Here are tonights dyno runs. the first is on straight alky. The next is 10% NM then 20%NM then 30% NM

Notice we are making slightly more hp on straight Alky with the HP4's than we did with the 109's w/ 20%NM. Hmmmm.

Notice the first 10% increased hp by about 11 hp. The second 10% only added about 5 hp and the third 10% also only added about 5 hp.

I wonder if the extreme timing advance isn't responsible for the motor posting weak numbers on straight Alky. I think the timing advance is almost optimal for 10% NM........that is why we see the biggest gain when adding the first 10% of NM. We are getting more power by adding more but the incremental gains are cut in half. We might need more advance to optimize running more than 10% NM. Tonight is a bit colder than last night, that might account for the 2 hp loss at 20% from what we ran last night.

The other thing that might be holding the 20% and 30% back is lack of sufficient fuel delivery. We might be looking at a loss of carburator efficiency past 10% NM also...............Interesting stuff, huh?

Dyno Runs

 

Looks good. Good backup report. Maybe the 109s cant handle the timing. Might be the prob with them. I dont know. I will see how the lectron handles alky, The true test for me this weekend is to get it dialed in at around 50 degrees. With this cold front in town, I feel that if I can get 10 more ponies on alky in this weather condition I will be sitting pretty at 75 degrees. fun, fun, fun...



Hey DSNUT, Ill bet you feel like a punk in prison with these findings!!! LMAO I had to use that line on ya.. Bomber used that one the other day.lol

 

LMAO![img]i/expressions/face-icon-small-happy.gif[/img] I am little more than that! I am going to stick with race gas and add a Boss Noss system for now.

 

I hear super jet sales might be up soon!!!!! LMAO sssssshhhhh[img]i/expressions/face-icon-small-wink.gif[/img]

 

"Looks good. Good backup report. Maybe the 109s cant handle the timing. "

And maybe stock is better than 109's after certain points. Stock cams should always be used as null set to prevent comparisons between a products weak points which may be worse than stock: elevating the compared product unfairly.

 

"LMAO! I am little more than that! I am going to stick with race gas and add a Boss Noss system for now. "

Vendors like that. If you could get same performance out of alkyhol and it runs cooler for the engine why would you want to use something more undependable for your engine? I thought you wanted reliability with performance.

 

2 questions- how did you advance the timing? How much did jetting change with 20% NM over alky?

 

Alcohol performs better under the right conditions and not as well under others. Gas is more consistent and the new regulated Boss Noss system seems to be quite safe. I guarentee you it is less of a risk to your motor than trying to find and keep the right balance on NM. Nitromethane has put a lot of motors in the graveyard.

I think gas on NO2 is much more reliable with modern improvements to "NOSS". On the other hand, you have the potential to be lighter running NM than you could ever be running NO2. Lets say these DS's get down to 250 lbs. If you can make comparable hp with NM, you won't have the added weight of a NO2 system..........and don't tell me those few pounds don't matter because in the top bracket, the day will come when ounces and 1/4 hp are sought after.

Ron

 

I will answer this only because it is available, I think, if you did the right search but don't try this until you know how to calculate the degrees of timing you are after. The contact on the flywheel is a certain length. The connection is made at the back end of the tab. If you manually shorten that tab from back to front, the more you shorten it, the more advance you will have.............but you will have the advance all the time so you really need to set your motor up for the percentage NM that you want to run which means you will have to run NM to keep from having preignition (remember the slow burn?) on alcohol with the kind of advance numbers we are talking about.

Nitromethane acts like a tremendous oxygenator. The more you run, the more alcohol it pulls through the motor with the air. If you don't have a fuel delivery system that can handle huge amounts of alcohol, you will run lean if you run too much NM and blow your motor up. I would say we double the amount of Alcohol we push through at 20% NM. That is hard to determine for sure though. How about alky at $3.50 per gallon and NM at $40 per gallon then you go through it at roughly 3 to 4 times the rate you use racegas...................

I could buy a Boss Noss system after one season of riding with the money my fuel alone would cost me on this system.

 

nitrous now were talking any tuning ideas there? and as far as a safe system that is interesting, what causes nitrous engines to go is to much heat, from lack of fuel. they have temp gages that you point at the engine and tells the temp, regular run, and nitrous run should not change a lot. if people will do these checks they may have a nitrous system that lasts, maybe a couple of years[img]i/expressions/face-icon-small-smile.gif[/img] then if they will spend the money to install a fuel pressure safety switch they should be fine. well get on that boss noss system i want to see it in action. then we can report boss noss vs. nx [img]i/expressions/face-icon-small-smile.gif[/img] I'll have to find some bigger jets to make up that 20 hp I'm behind on the cams though.[img]i/expressions/face-icon-small-smile.gif[/img]