fuel for nos system

[doctor408]

this puzzles me. i local guy at the track has a sbf alcohol (carb) and has a seperate fuel tank for nos and uses 87 octane in it??? i know the lower the octane level the hotter it burns, but why would you guys guess he id doing this.. the car is absolutly riduclously fast and runs it 4-5 times every weekend so he not breaking parts. he is 1/2 faster than me with almost identical engine combo's and im proly a little lighter. but he is real irragant and i cant talk to him.. just curious why he does this, i have never heard of it before??? thanx for any replys

[John_Heard]

He's probably pulling your leg... I've never tried something like that but the 87 octane should light off a lot sooner than the alky and "should" make it prone to detonation. Stop by next time he's filling the little tank and take a look at what color the fuel is.

[doctor408]

naw, he's not pulling no body's leg... he made a little senirio at the track with the two different fuels,, he took 112 and poored a cap full on the cement and lite it and it never ca-boomed up, just a slow burn kinda like deisil fuel just alittle bite faster,,then with the 87 the same cap full and lite it and it ca-boomed 3 times bigger then the 112. he says with the alky running so much cooler and timming higher, he has more room for hotter cylinder head temp. when he hits a 200hp shot, it sounds like 3 more motors jump in....... it sounds frightning!

[Racer704]

Damn i am really late here big time, the 87 octane flashes quicker and burns faster rate and it acts like a blasting cap to TNT for the Alky.It accelerates the burn on it also. Alot like the 15% gas for the 85% ethanol.I ran my best with a toilet bowl on methanol and a 250 plate on gas now at the time i didnt understand burn rates and what not.The unleaded fuel does burn quicker and hotter as proof when we had to switch to the unleaded fuel in the 70's 80's it burn alot of valves and seats because of the heat.

Here is something else for you to think about if you run a hiughert octane in a mtotr thats not needed it will carbon up the engine and also makes less power as it doesnt have the compression and timing to burn all the fuel so that swhy its important to only run as much octane as you need for your application.

This is one of ther benefits of alky is that its made up of all the same atoms, with gas you have manyt differant atoms that burn at differant rates and more prone to pre igntion or detonation if its not all set right.

[supernova]

He's probably pulling your leg... I've never tried something like that but the 87 octane should light off a lot sooner than the alky and "should" make it prone to detonation. Stop by next time he's filling the little tank and take a look at what color the fuel is.

Yep, it does work!
The thing here is that alky has almost unlimited octane. If the motor has high compression, it needs a high octane fuel, thus alky. When you run a low octane gas fuel in the n2o system the akly makes up for the low octane and you still get the explosiveness of the low octane gas fuel. Setting the timing right is the key and you better be able to read a spark plug.

Thats what I know!