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Nitrous tune question

Posted By: turner

Nitrous tune question - 05/12/12 03:08 AM

I have installed a NOS plate system and intend on making some time trials to see if I can break into the 10 second club, my car has run many 11 teens. I have the plate kit set-up for a 100 shot.....this is on my 440 w/ported Edelbrock heads. I have 37 degrees timing, Autolite 3923 plugs, 93 octane gas, forged pistons, msd ignition...my NOS instruction manual says that 2 degrees-no change in timing is necessary for the 100 shot, after that significant amounts of timing are pulled out. I was wondering what to expect from my plugs and if I should add some octane boost or mix some race gas for the nitrous runs.
Posted By: MoparBilly

Re: Nitrous tune question - 05/12/12 03:20 AM

I wouldn't have it at 37 on motor with 93, but that's just me, I guess.

I've never run that small of a hit either...32, a couple gallons of race gas and jet up after the first hit.

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Posted By: turner

Re: Nitrous tune question - 05/12/12 09:20 AM

When you say "jet it up", are you changing the primary and secondary jetting? I currently have 75 in the mains and 78 in the secondaries....how many jet sizes should I go up with the 100 shot and how much more timing and jetting if I put the 150 shot to it, the system is the NOS Powershot. Should I be pulling my timing with a timing light and locking the distributer where I see fit or should I buy a timing computer.....money really isnt that big of a deal, swapping out chips instead of messing with my distributer seems easier and way more precise......any input on wich timing computer, I have all MSD now.

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Posted By: fasthawk6

Re: Nitrous tune question - 05/12/12 12:18 PM

As for the timing retard get a digtel 6 plus and hook the retard wire to the nos button or trans break button to pull timing when nos is turned on. You may not need to pull timing on a 100 shot but it is better to be safe then sorry.

If jetting on car is already good do not mess with it.As far as what plugs should look like on a nos tune go to induction solutions web site , steve has a place where guys send pics of plugs in and he tells them what is going on.

Make sure your fuel pump is large enough to support both systems. we run a 500 with 2 regulators one for motor and one for nos tune.

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Posted By: MoparBilly

Re: Nitrous tune question - 05/12/12 04:08 PM

Turner,
I was refering to jetting up the nitrous, because a 100 hit on a low 11 Big block will seem pretty tame. It should give you the required 10.XX time slip you desire, however.

I wouldn't worry about a retard system at this point, but if you fall in love with the spray, and get a big-shot plate and want a 9 sec time slip, then I'd consider it.

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Posted By: RobX4406

Re: Nitrous tune question - 05/12/12 05:18 PM

Nitrous is not for the lazy...

I would retard the timing regardless of what the instructions say and sneak back up on the total number that it runs best. Just do it manually to start with if you don't have a retard module, etc. Detonation is a KILLER with n2o tune ups. What's it gonna hurt if you back out 4 degrees and see how it runs for MPH? Then add 2 back and see MPH again. If it slows down, as long as everything is constant, you know you went a bit too far. Get back to your original total number no biggie, BUT, you didn't risk smoking something because it had too much to start with.

Jetting on your carb will not change. You adjust the nitrous/fuel pills to keep things happy and in tune. You can also tweak it raising or lowering fuel pressure in a pinch. Fat tune up is bad too... don't believe the fat is good/safe crowd.

Most of us have some decent money in our engines. Whether it's 1,000 or 20,000, cooking it because you went too far from the start seems risky to me. Call me conservative, I'll err on the safe side and sneak up, than balls out and dead!

Good luck with it.
Posted By: Cab_Burge

Re: Nitrous tune question - 05/12/12 05:23 PM

Quote:

When you say "jet it up", are you changing the primary and secondary jetting? I currently have 75 in the mains and 78 in the secondaries....how many jet sizes should I go up with the 100 shot and how much more timing and jetting if I put the 150 shot to it, the system is the NOS Powershot. Should I be pulling my timing with a timing light and locking the distributer where I see fit or should I buy a timing computer.....money really isnt that big of a deal, swapping out chips instead of messing with my distributer seems easier and way more precise......any input on wich timing computer, I have all MSD now.

When NOS guys say jet up there usually talking about the fuel jet in the NOS system, not the carb. If your carb. is jetted good now leave it alone, jet up or down the NOS system gas side jet
Posted By: Leon441

Re: Nitrous tune question - 05/13/12 01:49 AM

Don't know what they gave you for a 100HP tuneup but NOS used to give some bad advise. There tuneups were dead rich and they were slow to tell you to take timing out. What this causes is detonation with fuel puddling. At 100 HP you can get away with a bad tune but why would you want to.

For a 100HP shot I would run a .053 nitrous pill. Depending on fuel pressure for the fuel pill but, a maximum of .047 with 6 psi of fuel pressure. If you have something in the low .04's or maybe even a .038 may be necessary to get a good tune.

Like someone else said 37 degrees of timing is a lot. Most of these engines will run better at 32 degrees. Roll the timing back to 30 if doing it with a retard box. This should be safe. If you get a retard box keep pulling timing until the car slow down. Tune for MPH sense this is the best observation of HP.

Contrary to popular belief. Lean is Mean and fat will hurt the health of your engine. So if it is lazy and your buddies tell you to add timing they are probably full of bull. Try a smaller fuel jet or lower fuel pressure to the nitrous fuel soleniod. Please watch your bottle pressure if you do not have at 850 it aint going to run. You should shoot for 925 PSI or better yet buy a cheap Harbor Freight temp gun and get the bottle to 92 degrees temp. This will provide the necessary pressure.

Happy spraying.

Leon
Posted By: turner

Re: Nitrous tune question - 05/13/12 02:48 PM

Thamks for all the advice guys, I truly appreciate it! I had the car dyno tuned , so I feel that the carb tune-up is right on. I have installed the pills as suggested by NOS for the 100horse shot and that is a 47N/53F. I have a 6AL so instead of buying components for that old style system I think ill just manually retard the timing. I do not have an assortment of fuel pills, is that something that I should purchase?

As far as my fuel system goes, I have the Holley "HP150" billet pump. that states its 140gph@16psi or up to 900 horses...I have -8 line feeding the engine dead-headed with 7 pounds to the carb and I have put a tee below the carb. reg to tap the fuel line and installed another regulator for the nitrous and set it at 6 pounds, I also have a low pressure swith in the line b4 any regulators and its set at 5 lbs., does anybody think when my fuel bowls need more fuel and the floats open that my main fuel line will go below 5lbs......that is the question

I have tried to post some questions on Yellowbullets nitrous tech with induction solutions, but I cannot register, they must have all the users the want. I tried to buy a system from Monte but after sending 3 email requests for info and getting no responses I had to go another direction and that is why I chose a NOS system
Posted By: gsmopar

Re: Nitrous tune question - 05/13/12 03:35 PM

Those sound like the old nitrous tune numbers. Most of the revised stuff has jetting square. Go to the nos website and verify, but I think you'll want 52 n and f for a 100 shot.
Posted By: Big Squeeze

Re: Nitrous tune question - 05/13/12 03:42 PM

Quote:

......I tried to buy a system from Monte but after sending 3 email requests for info and getting no responses I had to go another direction and that is why I chose a NOS system



That's odd.......It must have been going to junk mail.......He's really good about replying to emails and texts.......Hit him up tomorrow with a text or give him a call...256-783-3418

If it were me......52 nitrous jet is about 150hp....I'd put a 42 fuel jet with it at 5psi FLOWING...at least 100 octane fuel....and -8NGK plugs......I'd put the timing at 25* and work from there.........Keep leaning it out 2-3 numbers with the fuel jet until it stops gaining trap speed.....once that tops out, put timing into it 1 degree at a time until it stops gaining trap speed......you'll end up somewhere around 27*-30* depdending on what your quench is.......

If you want to run the 47 nitrous jet, start with a 37 fuel jet at 5psi......28* degrees timing.....stock plugs and pump gas will be fine.....start leanging it out from there and then creep timing back in 1 degree at time......you'll end up around 30-34*, depending on quench.......You want to run as little fuel and timing as possible to make it MPH the best......

Like mentioned, using a temp gun and setting the bottle temp at 92* is best.....using a water bath is a HUGE help.....The bottle needs to be a UNIFORM 92*........

Like already mentioned, too rich and too much timing are piston killers.......so, you need to get the tune CLEAN and then put timing into it.....As long as it doesn't detonate, you won't hurt it......There are three things that make a motor detonate.........Not high enough octane fuel for the cylinder pressure your motor makes, oil getting into the combustion chamber either past the rings, guides or intake gasket, or too much timing.........

Having said that, Monte can get you there much faster than doing it that way.....
Posted By: cbarracuda

Re: Nitrous tune question - 05/13/12 05:11 PM

Very interesting thread. Iīm learning from you guys. I also want to squeeze 100 hp of NOS. I have 2 fuel pumps and two regulators because I have a tunnel ram. I would have to put one more regulator because the fuel presion of my carburetors is about 8 1/2 pounds, so I would run the NOS at 6 pounds and I would like to know the size of the jets that I need for dual plates.
Didnīt mean to steal the thread but it makes no sense to start another one since thereīs plenty of information right here.
Posted By: Cab_Burge

Re: Nitrous tune question - 05/13/12 06:07 PM

Quote:

Thamks for all the advice guys, I truly appreciate it! I had the car dyno tuned , so I feel that the carb tune-up is right on. I have installed the pills as suggested by NOS for the 100horse shot and that is a 47N/53F. I have a 6AL so instead of buying components for that old style system I think ill just manually retard the timing. I do not have an assortment of fuel pills, is that something that I should purchase?

As far as my fuel system goes, I have the Holley "HP150" billet pump. that states its [Email]140gph@16psi[/Email] or up to 900 horses...I have -8 line feeding the engine dead-headed with 7 pounds to the carb and I have put a tee below the carb. reg to tap the fuel line and installed another regulator for the nitrous and set it at 6 pounds, I also have a low pressure swith in the line b4 any regulators and its set at 5 lbs., does anybody think when my fuel bowls need more fuel and the floats open that my main fuel line will go below 5lbs......that is the question

I have tried to post some questions on Yellowbullets nitrous tech with induction solutions, but I cannot register, they must have all the users the want. I tried to buy a system from Monte but after sending 3 email requests for info and getting no responses I had to go another direction and that is why I chose a NOS system

I Have a freind who has emptied many big 15 lb NOS bootles and burnt up a bunch of parts learning how to go fast with NOS, make your fuel jet the same size as your NOS jet to start with As far as the needles and seast put the biggest ones you can get in it, .120 vitons work well Set the fuel pressure a little lower with the bigger neeldes and seats, I use 5.5 lbs now with the .120 instead of 7.5 lbs with the .110 My car was running out of fuel with the .110 at 7.5 lbs, switch to the .120 at 5.5 lbs and the car slowed down due to being to rich, lean the jets down and the car ran a new best Test, test and then test some more
Posted By: RobX4406

Re: Nitrous tune question - 05/13/12 06:31 PM

Quote:

make your fuel jet the same size as your NOS jet to start with



Only if you want a rich tune up out of the box with recommended fuel pressures for the system. If you have a wideband O2 sensor it will help a bunch!

Follow what Big Squeeze said and you'll be good. Want a 100 shot, about a .047 n2o jet and something in the .037-.040 fuel jet. Ask Monte if you get hold of him about a good baseline jet package. Even the new/revised kit recommendations are still fat. The old 150hit n2o/F was .063/.071, new is .063/.063. The new 100 hit is .047/.047, still fat. A general guideline is if your fuel jet is same or larger than you n2o jet, it's a FAT tune up.

I'm might be doing a 100 shot on my car and it's going to be .047/.039 to start with as far as plate jetting with 6PSI fuel pressure. If I jump to a 150, .063/.053 to start.

Why I wrote bump timing it 2* at a time, must have had setting initial on my mind... Do 1* at a time. I think NOS says 2* per 50hp and then an additional 2* safety margin. Better to take a bunch of timing out and not hurt it than not enough and cayse issues. Just like the plate jetting, sneak up on the best combination.
Posted By: Leon441

Re: Nitrous tune question - 05/13/12 07:27 PM

For the guy who wants to get 100HP NOS with dual carbs in Peru.

The tuneup is pretty close to the cross plate which has two spray bars. I ran one for a second stage with the fogger I had. .036 Nitrous jets .032 fuel worked good for me with 5.5 lbs of fuel pressure to the system.

Leon
Posted By: Big Squeeze

Re: Nitrous tune question - 05/13/12 08:20 PM

Quote:

..........make your fuel jet the same size as your NOS jet to start with .....



ANYTHING that is square jetted is going to be FAT........You can easily and safely go AT LEAST 10 numbers smaller on the fuel jet even with a small tuneup, AS LONG AS THE TIMING is back where I'd recommended......
Posted By: A57_RT

Re: Nitrous tune question - 05/13/12 11:41 PM

Great post, and good info Wish Id read it several years ago.

Window switch or controller is a nice add on is all I can add vs a micro switch (they can stick).

But if you have an older 6al, the 3 stage retard is a nice unit.

Some of us are hard headed (stupid) and learn the hard way.

Never rush the adjustments and make sure all is working properly.

Nitrous is a great power adder after you learn the ins and outs.

This was all avoidable, 100% human error on my part. But only took some paint work, a tear down and alot of parts magged and six boosters in the carbs. And a new set of muffs, just the guts were tossed out.

Not an issues since....because I no longer rush and inspect the system prior to every use. And I only spary on the streets 1/10 as much as I used to.

http://s1117.photobucket.com/albums/k589...rent=RTWEB1.mp4
Posted By: turner

Re: Nitrous tune question - 05/14/12 12:41 AM

Thanks all for the time you took to help, I will try to contact a few of the mentioned people and get some opinions and additional support. I will be at a bracket race here in Michigan on Memorial day and intend on making some NOS time trials, I know that my 10 second pass is a sure thing!

Keep the info coming


What MSD unit can I buy to adjust my timing with the retard pills, I have the 6al....If im going to be doing alot of timing changes this seems the only way to go
Posted By: A57_RT

Re: Nitrous tune question - 05/14/12 05:07 AM

What MSD unit can I buy to adjust my timing with the retard pills, I have the 6al....If im going to be doing alot of timing changes this seems the only way to go


I use the 6al, with the msd 3 step box plugged into the rpm chip slot, one goes to the retard box and the other is the launch chip.

If you got the msd site and look at all the different configs to istall its pretty easy to figure out what your doing and what you need.
Posted By: MoparBilly

Re: Nitrous tune question - 05/14/12 05:29 AM

I tend to jet for a fat tune-up, that way when the t-d line from my carter mechanical starts running out of pressure at 900ft, I can still make the finish line with the spark-plugs and head gaskets intact.

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Posted By: MoparBilly

Re: Nitrous tune question - 05/14/12 05:46 AM

I know this is no big deal when you are talking about pulling just few degrees of timing out with a retard box, but the more you pull out, the further out of phase the rotor and cap are. Back when I was hitting the Challenger with 2 systems, I was pulling 9 at the hit and 6 more on the second.Crank trigger, so I phased it for the retard.

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Posted By: fasthawk6

Re: Nitrous tune question - 05/14/12 11:11 AM

Quote:

Thanks all for the time you took to help, I will try to contact a few of the mentioned people and get some opinions and additional support. I will be at a bracket race here in Michigan on Memorial day and intend on making some NOS time trials, I know that my 10 second pass is a sure thing!

Keep the info coming


What MSD unit can I buy to adjust my timing with the retard pills, I have the 6al....If im going to be doing alot of timing changes this seems the only way to go





Save yourself the headachs and get a dital 6 plus box or a programable 6 clean and easy to use.

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Posted By: Big Squeeze

Re: Nitrous tune question - 05/14/12 12:38 PM

Quote:

I tend to jet for a fat tune-up, that way when the t-d line from my carter mechanical starts running out of pressure at 900ft, I can still make the finish line with the spark-plugs and head gaskets intact.



A guy would think you'd just put a fuel pump on it???
Posted By: A57_RT

Re: Nitrous tune question - 05/14/12 05:37 PM

That would spook even me seeing the fuel pump start to give out way too early, I run one big pump for the six pack and the plate kit at 100, then one seperate same type pump for the fogger system for another 250.
Posted By: MoparBilly

Re: Nitrous tune question - 05/15/12 03:48 AM

Quote:


A guy would think you'd just put a fuel pump on it???



Head gaskets are cheaper than a good fuel pump...
Posted By: Big Squeeze

Re: Nitrous tune question - 05/15/12 12:37 PM

Quote:

Quote:


A guy would think you'd just put a fuel pump on it???



Head gaskets are cheaper than a good fuel pump...



lol....so, what you're saying is you have a lot of free time on your hands??
Posted By: turner

Re: Nitrous tune question - 05/19/12 01:55 AM

I talked to Monte today and he gave me some jet recomendations and a tune to start with....I have in my super powershot nitrous kit six jets 47-53-55-61-63-71, I was told by Monte to start with the following tune (without buying additional jets) 55N/47F, 30 degrees timing, and 5 lbs fuel pressure.


Robx, Leon, Big Squeeze based on me and Montes conversation you were all correct in one way or another, thanks for the help
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