'86 250R and '86 350X on dyno tonight....

[fyi]

The guys and I had a chance to baseline dyno these two machines tonight after work and the results were surprising.... (at least to us anyway) Both machines had the pulls done in third in an effort to save the engines, clutches and for my personal safety. (don't want any tires flying off at speed!)

One is my 1986 250R I just bought Saturday~ running on a mixture of stinky Torco pre-mix oil, 108 octane VP racing fuel and VP Nitro-Methane fuel mix. The only items not stock that I can see is that the airbox lid has been drilled, and it has a FMF fatty muffler/silencer combo. It's a pretty clean and strong machine...

The other is my 1986 350X I bought a while ago from a link on this board, running a completely stock set-up and VP 108 octane racing fuel. It's kinda tired...


I don't know how accurate the figures are, but I really don't care because I can still use this as *OUR* baseline so the power increase/decrease delta can be measured after future mods. Even if they only made 1 HP, we still had a ball doing it!

Both of them held together believe it or not and the 250R made more power than we thought it would... The only bad part about this fuel mixture was that the dyno cell smelled like a Top-Fuel Dragster after pulling this thing, where our lips/mouth/eyes burned and were watering the whole time!

I also super-imposed my '85 350x dyno graph against the '86 just for comparison sake. Do these figures look even close to what you guys have seen around for either of these two machines?

[fyi]

Here's the machines...

[fyi]

Here's the fuel we used in the "R"... Good stuff.

[OldSchoolin86]

Thanks for the info fyi, the numbers look pretty good. Your right, no matter what it's a good baseline to work from. The only thing that concerned me was that the 250r didn't start pulling the front in 3rd untill you used the fun fuel. It should have done that on cheap pump gas and the FMF alone.

[fyi]

I agree with you oldschool....

When I first got it off the truck and rode it for the first time, it was a real slug with no real powerband hit. It looked as though the oil/fuel ratio was wayyyy rich on oil and the jetting was also wayyyy rich. Those combined made it feel real "soft" on the throttle. In fact it was o oil rich, there was a heavy oil sludge all over the header pipe from the engine "snotting" all over itself from over-oiling.

I think the combination of leaning out the oil mixture ratio with racing fuel and the addition of the oxygen-rich nitro methane, it leaned the engine out enough to where it would run right...

That nitro is some good stuff though, if you can stand the Top-Fuel stink everywhere you go....

[bigyellow4x4]

how much nitro did you us in it?

[fyi]

1 quart per tankful.

[bigyellow4x4]

thanks for the info if you were on if the jets how much biggger should one go?

[fyi]

Beats me, we never dug into it that far and proper jetting would be determined by exhaust air/fuel ratio.

[HRC1]

Just wondering why you used the fuel you did as apposed to pump gas? They will both run on 87 just fine. What fuel do you use in them when you ride? I have seen cars run slower at the strip when using octane they didn't need.

The only bike i own that i run 110 torco in is my 350x, and that's 12:1
What was the ARF?

[fyi]

I chose to use race fuel because that is simply what I had on hand here....at the shop.....right at that time and the engine did respond favorably to it when added; hence it's continued use.

What was the ARF?

I assume you mean AFR? (air/fuel ratio...) As I stated in the post~ I had no idea what the AFR was at anytime we were running that fuel-mix and I really didn't care anyway... I was more curious to see how the engine responded to the unorthodox nitro-race fuel mixture I was running through it than anything.

If it blew up, so what~ I am building another new engine for it now anyway so it just didn't matter that much to me at that date and time.. I have quite a depth of parts here for all three of our ATV's/ATC's and machines to produce/machine/fabricate just about anything we want, for whatever we want~ so the fear of hurting engines just isn't there when we can repair/rebuild them easily and quickly.

[hrc85250r]

well, i dont know why you used the race gas with a stock motor....you def lost hp with that...run premium pump gas and i bet you get a horse or two back...

[fyi]

Like I said, we really didn't care what it made or how it made it or if the stupid thing blew all over the shop... We were just curious to see how it would fair with that exotic fuel. If it only made 1 HP, that would have been fine for us as it was still fun doing it and we certainly have nothing to prove to ourselves or anyone else.

For us guys here, it's all about the fun, that's all...nothing else.

[HRC1]

I almost think your taking offense to my and hrc85250r's posts about the fuel. I was just wondering if you had taken a reading because as you know. HP/TQ is quite affected by the afr. I thought you were looking for a baseline, but that is hard to get if the bikes are not optomised in the first place. As far as your extensive array of equipment and parts, they will not do you any good if the bike is not tuned to run right. Sorry for asking.

[fyi]

You're incorrect.

Not taking offense at anything and why would I? As I've stated now 3 times, I have nothing to prove to anyone and I really don't care who agrees with me or not... We're doing this for ourselves and ourselves only, for fun and posting our results here for anyone to see if they are interested. If you don't like the way I do something, that's fine, I really just don't care, as this is my machine, not yours. If you like the results you see, that's fine too, but again, I really just don't care, it's still my machine, not yours.

I'm having fun doing this my own way and I'll not change those ways just because some total stranger on the internet says I'm "doing it wrong". I'm not trying to sell anything, I'm not trying to teach anyone anything and I'm not trying to change the world~ I'm just doing this for my own knowledge, right or wrong.

If I feel like testing this machine without an AFR sensor, I'll do it.. If it blows up, who cares.. If I want to test this on a car dyno where an ATC was never meant to be, I'll do it.. If I decide to test the machine on race gas instead of pump gas, I'll do that too~ because I could care less if the internet community agrees with me or not. I'm doing this for me, right or wrong and I'm not out to please or agree with anyone.

Since these machines were nearly stock, I didn't care what they did regarding power, or how it did it. When both of these machines are completed the way I want them in the Spring, they will have all of the technical knowledge we know here applied to them for optimum performance in regards to machining processes, port work on the flow bench and on the chassis dyno. Until then, we're just going at this to see what they will do.

If you agree with it, fine. If you don't agree with it, that's just fine with me too~ I just don't give a care either way. That's why we live in America.