Kubota 4240 non turbo v JD 3720 turbo at hi alt

[jaj2]

I am looking at both K 4240 normally aspirated and JD 3720 turbo. I live at 9000 ft above sea level. Not much air up here, but dealer saying non-turbo not a problem. I need some real life advice. Anyone know how performance on Kubota will be affected?

 

[art]

Do to the lack of air both turbo and non turbo will loose horsepower. There should be no difference.

 

[aczlan]

Do to the lack of air both turbo and non turbo will loose horsepower. There should be no difference.

Non-turbo will lose more power than the turbo will when going up in altitude, but the turbo may require more maintenance.

Aaron Z

 

[jenkinsph]

I can only tell you that I live at 7,500 ft elevation and work between 6,000 and 9,300 ft elevation. Up to 8,000 ft roughly I find no real noticeable difference, but when I am working around 9,000 ft or higher the turbo does better. My Deere 110tlb is natural and the 4520 is turbo, bear in mind though that the 4520 has more power to start with for its weight.

I would say the non turbl would not be a deal breaker but I would prefer the turbo at your altitude.

 

[jaj2]

Thanks for your thoughts. I wonder if there is an aftermarket turbo normalizer (which in general aviation compensates for high altitude on piston engines) for the Kubota

 

[art]

Non-turbo will lose more power than the turbo will when going up in altitude, but the turbo may require more maintenance.

Aaron Z

I'd like to see some printed material on that. I know turbo's require more maintanence at any altitude but I've never heard of that comparison to say that a turbo would loose less at altitude.

 

[aczlan]

I'd like to see some printed material on that. I know turbo's require more maintanence at any altitude but I've never heard of that comparison to say that a turbo would loose less at altitude.

What a turbo does is cram more air into the cylinders, it is (as you probably know) powered by the exhaust gases and impeller speed is limited by the allowed boost pressure (and as such the air density).
As I understand it, at higher altitudes air is not as dense and as such, the same amount of exhaust leaving the engine will push a larger volume of lower density air into the engine and due to this, the engine will get the same (or almost the same) amount of air at the same density as it would at sea level.

See the following links for more info:
Turbocharger - Wikipedia, the free encyclopedia
Swedespeed Forums: Quick overview of the Turbo concept. (For non technical minds)
http://www.tractorbynet.com/forums/general-atv-utv-discussion/64045-turbo.html
http://www.tractorbynet.com/forums/...ng/48034-jd-turbo-vs-naturally-aspirated.html


Aaron Z

 

[Spudland_Dave]

I know turbo's require more maintanence at any altitude

What "more maintenance"?
Other then using better engine oils, and/or changing the oil more often, I know of no additional maintenance...and we have plenty of turbo's around....