I have some people ask me about my setup over PM's, so i figured i will do a quick write-up for those, who would want to take a similar route. I also have nothing better to do today
I do not have a dyno sheets and do not expect to do any for a while as my car is not yet finished.
Ok, so for one why E85? Here's what I know about this fuel's benefits:
- Octane rating is around 105, so that allows you to run higher cylinder pressures without knock by simply turning up the boost. I run 28 psi (and did the same when i had my stock 16G 9.8 viii turbo)
- Ethanol burns at a quicker rate than gasoline, which means your pistons spend less time compressing the ever-expanding burning mixture. It should theoretically mean ethanol needs a lesser MBT than gasoline.
- I run more timing with ethanol than i did with gas. While my engine does not like a lot of advance at peak VE, i run up to 21-22 by redline.
- Ethanol has less energy by weight compared with gasoline, but because it has a richer afr (its lambda is 9.7 as opposed to gasoline's 14.7) there's more energy in the combustible mixture.
- It has a higher than gas heat of vaporisation, basically it means it absorbs more heat and therefore leaves the chamber cooler for the intake charge (nothing compares to water in this department though)
- Keeps producing power at richer AFR range than gas. (up to 30% richer than lambda, whereas gasoline starts to fall off at 15%)
The only requirement to run E85 is you need to give your engine more fuel. I'm sure you've heard it needs 30% or so more fuel. Why? Because its stoichiometric ratio is 9.7 as opposed to gas' 14.7
Does it mean that your mileage is gonna suffer just as much? No, at the same boost levels you will need less throttle to go the same distance, because of more energy in the e85 mixture and its quicker burning.
I get around 170 miles out of my tank at 28 psi and i step on it often. What do you get on race gas? Maybe 220?
So, basically to run your stock turbo on E85 you will need a walbro pump and 1000 injectors. You will also need to reprogram your ECU to use more fuel. It's not gonna "learn" to do it automatically. My 1000 injectors are scaled at 609 in ECUFlash and that should work for most people, plug whatever injector latencies your vendor suggests for a given brand of injectors, you can fine tune them later. You will not need new fuel lines, fpr, or rail. All that can be left stock. Timing maps can be left the same, you can fine tune them later. If you have an VIII you will need to rescale your fuel and timing maps' load to at least 300.
TIMING: This fuel burns faster than pump fuel, also by upping boost, you will produce higher cylinder pressures; Those 2 things combined is the reason why you should not expect to run any crazy timing numbers on E85. It will actually look similar to regular pump timing. I for one, run 0-2* at peak and up to 21 at redline on my VIII.
FUEL:
When it comes to green, you will run out of fuel with one pump. If i run over 22 psi after 6000 rpm's, my IDC's go over 100%. So the solution that i am using for now is called boost taper
My boost is controlled through ECU with a GM BCS and while i have 28psi at peak, 25 at 5k, i have to reduce it after 6k to about 21 by redline. So that is part of the reason there's no dynographs. My car is not producing all the power it can. If you have an MBC you will probably get away running 27-28 peak, so long as it tapers to 21-22. The proper solution is a bigger or a dual fuel pump, which i am going to invest in next spring.
For the stock turbo one Walbro pump is enough.
AFR's: most widebands are gasoline cofigured so they will read AFR as lambda multiplied by 14.7. On such a wideband you will want to tune for 11-11.3 There's no need to make it leaner as again it keeps making power down to 0.7 lambda.
The way it is now it makes around 400hp/tq and is an absolute blast to drive! The torque is there right away, and stays there for a long time. So here's my suggestion: E85 coming your way? Switch! Such a setup will allow you to do everything fast:street driving, autoX, track, 1/4 mile.
My car is a VIII with:
Stock long block with exception of HKS 280 cams
20G-LT/Evo Green
Most regular bolt-ons (TBE, LICP, UICP, Ebay FMIC, Cone air filter, DV)
1000cc injectors, one Walbro 255 pump
Boost control with GM BCS
Boost is logged with JDM MAP and ZT-2
List of E85 stations is here
http://e85vehicles.com/e85-stations.htm
Or you can use google maps.
Well here's a DLL dyno sheet from early november, this is on E70 (winter blend of E85) at about 26 to 21.5 psi Waves are a result of imperfect ECU boost tuning and wrong heat range plugs i had in at the time. No correction.
12/05/07 update. Cold Starts: Last night it was 13*F, and my car has been sitting in the driveway for the last couple of weeks, had like a foot of snow on it, the battery was dead. I hooked up some jumper cables to it and it fired right up, no hesitation, no cranking, no nothing - right up!