NOS jetting + tuning chart.......

Found this while looking for an NOS nitrous/gas jetting chart........


http://www.nitroussupply.com/baselines.php

Definetly not trying to start a debate here but it could be a good one ....alot of those factory tunes are very rich .... the tune really depends on the entire combination cylinder heads, compression, fuel timing !!! 95% of the time its too much fuel and not enough timing is pulled from the nos tune .....


always remember your plugs are your window to a happy engine

The Nitrous Express plate I have (thanks Chuck) uses much different jetting than what is in that chart.

The instructions say to use a very small fuel jet and a bunch of pressure. Like 10.5 psi to start.

I'm finally down to 8.25 psi and am seeing indications of lean, so I'm going to be upping back to 8.5 psi and see how it goes.

Greg

605FOX wrote:Definetly not trying to start a debate here but it could be a good one ....alot of those factory tunes are very rich .... the tune really depends on the entire combination cylinder heads, compression, fuel timing !!! 95% of the time its too much fuel and not enough timing is pulled from the nos tune .....


always remember your plugs are your window to a happy engine

I agree. That jet map is a solid place to start and be real safe I think. There's a lot of room there for dialing in what your combo likes.


So Greg, wouldn't you be able to jet a tad fatter on the fuel side and be able to keep the pressure down? Or is that entirely against NX's religion? I bet their plate is just meant to use the higher pressure for how it atomizes the fuel. I guess I think its odd they want you to run that high a fuel pressure. I guess it don't matter if you have a dedicated fuel system for it right...

I'm not sure why they have it that way. I do have a dedicated fuel system, so it's not a big deal, but it is unusual.

Greg

Most of the big manufactures seem to almost build in to much safety to there kits... It's no secret that the factory jetting is set to be a "fits all" and there's usually a lot of room for improvement.. We flow a lot of systems and base a good starting point based off of these numbers. One tune can't be right for every combo out there.. Thanks, Steve

That's exactly why the "factory" jetting is/was so rich (especially on the older systems), they wanted that safety factor. It would have been harder for them to sell a ton of systems years ago if people were burning up their shit right & left if the factory jetting was out of the box "on kill" aggressively lean.

I for one went on the low side of NOS's tuning specs last year on my sbf and at the 1/8th mile marker it blew the head gasket, torched the head, and lifted the ring lands on two pistons. This was on a 24/24 jet spread at 6psi of flowed fuel and taking 2 out per 50 on a 175 shot. I now run a 24/20f spread at 5psi on my bbf and she runs wonderful now. I still haven't fined tuned but the jet recommendation I was given from Monte Smith works great to get started. I will share it with you all.

Gold jet holders is an "A" nozzle. You need .024N .020F for about a 175 hit at 5 psi. .028N .020F at 6 psi for 250 and .034N .028F at 5 psi for the 300. This will get the tunes you want, with the minimum number of jets.

Monte Smith
Motorsports Technical Representative
Nitrous Oxide Systems
ph. 256-783-3418
email gtxmonte@msn.com

I wonder though on the 300 tune if Monte meant 32N instead of 34N? We put that tune 32N28F@5 psi and it ran too lean, if we had of ran the 34N it might have hurt something

On the smaller tune ups 4 spreads at 5-6 PSI will normally run pretty well as long as the proper timing is removed... The 8 jet spreads are a little aggressive for most... SJ

i was thinking about stepping up mine i am running one of the 8 jet spreads 20fuel and 28nos at 5.5 fuel with the brown nos foggers wonder what the next step would be my best time was 5.76 but it normally runs 5.80- 5.85 on that tune i was thinking of 32n 24f i busted 8 pistons when i first got the fogger running 28 28 with 6 psi lifted the ringlands on all 8 pistons, so i would rather take my chances lean than rich. maybe a 32n 26f @5psi wonder what hp that would be? wonder what type of gains in the 1/8

Dang Steve, very glad to have you on here. You should get Bruno to start a thread for you to introduce yourself and have and ask/answer section. Thanks for taking the time for us!

Thanks Curt !!! I will try and drop in as I can, sometimes I run out of hours in the day. Or maybe run out of hours I can stay awake and working !! Were still in the shop now trying to shoot photos for our web site of our products... Trying to up date our site and get more info and parts out there.. Thanks, Steve

I know Steve is very busy , ive asked him to drop by every know and then to gives us a hand answering some nos tech questions ...he is more then welcome to introduce himself whenever he has time


thxs again Steve

Cool to have ya Steve

studly wrote:i was thinking about stepping up mine i am running one of the 8 jet spreads 20fuel and 28nos at 5.5 fuel with the brown nos foggers wonder what the next step would be my best time was 5.76 but it normally runs 5.80- 5.85 on that tune i was thinking of 32n 24f i busted 8 pistons when i first got the fogger running 28 28 with 6 psi lifted the ringlands on all 8 pistons, so i would rather take my chances lean than rich. maybe a 32n 26f @5psi wonder what hp that would be? wonder what type of gains in the 1/8

I am not a guru by far but I would highly recommend you not start there. We started tuning ours Sat with the 28/24 at 5.25 dropping 10 degrees and then went 5.5 psi dropping 8 degrees then 5.75 dropping 6 degree's. I think that is as close as I wanted to get. IMO that tune of 32/26 @ 5psi would burn nice size holes in several of your pistons.

on the 28nos 20 fuel tune i run now i pull 14 degrees out, I guess every motor is different still do not know if i am brave enough to hit the motor with the 32/34 jet what does your plugs look like mine have a very light ring when you cut them apart after a run almost like someone just barley shaded them with a pencil. when i run the factory nos tunes(lifted ring lands) the fuel ring looked like a brown ring around the bottom but i was only pulling 6 degrees of timing per the instructions.

These guys like Steve must have a warehouse full of messed up parts from nos its amazing they can run fast and not hurt parts

studly wrote:on the 28nos 20 fuel tune i run now i pull 14 degrees out, I guess every motor is different still do not know if i am brave enough to hit the motor with the 32/34 jet what does your plugs look like mine have a very light ring when you cut them apart after a run almost like someone just barley shaded them with a pencil. when i run the factory nos tunes(lifted ring lands) the fuel ring looked like a brown ring around the bottom but i was only pulling 6 degrees of timing per the instructions.

These guys like Steve must have a warehouse full of messed up parts from nos its amazing they can run fast and not hurt parts

When you run the spread above you have to pull a lot of timing out. Less timing = less fuel = less horsepower. On my 28/24 @ 5.25 the plug showed lean and the timing mark was around the bend headed to the threads. As you add a 1/4 pound of fuel you can add 1-2 degrees of timing and the plug will stay close to what it was. Every time you add timing you have to add fuel if your showing perfect or a tad lean. Keep going a inch at a time adding fuel and timing and watch for signs of detonation or the plug getting too hot then when you have pushed it as far as you feel comfortable or start to show signs of detonation stop and maybe back up a step. Timing and fuel adds power to a point. My car was much stronger pulling 6 degrees out with 5.75 fuel than it was at 10 degrees pulling 10. But you have to start very safe and go slow small steps or you will burn it up. But like I said above, I am not a guru and have no business making recommendations to anyone, only telling you how I tune mine. I beg guys like SJ and Monte Smith for advise all the time.

[quote="wreckless4thfBut you have to start very safe and go slow small steps or you will burn it up. quote]

AMEN.....

It took me a year and a half of making small steps to finally see lean/detonation on my plugs..... took out 2 degrees and added .25 psi on the fuel and that's where it's gonna stay!

Greg

Thanks guys !!! SJ

Mess with any M5 alky set ups??????

I seem to need some more ass here lately lol.

wreckless4thf wrote:

studly wrote:on the 28nos 20 fuel tune i run now i pull 14 degrees out, I guess every motor is different still do not know if i am brave enough to hit the motor with the 32/34 jet what does your plugs look like mine have a very light ring when you cut them apart after a run almost like someone just barley shaded them with a pencil. when i run the factory nos tunes(lifted ring lands) the fuel ring looked like a brown ring around the bottom but i was only pulling 6 degrees of timing per the instructions.

These guys like Steve must have a warehouse full of messed up parts from nos its amazing they can run fast and not hurt parts

When you run the spread above you have to pull a lot of timing out. Less timing = less fuel = less horsepower. On my 28/24 @ 5.25 the plug showed lean and the timing mark was around the bend headed to the threads. As you add a 1/4 pound of fuel you can add 1-2 degrees of timing and the plug will stay close to what it was. Every time you add timing you have to add fuel if your showing perfect or a tad lean. Keep going a inch at a time adding fuel and timing and watch for signs of detonation or the plug getting too hot then when you have pushed it as far as you feel comfortable or start to show signs of detonation stop and maybe back up a step. Timing and fuel adds power to a point. My car was much stronger pulling 6 degrees out with 5.75 fuel than it was at 10 degrees pulling 10. But you have to start very safe and go slow small steps or you will burn it up. But like I said above, I am not a guru and have no business making recommendations to anyone, only telling you how I tune mine. I beg guys like SJ and Monte Smith for advise all the time.

My tune up came from Monte Smith and i have been racing on this tune up for over 100 passes this year, with no hurt parts, i do not agree with the more fuel more timing makes more power. the combination of fuel and combustion efficiency makes power you can put too much fuel in and if it does not burn it is not making power. and from the group i race with on the same tune up i can normally run .10 quicker with less timing than a 4 jet spread with more timing I have seen more lifted ring lands than holes burnt in pistons i do believe in taking it slow and watching the fuel ring i just like to keep my timing mark at the end of the plug not at the bend and very little to no fuel ring. but i guess there is more than one way to get the job done I may start with a 4 jet spread but if the plug shows fuel i will lean it up immediately and take timing out.

studly wrote:

wreckless4thf wrote:

studly wrote:on the 28nos 20 fuel tune i run now i pull 14 degrees out, I guess every motor is different still do not know if i am brave enough to hit the motor with the 32/34 jet what does your plugs look like mine have a very light ring when you cut them apart after a run almost like someone just barley shaded them with a pencil. when i run the factory nos tunes(lifted ring lands) the fuel ring looked like a brown ring around the bottom but i was only pulling 6 degrees of timing per the instructions.

These guys like Steve must have a warehouse full of messed up parts from nos its amazing they can run fast and not hurt parts

When you run the spread above you have to pull a lot of timing out. Less timing = less fuel = less horsepower. On my 28/24 @ 5.25 the plug showed lean and the timing mark was around the bend headed to the threads. As you add a 1/4 pound of fuel you can add 1-2 degrees of timing and the plug will stay close to what it was. Every time you add timing you have to add fuel if your showing perfect or a tad lean. Keep going a inch at a time adding fuel and timing and watch for signs of detonation or the plug getting too hot then when you have pushed it as far as you feel comfortable or start to show signs of detonation stop and maybe back up a step. Timing and fuel adds power to a point. My car was much stronger pulling 6 degrees out with 5.75 fuel than it was at 10 degrees pulling 10. But you have to start very safe and go slow small steps or you will burn it up. But like I said above, I am not a guru and have no business making recommendations to anyone, only telling you how I tune mine. I beg guys like SJ and Monte Smith for advise all the time.

My tune up came from Monte Smith and i have been racing on this tune up for over 100 passes this year, with no hurt parts, i do not agree with the more fuel more timing makes more power. the combination of fuel and combustion efficiency makes power you can put too much fuel in and if it does not burn it is not making power. and from the group i race with on the same tune up i can normally run .10 quicker with less timing than a 4 jet spread with more timing I have seen more lifted ring lands than holes burnt in pistons i do believe in taking it slow and watching the fuel ring i just like to keep my timing mark at the end of the plug not at the bend and very little to no fuel ring. but i guess there is more than one way to get the job done I may start with a 4 jet spread but if the plug shows fuel i will lean it up immediately and take timing out.

I said fuel and timing makes more power to a point. If you watch your mph you will know when the car stops making power. Every time I pulled less timing out Sat the car sped up. More timing makes more power on nitrous because it burns more fuel, but if you put to much you will burn it up. Above you said: I may start with a 4 jet spread but if the plug shows fuel i will lean it up immediately and take timing out. Well when you take the timing out you just richened it up again. Also when you pull fuel out your plug will show the timing mark further toward the plug. Nitrous don't make power, fuel makes power and nitrous makes it burn. The most hp you can make is with the most fuel that you can burn with the help of the oxidizer (n20), leaning a motor in the less fuel direction doesn't. Hopefully if I am telling you wrong SJ will correct me.

timing does not richen or lean a motor only a fuel or nos adjustment will do that the spark plug does not put out a bigger spark or burn more fuel with timing it only adjust cylinder pressure. if its rich at 32 degrees timing it will be rich at 40 degrees timing. it may make more power at 40 trying to compensate for the fuel but it will still be rich.

studly wrote:timing does not richen or lean a motor only a fuel or nos adjustment will do that the spark plug does not put out a bigger spark or burn more fuel with timing it only adjust cylinder pressure. if its rich at 32 degrees timing it will be rich at 40 degrees timing. it may make more power at 40 trying to compensate for the fuel but it will still be rich.

I agree to disagree. Maybe someone else can add to this. Timing does lean a motor out or richen a motor up. If you were watching your plugs while you changed timing you would see this too. If you would like here is a awesome article from Mike Canter on nitrous you might enjoy.

http://www.dragstuff.com/techarticles/reading-spark-plugs.html

And one from Monte Miko that is a good read as well.

http://www.yellowbullet.com/forum/showthread.php?t=7255