NIce data but I've gone cross-eyed trying to read it. It seems like TK fixed you up nicely. Too bad the number of e85 stations in CA is few and far between. Such a pity for a self-proclaimed green state.

 

I was expecting to lose mpg, but I am seeing no lose in mpg.

The anecdotal evidence suggests no change in mpg , I was averaging 15 mpg on 93 Oct and 15 mpg on E85
derived this number from dividing miles driven by gallons added (120/8=15). My on board computer shows
15.2 mpg on E85 and showed 15.2 mpg on 93 Oct.

I have run this by a couple of people and they suggested a properly tuned forced induction should not loose mpg
compared to gasoline, different matter entirely on normally aspirated.

In my case went from $2.95 a gallon 93 to $2.21 a gallon E85 with no loss in mpg, more dollars in my pockets.
One more reason to consider switching to E85.

 

i hear ya , i have a gas station right down the street from me and has e85 but then theres no other gas station in town.....

 

You should then switch to E85, see my earlier post on being able to run 93 gas on E85 tune. You can always flash to 93 tune from E85 Tune is minutes, if you need to.

 

Hi Dave,

Could you please explain this? 80% of what? And what does the O2 sensor run normally? I am a noob so please be as detailed as possible.

Venk.,

Thanks for the very interesting thread (and Keith's too). Do I understand it correctly, that to use E85:
a. You must change to the 5 Bar FPR, and
b. This is the *only* hardware change that is necessary?

 

Can

a. You must change to the 5 Bar FPR

Not a must, this I was willing to do as it was easy enough.
Gives more head room on fueling.

b. This is the *only* hardware change that is necessary?

I only changed the FPR, nothing else to run E85
You should try it, I know gas sucks in cal.

 

Very nice to see such great results. I was alittle disappointed when I read about another posters minimal gains with meth injection. From what i have seen most of the country only has e85 3 months of the year. So My question is... How will the can react to e70? Is e70 still better than let's say 100 octane?

 

Hi Can, Wideband O2 sensors can measure ~7-20:1 afr fairly accurately. If you're on e85, you're tuned for ~9.8 afr (CA pump gas ~14.0) which simply means more fuel is required for the same amount of air for a complete combustion. Now you dump pump gas into your tank. The e85 tune will attemt to deliver the same amount of (e85) fuel as it normally does but now there is pump gas in your tank. As a result you will be running very rich. If you go beyond the sensors working range or the hardware limitations on the vehicle you will run into problems. This explanation is less than technically detailed (I know) but I'll look forward to reading your monograph on the subject matter when you have it ready. Dave

 

Yep, you'd still be better off running e70, cheaper and higher octane. 0.7x113+0.3x87=105 for e70. This assumes worse case scenario where ethanol was blended with 87 pump.

 

Nice!

 

Venk.,

Thanks. As best I could read (I have no experience), the 5Bar FPR is needed in some high power 997 TT's, otherwise timing would be pulled and boost reduced as AFR becomes too lean?
So am I correct in assuming that an E85 tune inherently demands more fuel because its ideal AFR is lower, 10 versus 12 for gas? And maybe this is why the 5bar FPR is actually necessary for *any* E85 tune?
If and when you use 93 gas, will the 5bar FPR behave just like the stock FPR?

Thanks again for sharing the information. Very interesting indeed.

 

Got it. Thanks Dave. I've been lurking and learning from your posts.

BTW and OT: Am I understanding it right that it seems all Protomtive customers get more a less a custom tune based on data logging? I mean the process seems to be that Todd would send a basic tune, customer data logs, sends back data, then Todd would revise the tune and sends it back for trial, and so on? If so, it's really fantastic, and quite amazing.

 

My protomotive tune is spot on, didn't need any adjustments at all (I did send my logs to him) . You have to let Todd know what you are looking for in the tune, and he will build them in for ya. Then he will send you a few files to play with first, and see which file your car likes the best. (My car loves the ms109 normal boost file btw, still got the high boost one to try out). Some file has lower boost, some higher, some has break boost ect....

 

Can

You are correct a few tuners do require a 5 Bar FPR for their higher HP tunes, E85 does require more fuel and certainly a 5 Bar FPR helps.

Todd provides a 93 Oct tune with 5 Bar FPR (although I am told the ECU will adapt) as part of the package to take into account for the higher fuel pressure.

Todd is only a phone call away very helpful/knowledgeable, call him.

 

One thing I like about Todd... He doesnt have to lurk the forums and prey on everyone who makes a thread about a flash. He for sure isnt pulling customers in from his website. Word of mouth... All his Customers speak very highly of him!