Two stage nitrous guys, ? about pressure drop in the bottle when hitting 2nd stage
06-28-2009, 06:24 PM
#1
Two stage nitrous guys, ? about pressure drop in the bottle when hitting 2nd stage I am putting a 2 stage system on my car as we speak. I was discussing it with one of my buddies and he asked me if I was running both stages on one bottle and I said yes. He says I will see a pressure drop from the first stage and the the second stage won't hit as hard and I will see a rich condition due to not enough bottle pressure. I want to ask the guys who have 2 stages on their car if they have encountered this and what was their cure for this. Did you use 2 bottles(one for each stage)? Did you put on a NANO system? Lets hear it guys. Let me know what to do. I am running a 75 shot on the first stage and a 125 shot on the second.
06-28-2009, 06:39 PM
#2
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Well there are mutliple scenarios here but they are all easy to cope with.
#1 if you are running all dry past the MAF it makes no difference.
#2 if you are wet....tune the first stage as you normally would at your desired AF ratio. But for the second stage...make sure you tune ONLY when using both stages at the same time....and only mess with the jets for stage 2 at that point to get overall AF ratio. You already adjusted stage 1 first...so dont mess with that. In other words...dont tune the second stage all by itself. And of course dont forget to never run the second stage alone (since its tuned with the first stage flowing). Always 1st stage alone or first stage + second and never second stage alone.
Second thing...a NANO type system will pretty much alleviate this minor issue.
I always ran one 15 lb bottle with dual stages up to 325 shot or so. Of course that was dry. But I have done other setups that where duals stage wet and dual stage dry/wet.
You can run two bottles...but with a little foresight and planning I dont see the need. Especially for a 175 shot toal.
#1 if you are running all dry past the MAF it makes no difference.
#2 if you are wet....tune the first stage as you normally would at your desired AF ratio. But for the second stage...make sure you tune ONLY when using both stages at the same time....and only mess with the jets for stage 2 at that point to get overall AF ratio. You already adjusted stage 1 first...so dont mess with that. In other words...dont tune the second stage all by itself. And of course dont forget to never run the second stage alone (since its tuned with the first stage flowing). Always 1st stage alone or first stage + second and never second stage alone.
Second thing...a NANO type system will pretty much alleviate this minor issue.
I always ran one 15 lb bottle with dual stages up to 325 shot or so. Of course that was dry. But I have done other setups that where duals stage wet and dual stage dry/wet.
You can run two bottles...but with a little foresight and planning I dont see the need. Especially for a 175 shot toal.
06-28-2009, 10:13 PM
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well then its probably either NANO or two bottles to make things perfectly maintainable as far as AF.
But even on a 200 shot...as long as you have good pressure and no line restrictions...I bet your second stage would not be so rich as to cause issues. As a matter of fact it may work to your advantage.
If you do a 75 shot tuned at 11.8 to one or so...no issues there.
If you tune your second stage 125 shot by itself and have it at 11.8 to one or so...no issue there either. At that point you can select either or.
If you hit the second stage 125 in addition to stage one 75 shot with the above tune up you may end up in the 11.2-11.5 range. I still dont see an issue with that.
I would try the single bottle first. IMO two bottles is for MUCH more than a 200.
But even on a 200 shot...as long as you have good pressure and no line restrictions...I bet your second stage would not be so rich as to cause issues. As a matter of fact it may work to your advantage.
If you do a 75 shot tuned at 11.8 to one or so...no issues there.
If you tune your second stage 125 shot by itself and have it at 11.8 to one or so...no issue there either. At that point you can select either or.
If you hit the second stage 125 in addition to stage one 75 shot with the above tune up you may end up in the 11.2-11.5 range. I still dont see an issue with that.
I would try the single bottle first. IMO two bottles is for MUCH more than a 200.
06-29-2009, 08:55 AM
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The pressure drop on the second kit wont be as severe on that small of a shot. As Al mentioned, you just need to tune the second kit while the first kit is activated. If you ran two bottles you could tune each kit individually. Also, tune your first stage with a bottle pressure of around 900psi, rather than a 1000+. You will see less of a pressure drop with this.
Depending on how you pull timing, your most likely going to have it all pulled when the first kit is activated. So with more than enough timing pulled you can run the first stage slightly leaner then you would normally tune it for. Some where around 12.0-12.5. This way when both kits are activated you can get them to settle in between 11.7-11.9 or so.
Depending on how you pull timing, your most likely going to have it all pulled when the first kit is activated. So with more than enough timing pulled you can run the first stage slightly leaner then you would normally tune it for. Some where around 12.0-12.5. This way when both kits are activated you can get them to settle in between 11.7-11.9 or so.
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06-29-2009, 11:46 AM
#8
Iwas going to try to do just the opposite and pull no timing at all and run the first stage a lil fatter then pull my timing on the second stage only. Will that be ok? Or will I see an issue with that. This car will be run on the street and that is the reason I have to be able to play with both shots independently. Gotta let them know I am only one car faster them in the quarter, HAHA!
06-29-2009, 01:05 PM
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I agree being TOO rich is bad as well. But what exactly is TOO rich? Some newbies may be thrown off by the way you put that out..lol. From your experiance....what range is too rich?
06-29-2009, 01:28 PM
#13
On a 150 shot you can be a good ways off and never hurt a thing, it just wont run as fast as it should. On a big shot 300+ you can melt the corners or pinch the ringlands pretty fast with to much fuel.
The problem is there is no set rule of thumb that works for every engine. They all want something different depending on cam, valve angle, chamber design, fuel, plugs, etc...
Best thing to do is start small, learn how to read plugs on the way to going bigger on the shot. While your working up you will find out what the car likes, play with the jetting without touching the timing and see which way goes faster ... then leave the fuel alone and play with the timing to see what it likes. If you do that with 150 shot then it will give you a great start at 2 stages or going bigger with the shot without tearing up your stuff.
I know you know all this stuff but alot of guys dont.
06-29-2009, 07:03 PM
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Well its all depends on the size of the shot.
On a 150 shot you can be a good ways off and never hurt a thing, it just wont run as fast as it should. On a big shot 300+ you can melt the corners or pinch the ringlands pretty fast with to much fuel.
The problem is there is no set rule of thumb that works for every engine. They all want something different depending on cam, valve angle, chamber design, fuel, plugs, etc...
Best thing to do is start small, learn how to read plugs on the way to going bigger on the shot. While your working up you will find out what the car likes, play with the jetting without touching the timing and see which way goes faster ... then leave the fuel alone and play with the timing to see what it likes. If you do that with 150 shot then it will give you a great start at 2 stages or going bigger with the shot without tearing up your stuff.
I know you know all this stuff but alot of guys dont.
On a 150 shot you can be a good ways off and never hurt a thing, it just wont run as fast as it should. On a big shot 300+ you can melt the corners or pinch the ringlands pretty fast with to much fuel.
The problem is there is no set rule of thumb that works for every engine. They all want something different depending on cam, valve angle, chamber design, fuel, plugs, etc...
Best thing to do is start small, learn how to read plugs on the way to going bigger on the shot. While your working up you will find out what the car likes, play with the jetting without touching the timing and see which way goes faster ... then leave the fuel alone and play with the timing to see what it likes. If you do that with 150 shot then it will give you a great start at 2 stages or going bigger with the shot without tearing up your stuff.
I know you know all this stuff but alot of guys dont.
06-30-2009, 02:17 PM
#19
Ok I just finished all the plumbing and no leaks. I just noticed that Nitro Dave's doesn't have a 75 or a 125 jetting so it looks like I will be spraying a 50 and 150 instead. Its going to the dyno in a week or two so we will see what the a/f looks like.
