Nytro boost level question

[nytro boy]

Ok your Tony's buddy that I did the bung for tonight with the SE right that custom clown did the install for? Did they clutch that sled at all or anything?

Fuel system is a NECESSITY beleive me that motor will be in a box without it, I probably know more about those kits then anyone. If you do not do the fuel system it will blow. Yes they are charging extra on the damn fuel system, did they do a fuel pressure regulator as well?

The forumal to figure out the SC rpm is all you can use to get close.

Examples are take your gears. 25 and 29 divide the bottom gear by the top = 1.16 gearing ratio

Take RPM x 12.7 which is sc internal gearing x ratio = 125222 sc rpm.

To give you an idea I was playing around with the pulleys. I had a 26t on the top, I beleive the only gear I could get for the bottom was a 30 but you will have to ask tony I cannot remember.

this works out to a sc rpm of 124,000 I know for a fact that that the 124,000 rpm was producting 8+ psi to close to detonation on pump fuel for me.

This is assuming 8500 rpm the only way to decrese boost then is to run less rpm, which would need more gearing to achieve the same top speed at a lower rpm.

Hey Jamie,

you did have a 29 gear in the bag of tricks you had that had been used. I now have a 27 top and a 29 bottom which when I do the math puts me at 115,507 assuming 8500 rpms which would be between 6-7psi yes/no but isn't the clutch set up you had closer to the 9400? and would that not put the psi up over 8psi ?

 

[TurboJamie]

Ok your Tony's buddy that I did the bung for tonight with the SE right that custom clown did the install for? Did they clutch that sled at all or anything?

Fuel system is a NECESSITY beleive me that motor will be in a box without it, I probably know more about those kits then anyone. If you do not do the fuel system it will blow. Yes they are charging extra on the damn fuel system, did they do a fuel pressure regulator as well?

The forumal to figure out the SC rpm is all you can use to get close.

Examples are take your gears. 25 and 29 divide the bottom gear by the top = 1.16 gearing ratio

Take RPM x 12.7 which is sc internal gearing x ratio = 125222 sc rpm.

To give you an idea I was playing around with the pulleys. I had a 26t on the top, I beleive the only gear I could get for the bottom was a 30 but you will have to ask tony I cannot remember.

this works out to a sc rpm of 124,000 I know for a fact that that the 124,000 rpm was producting 8+ psi to close to detonation on pump fuel for me.

This is assuming 8500 rpm the only way to decrese boost then is to run less rpm, which would need more gearing to achieve the same top speed at a lower rpm.

Hey Jamie,

you did have a 29 gear in the bag of tricks you had that had been used. I now have a 27 top and a 29 bottom which when I do the math puts me at 115,507 assuming 8500 rpms which would be between 6-7psi yes/no but isn't the clutch set up you had closer to the 9400? and would that not put the psi up over 8psi ?

Perfect glad Tony chimed in, I was bitching at MPI all winter that we needed a custom built 28 for the bottom, IMO that is what you guys need to make the sea level boost numbers or we have to clutch em for less rpm, less rpm with stock gearing = less speed, even less rpm with the gearing I gave you Tony = less speed.
Was the 27 from MPI?

I beleive now I had 29 bottom and 26 top correct?

Spinning 8800 = 124,655


29/27 spinning 8800 = 120,000 I believe this should get you very close to 7 psi on pump gas sea level. Which is perfect, we may need to add / subtrack tip weight to get our peak RPM where they need to be for safe boost. Better to play with the lower boost pulleys and take a gram of weight out and gain rpm which will = speed with your gearing. Then run most boost and lower rpm.

Things we need to consider though are more rpm with boost = higher chance of detonation on that big piston in the nytro.

Lower RPM with boost = less chance of detonation just depends what game were playing here.

Low boost say 6-7 psi at 8800 -9000 rpm would be my game instead of 6-7 psi at 8500 rpm.

You getting a 27 on top is the same as dropping a tooth off the bottom so you should be very close to where you want to be. I beleive you had to remove that oil tank boss off the frame to fit that 27 no?

 

[Skydog]

25 top
29 bottom

Where does that put me? At 8800- 8900 RPM.

THANK YOU Skydog

 

[TurboJamie]

131,xxx rpm likely around 9 psi of boost to high for pump gas.

 

[nytro boy]

Perfect glad Tony chimed in, I was bitching at MPI all winter that we needed a custom built 28 for the bottom, IMO that is what you guys need to make the sea level boost numbers or we have to clutch em for less rpm, less rpm with stock gearing = less speed, even less rpm with the gearing I gave you Tony = less speed.
Was the 27 from MPI?

I beleive now I had 29 bottom and 26 top correct?

Spinning 8800 = 124,655


29/27 spinning 8800 = 120,000 I believe this should get you very close to 7 psi on pump gas sea level. Which is perfect, we may need to add / subtrack tip weight to get our peak RPM where they need to be for safe boost. Better to play with the lower boost pulleys and take a gram of weight out and gain rpm which will = speed with your gearing. Then run most boost and lower rpm.

Things we need to consider though are more rpm with boost = higher chance of detonation on that big piston in the nytro.

Lower RPM with boost = less chance of detonation just depends what game were playing here.

Low boost say 6-7 psi at 8800 -9000 rpm would be my game instead of 6-7 psi at 8500 rpm.

You getting a 27 on top is the same as dropping a tooth off the bottom so you should be very close to where you want to be. I beleive you had to remove that oil tank boss off the frame to fit that 27 no?


ya Jamie you were running the 26/29 pullies, I don't know about the oil tank boss as I don't have the tank back on yet but now that I have my frame back and installed I will be mounting this tonight and I will let you know about how it fits tomorrow. The bung you welded on for me last night is in the perfect place and the sensor fits great, thanks again for your help.

MPI also sent me the instaructions today for the fuel pump install so i don't need that info anymore, they seem great when it comes to this kind of stuff but I can totally understand how frustrating it must of been last year when their kit didn't have these add ons and they truely did not understand the ramifications around it. I still don't understand why they don't have more info readily available such as gearing options, psi charts at different elevations, clutching etc....

Hopefully I can get some running in next week to see where I am at as I think that will be the only way to know for sure where the psi level is at

 

[TurboJamie]

Perfect glad Tony chimed in, I was bitching at MPI all winter that we needed a custom built 28 for the bottom, IMO that is what you guys need to make the sea level boost numbers or we have to clutch em for less rpm, less rpm with stock gearing = less speed, even less rpm with the gearing I gave you Tony = less speed.
Was the 27 from MPI?

I beleive now I had 29 bottom and 26 top correct?

Spinning 8800 = 124,655


29/27 spinning 8800 = 120,000 I believe this should get you very close to 7 psi on pump gas sea level. Which is perfect, we may need to add / subtrack tip weight to get our peak RPM where they need to be for safe boost. Better to play with the lower boost pulleys and take a gram of weight out and gain rpm which will = speed with your gearing. Then run most boost and lower rpm.

Things we need to consider though are more rpm with boost = higher chance of detonation on that big piston in the nytro.

Lower RPM with boost = less chance of detonation just depends what game were playing here.

Low boost say 6-7 psi at 8800 -9000 rpm would be my game instead of 6-7 psi at 8500 rpm.

You getting a 27 on top is the same as dropping a tooth off the bottom so you should be very close to where you want to be. I beleive you had to remove that oil tank boss off the frame to fit that 27 no?


ya Jamie you were running the 26/29 pullies, I don't know about the oil tank boss as I don't have the tank back on yet but now that I have my frame back and installed I will be mounting this tonight and I will let you know about how it fits tomorrow. The bung you welded on for me last night is in the perfect place and the sensor fits great, thanks again for your help.

MPI also sent me the instaructions today for the fuel pump install so i don't need that info anymore, they seem great when it comes to this kind of stuff but I can totally understand how frustrating it must of been last year when their kit didn't have these add ons and they truely did not understand the ramifications around it. I still don't understand why they don't have more info readily available such as gearing options, psi charts at different elevations, clutching etc....

Hopefully I can get some running in next week to see where I am at as I think that will be the only way to know for sure where the psi level is at

Sounds good Tony,

when going to install the top gear for the SC you are going to hit the boss for the oil tank on the frame, its going to have to be cut off or something and a new tab made for the oil tank to bolt to. You will see what I am talking about when you get there. I had ground my boss and machined the 26t gear to fit however the 27 being bigger the boss is going to have to go, but the boost should be near perfect!

 

[nytrosedude]

Tony is used to grinding / hacking parts off of everything he owns so a small boss mount will not slow him down !...I think MPI came out with a 28B pulley so this may be a better way to go and just put the 26T back on top....What is SRXSPEC running for pulleys on his SC setup ? I don't have my fuel pump yet but I want to try this sled out...do you think it would hurt it at all to run it at low speeds (70 -80 mph) until my fuel pump arrives ?

 

[TurboJamie]

Tony is used to grinding / hacking parts off of everything he owns so a small boss mount will not slow him down !...I think MPI came out with a 28B pulley so this may be a better way to go and just put the 26T back on top....What is SRXSPEC running for pulleys on his SC setup ? I don't have my fuel pump yet but I want to try this sled out...do you think it would hurt it at all to run it at low speeds (70 -80 mph) until my fuel pump arrives ?

DO NOT ride it at WOT at ALL or I can guarantee it will hurt it, even with race fuel you can't get enough fuel to it to save the motor.

 

[nytrosedude]

Thx for the info Jamie...on another note was it you that had purchased Dalton springs and weights for your old Nytro ? If so where did you purchase ? I think Winner's Circle in Markham is a distributor ?

 

[TurboJamie]

Thx for the info Jamie...on another note was it you that had purchased Dalton springs and weights for your old Nytro ? If so where did you purchase ? I think Winner's Circle in Markham is a distributor ?

I cannot remember without looking at my notes what I ended up running in Tonys clutches. If you are running the same boost I would start with that setup I can guarantee its about right on.
I get all my stuff though Bondi Engines in aurora here, he can get everything from winners circle and happens to be a good friend of mine.

 

[slymax]

So, back to my original train of thought on my MCX Nytro. I am mapped to 18lbs. What if I run stock motor, no headshim or cam changes. Put in the 10mm hardened headstuds. Run straight 100ll and water/meth injection? and run it up to 18lbs. Will it live? The water/meth will eliminate deto. What will the difference be versus running the headshim? Same horsepower, more torque?

 

[mr.]

jamie is on the money i built same sled with same results, i ran race fuel for 1700 kms $$$$$ couldnt get solid info from mpi. they should spend some of their advertising cash on r&d.(tired of riding sled like a dog shitting razor blades, nervous) gonna try powderlites kit comes a little more complete with r&d.and support.

 

[Skydog]

water/meth injection works but man lots more crap to go wrong. Not go for a trail sled if you ask me...

Skydog