2 stroke Nitrous Question for the experts!

[nosguy]

Sorry to post in 4 stroke forum, but there is much more on nitrous over here! I have a 2000 SRX 700 with a NOS wet system, fogger nozzels in each carb boot with 46nos 52fuel jets and an electric fuel pump made by NOS, pumps at 4psi. I try to keep bottle pressure a 900psi, clutching is 40/10 heel clickers with engagement notch fully loaded (64grams), red spring, silver secondary spring at 80' and advant-edge helix 46-41. Gearing is 19-40. I run this sled on 500' grass. The nitrous system is activated using a Dynotune nitrous controller set a 1.6 seconds (was set at 0.8 seconds but almost flipped the sled!) I trying to get this sled to run in the 4's. My only pass on nitrous has given me a 5.58 et at 84mph which I thought was very slow. Off the bottle was 6.45 at 72mph.
Question, after I passed the finish line and let off the throttle the sled stalled. Pulled it over a couple times, started and ran fine. Seem like it was flooded. Too big of a nitrous fuel jet you think?
As for clutching I don't know what rpm I'm turning. I don't have a VDO on the sled. Without nos and trying to watch the stock tach it looked like it was running 8500 rpm. Do you think 64grams is enoungh weight with nos? I can't add anymore weight to the clickers. What would you do for clutching?
Last question what are the biggest nos/fuel jets have you ever run? What added horsepower do you think it made? I have seen a stock 1994 Polaris 800 on nos running a 4.90 et. What jets he was running I don't know but they must have been bigger than mine!

 

[NOS-PRO]

Sorry to post in 4 stroke forum, but there is much more on nitrous over here! I have a 2000 SRX 700 with a NOS wet system, fogger nozzels in each carb boot with 46nos 52fuel jets and an electric fuel pump made by NOS, pumps at 4psi. I try to keep bottle pressure a 900psi, clutching is 40/10 heel clickers with engagement notch fully loaded (64grams), red spring, silver secondary spring at 80' and advant-edge helix 46-41. Gearing is 19-40. I run this sled on 500' grass. The nitrous system is activated using a Dynotune nitrous controller set a 1.6 seconds (was set at 0.8 seconds but almost flipped the sled!) I trying to get this sled to run in the 4's. My only pass on nitrous has given me a 5.58 et at 84mph which I thought was very slow. Off the bottle was 6.45 at 72mph.
Question, after I passed the finish line and let off the throttle the sled stalled. Pulled it over a couple times, started and ran fine. Seem like it was flooded. Too big of a nitrous fuel jet you think?
As for clutching I don't know what rpm I'm turning. I don't have a VDO on the sled. Without nos and trying to watch the stock tach it looked like it was running 8500 rpm. Do you think 64grams is enoungh weight with nos? I can't add anymore weight to the clickers. What would you do for clutching?
Last question what are the biggest nos/fuel jets have you ever run? What added horsepower do you think it made? I have seen a stock 1994 Polaris 800 on nos running a 4.90 et. What jets he was running I don't know but they must have been bigger than mine!

nosguy - I have the same setup on my 2000 srx with the fogger nozzles, and after I let off of the button, there is gas still being sucked into the engine from the line. That is why most companies ask to have the solonoids as close as possible to the nozzles. I keep burping the throttle after I let off, and as I slow down, I keep the throttle open about 1/4 way till it runs clean.

I think you are good for clutching as it will increase to 10,000+ with your setup.

You have some pretty big jets in there now, and don't know how big Holley Brand makes them, but it can't be more than that. I will look in my book at home for jet sizes. funnel jet, right?

Terry

 

[nosguy]

Yes they are funnel jets NOS-PRO, and my nitrous and fuel solenoids are connected to the fogger nozzels using NOS high pressure tubing, each one mearsureing about 8" long.
As for clutching, I always thought that you should add weight to you primary to bring the rpms down to normal (8500) while on the bottle. Is this true? Yes I know it will be a dog off the bottle because of the added primary weight, but I would be getting full advantedge of the added horsepower when it does activate. Also, what shot do you think I running with these jets?

P.S. thought you might like this picture. This was with the nitrous controller set at 0.8 seconds. After I just passed the christmas tree, I let off the throttle because the sled almost flipped over!

 

[NOS-PRO]

nosguy, I thought you were at 8,500 rpm's. You must be at 9,000 right now then? I would bring it down a little bit.

It was a little hecktic here last night as we had storms all evening, with trees down in the neighborhood, and power outages. I will check tonight for the jet chart.

 

[nosguy]

My first pass without the bottle and watching the stock tach, it looked like 8500-8700 rpm.
My next pass with the bottle on, I was unable to watch the tach, but I would think the rpm's would be near 10 000. I will be buying a VDO within the next week or so.
Do you know when the rev limiter kicks in on these sleds? Is it ok for the rpm's to go into the rev limiter while on the nos?
I can't add anymore weight to the heel clickers, they are fully loaded 6 washers in the heel, 3 middle and 3 in the tip (64 GRAMS). I'm thinking about buying the Super Tips or Hauck Launching weights because I can add more weight to them, but I just got the clickers. I hate clutching! What would you do if this was your sled?

Do you think my nos and fuel jets are to wide spread?
Sorry about asking so many questions! I just need some help with this thing to make it work.

 

[hlmrx1]

If these heal clickers are like mine get some tungsten washers for the tips, that what I had to do with mine once I added the turbo, although I had to grind a little off for them to fit. The clickers don't have enough weight, you run out of room with the washers they come with.

 

[NOS-PRO]

nosguy, I have seen 10,500 on my srx, not that I liked it at that much rpm, but have seen it. I thought the rev limiter was 9,500, but that is not so. If you hit the rev limiter, it will start to pop, which if done for a long period could hurt the reeds. I had nitrous on my four wheeler with an air shift, and it would pop when shifted, no problems, but changed the reeds every 2 months.

It is better to have more fuel than nitrous on that setup, so it is better to be widespread. I usually set the nozzles about 4-6 apart, is where you are at now. toom uch fuel and it will bog when it is engaged.

I would contact SRXMAGIC, or Srxspec on clutching issues to see what they say.

I have yet to try that big of a shot. Hopefully soon!

 

[nosguy]

thanks for all the help Nos-Pro and hlmrx1

I'm going to try finding some tungsten washers and bolts for my heel clickers and add more weight to them. Checked all my local hardware and specialty fastener store's but can't find any yet.

I'm also going to switch my solenoids. I currently rum NOS powershot solenoids, but they only flow
enough nitrous for a 150hp shot because they have .072 orfice size. I have some Super Pro Shot solenoids wich are have a 400hp flow limit (.110 orfice size) that I will try.

Last change will be nos/fuel jets. I'm going to try 52nos 55fuel jets since I have them here. On a nitrous jet calculator, 52/55 should be good for 120hp shot per cylinder.

I have another question. I run a NOS small displacement fuel pump part # 15760. Do you think this is enough fuel with this pump? The pump draws fuel via a "T" fitting thats mounted on the feed line between the stock fuel tank and the stock srx fuel pump. On the outlet side of the nos pump, it runs directly to the fuel solenoid. Is this how you have yours mounted?

 

[hlmrx1]

thanks for all the help Nos-Pro and hlmrx1

I'm going to try finding some tungsten washers and bolts for my heel clickers and add more weight to them. Checked all my local hardware and specialty fastener store's but can't find any yet.

Try just washers to start, I think one will replace several of the standard ones that came with the kit. I don't think you'll need the tungsten bolt, probably hard to find, as the threads will have to match and you'd have to make sure you have the clearance for the head. Weigh what you have in there now and weigh the tungsten washers, you probably find that these weigh quite a bit more.

 

[pro116]

Nosguy your sled loses power over 8500rpm's nos pro has a race cdi box because he has a full prostock motor and pipes so his is different.
I would recommend getting some super tips.
I had 69grams of weight in my heel clickers set up for grass I know some guys ran more yes you need tungston washers.Run a softer compound beldt also.