Jump to content
LegacyGT.com

Got an e85 tune


johnAWD

Recommended Posts

  • Replies 63
  • Created
  • Last Reply
There honestly isn't much HP to gain from E85. WHP on the vf40 can be just about maxed out on pump gas. E85 would mostly shine down low on the torque side of things.

 

I disagree. You can run a LOT more timing and a higher lambda when E85. That's with the VF40 pushing the same amount of air. I have seen acceleration plots to prove it.

 

The only time where I saw hp wasn't increased was cars tuned on stock injectors. In this case, the tuner turned down boost at high rpm to prevent the car from leaning out.

Link to comment
Share on other sites

You can run a LOT more timing and a higher lambda when E85.

 

I agree. Here is a timing plot from 3 weeks ago on 91 octane vs. a timing plot from this morning on E85. Same car, and both runs at 70F FWIW.

 

http://www.beeez.com/lgt/e85timing.jpg

My '05 LGT

My '07 Supercharged Shelby

Link to comment
Share on other sites

The lambda (excuse the lumpiness of my current E85 tune... I'm still working on smoothing it out) can definitely go leaner too. The dashed line is what I am targeting with E85, btw (that's around 12.3:1 gasoline equivalent).

 

http://www.beeez.com/lgt/e85afr.jpg

My '05 LGT

My '07 Supercharged Shelby

Link to comment
Share on other sites

I disagree. You can run a LOT more timing and a higher lambda when E85. That's with the VF40 pushing the same amount of air. I have seen acceleration plots to prove it.

 

The only time where I saw hp wasn't increased was cars tuned on stock injectors. In this case, the tuner turned down boost at high rpm to prevent the car from leaning out.

Right but in comparison to 100oct vs pump there is close to nill whp gained. You solely have to depend on the timing as boost where peak HP is made is dropping off hard. I stand by my statement. :)

Link to comment
Share on other sites

I do think the torque gain is more significant than the hp gain. If I had to estimate my gains on my stage 2 setup, I'd say I gained ~15whp and ~30tq.

This is close to what I would estimate on a TMIC as well, with a FMIC I can push the envelope a bit more. I usually see about a 7-8whp increase and a 30-35wtq with 100oct vs pump CA91.

Link to comment
Share on other sites

I agree. Here is a timing plot from 3 weeks ago on 91 octane vs. a timing plot from this morning on E85. Same car, and both runs at 70F FWIW.

 

http://www.beeez.com/lgt/e85timing.jpg

This is a good example of what I was saying, look how much timing can be ran in the midrange (Torque) but look at how small of an increase it is at 5200+rpms (Horsepower). Boost will be EXACTLY the same above 5K rpms.

Link to comment
Share on other sites

You are forgetting

 

1. faster flame speed

2. more moles exhaust gas per mole of air intake

3. Legend just started tuning his car.

 

And your statement was PUMP gas.

 

WHP on the vf40 can be just about maxed out on pump gas.

 

Pump gas is not race gas.

 

My wager is 15 to 20 whp more on E85 vs pump gas. This is at 5000 feet too so the percent increase is quite high. At sealevel, it will be more.

Link to comment
Share on other sites

You are forgetting

 

1. faster flame speed

2. more moles exhaust gas per mole of air intake

3. Legend just started tuning his car.

 

And your statement was PUMP gas.

 

 

 

Pump gas is not race gas.

 

My wager is 15 to 20 whp more on E85 vs pump gas. This is at 5000 feet too so the percent increase is quite high. At sealevel, it will be more.

I stand by that as well I was refering to CA91 I was using 100 oct as a comparison to E85. You DEFINATELY would not see 20whp unless your pump gas tune was leaving tons on the table.

Link to comment
Share on other sites

It's true my 91oct was much more of a finished tune than my current E85 work in progress. When I am finished I will post the details. The only reason I am running the timing I am now on E85 is because that's what my research has led me to as a starting point. I've been able to easily add as much timing as I want and I haven't knocked.

 

The only reason I've only added a degree or two in the higher rpms is because I knew I could quite easily. I don't know where the threshold is where increased timing will result in lesser performance or detonation. On my 91oct tune, I was right at that threshold. I still have room to play... it will likely take me a while to set this tune optimally for E85. I wish one of you tuning gurus had E85 available - I'd like to see more of what's happening on other LGT's.

My '05 LGT

My '07 Supercharged Shelby

Link to comment
Share on other sites

I stand by that as well I was refering to CA91 I was using 100 oct as a comparison to E85. You DEFINATELY would not see 20whp unless your pump gas tune was leaving tons on the table.

 

You're missing the point. There is more to E85 than higher octane rating. Did you see Legend's acceleration plot where he did nothing other than scale his injectors.

 

http://www.legacygt.com/forums/showthread.php?t=91492

 

I don't believe he had even increased timing or changed lambda but he was still accelerating a lot more.

Link to comment
Share on other sites

You're missing the point. There is more to E85 than higher octane rating. Did you see Legend's acceleration plot where he did nothing other than scale his injectors.

 

http://www.legacygt.com/forums/showthread.php?t=91492

 

I don't believe he had even increased timing or changed lambda but he was still accelerating a lot more.

I seen that read about it understand the flame speed and everything. The point is the characteristics are similar to that of high octane petroleum. On the stock turbo there are two mechanical limits which can be reached farely easy, that is timing and boost. Boost can be maxed out in the higher rpms on pump gas. Timing cannot, however MBT can be reached on race gas along with a leaner fuel mixture. The difference between 100oct and E85 would be energy which would I feel be a negible difference.

Therfore I can accurately make a good comparison of the two (91oct vs E85/100oct) I can pull about 285-295whp out of straight CA91 and 290-300whp out of 100oct(according to Airboy's spreadsheet) on a FULLY MAXED out vf40. However the torque numbers greatly differ.... ;)

Link to comment
Share on other sites

I seen that read about it understand the flame speed and everything. The point is the characteristics are similar to that of high octane petroleum. On the stock turbo there are two mechanical limits which can be reached farely easy, that is timing and boost. Boost can be maxed out in the higher rpms on pump gas. Timing cannot, however MBT can be reached on race gas along with a leaner fuel mixture. The difference between 100oct and E85 would be energy which would I feel be a negible difference.

Therfore I can accurately make a good comparison of the two (91oct vs E85/100oct) I can pull about 285-295whp out of straight CA91 and 290-300whp out of 100oct(according to Airboy's spreadsheet) on a FULLY MAXED out vf40. However the torque numbers greatly differ.... ;)

 

 

My point is that they are not the same.

 

If you ran 100 octane race gas with the same timing and lambda as you 91 tune would you get an increase in acceleration?

 

Legend showed that E85 will increase acceleration.

Link to comment
Share on other sites

My point is that they are not the same.

Yeah I know there not the same, this can be seen clearly in dyno charts. Lower psi numbers acheiving bigger power number than gas. However I think it is close enough to make a comparison. I think the vf40 is just to small and inefficient for it to make a great difference, especially on a vf40 setup which is already maxed out. Just take a glance at the PDX thread and look at the numbers on pump vs E85 on a basic stg 2 setup (although even on stock injectors).

Link to comment
Share on other sites

The last 2 tanks of 91 I burned after the upgrade were 24.0 and 25.2 mpg respectively. On my first full tank of e85 I got 20.3 mpg, and I'm pretty pleased with it.

 

2nd tank of e85 - 16 mpg. My foot is just a bit too heavy. :)

Link to comment
Share on other sites

scroll down to the first graph?

 

view

profit

...?

Okay???

I see a 31TQ gain (which I stated) and a 15whp gain on a basic stg 2 setup which I also stated would see these numbers. That is not nearly a maxed out vf40. I even stated to use that car as reference for it not being much to gain on the stock turbo, horsepower wise.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.




×
×
  • Create New...

Important Information

Terms of Use