Do you have to adjust you injection timing in order to run B20? I just read that you need to adjust timing 2to3 degrees if you run BD (I think they meant if you're running B100).

Does it need advanced or retarded? With the Dmax, this would have to be done with a programmer, since all injection is electronically controlled.

This thread could get interesting.

Some people say increased Cetane makes the fuel burn easyer while others say it makes the fuel resist burning.

Some decribe cetane identically to octane. More is better, and it makes the fuel resist combustion.

Some additive comapnys specifically warn you not to use diesel additives in gas, because it will REDUCE OCTANE?

So I think it all comes down to Cetane and what an increase in cetane really does to the burn time/characteristics.

B100 has the potential of 15 cetane points higher than #2. Depending on compared grades. Meaning the absoute best biodiesel has a cetane rating of 15 higher than your standard UPUMPIT junk #2 diesel.

On average B100 is 6-8 points higher in the cetane department.

Ive always heard that cetane is the measurement of the resistability of diesel fuel to combust...............

But if more cetane is better, seems like it would necessitate a change in timing. Maybe these modern TD's can do this by themselves.?

But to answer the question: No need for timing adjustment, IMO.

I read about the timing issue on www.journeytoforever.org. I tried to paste the exact link to the article but their website is down.

It claims that you have to retard your timing by 2to3 degrees. If you don't BD will make your vehicles idle faster and run hotter? I just fueled up with my first tank of B20 yesterday and have yet to experiece a change in idling or temp.

Has anyone noticed a change in idle speed or temp?

I used the Quadzilla economy tune, 30HP. It is rumored to be timing only. I would assume advanced timing. This is opposite of the journey to forever article.
I had no performance issues. Mind you the stock guages are hard to pinpoint.

Also if journy to forever is recomending retarding the timing, that would suggest the higher cetane bio burns easyer.

Bronco,

That is what I understood about pure bio...is that due to its oxygen content it will burn easier..more efficient. That is why people do not report a straight 10-11% drop in mpg...which is about the difference in Btu for the two fuels(D#2 vs B100)...but rather a lower say 7% drop.

The other issue about timing that I remember...is that it would help reducing Nox if it was delayed by several degrees. Would this not imply that the average temperature of the combustion process is being reduced from the baseline timing?

http://www.buyduralt.com/cetane.html

This is some good reading in regards to cetane and diesel fuel in general.

To answer the original question in this thread, The Dmax computer does a real good job of optimizing engine performance. So no adjustment ir REQUIRED. With careful testing I am sure some mapping could be changed to maximize bioperformance.

Ron I agree, bio contains more O2 and therefore burns easyer. This coinsides with the higher cetane rating.

centane and octane work backwards from one another. Octane, the higher the number the slower it burns in return controls detonation. Centane on the other hand the higher the number the easier it will be to ignite. If you do a search on high performance diesel fuel you will find that most of the high end pull tractor will use a fuel of roughly 63 centane and the specific gravity is higher. The heavier the fuel the more can be put into the injector at that point of time. I keep a hydrometer and a beaker in the truck to check the API rating of the fuel that I am getting at the pump. People just look at me like I am making crack at the gas station.:eek:

So if you are testing API, who's pump gas will give us the best bang for the buck?

Probally why so much difference in fuel milage, some people fuel just has a higher API.

Gas and fuel here comes out of Knoxville, TN. As far as on highway pump fuel the most dense fuel I find goes between BP and Speedway which is part of Ashland oil. Marathon also belongs to that group but there centane is rated at 40 rather than 45 like most. The fuel would have to be checked from one part of the country to another, ie. different refineres, etc. The densest fuel that I can find is off-road "red fuel". It makes much better power. But what works here may not work else where. The main thing is to keep fuel as cool as possible. The cooler it is the dense it will be.

With off road fuel being denser can make up to 2 psi difference on boost.