High performance Kubota B7800

Muleskinner · Feb 2, 2004

As my background is in high performance vehicles, I am interested in seeing who can come up with the best idea for a K&N style air filter and air box for the Kubota B series tractor.

The stock air filter gets dirty fast and the air box and filter leave a lot to be desired as far as air flow goes. Yes I know 2600 RPM is the redline for the engine, but horsepower and torque can be improved at low RPM's, as shown by the Cummins modifications performed by their owners. (Redline at 3500 RPM)

And then I wonder about using the same size exaust pipe to finish the system as Kubota uses from the exaust manifold to the muffler, instead of the smaller step down exit pipe. And a high flow muffler also. (Flowmaster?) /forums/images/graemlins/grin.gif

Ahhh,,, and then a turbo. Kubota lists a turbocharged version of the engine on their web site. /forums/images/graemlins/shocked.gif

Moon · Feb 4, 2004

Yea, yea, yea. I don't have the answer for your questions but I like the way your thinking. I have never paid much attention to the exhaust, but eliminating the step down would have to add a little more HP. A K&N filter for tractors! What a concept. Next we'll have to have a Tim Taylor tractor racing thread!
Keep us posted if you try any of these mods. I for one would be interested.

CTyler · Feb 4, 2004

Take your tractor down to the local dyno shop and get a base line. Then add your mods one at a time and see what it does.

You might want some earplugs or a loud radio. This would help drown out the laughing as they point at the crazy guy dynoing his tractor /forums/images/graemlins/crazy.gif

Henro · Feb 4, 2004

Zero to 11.9 in how many seconds? /forums/images/graemlins/blush.gif

Muleskinner · Feb 4, 2004

Yea I know. My wife keeps telling me, "Why do you need more power. It's got all the power you need." I guess it's not about needing more power, it's about improving on things that can be improved.

The air cleaner issue is one I'm going to be working on, as the filters are expensive and seem to get dusty very quick. I have to blow the filter out just about every time I use the tractor for any amount of time. I have been surfing the net looking at the cold air boxes and systems for Hondas etc. Also the air box systems the diesel truck guys are putting on their beloved diesel pick ups. There are some real nice well thought out systems out there.

As far as the exaust system goes, I know a guy who owns a high performance exaust shop who could make up a custom system. The question I have is the increased noise issue. I find my tolerance for loud exaust systems has declined in my old age and I'm not sure if I want to listen to a loud exaust system on my tractor when I'm on it for several hours. Although most of the eary tractors I have seen had an exaust system without mufflers.

As far as a turbo, well if I had an unlimited budget I would do it in a heart beat. The increase in power and torque would be awsome.

JerryG · Feb 4, 2004

What you need is a pre-cleaner. They are used on all sizes and types of off road equipment. Here is one company, but there are several different companies that make them. Sy-Klone

dieseltoys · Feb 5, 2004

A precleaner might be the simple solution, but I agree a K&N would be nice, if you could adapt a larger filter airbox you would gain some by having a larger filter surface area so it won't get dirty quite so fast. As far a performance you would probably gain more through modifying the exhaust. I used to have an old L245DT that I mounted a hydralic snowblower to the FEL. I always had plenty of power until I did that. The first thing I tried was to punch the center baffles out of the muffler which helped out quite a bit, granted it was louder but not untolerable, just sounded powerful. I also tweaked the injection pump for more fuel and rpms. The stock setting was 2800 rpm and it would never make a hint of smoke even when lugging down. The amount of smoke coming out of a diesel under load is a good indication of how it's performing, a little black haze is about right, thick black or grey plumes indicate overfueling and could result in overheating. I suppose thats alright if you're planning on hitting a tractor pull. /forums/images/graemlins/laugh.gif After I cranked mine up I was getting 3500 rpm and a good black haze under a heavy load. I'm sure I gained at least 5 HP. I ran it for several years like this without any trouble. A turbo would be the ultimate upgrade if you have the room under the hood. You just missed one on e-bay that probably would have been the right size. /forums/images/graemlins/frown.gif

Henro · Feb 5, 2004

One thing I don't think has been mentioned.

Kubota seems VERY strict about repairing anything under warranty if it has been modified by the owner.

If you modify the air cleaner or exhaust and have an engine warrenty issue, you may not be covered.

I would wait until the warrenty expired before making any changes myself...or at least keep all the original parts and put them back on if I had a problem, BEFORE I spoke to the dealer about the problem [Ethics? What's that?].

RobertN · Feb 5, 2004

For the air cleaner, you would still need a pre-filter/trap(little dust cup). When I work in dusty condidtions with my older B8200, the dust trap fills fairly quick, I can clean it a few times before I need to worry about the filter itself. Your B7800 must have something similar? Even if you ran a K&N, you'd want to catch the bulk of the dust before it...

You could run an open exhaust. I have thought along similar lines, using a single size pipe up to an old exhaust tip from my Harley(get a little chrome on there /forums/images/graemlins/smile.gif ) I too am more sensitive to sound as the years go by. If I'm on the tractor for more than 15 minutes or so, I wear ear muffs. In stock form, they are not very loud. But, listening to the drone of the motor for a period of time gets annoying.

The only thing about running an open exhaust, that I would particularily worry about, is sparks(fire danger) and running a lean exhaust which may burn an exhaust valve...

slowzuki · Feb 5, 2004

Another problem, if your filter is getting dirty you do not want a K&N.

They have been shown to increase contaimination of oil when used in construction equipment.

Ken