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Who is running a 2.75 on pump gas?

parttimer

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#1
Looking to upgrade and shrink my pulley, running a 2.8 and looking to drop down to a 2.75 and re-tune since i've gotten the blower rebuilt and ported. Pump gas is all that is available here so no e85. I already have 1050's installed so not worried about that part. It used to be 2.75 was rumored to be too much for pump 93. This still true? If not, who did your tune?
 

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You can. You will need to have your tuner pull a ton of timing. With Curt's flex tune I can and have run pump gas 93 octane with 24lbs of boost. Most people will not recommend you run that much boost on pump gas. I have been doing this for a few years now.
 
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parttimer

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Thread Starter #3
Ok, flex tuning is a bit out of budget, I'm seeing over 4k for that and a week with no car. Plus shipping the car.
 

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#4
Ok, flex tuning is a bit out of budget, I'm seeing over 4k for that and a week with no car. Plus shipping the car.
Curt does a flex tune through email for less than 1/2 the price of what you're seeing. Unless that changed dramatically in the last couple years?
 

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Tell me more about who is doing flex tuning please. My car is on 2.85, ID1050s etc now with a 93 tune and a 116 tune. I'm Flex tuning the GT350 literally as I type this and I'm getting interested in running a lil corn in the cat. I know I'll need a boost a pump and ID1300 which is what is holding me back at the moment. That and my tuner doesn't do Flex just pure E85.
 

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fubar569

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You will see some bickering back and forth over what exactly is "true flex fuel"

2 big names/groups currently each offer a different style.

Barth, Satera and Hemituner each offer Satera's "true" flex fuel using an innovate Ethanol sensor/gauge wired to the stock ECU. This provides a near instantaneous measurement of E content at the rail before its burnt. It's also a little expensive, can require in-person install only and requires switching out one of the other measured parameters. I will say it can be more accurate and has better response time so if that's really that important to.you...

Then there's Curt. Curt uses "inferred logic" flex tuning. This calculates the ethanol content using the factory wideband sensors and does not use a direct sensor like Satera. This is how Dodge and Ford BOTH do OEM flex fuel for their vehicles. It requires the fuel to be burnt first before a percentage can be derived. Because of this it will not have the response time of the other option...however it still responds to changes relatively fast (couple miles essentially) and has been ran for years by MANY without an issue. Myself included.

Either option will require a BAP or Dual Pump drop-in system and appropriate fuel injectors.

Your base pulley should be one that is compatible with BOTH fuels for maximum performance on pump gas.
 

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#8
@Speedy! did it for awhile and I believe he had great results. That’s 93 octane right?
 

762CAT

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You will see some bickering back and forth over what exactly is "true flex fuel"

2 big names/groups currently each offer a different style.

Barth, Satera and Hemituner each offer Satera's "true" flex fuel using an innovate Ethanol sensor/gauge wired to the stock ECU. This provides a near instantaneous measurement of E content at the rail before its burnt. It's also a little expensive, can require in-person install only and requires switching out one of the other measured parameters. I will say it can be more accurate and has better response time so if that's really that important to.you...

Then there's Curt. Curt uses "inferred logic" flex tuning. This calculates the ethanol content using the factory wideband sensors and does not use a direct sensor like Satera. This is how Dodge and Ford BOTH do OEM flex fuel for their vehicles. It requires the fuel to be burnt first before a percentage can be derived. Because of this it will not have the response time of the other option...however it still responds to changes relatively fast (couple miles essentially) and has been ran for years by MANY without an issue. Myself included.

Either option will require a BAP or Dual Pump drop-in system and appropriate fuel injectors.

Your base pulley should be one that is compatible with BOTH fuels for maximum performance on pump gas.
Thats great input thanks!! Ya the GT350 Flextune is operating of inferred logic as you stated. I'm pretty good with that. My car (hellcat) ran 10.1 @ 136 in 1500 DA with a lot left in the 116 tune. Got a revision and some GFORCE axles....then COVID shut everything down. Whomp whomp. I'm confident I can pull a high 9 on the setup. On 93 same day it ran 10.5. It's very streetable on the 93 tune but I'd love to have just a lil more available by throwing some Corn on top of it for those occasions when playing with friends. Pure E85 not an option where I live. I'll be storing a 55 gallon drum as is. A lil extra at 1.39 a gallon is certainly more palatable than 85 a pail for 116.

Ideally I'd keep the 116 tune for the track and run Flex on the street with out changing the pulley. I'm very happy with a high 9 second car. The spark in interest for Flex stems partly from getting into it with the 350 and partly from an acquaintances boosted Honda on the corn lol. My car is faster than a redeye on the street tune and anything else I've come across but that lil Honda was neck and neck. On 116 I'd put a bus length on him with Flex I would to. PROBLEM is I'll have to invest even more to do it......... Race car problems. LOL.

EDIT: I guess I should add that 10.5 was a shake down pass with a terrible 60ft. Squeezing the 93 out of it before I put in the sauce. seem to recall a high 1.6 or even 1.7 i'd have to go back and look
 
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Speedy!

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Did someone say 2.75 on 93? LOL Man that was a huge debate last year. Yep, I actually run the 2.72 Hellraiser on 93. @ostmike handles tuning for me but @curt_dusterhofftuning is excellent as well as the others mentioned. You do have to adjust the timing a bit the more boost you run, but it's not a huge difference from a 2.85. One thing to realize is that WITHOUT better than 93 fuel you're probably going to make the same power as a 2.85 due to heat, etc. Once you get better fuel in there, that changes and the 2.75 will give you more.

You do have to be more careful going below a 2.85 on 93 as some of the safety margin for bad gas is removed. Keeping knock sensors close to stock is also advisable.

Mike taught me how to do a lot of the tuning myself, and what to look for, so I started really digging in last summer. What I found is that on summer Shell brand 93 octane things were splendid. Once the temps dropped in the fall and the stations switched over to winter blend fuel the same Shell 93 was seeing 1.5 ish of STKR in a place or two at max boost. I was surprised to see this as I thought in cooler temps I'd be less prone to STKR, but didn't consider the fuel change. 1.5deg STKR isn't a huge deal but I did adjust my tune so I never see more than .5 to keep that safety margin.

I've now started playing with Flex Fuel with Mike from OST tuning (inferred version) with great results. I have E85 all over the place that tests VERY well so I'm lucky there. Here's my thread on that with lots of testing details: https://www.hellcatforum.org/threads/those-running-flex-fuel-get-in-here.5711/

We're almost finished there and I'm on dual drop in pumps and the old ID1000 injectors.
 

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#11
I believe you will find out the E85 will run as fast minimum, most see faster . Plus as you stated the price per gallon is MUCH cheaper. BUT, you also use a 1/3 more fuel compared to Gasoline. My opinion is to get the flex tune and see for yourself, you won't be sorry.
 

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@Speedy! - Have you seen similar results in the summer when the temps drop as you did on winter blend fuel?

I don't know what you're able to see, but I imagine a drop in ambient temps would be more pronounced than a degradation of fuel quality because of a winter blend. Can you tell the difference in the logs? One would be cold air which would make it more lean, not sure what winter blend fuel looks like other than some knock.
 

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@Speedy! - Have you seen similar results in the summer when the temps drop as you did on winter blend fuel?

I don't know what you're able to see, but I imagine a drop in ambient temps would be more pronounced than a degradation of fuel quality because of a winter blend. Can you tell the difference in the logs? One would be cold air which would make it more lean, not sure what winter blend fuel looks like other than some knock.
Not sure what you're asking.
 
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parttimer

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Thread Starter #14
Did someone say 2.75 on 93? LOL Man that was a huge debate last year. Yep, I actually run the 2.72 Hellraiser on 93. @ostmike handles tuning for me but @curt_dusterhofftuning is excellent as well as the others mentioned. You do have to adjust the timing a bit the more boost you run, but it's not a huge difference from a 2.85. One thing to realize is that WITHOUT better than 93 fuel you're probably going to make the same power as a 2.85 due to heat, etc. Once you get better fuel in there, that changes and the 2.75 will give you more.

You do have to be more careful going below a 2.85 on 93 as some of the safety margin for bad gas is removed. Keeping knock sensors close to stock is also advisable.

Mike taught me how to do a lot of the tuning myself, and what to look for, so I started really digging in last summer. What I found is that on summer Shell brand 93 octane things were splendid. Once the temps dropped in the fall and the stations switched over to winter blend fuel the same Shell 93 was seeing 1.5 ish of STKR in a place or two at max boost. I was surprised to see this as I thought in cooler temps I'd be less prone to STKR, but didn't consider the fuel change. 1.5deg STKR isn't a huge deal but I did adjust my tune so I never see more than .5 to keep that safety margin.

I've now started playing with Flex Fuel with Mike from OST tuning (inferred version) with great results. I have E85 all over the place that tests VERY well so I'm lucky there. Here's my thread on that with lots of testing details: https://www.hellcatforum.org/threads/those-running-flex-fuel-get-in-here.5711/

We're almost finished there and I'm on dual drop in pumps and the old ID1000 injectors.

How are you getting by on 1050's when everyone says you need 1300's for e85?
 

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#15
1050's at higher rail pressure are 1200's...talking about difference between HC and RE/Demon pressures.
 

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#16
1300 gives you additional headroom for more power down the road.

Realistically...you want to run as small of an injector for your anticipated power that gives you no more than 85% or so DC under full power.

Too large of an injector for a given application could conceivably affect idle and part throttle performance as the injector becomes unstable at such small pulse widths.

And yes...fuel system behind those injectors has a substantial effect...
 

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#17
Mine aren't 1050s just for clarity. They are ID1000s. ID1050s would have about 5-7% more overhead then my 1000s.

It's all about the pumps behind them I think. The dual pumps gave me quite a bit of overhead on my fuel system at my boost level. I've tested the car in 50 deg air and was right around 85% max DC right at 6500 RPM and 1800+ aircharge (17.5+psi).

For clarity, I was maxing out the fuel pump and losing fuel pressure on the stock fuel system, so I added the dual drop in system, and logs showed I then had A LOT of fuel system overhead. All that is detailed in my Flex Fuel thread.
 

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Mine aren't 1050s just for clarity. They are ID1000s. ID1050s would have about 5-7% more overhead then my 1000s.

It's all about the pumps behind them I think. The dual pumps gave me quite a bit of overhead on my fuel system at my boost level. I've tested the car in 50 deg air and was right around 85% max DC right at 6500 RPM and 1800+ aircharge (17.5+psi).

For clarity, I was maxing out the fuel pump and losing fuel pressure on the stock fuel system, so I added the dual drop in system, and logs showed I then had A LOT of fuel system overhead. All that is detailed in my Flex Fuel thread.
So you think if I kept a 2.85 added the dual pumps I'd be good with ID1000 or 1050s? I have one or the other I forget which. Have to check. Not having to switch to 1300 would save 1800 plus install so well over 2K. That'd be nice. I'm making about 16PSI of boost. Car also has a new short block with all forged internals so I could really crank the power up if I wanted. That being said I don't wanna skimp just to save a couple grand and risk anything.
 

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#19
I'm doing just fine on mine.
 
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parttimer

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Thread Starter #20
Man, i'd really like to find someone to tune my car then with the 1050's cuz yeah, ID 1300 I can get for $1400 but still need the pump, another $1500. I'd rather just add the pump!
You are running a 2.85 with E85 on yours? Not a 2.75 now?
 
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