What Octane?

[TokyoJoe]

I have a 420 Windsor that is at a 13:1 compression running a locked out timing of 38deg and around 28deg on a 250 fogger shot. I have a seperate tank for the nitrous and was thinking about having 110 in that tank. Not sure if I even need that much?

What Octane should I be able to get away with on the motor? Also can I get away with that same octane when I spray as long as I have the 110 in the nitrous tank?

Thanks

 

[87AODGT]

you're stuck with race gas regardless with 13:1 compression

 

[TokyoJoe]

Yeah I got that. Wanting to know what mix I can get away with in the main tank. I dont think Id have to run straight 110. But I'm not sure about at that timing. I could run straight 28 locked out if I could get away with closer to 100 octane on the motor. Just need someone to steer me the right direction.

 

[84Ttop]

I would stick to 110 all the time with that combo, your compression is kinda high. do you plan on street driving this? maybe a thicker head gasket can get your compression down some. Are you still running a 23 degree head? i'm assuming so with that much timing. what kind of jetting are you running in your kit? r u running a Progressive?

 

[srtthis]

C12 on the motor... c23 on the bottle...

 

[TokyoJoe]

I would stick to 110 all the time with that combo, your compression is kinda high. do you plan on street driving this? maybe a thicker head gasket can get your compression down some. Are you still running a 23 degree head? i'm assuming so with that much timing. what kind of jetting are you running in your kit? r u running a Progressive?

Street driven as in trailoring it to a location and then loading it back up later. But not a driver.

I forget which HG we went with but I think there is only 1 or 2 more sizes to go up which didnt offer much...would still be over 12 so we went with the compression. Only option here would be to go to the 72cc head but thats not what I'm after now.

On a AFR 225 head. I wouldn't mind running lower timing but the motor just doesnt like it at all. Anything under 25ish and I have pretty bad idle problems.

Playing with the jetting..but on Q16...so I'm prob going to have to change it for the 110. Wasnt really impressed with the amount of fuel I had to add with the Q, but as it sits I think I have it 28N and 32F on an Edelbrock Progressive


If it needs to be 110 then that is what is gonna be in it then. Just didnt want to mix it down to the 104 range and start having a bunch of problems.

 

[84Ttop]

From my experiance, q16 has been nothing but problems. if not stored properly the lead literally falls out of the fuel. my buddies outlaw radial car runs q16 and he drains the fuel system every time he takes the car out, constantly cleans the filters and has all 16 injectors rebuilt at least once a year. I think you'll be fine on 110 with a conservative tune up, 28 degrees of timing still seems like alot on a hit but the only nitrous car that's really been fast (8.20's) that i've played with has 15 degree heads on it an we run 8 degrees total timing on a 250 hit with the progressive out 2 seconds. Running the car this coming weekend in nmra true street so we'll see what happens, good luck man, sounds like a nice combo!

 

[srtthis]

personly id run 1 tank running C23 in it as i said before... the motor in the race car has a bit more compression (.8) and thats what we need to run....

 

[TokyoJoe]

What are you guys runnign for timing?

84ttop: are you talking base timing with a mech advance? I'm locked out on my dizzy. What is the total timing? 8 just seems too low to me? edit: I see you said total but damn, I dont think the car will even want to idle at 8 deg. I'll start playing with it. I think you are right tho that I wont be able to get away with over 20deg let alone 28.

 

[srtthis]

believe we are running like 32* base timing. yanking 15* at the hit of the converter on the first kit ramping the timing back in to 10* retard

 

[TokyoJoe]

Thanks. I'm going to try starting at 28 and pull back to 18 then. I'll give some C16 a try in the tank for now since I already have a couple gallons. When I can get a hold of some 23 I will give that a shot and see where I can get with the timing.

 

[84Ttop]

on the hit i'm talking 8 degrees total timing, but remember it's a 15 degree head and totally different ball game. i think your on the right track though with your combo, better safe then sorry with the timing

 

[92redfox]

this is kind of unrelated but what kind of power increase would you get from a stock stang runing 87 to runing like 96 octane

 

[srtthis]

this is kind of unrelated but what kind of power increase would you get from a stock stang runing 87 to runing like 96 octane

unless you add timing, you'll be loosing a few.

 

[90lxcoupe]

this is kind of unrelated but what kind of power increase would you get from a stock stang runing 87 to runing like 96 octane

wouldnt be worth the trouble and money for good gas