No need to run the tank dry on either end as stated already. I had 2 or 3 gallons of 93 left in the tank when I switched over with no issues. Frankly, a little E85 mixed in with your pump gas on the pump gas map will have nothing but positive benefits. No issue there in the slightest when going from E85 back to pump.

 

yep 997TT ecu can swing the fuel 25% up or down from target. that will be enough to compensate for some big variances in ethanol content.

also the point a lot of people make that you need 85% content is moot. on my 996tt which had a flexfuel sensor my tune didn't even start decreasing boost or power until content was below 70%/

 

[QUOTE=xbox_fan;4295077]It takes 20sek to flash a 93 map with the AP when I travel to places without E85, cobb really rocks![/yQUOTE]

Yes, it is idem with the Protomotive apply, I can switch files in approx, 20-30' without any internet acces.

 

Good grief, breaking into the 5s with so few mods is insane. Great work PTF and OP, unreal.

 

Congrats on the record. That's moving--any plans to take it to the drag strip?

 

Congrats to the OP, that's an awesome run! To the guys at Champion, how do I get near this time? I've got the CMS IC's along with stage 2 GIAC tune and all the mods to go with it, 100 octane etc. I'm getting tired of losing to a frickin Dodge neon at the track! I can't get below 11's.

 

Do you have a .1 or a .2? Auto or manual?

 

He has an 07 tiptronic car

 

.1 with tip, 60' are at 1.5 consistently, trap is 125. Mods include exhaust, IC, giac, ipd plenum, tb, BMC filter, 104 octane. Can't break 11. :-(

 

Is that a dyno tuned or box tune giac?

 

Box tune, but I have all the exact mods the tune was setup for. Even so, I figured I should be under 11.

 

alot of it has to do with driving... a good datalog and maybe a touch up would help... mind you, E85 is like C16 race gas and you cant beat that... so meanwhile it seems its on pump gas its not... e85 is a massive high octane fuel.... I just like not to use it because of the inconsistency. Last client that switched tuners on me form 93 and 100 octane setup blew it up 2 weeks later on e85. the tune has to be spot and the owner really needs to be responsible.
markski

 

That's why I run pretty low boost regarding my setup when E85, 1,5/55bar in despite E85 and my engine could hold 2Bar.
"better safe than sorry"...

Anyway, out off hijacking, this time is outstanding, contrats

 

E85 is indeed a wonderful fuel. We've been tuning cars all over the US and Europe on pump E85. We've had people testing and reporting E85 quality to us over the years. Lowest we have ever seen it go is E70 (70% ethanol, 30% gasoline) levels in case of "winter blends" and we've seen it go as high as E90. In warmer climates its concentration really doesn't vary much at all especially E85 at top tier gas stations.

Countless dyno sessions, road course/drag tunes, competition racing, we've learned that octane differences between E70, E85 and E90 are quite negligible when it comes to tuning for power. Great tuners will never tune any car to the ragged edge of what octane will provide as that last 5-10hp never justifies the risk involved and is simply a dyno number.

E85 should never be run on any gasoline based tune (93 or 100). E85 requires roughly 30% more volume than gasoline at the same power levels. If one fills up with E85 and decides to run a gasoline tune (especially a 100 octane one that creates has a higher demand on the fuel system vs. a 93 octane while running considerably more aggressive ignition timing and/or boost) the DME and the gasoline tune flashed on it will not be able to supply enough fuel via its fuel trims even if all the hardware (pump/injectors) supports it. It gets even worse if the fuel system hardware doesn't have the capacity to support the fuel volume demand E85 imposes on the fuel system, dropping out fuel pressure and maxing injector duty cycles. Its simply a bad idea running E85 without an appropriate tune and fuel system hardware for it.

When it comes to C16 vs. E85, you can actually throw C16 in the tank and not worry much. O2 sensors won't like it as the fuel is leaded and they won't last long but its a gasoline based fuel and won't impose a fuel demand on the fuel system hardware or tuning like E85.

Cobb AP makes datalogging really easy with no need for a laptop and in our case customers are provided lifetime support on their custom tunes with direct contact to their tuner to discuss, review and adjust their tune on an ongoing basis free of charge provided no significant hardware modifications (e.g. different turbos, built motor). Switching maps from E85 to gasoline (91/93/100) takes about 30 seconds.

 

Ptf- are you working on a fuel system solution for the 997.2 turbos?