Looking for some nitrous info

[Hitndahedfred]

Hey guys,,

I know there are some high performance members here and I would like to run this by those who know.
Building my first, and probably the only bike I will own so I am taking my time and doing the things I want.
It is a 1979 XS Special with an engine from an 82 as the original engine was in a flood and is still locked tight.
Compression is decent,,over 100 pounds so I don't think I will do the top end till it suffers or displays symptoms of being blown. I haven't seen this engine run yet but it did run when it was removed from the original bike it came from.
So,, I went with the Joe Wiseguys "Tracker" manifold which angles the carbs (New VM34s with velocity stacks) out a few degrees from the factory "straight" back orientation. On the manifold there are 2 set screws on top of the runners, 1 for each runner. I had a wild idea of using these "ports" for a light volume nitrous injection system.
I am NOT looking for quarter mile performance, just an increase in power when it is needed so from the initial investigation I have read, the engine MAY be suitable for this.
So I am asking those who have done this either on any vehicle, but especially on the XS to chirp up and let me know if this is a possibility. The manifold I have is black and not the chromed one shown.
Attached are images of the bike and the intake for your perusal.
Thanks guys

 

[member3480]

OK have done it on many drag bikes but not a XS650. I am doing a turbo setup now on one and only running small boost because of the motor design.
So here is what to think about??????
If you do put a bottle on it what pill you going to use 50 - 100 - 150 - 200. Me I don't think more than 50 will work because you are trying to double the horsepower with just 50 pill. CRANK TRANS CLUTCH could it take it?????? NITROUS is right away when you push the button and it either goes faster or goes BOOM! So now you have to ask yourself is all that work worth it on a XS650 getting the gas to match the bottle?
I have drag raced for over 25 yrs and used a lot of nitrous on motors but I had more money in the bottom end to keep it together than the bike costs. Plus I had three bad nitrous explosions one on a GS1100 and the clutch basket decided to exit the bike. One on a HAYABUSA that wanted to show me the rods up close and one on a KZ1000 that back fired threw the carb and lite me up like a crispy critter. So yes you can do anything on a bike but if you have no experience in doing it and don't have a proven motor to handle it why try. You could maybe find a kit that has a 25 pill and try it a couple times but if you want to play with nitrous buy another bike that could handle it with a stock proven bottom end. I am building the turbo for show and I know some guys that have pushed 12 pounds of boost on a XS650 motor but for how long.
I always tell people that use to come into my show that want to go fast DO YOU WANT A RACE BIKE OR STREET BIKE????? There is a difference. Nitrous boom's are quick and dangerous so I would look into this a little more before I would go out and bolt a bottle on the bike and over power the STOCK motor. Will stay tuned to see how you make out

 

[TwoManyXS1Bs]

...getting the gas to match the bottle?

Very important consideration. You must add extra fuel with the NOS.
How, where, and how much?

You could be inventing the wheel here.


And blowing it to smithereens...

 

[retiredgentleman]

"Looking for just an increase in power when needed".With only 100 psi compression, a wise man would do a top end re-build before thinking about NOS.

 

[figure8]

He said its over 100 psi.

 

[retiredgentleman]

OK lets say its 105 psi..................it still needs a top end overhaul.

 

[member3480]

Its not the top end I would worry about. Cowboy had to make a lockup clutch for his turbo and NOS comes in quicker so I would be worried about clutch plates coming apart.
I been on bikes that went boom and learned the hard way with my GS1100. The clutch basket exploded in 3rd gear about 800 feet out and motor locked up and almost took out my leg and tried to throw me over the bars. Wakes you up fast. I know so many people that listened to the counter guy at the speed shop and blew up car motors because they had no experience. Fogger system with a plate is the safest. Injected in both ports is a little more tricky with matching the gas. Just remember if you do it go with much bigger gas ports so you have way more gas.

 

[FLEA]

mmmm

 

[Hitndahedfred]

You guys seem to be missing that this is NOT going to be run like a drag bike. I am looking for the minimum amount of NOS that will make a gain. It will probably only be used when passing a long line or to get "away" from something. I do not need quarter mile performance. And I will probably rebuild the top anyway before I add it just because it is below spec.

So DADDYG,,,You seem to think an injector plate would be best? If needed to use that,, I will. I was thinking though that since the manifold already has "ports" on each runner I may as well take advantage of them. I am open to a working idea guys.

 

[TwoManyXS1Bs]

I'm thinking that a 'wasted spark' system would add a degree of risk. Justa thought...

 

[member3480]

I understand what you are trying to do . So if you were going to use each port that way you would need a Y for NOS and gas and I would look for the smallest pills I could get for the NOS. If you put 25 pill in each you almost doubled the horsepower. That would be a 50 shot and that may work for what you want. You could always try it I have done some crazy things too . I know I tried 20 lbs of boost on some bikes and blew the boots right off but I also have put a 100 shot on a stock bottom end Hayabusa and had no problem. My only concern is the clutch basket on a XS650 and if it will hold up.
Good luck post you results.

 

[cowboy3669]

the stock pistons won't last very long with a 50 shot. I know from experience only about 5-6 10 second passes.I dropped down to about a 12 hp (.015 jets in both the fittings on a Fogger setup) shot in each cyl. with about 13 lbs. of boost the pistons last almost the whole season.On my setup the nitrous is on for whole 10 sec. run.
Cowboy

 

[cowboy3669]

The stock clutch springs and plates won't hold a lot of power.

 

[member3480]

Now here is the guy to ask the questions. He builds XS650 to get the max performance out of. I am surprised it can take a 30 shot without destroying the clutch plates. I have cleaned clutch plates with 10 pounds of boost on some motors. I would think that for what he want's just as a passing gear around cars in traffic that a something below a 30 shot would work but what would be the gain? I am glad you jumped in here because I have seen pictures of your bike and the performance you have got out of a XS650. I just ride my XS650 and don't try and get crazy going threw traffic. So we are down to maybe damaged pistons damaged clutch plates and springs so I am assuming trans and crank can take the abuse.

 

[cowboy3669]

the trans has not been a problem except when I tried the over drive 5th gear.as people has found out there is little or no undercut on the dogs and mating slots.so under full power the two gear twisted away from each other and force the shift drum out of place,breaking the case ending my day at the track.
I welded the crank pins to the wheels to keep them from spreading from the rpm and twisting forces.
for use as a passing gear ,stiffer springs should be the thing you need.
Of course only a recommendation USE AT YOUR OWN RISK.
Cowboy

 

[Hitndahedfred]

SO Cowboy3669,,,

Using the parts I have, and the desire to have a low OSI shot only, (25#or less),
What parts do you recommend for me to use? I would like to have a bottle of 10 ounces or so due to space neede3d for electrics and whatnot.
If you can lay out a "plan" for me That would be cool,,,
OR I can pay you for your knowledge and experience, putting a parts package together for me to either purchase from you or a trusted supplier.

Hit

 

[Brew]

just add some flame throwers in the exhaust if you want to look cool...

 

[Hitndahedfred]

just add some flame throwers in the exhaust if you want to look cool...

Not interested in looking "cool"...
I want the 4 barrel performance for passing lines of cars or for that "Oh SHIT" moment where ya need more than ya got.
NOT interested in quarter mile times either. The NOS is strictly for a "just in case" event.

 

[Brew]

Can you paint a picture of a oh shit moment where you will need to get all fast and furious? My oh shit moments normally call for more brakes, not more speed.

 

[Brew]

http://www.xs650chopper.com/2008/12/yamaha-xs650-bobberon-nitrous/