaned out. When I wanna do this I run the car down to near empty of E85 and load my flex fuel tune to make the switch to 93 run the 93 out, switch back to E85 and leave the flex tune in until I'm back to around E80. Then I go back to my E85 tune.

My flex fuel tune works just about perfect but I'd never suggest someone race on one etc. I did learn through LOTS of testing that flex fuel tunes are meant for a fuel swap for the most part. Like going from almost empty on 93 to a full tank of E85 or vice versa. Adding a few gallons here or there trying to go back and forth also works, but takes the car longer to figure out. A good compromise might be to get it stabilized around E60 or so to get some fuel mileage if you're gonna drive a lot and still want a decent octane in the tank.

I watched your last video. You looked all spiffed up for a date or something?

 

[ostmike]

Perhaps my question is the subject for new thread but, what are the advantages of an e85 vs. 93 vs flex tune on a street car?

I think most folks know my take on running ethanol in any configuration vs. 93+ race fuel or straight race fuel. I also know this will cause some backlash but I will put my opinion out there.

First and most important I would never race on a Flex tune. Since I primarily race and drive my car hard this is not an option I can recommend for race applications.

E85 from a drum is a great alternative to race fuel if you can afford the extra cost of fuel system upgrades (injectors and pumps).
E85 in a drum is as expensive as race fuel in a drum.
Ethanol from the pump is questionable and should always be tested.
Ethanol fuel mileage for daily driving is horrible.
If you do not have ethanol readily available you may be driving further to fill up burning even more fuel.
Ethanol at the pump marked "E85" is only required to be E50 in many areas and the remaining 15-50% of non-ethanol is NOT required to be gasoline - it just has to be something that burns like gasoline. That does not give me a warm and fuzzy feeling.

Running 93, 93 plus race fuel or straight race fuel is a much cheaper alternative to running ethanol from a drum, does not require upgraded injectors or fuel pump system and you get substantially better fuel mileage.

Our shop Hellcat with the original factory engine, factory supercharger/TB, full factory exhaust, no 15" conversion etc. has gone 8.7@155 running ID1000's, race fuel and the OST dual fuel pump system. When I want to take it out for a street drive I load my street tune (50 seconds), just stop at any gas station, fill-up with 93 octane and enjoy the day.

If I were to spend the additional $3000+ to upgrade injectors and fuel pumps to run my car on ethanol it is unlikely I would gain any ET or MPH and I would definitely loose fuel mileage for daily driving.

The major benefit of ethanol is that you have a "wider" tuning window which allows for more flexibility in fueling and timing due primarily to the cooler burning in the combustion chamber.

With all of that being said we do both Flex tunes as well as straight E85 tunes for our customers since this is a very common request.

 

[jonx96]

I think most folks know my take on running ethanol in any configuration vs. 93+ race fuel or straight race fuel. I also know this will cause some backlash but I will put my opinion out there.

First and most important I would never race on a Flex tune. Since I primarily race and drive my car hard this is not an option I can recommend for race applications.

E85 from a drum is a great alternative to race fuel if you can afford the extra cost of fuel system upgrades (injectors and pumps).
E85 in a drum is as expensive as race fuel in a drum.
Ethanol from the pump is questionable and should always be tested.
Ethanol fuel mileage for daily driving is horrible.
If you do not have ethanol readily available you may be driving further to fill up burning even more fuel.
Ethanol at the pump marked "E85" is only required to be E50 in many areas and the remaining 15-50% of non-ethanol is NOT required to be gasoline - it just has to be something that burns like gasoline. That does not give me a warm and fuzzy feeling.

Running 93, 93 plus race fuel or straight race fuel is a much cheaper alternative to running ethanol from a drum, does not require upgraded injectors or fuel pump system and you get substantially better fuel mileage.

Our shop Hellcat with the original factory engine, factory supercharger/TB, full factory exhaust, no 15" conversion etc. has gone 8.7@155 running ID1000's, race fuel and the OST dual fuel pump system. When I want to take it out for a street drive I load my street tune (50 seconds), just stop at any gas station, fill-up with 93 octane and enjoy the day.

If I were to spend the additional $3000+ to upgrade injectors and fuel pumps to run my car on ethanol it is unlikely I would gain any ET or MPH and I would definitely loose fuel mileage for daily driving.

The major benefit of ethanol is that you have a "wider" tuning window which allows for more flexibility in fueling and timing due primarily to the cooler burning in the combustion chamber.

With all of that being said we do both Flex tunes as well as straight E85 tunes for our customers since this is a very common request.

Out of curiosity your shop car is that a stock 8 speed as well?

 

[vortecd]

I think most folks know my take on running ethanol in any configuration vs. 93+ race fuel or straight race fuel. I also know this will cause some backlash but I will put my opinion out there.

First and most important I would never race on a Flex tune. Since I primarily race and drive my car hard this is not an option I can recommend for race applications.

E85 from a drum is a great alternative to race fuel if you can afford the extra cost of fuel system upgrades (injectors and pumps).
E85 in a drum is as expensive as race fuel in a drum.
Ethanol from the pump is questionable and should always be tested.
Ethanol fuel mileage for daily driving is horrible.
If you do not have ethanol readily available you may be driving further to fill up burning even more fuel.
Ethanol at the pump marked "E85" is only required to be E50 in many areas and the remaining 15-50% of non-ethanol is NOT required to be gasoline - it just has to be something that burns like gasoline. That does not give me a warm and fuzzy feeling.

Running 93, 93 plus race fuel or straight race fuel is a much cheaper alternative to running ethanol from a drum, does not require upgraded injectors or fuel pump system and you get substantially better fuel mileage.

Our shop Hellcat with the original factory engine, factory supercharger/TB, full factory exhaust, no 15" conversion etc. has gone 8.7@155 running ID1000's, race fuel and the OST dual fuel pump system. When I want to take it out for a street drive I load my street tune (50 seconds), just stop at any gas station, fill-up with 93 octane and enjoy the day.

If I were to spend the additional $3000+ to upgrade injectors and fuel pumps to run my car on ethanol it is unlikely I would gain any ET or MPH and I would definitely loose fuel mileage for daily driving.

The major benefit of ethanol is that you have a "wider" tuning window which allows for more flexibility in fueling and timing due primarily to the cooler burning in the combustion chamber.

With all of that being said we do both Flex tunes as well as straight E85 tunes for our customers since this is a very common request.

Think it comes down to what works best for you. For me it makes more sense to run e85 all the time. I daily drive my car and have e85 all around me but fill up at the same station 95% of the time. With e85 being $1.50+ cheaper then 93 it more then makes up for the loss in mileage. I don't have to worry about a drum running out or the cost of that drum (ms109 is over $20 a gallon} out and don't have to pull a lot power out to run 93

 

[DavidKFla]

Think it comes down to what works best for you. For me it makes more sense to run e85 all the time. I daily drive my car and have e85 all around me but fill up at the same station 95% of the time. With e85 being $1.50+ cheaper then 93 it more then makes up for the loss in mileage. I don't have to worry about a drum running out or the cost of that drum (ms109 is over $20 a gallon} out and don't have to pull a lot power out to run 93

At the VP truck it's $100 and the dealer it's $125 - $130 for 5 gallons.

 

[catdad]

Back to the suspension controller. I would recommend disconnecting it before a flash. As you know mine was bricked after a flash but was a ver3 board. My friend has one and it was a ver4 board. He had me flash his tune and we loaded his car for the track. Unloaded his car at the track and the suspension damper error was on. The new in the box controller I received from Diablo was a ver4 so it doesnt make a difference on the board layout.

 

[DGatzby]

Back to the suspension controller. I would recommend disconnecting it before a flash. As you know mine was bricked after a flash but was a ver3 board. My friend has one and it was a ver4 board. He had me flash his tune and we loaded his car for the track. Unloaded his car at the track and the suspension damper error was on. The new in the box controller I received from Diablo was a ver4 so it doesnt make a difference on the board layout.

I 100% agree, they are not telling us everything. The only thing I did different the SECOND time it bricked last year was begin to flash tunes.

 

[ostmike]

Out of curiosity your shop car is that a stock 8 speed as well?

Our street Hellcat is a HP90 modified by SHR.

 

[vortecd]

At the VP truck it's $100 and the dealer it's $125 - $130 for 5 gallons.

So $20+ a gallon like I said

 

[DavidKFla]

So $20+ a gallon like I said

I was confirming your post not arguing.

 

[covidcommander]

ost doesnt make the cables but Im going to assume that its a manufacturer issue? Poor components? User install?

Got 2 from 12v solutions, so far so good

 

[jonx96]

Our street Hellcat is a HP90 modified by SHR.

Nice thats a pretty solid pass!

 

[covidcommander]

A tune for a specific fuel (93 or E85) is not relying on any external variables to determine what fuel the car is actually running. It's more static so less to worry about from a variability perspective.

A flex tune is reading various sensors, injector pulse width, and even the fuel tank level at times to determine when to calculate and how the fuel in
the tank is determined to be what it is.

I've gotten to where I mostly run my straight E85 tune. It works fine for the E85 I get around here which ranges from E70 in the winter to E89 in the summer. I personally like to run a half a tank or so of 93 through the car about once a month just for peace of mind on keeping the fuel system cleaned out. When I wanna do this I run the car down to near empty of E85 and load my flex fuel tune to make the switch to 93 run the 93 out, switch back to E85 and leave the flex tune in until I'm back to around E80. Then I go back to my E85 tune.

My flex fuel tune works just about perfect but I'd never suggest someone race on one etc. I did learn through LOTS of testing that flex fuel tunes are meant for a fuel swap for the most part. Like going from almost empty on 93 to a full tank of E85 or vice versa. Adding a few gallons here or there trying to go back and forth also works, but takes the car longer to figure out. A good compromise might be to get it stabilized around E60 or so to get some fuel mileage if you're gonna drive a lot and still want a decent octane in the tank.

Smart, like your style 😎

 

[Speedy!]

To Mike's point my only complaint about running E85 around town is the mileage. I don't even care about it that much but I feel like the only thing I can't pass is a fuel station. I average right about 10mpg around town. Out on the highway cruising at 75-80 it's about 15mpg but I'm usually running around town. I've found that mixing in just a little 93 goes a long way to get more miles out of a tank if you run flex fuel. E50 to E60 is still at or above 100 octane.

I've not found the limit on E85 at the track yet. To Mike's point about drum racing E85 and price, I typically run 5gallons of pump E85 (measured to be E85) and 5 gallons of Renegade E85 mixed in. This keeps me at or above 1/2 tank and I know I've got a good fuel in the car and it's a little more economical than two cans of Renegade Race E85. Then I don't feel so bad driving home and burning it up. If I can trailer then I'll drain the fuel from the car, run two cans of Renegade Race E85 and drain what's left at the end of the day and put my original fuel back in the car. It's rare I trailer the car though.

I did find the limit on the Renegade RM109 unleaded race fuel. I'd start to get some STKR above 16 or so degrees of timing and 1700 aircharge. Going to their K16 leaded fuel product eliminated that knock so I know it was real. I just didn't want to run leaded fuel in the car. Crew Chief Greg runs K16 and has for years with no issues though.

 

[ostmike]

Nice thats a pretty solid pass!

Jon, do you have an OES? I'm not on FB much but I saw your profile pic and wasn't sure if your dog is an OES or not?

 

[jonx96]

Jon, do you have an OES? I'm not on FB much but I saw your profile pic and wasn't sure if your dog is an OES or not?

He is a white golden doodle. But he is extremely fluffy depending on how short we decide to cut him

 

[vortecd]

To Mike's point my only complaint about running E85 around town is the mileage. I don't even care about it that much but I feel like the only thing I can't pass is a fuel station. I average right about 10mpg around town. Out on the highway cruising at 75-80 it's about 15mpg but I'm usually running around town. I've found that mixing in just a little 93 goes a long way to get more miles out of a tank if you run flex fuel. E50 to E60 is still at or above 100 octane.

I've not found the limit on E85 at the track yet. To Mike's point about drum racing E85 and price, I typically run 5gallons of pump E85 (measured to be E85) and 5 gallons of Renegade E85 mixed in. This keeps me at or above 1/2 tank and I know I've got a good fuel in the car and it's a little more economical than two cans of Renegade Race E85. Then I don't feel so bad driving home and burning it up. If I can trailer then I'll drain the fuel from the car, run two cans of Renegade Race E85 and drain what's left at the end of the day and put my original fuel back in the car. It's rare I trailer the car though.

I did find the limit on the Renegade RM109 unleaded race fuel. I'd start to get some STKR above 16 or so degrees of timing and 1700 aircharge. Going to their K16 leaded fuel product eliminated that knock so I know it was real. I just didn't want to run leaded fuel in the car. Crew Chief Greg runs K16 and has for years with no issues though.

I believe mpg with cost of fuel it is cheaper to run e85. You are running out faster but costing a lot less on fill up. Guy at work uses a calculator to compare 87 to e85 in his 2011 f150 5.0 and said it was cheaper with e85. 93 is another .80 cents more or so

 

[Speedy!]

I believe mpg with cost of fuel it is cheaper to run e85. You are running out faster but costing a lot less on fill up. Guy at work uses a calculator to compare 87 to e85 in his 2011 f150 5.0 and said it was cheaper with e85. 93 is another .80 cents more or so

Hmmmm, could be. Feels like I'm at the gas station all the time when I run E85 though

Here E85 last fillup was $2.65/gallon. I get 10mpg.

93 was $3.49 and I'd get 15mpg around town.

Maybe a wash other than the time at the pump I spend?

 

[vortecd]

Hmmmm, could be. Feels like I'm at the gas station all the time when I run E85 though

Here E85 last fillup was $2.65/gallon. I get 10mpg.

93 was $3.49 and I'd get 15mpg around town.

Maybe a wash other than the time at the pump I spend?

For you it would be around 25%. Here is a snapshot right now for me e85 $2.59 87 $3.59 93 $4.59. Price difference for e85-93 has been $1.50-$2.00 a gallon. If you say by using 30% more fuel on e85 then the cost would need to be 30% lower im around 43% lower