10-19-2007, 06:58 PM #1
Nitrous... a dry system for efi gp1300r
Some of you have read some of my testing with nitrous, but I created this forum to try to make it easier to follow for those curious. Please keep posts in this thread to comments, ideas and questions about nitrous.
Let me say this also, before you even consider installing nitrous, make sure your hull is set up right, engine is running perfect, and no handling problems. Nitrous is a lot of horsepower, more then any other single modification and can put you at a very high speed in blink of eye. With just a big impellar, stepped sponsons, ride plate, efi controller and nitrous you can hit the elusive 80mph mark.
Please, I can't stress this enough, if your setup isnt right, you can get damage your ski, engine or worse get hurt. You can accelerate to a very dangerous speed. Please contact local WFO (he is flying with these efi skis) , BEN HERMAN, KERRY, FERCHO, ISLAND RACING, JIMS or some other professional or experienced person to help you with setup if your not sure your set up for those speeds safetly.
This point was ground into me, so I will relay it...NEVER EVER ride over 65 with stock intake grate.... Severe handling problems can occur. Its happened to me and many others
What nitrous does is incredible power for short bursts until the bottle is empty. With my typical riding a bottle will last me all day. Its perfect for dragracing environment. If your wanting it for extended runs you will be very disappointed in nitrous. It can make you go very fast for a short period of time but then your back to slower then it was before mounting the nitrous when gas runs out due to extra weight and changes you made in your setup to accomodate the nitrous. Nitrous doesnt burn, so I do not think it adds a fire hazard ( unless you cut your block in half fireball) as we arent adding any fuel lines or changing anything in our fuel system.
My ski is work in progress. I will push it very hard in next few weeks to find limits of jetting on stock ski because I want to go with BB ported engine this winter and if I whoops my current setup, it wont be end of world to me. Plus i have 2 other skis to ride and my downtime will be minimal. All this information is just from my personal experiences and may not reflect what you would if we have different setups.
My setup is very very simple and easy to duplicate. Feel free to message me for any details you want more information on or to just say hi. I will freely share my phone number if you want to talk about it, and will never charge a dime to help you out or install a system for you. My job is sporting goods, not jetski performance. I do 100% feel you should support an experienced tuner in your area.. thats how they make you safe and fast while earning a living.
OK... so your still curious about it ???
FIRST and foremost, you have to have an experienced tuner get the set up correct. Once engine is running perfect and your hull is setup to maximize the power increase then the bottle can offer tremendous fun at low cost for short bursts. I am a big fan of nitrous, the bottle on the back is a great conversation piece Searching GREEN HULK forums is the biggest speed increase of anything I have done
In addition to being properly setup, you will need a tach, egt (see my thread on how to get one cheap) nitrous solonoid ( not fuel) line, bottle and mounts. You can find used nitrous setups on ebay under 200.00
to duplicate my setup costs...
tiny tach 55
egt 50.00 if you have to buy new
nitrous line, tank, and solonoid ( usually 150-200 used on ebay)
nitrous jets 4.50 each.. recommend .018 to start... I have sizes .018 .022. .024 .028 .032 .039
efi controller 175 used
most performance efi skis should already have all but the 150-200 for nitrous parts, so you see this is pretty inexpensive
I installed my bottle on back of my ski using short bracket for top, and hose clamps for back. I ran my braided line under the seat and to the nitrous solonoid. I started with .028 jet and ran from solonoid where the jet was located to a braided line, then to a 40 inch 7/16 fuel line which allows the nos to warm up and be able to disperse easier with the ambient air. I then ran the line into front of air plenum where I had removed the big plastic triangle shaped bulb. The .028 jet was too big for a stock 14/20 impeller as it would bang the rev limiter hard with only 2 seconds on the button.
My stock settings on the efi controller are 3 3 1 7. Lowell Horning suggested with nitrous I set my 4 pot to 5.5 and 11 on the 3 pot so all my nitrous testing has been like that. I would rather be fat and safe then lean and being towed in.
In all my testing, I would accelerate to 65 mph without nitrous and when I was over 65 and red light on the controller, I would hit button and HANG ON!!!! IT RIPS! Engine changes tone and ski leaps ahead...
I didn't try the smaller jets with stock pitch 14/20 dynafly ( only had the .028 with me) but I feel like on my setup 75 mph could be achieved with a .22 jet at 7400 rpm. It could possible run 76, but with my .028 jet, I banged the rev limiter so hard and fast the ski only accelerated to 75.3 with stock pitch.
If you want a good place to start thats mild, install a .020 jet efi controller 3 3 11 5.5 and you should get 3-4 mph with stock dynafly
I tried 22 pitch ( give or take, I had never repitched an impeller before and was using a gauge i had printed on paper so could have been pitched from 20-22 ) and with the .028 I was still banging the limiter but went 77mph.
Over the next couple weeks I will try different settings, pitches and jetting. I feel like with 24 or 25 pitch I would hit 80mph with my .028 jet or possibly the .032
My EGTS are 1200 wfo without nitrous and 1300 cruising part throttle. I will try to tune ski to maximum until I hit a speed where I dont have resonable degree of safety or stock fuel system can't supply enough fuel to keep temps below 1250 ( in which case I may go to wet gas or methanol system and still go after bigger numbers.
I think 90% of people will be happier with their skis with vf3 reeds, keyways, heads, compression, porting, or bigbore because the power is there, and they dont have to worry about nitrous running out right when they are about to race that guy on stage 3 rxp. But for the guys who want the rush that nitrous gives, I hope my thread helps......
one thing, since I do not know limits of efi controller, so the guys with all the engine mods, most likely will not see the same increase in speed a stocker will..... in drag racing, nitrous can make a 10 second stock 1/8 car into 8 second, but can only take a 4.50 et 1/8 mile car off nitrous down to 4.30s ....
BTW, I am looking for a bad efi controller that so I can adapt to making a 5th pot switchable for nitrous. If you have one you can send me to experiment with, if i can get working properly, I will be happy to modify one for you for free msg me if you have one.
some pics of my install, as I work with it will provide some videos with my camera phone...
SAFETY TIP ... Do not press button if engine is cut off. It will cause very lean pop when trying to crank and could damage your reeds. IF YOU have a nitrous solonoid stick ( happened to me one time in 10 yrs, but it can happen) Just kill your engine, turn off bottle.... and wait minimum 5 mins to restart with seat off.
Warning... THIS WILL CAUSE arm ripping acceleration! Nitrous is much more effective at lower rpm, while I am using it for top speed runs, If you hit button 1 sec after nailing throttle ( dont hit from idle) It will accelerate like crazy!!!!
The seadoo guys have superchargers as power adders ( and some nitrous) this will level the playing field
THANKS for all the words of encouragement and PM's... hearing the excitement of people interested makes it more exciting to me
link to my EGT http://www.greenhulk.net/forums/show...ht=temperature
Last edited by RUNWME; 10-19-2007 at 08:06 PM.
10-19-2007, 07:02 PM #2
more pics .. please keep this forum constructive and on topic.. also, many of you may have more experience with nitrous or these skis ( FOR SURE!! ) and I would welcome any constructive critisism or suggestions in this project
To keep all of this easy to read for future readers.. I will put most of questions and responses ( mine or others ) in this field... If you see anything I write is in error, please PM me and I will correct now.. lets have some fun!!
Last edited by RUNWME; 10-19-2007 at 07:42 PM.
10-19-2007, 07:04 PM #3
RUNWME,whats the hp shot on the gas?
10-19-2007, 07:10 PM #4
I spoke at legnth with the guys at NOS about this..... 1300 cc 2 stroke .028 is approx 30 hp
The jetting hp increase is effected by engine size. If you have more compression and bigger bore, I think it would be closer to 27 hp
the .20 I feel like will be about 20 hp the .32 about 35-38 hp
10-19-2007, 07:24 PM #5
Nice work keep us posted on the testing. I love NOS I had it on my VW 1835 Sandrail when I lived in Cal.
10-19-2007, 07:53 PM #6
Very good post thank you for sharring this info so freely i have a eldelbrock double trouble nitrous kit laying around and was looking for a way to put it on my ported 1300 i will be pming you for a little direction. like you said if it blows go 1400
10-19-2007, 08:09 PM #7
as far as drag strip my harley goes 10.8 in the 1/4 on motor and 9.8-9.9 on the bottles 35 shot.
10-19-2007, 08:14 PM #8
What size jet do you have in your harley?? thats things flying!! Sounds like you already have everything you need to make it roll... send me an email or pm and we can talk about our setups....
10-19-2007, 08:29 PM #9
Thanks for being an information contributor. Also if you have not already, please reinforce your pump tunnel. Being passive and accepting constructive feedback is a positive here, as it develops more thought process and interaction with other members of this forum. There is alot of information here on this forum. Always keep safety number one on your agenda. I advise this to every member.
10-19-2007, 09:10 PM #10
I like the pics! I did a friends dry setup like this once, it was just a quick install on a LS1 F-body. Just took a noid connected it to the bottle and then had a plastic hose coming out of the noid to the airbox. Worked great for a 100 dry shot.
If this all works out I think the next step would be for shark nozzles to be placed in the throttle bodies right before the throttle blades. Tap the fuel line for the fuel. Then you would have the ultimate setup. Wouldn't want to get too close to the reeds... wouldn't want to freeze them.
Not sure of any benefit since the pill sizes are small but that would be one cool setup!
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