Nitrous anyone

Has anyone used Nitrous on a xj550? I've used it on my race car and my DD I have a lot of exprience with it and dollar for dollar its the cheapest way to go fast. I was just wondering if anyone has done it and how it worked out. I'm going to spray it with 18/22 (n2o/fuel) jets which should give me about a 12-15 HP per cyl increase for a total gain of 48-60 Hp pretty much doubling what it has now putting me at around 100+hp thats a power to weight of .23 :twisted: a cbr600rr is .28 and a viper SRT10 is .15 so it should move out pretty good. I'm just wondering how the gearbox is gonna handle the power as well as the clutch. any ideas?

 

back in the late 80s i helped out a yamaha dealer for bike week we put a small set up on a 750 seca jetted it really rich after the first time checked the plugs went richer on the fuel since you cant change the timing went thru 2 gears got pretty deep into 4th dropped a rod thru the pan i wasnt driving it but they said they herd no pinging . but that was over 20 years ago things got alout better since. i had good luck with it on my fi mustang but the kit was made for the car. if you get 100 hp out of it i really dont think the internals will hold it you will probbibly blow the head off it or adleast the fiber head gasket it doesnt even have a steel ring around the cyl i dont believe best of luck it will either go or blow the crank and rods arent nearly as beefy as the old kawisakis or suzukis much lighter and weaker wasnt made for the 1.5 times displacement nos does

 

hmm i didnt know the rods and crank were that weak. we ran a similar setup on my dads kz650csr so I assumed with the 100cc difference I would tone it down a bit from the jets he ran but I had no idea about the weak internals

 

they really arent that weak but designed for making that kind of power but yamaha as well as a bunch of others was trying to save weight to try to stay ahead of the game most of the bikes in the early 80s made close to the same power lighter they could make them the more advantage they had higher rpm rev quicker most of the weight in the motor is the crank thats where they took most of the weight off. if the crank was welded it would probably be fine but to make the power your looking for your going to have to give it a pretty big puff . did you notice on the old kawi how much bigger everything was and hevier it seemed the crank had the same design as the 900s and 1000s wich are know for strong bottom ends

 

OK, here's the thing.. Last time I had my XJR dyno'd, it was putting down 117bhp on the rear wheel with the mods I've done to it (not nitro)

I've a friend who has NOX'd up his XJR and eats through clutches like they're dinner plates at a Greek wedding.

Now the XJR is a heavy bird, but it was built for high torque. Stock, my year bike gives 106Nm @ 8000 rpm and 105 BHp at 6500 rpm, but it weighs a mean 224 kg dry. But from that, I still get 0-60 in 3.6 secs or so. My mate with the nitro gets 0-60 in 1.8 and does the 1/4 mile in 10.8 secs. The rear tyre is 180 wide.

The reason I'm teling you this is cos the 550 weighs only 20Kg less than mine, but was built to handle 50 horses, it's a 26 year old fat lady with a skinny 110 rear tyre.

Putting it bluntly, it's not going to handle the power.. Something is going to break.. And even if you manage to get the power down through the drive shaft to the back wheel without killing the bird, all you're going to do is spin the rear wheel while that knife edge tries to shift all that bulk.

I think you're better off getting a bigger bike and playing with that, maybe an XS1100. Oh and one last word of warning.. NOX'd bikes are no food for corners, the power comes in one big hit, you can't use it.. That might not make any difference to you, but for me, here in the mountains it's essential I have predictable power delivery.

 

this would be strickly for the track, 1/4 mile on a prepped track I dont think itll be a problem getting the power to the ground but it just doesnt sound like the lower end will handle it.

 

Boss, if you want to play around, check out what this guy did:

http://www.xjbikes.com/Forums/viewtopic ... crank.html

Read about his 600 CC upgrade too.

 

great thinking i forgot about that article. even tho the nos would be much harder on it then bumping compression and changing cams. the crank that is . but i would like to see him build it and run the nos would be great reading would like to see how it would stack up against the new 600s if it would run with them he did a great job . the only thing the new 600s would have over it would be aerodynamics wich would show in mph at the end . but could see the look on their faces when an old 550 ran with them . i would think you would have to drop the rear sprocket alout since the redline is gonna drop adleast 500 rpm

 

I still don't think you're going t do it, the engine's too fragile, and you really thing you're going to be able to put 100+hp on the ground on a 110 tyre?? You'll cut a groove in the track!

But I can't wait to be proven wrong.. Good luck with this. If it works (and even if it doesn't) YouTube your first 1/4 mile!!

 

I doubt the Mill is going to handle the Nitros.
Something has to give.

You'll probably blow the thing up.
Without a Scatter-shield ... you could be badly wounded.

 

the reason i think itll hook is because it will be rolled on launch. if it doesnt hook a slick will. I will deff youtube and post the video here, I'm pulling the engine apart 2moro to see what I can do to strengthen it. I'm thinkin Diamond forged pistons and rods, O ring the heads, see if I can get a forged crank or mine beefed up. It helps that I have a lot of friends in the drag racing and engine building industry so the custom parts are not as hard to have made. if there is anything else you think i should do to strengthen it let me know. my main goal is to run a low 10 even if I have to step up to a bigger tire. I've cut a good amount of weight from the bike and i only weight about 125. and rick thats the main reason I havnt done it yet, I can get a new engine easy but if it blows its gonna be nasty. thanks guys for your ideas and opinions

 

what size chain are you putting on this monster ?

 

why are you doing all this work to one of these bikes? also, what are you going to do to give it a crap ton of fuel when you hit that nos button so you dont hole a piston right away? maybe you could try using the enrichment circuit and jet it rich

 

Rich = Slow

The Richer Mixture ignites as the Spark Plug Fires. Because the Mixture is RICH, ... the "Burn" takes longer because there is more Fuel present. Because the Burn takes an eye-blink or two longer; a smooth application of power occurs.

A Lean Mixture is an EXPLOSIVE Mixture. The Burn is a rapid explosion consuming all the Fuel present in a rapid explosion with a percussive strength. The energy is greater. The Burn hotter and dangerous to aluminum components.

 

the way a "wet" nitrous system works is with a small fuel pump and fuel solenoid which supplies the extra fuel. the fuel runs from the petcock to the pump to the solenoid then to the nitrous/fuel nozzle. there are changeable jets in the nozzle to fine tune the nitrous to fuel ratio. the nitrous comes out of the nozzle at 90* and the fuel comes straight out, the pressure of the nitrous blasts the mixture together. so it's really a self contained system you don't really have to change anything on the fuel/air management side. There are dry systems which use only nitrous but personally I don't like them they are cheeper and easier to install but I don't feel as safe using them.
your first question, because nobody will see it coming and to say yeah I sprayed the shit out of a 550.

I just really hope its not gonna be wayyyy out of my budget to build it. I'm patient so I'm fairly confident i can make it happen even if I have to spray it with a much smaller shot. my only real concern is a rod through my leg or a piece of the head in my chest

 

with the wet system set up properly the overall air to fuel of the bike should not change on or off the juice. you add nitrous which adds oxygen and you add enough fuel to get about a 12.5:1 air to fuel ratio. essentially you are just packing more fuel and air into the cyl same as turbo or super charging

 

" ... my only real concern is a rod through my leg or a piece of the head in my chest ... sticking out of my neck, preventing me from dropping and rolling to extinguish the tornado of flames engulfing me from the waist-up, as the shocked crowd witnesses me burning alive, ... watching as the special emergency crew tries to catch-up with and corral the flaming, adrenaline-fueled madman, seemingly trying to take fight before being consumed by the flames which will glow for others to see, immediately, in video on YouTube, before the last fire bottle douses-out your remains."

Flaming Nitrous Guy Fail -- ........ 22,678,323 Views

 

I'm gonna watch this thread.. I love it when people do stuff even though they're told they can't, and prove everyone wrong. Where would we be if the Wright brothers had said "Oooh they said we would fail and might get hurt.. Let's go home"

I still doubt you'll put the power on the ground with a 110 rear tyre, even on slicks with a rolling start, you just don't have enough rubber on the dirt. My XJR has a 180 on the back and has a similar power to weight as the set up you're talking about, and I get a gradual power delivery when I twist the throttle, you're going to have half as much rubber, or less (I'll go out and measure the contact patches between my XJR and my XJ750 tonight if you like) and I can still burn out a worn tyre. I think I read somewhere that the 550 could take a 140 with a few mods, I think that's worth looking into.

And then, if you've got the tyre sorted, when you dump the nox, your front end is going to try to lift if you deliver the gas in one big hit. You'll need to add a brace ot something out the back.

Then if you have the traction and the brace, your chain will want to snap when you dump the power in there. You'll want to put a better chain on.

And if you manage to get the chain to stay in one peice, the drive shaft will want to sheer. However, if you're only on the track, I would think you'll get a few runs before this will happen, unless it's already weakened by age.

The other thing you've got to think about is changing gears, because it's gonna be fast, you're going to have to dump the NOX, change gears and stick the NOX back on in a blink. My mate designed an automatic clutch kit for his XJR, powered by NOX itself. I think he said he got the changer down to 50ms on the track. Definitely look at that other thread on page 1, cos he said he was redlining at 12k, which brought him down to 7k, that'll give you a much wider power band to deal with your changes in.

I ain't saying you can't, nor that you shouldn't.. But it's a lot of work, and I doubt it's as cheap as you say. And I seriously doubt you'll get low 10's out of it.. An XJR weighing in at 225Kg with more than 230 horses and an automatic clutch can only get 10.8 (I think that's what he said he got), my bet is that your best time is gonna be in the mid 12's.

I wonder whether it wouldn't be cheaper and easier to stick a turbo on there instead..

 

Rick.. I think we get it that you think this is dangerous. But I know of HUNDREDS of motorbike accidents (My wife works in intensive care) Does that mean we should all stop riding motorbikes just because it's more dangerous than driving a car? I'm not into wrapping myself up in cotton wool thanks very much.

You're a mech head Rick, I've no beef with you, but it would be good at this point for you to give him some advice from your experience so that he can reduce the chances of ending up in a ball of flames with pistons sticking out of him like a porcupine attacked him! He's gonna do this whether you tell him not to, so you might as well help him to do it safely instead of watching the horror unfold and sitting there saying "I told you so"

Boss.. You want me to see if my mate will give you some advice on how he put his NoX'd XJR together? Might give you a few pointers, he's a very talkative guy when you get him on the subject of Nitrus. He's not on this forum though, if you PM me your email address, I'm happy to pass it on.

 

There should be another Forum where those who are going to Modify and Race Prep have the space all to themselves.

Before I became ill, I probably would have ducked-in to such a Forum to find a Frame Man and a Customizer to help me put a 900 Engine into a 750 Frame.

I have to try to help 75-Hundred people get and stay running, safely.
If I endorse some Mod or start giving advice on matters that might get someone hurt; chances are, ... with 7,500 people exposed to what I have to say, ... somebody might think its what you should do ... do it ... and wind-up having the Parade stop to leave them a wreath instead of riding in the parade.

 

What ill is hamerin' you, Rick?

 

rick if you ever feel the need to make that 900 happen I'd be more than happy to help. I have or have access to pretty much any fab tool or machine you need, doesn't really seem like it would be to hard, extend maybe widen it a little. hmm that gets me thinking my buddy has a wrecked R6 that still runs, maybe I've been going about this build the wrong way....I'm gonna look into this. might be a much cheaper option

 

that wrecked r6... is the front end on it ok?

 

where are you going to plumb the nozzles in? pre carb like a cheater shot or in the head?

i would like to see how it handles it. i would recommend cryo-treating the tranny guts at least.

 

Yeah, yeah, yeah. I've done a ton of drag racing and you shouldnt try more than a 30% increase in horsepower on an aluminum engine right off the start unless your your local parts store is owned by yur dad. Have you checked the price of pistons, rods and bearings for an XJ lately?
It's your bike and its your money and it's your legs it will be between, personally i've considered the same thing on my 750 rh but only about 20 hp worth. Xj frames have been known to crack by replacing the rear shocks with struts, so its not made for wheelies. Mine will do 50 in first and I can easily break loose the rear tire @ 3000 rpm's, (it's a 130/80x18) and it'll do 0-50 in about 3.0. It's all stock except the air intake the jets and the pipes. I'm saving my money to build something more durable and cheaper to buy replacement parts for. Not that my yamaha isn't good enough mind you, (it'll blow an 883 sportster off the road) but it's just to rare, not the right chassis, nor is it disposable. Besides on chain drives you can change the gear ratios stretch and widen the rear triangle or swing arms etc.

 

the 1 thing the 550 has over the rest is its chain drive

 

I'm curious Padre.

You've got Stage 3 jets and a ram air I take it.

According to Dynojet the stage 3 kit gives 10-15% power increase which equates to 90-95HP if the engine was new.. Yours is nearly 30 years old, I doubt it's pushing the exaggerated OEM figures..

To get 0-50 in 3 flat you'll need 105-110 horses..

Are you really getting an extra 15+ horses from that ram air kit?

I'm going to be putting stage 3's on my 750, with individual pods soon.. But if the ram air kit gives that kind of performance boost, maybe I should think about that.. Did you post a thread so I can see what you did and how?