nitro feul for KE25SP engine

[americaneagle878]

what ratio or pecent would be good for a KE25SP engine which is for a Mad Crusher GP-MT 4WD kyosho.

 

[Tunedfrog]

The Mad Crusher is an awesome truck. I had one but sold it because I'm just not a nitro guy.
I used this and it ran like a raped ape... Fast truck and fun to drive.

 

[americaneagle878]

The Mad Crusher is an awesome truck. I had one but sold it because I'm just not a nitro guy.
I used this and it ran like a raped ape... Fast truck and fun to drive.


View attachment 140490

is that 20 percent?

 

[Tunedfrog]

Yes.

 

[Cliffst3rz]

for that engine you want 25% or 30 if you can get it

 

[tudordewolf]

VP Fuels, Sidewinder/Morgan fuel, and Torco are all equally valid great answers.

Torco has no castor oil in it which is a personal choice for the driver, some prefer the protection of a little lacquer and the thicker castor oil, others don't want it potentially gumming up their engine. If you're just starting out, maybe try Torco as your second fuel once you're comfortable tuning.

The only "wrong" answer might be traxxas top fuel.

Percentage is up to you, popular opinion is that a higher nitro percentage will do 3 things:

Increase power (intuitively)
Increase fuel consumption (follows from above)
Decrease engine temperature. Now this last one is a bit counterintuitive, but here's the theory: less methanol and more nitro means less oxygen is needed from the atmosphere. you'll need a richer fuel air mixture, which tunes cooler.

That third detail is more complicated than the other two, and some dispute it.
You'll also want a cooler glow plug because higher nitro fuel advances the ignition point, which you'll need to delay with a cooler plug like an OS #10.

the best way is to feel out your preferences through experience with a couple different fuels.

I'd start with 20%, especially for break-in, and move up to 30%. That way you'll also see the difference instead of just considering 30% its baseline performance.

 

[johnnydmd]

For monster truck bashing/racing, I use 25/10 and that engine ran great when I had it in my Mad trucks. For an RTR, it's a really good engine.

I use that engine in my drag car, though it's modded with porting and ramping, ceramic bearings, SH .28 carb, and I use Bones 30/8 in that car and it screams. I can confirm that it runs cooler with the 30/8 fuel.