early85944

A post on the 944 board brought this topic up. Just wondering if anyone has tried running E85 mixed with gas in their 930?

nathanUK '81 930 G50

Just to say, you'd need to check your AFR's if you did this.

early85944

Yes I know it would require some tuning and you would have to maitain the same mix in your tank to avoid upsetting the afr's

turbobrat930

search this topic...there have been a few discussions on this already... I would not mix the two...as the E85 tends to soak up water, and in the long run, will not be good. Plus, you need to adjust mixtures, as the E85 has a lower BTU rating ( in other words, you must use more of it to get the same HP). IIRC, using straight E85...you need about 40 to 45 % more fuel to acheive the same HP.

Now for a turbo motor running a stand alone programmable EFi system... E85 is a no brainer!! 106 octane rating or there abouts... cooler temps, etc.. makes much more sense... But for a CIS car... I think the general concenus was not to do it....

early85944

I am not talking about 100% E85 but mor along the lines of 20 or 30% added to premium gas

turbobrat930

Yes, I unerstood that you did not mean 100% E85. But why would you risk it?? We all know that the stock CIS system is good in a stock enviorment, and it does not take much to push it to its limits... IE aftermarket turbo, exhaust, 1 bar spring, etc. Once at that threshhold, under boost, the stock CIS system is straining to provide enough fuel to sustain good A/F ratios. Then, adding the 20 to 30% of E85, which would further lean the mixture as stated in my above post, it has a a lower BTU rating.

I just dont think I would risk it. Maybe on a VW rabbit motor that is not anywhere near as expensive to rebuild as the 930. These things are just so darn expensive. and one question for ya, What are the reasons for you to consider mixing E85 anyway? Is it because it costs less per gallon? More octane? Just wondering.. not trying to me argumentitive, just as curious as you are. I will be running straight E85 in my car, but also have the programmable ECU and bigger fuel injectors to run it. I know that I will have to have two fuel maps as well...one for E85 and one for premium fuel.

early85944

For the octane benefits. I have plenty of fuel flow, even on boost so I wasnt worried about stressing the system to much. At a 20% blend I would have to add 10% more fuel which does not seem impossible

early85944

turbobrat this is a curiosity post more than anything. I really dont feel like retuning my car since it is running great right now

turbobrat930

Gotcha... well you have my curiousity peeked as well...hopefully someone who is running a blend will post up..LOL

nathanUK '81 930 G50

I think you've covered it all now. Why bother carrying extra weight I think the Dr. would turn in his grave...

early85944

I still want to know if anyone has tried it though