Blue Thunder said:
Excellent info hohn. Just what I was looking for.
A couple of questions:
2) Why no propane?? Doesn't it work with the fuel to help the engine run cooler?
4) Sorry, who's Don M. ?
7) I can't agree. I've got the 'full-boogie auto' and there is just too much space in between gears. I even geared down to 4. 30's (with 36" tires) so that I could have 4 gears from 0-70 instead of 3. I am leaning heavy towards the G56, just wish more was known about them.
You may need a little looser converter to help with the gearing gaps. But it's a band-aid, imo.
I don't like propane because it really ought to have a radically different calibration to perform optimally. When you start hitting propane, you need to have the timing retarded. The more propane, the more timing retard you need.
But this won't happen because the engine managment system can't "see" the propane being introduced, and even if it did, it wouldn't know to retard timing as a result.
Propane tends to speed up combustion-- which is a good thing, but ONLY when timing is adjusted properly. Now, small quantities if propane will only have a mild effect as far as creating the effect of advanced timing. This will probably help MPG, give a little more power and still be safe.
But the line separating "safe" from "too much" is far too thin for my liking. Overdoing the propane ends up simulating radically advanced timing (thus the need for the timing retard when using it).
The second thing is timing relative to engine load. In general, more load=less timing. So, now you go and add propane (which adds timing) while towing (which needs LESS timing), and it's a step in the wrong direction.
Possible consequences of this include a blown HG or worse in rare cases.
Nitrous and water/meth are much safer by comparison.
Nitrous makes available more oxygen for combustion. But IT IS NOT A FUEL. Therefore, the overall effect on timing is much less.
A simple analogy would be matches. How fast can you light matches? How fast can you make them burn?
Let's compare a fixed amount of ECM fueling to a book of matches-- i. e. a set amount of fuel.
Adding nitrous is much like lighting the book of matches in 2 places instead of one. Overall the book of matches will burn faster.
Adding water/meth is like lighting damp matches-- they burn, but slower and cooler.
Adding Propane is like adding another book of matches AND lighting them each in a couple places.
The autoignition temperature of Propane is 878°.
The autoignition temperature of Methanol is 851°
But that's for PURE methanol. When diluted with water, the overall effect in an internal combustion engine is milder for Meth than for C3H8.
Propane is fine, but I'd keep in <40hp to be safe. If you want/need more than 40hp boost, look elsewhere.
**JMO-- I'm no expert and this is just theory I have, so it may be wrong. Follow at your own peril**
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