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Discussion Starter #1
Just got my motor back off the dyno. The pulls were done with c-23, now upon further research I find that was not the best move. Motor is a 406 ford, c302 heads, with a wilson sheet metal intake with two prosystem 4500's. The motor has two foggers, and will run about 500hp of no2. The compression is about 12.6, it made 747.89 with the c-23 on Wayne Youngs dyno. Everybody that I have talked to says that its not enough compression or nitrous to run the 23. I have since switched to c-16, we have made six test hits and I have jetted the carb down twice. The motor still seems fat, and I was wanting some insite as to how far of the tune is on motor.:confused:
 

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Kenny, from what we have run in the past (lots of sbf's), with the power you are making and amount that you will be spraying I'd think the fuel you would want to use is VP NOS fuel. Now this fuel will not show best numbers on engine power only, but with the C heads you can use a little extra on the tuning window on spray. Also once you get it close on C-16 the engine's seem to be close with when you switch to NOS fuel. Good Luck...
 

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IMO the C23 is a better fuel than the n2o. Running that much gas I would stay with the c23.
 

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I am running c16 in mine now with one 32 pill but plan on running c23 with both kits on a 32 pill.
 

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Discussion Starter #5
Ok that makes me feel a little better, what they had implided was that n/a on the dyno it killed a good bit of power. I know that since we switched back to c-16 I have went from 80jets in the carb, down to 74jets in the carbs. The thought was that the carbs are making the no2 tune up richer than it really is. Being the specific gravity of c-23 is .713 does that inturn make it leaner burning over the c-16?
 

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Montgomery Ragland
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Not so much leaner burning. it maybe, I don't know about C23, but C16 is around 14.77stoich

but the specific gravity is .735 for C16 as where C23 is .713

somebody with carb and jet knowledge will know the numbers right off hand but think of it like this. C16 is heavier so more of it will fall threw the jet than the lighter C23. So a smaller jet is needed for the same fueling amount. Where the C23 is lighter and a bigger hole is needed. I think for every .010 in specific gravity it's a jet size or two.
 

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Ok that makes me feel a little better, what they had implided was that n/a on the dyno it killed a good bit of power. I know that since we switched back to c-16 I have went from 80jets in the carb, down to 74jets in the carbs. The thought was that the carbs are making the no2 tune up richer than it really is. Being the specific gravity of c-23 is .713 does that inturn make it leaner burning over the c-16?
Put that c23 in it and turn on both kits and get ready to fly. Lol
 

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Unless those are 750 Dominators with the full skirt on the boosters, 74 jets are extremely lean, way out of the ball park lean for normal 4500’s.

Your pro system Dominators are probably like most others, sloppy rich at part-throttle. If you try to cure that with smaller main jets the WOT will be way too lean. It is most likely that your “too rich” problems are in the idle and intermediate circuits.

The reason it seems richer with C-16 is because C-16 is blended with large amounts of aromatic solvent and so is a sootier burning fuel, it leaves more carbon soot, like acetylene when you burn it without oxygen.
 

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Discussion Starter #9
I will look into the jetting, I have been reading plugs and it doesn't appear lean. There 1050's and they do have the bells on the boosters. Like mentioned earlier, on the dyno it took the 80jets to make it happy. Now in the car it seems the tune up was way off since we swapped back to c16 from c23. I will probably wind up with no2 fuel in the car before its over. Right now we are just trying to get the first kit cleaned up and I think the carbs are making the No2 tune up look fat.
 

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Just take care that an over-rich condition at part-throttle isn’t hiding the possibility it is too lean at WOT. A WBO2 is your friend.
 

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I will look into the jetting, I have been reading plugs and it doesn't appear lean. There 1050's and they do have the bells on the boosters. Like mentioned earlier, on the dyno it took the 80jets to make it happy. Now in the car it seems the tune up was way off since we swapped back to c16 from c23. I will probably wind up with no2 fuel in the car before its over. Right now we are just trying to get the first kit cleaned up and I think the carbs are making the No2 tune up look fat.
The NO2 and C23 is designed for nitrous. The C23 cost more but you can get more aggressive with tune up. The C16 distillation is designed for higher inlet temps unlike nitrous. There is way more to fuel than just octane numbers. I realize alot of people use C16 and have for years in just about every combo not understanding much about fuels. You even see these programmers for new cars with C16 race tunes for an N/A motor LOL. Really? Like said stay with the 23 when you turn both foggers on:smt103
 

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Ok that makes me feel a little better, what they had implided was that n/a on the dyno it killed a good bit of power. I know that since we switched back to c-16 I have went from 80jets in the carb, down to 74jets in the carbs. The thought was that the carbs are making the no2 tune up richer than it really is. Being the specific gravity of c-23 is .713 does that inturn make it leaner burning over the c-16?
yea it prob did, C23 is nitrous fuel, not good for dyno pulls at all N/A

when dynoing on motor alone, use like C14+ or C25. C16 will dyno pretty good too, but with 12.6 on you compression is kinda low even for C16 on dyno. you prob could dyno wit hC12 real well on just motor with your compression
 
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