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

Muleskinner · Feb 5, 2004

I fully agree with Bill on the warranty issue. I don't want to buy an engine!!! Any modification I make will be removable so I can put the stock parts back on.

Interesting comment about modifying the injector pump. I noticed Kubota has a tamper proof wire and lead retainer on the wide open throttle set screw, but nothing on the idle set screw. I also noticed the tach reads up to I belive 3500 RPM, but at wide open throttle the engine stops at 2600 RPM.

What, if any, adjustments can be made to the pump as far as richening up the mixture or changing the pump timing? I know the Dodge boys make modifications to the older, non electronically controlled, Cummins injector pumps. I get a small ammount of black smoke when I'm pulling real hard digging with the FEL or using the rear box scraper.

I've seen some of the modified Dodge trucks pour out the black smoke when taking off from a stop light. My 2001 Dodge Cummings does not, so I know their running a chip or some type of fueling box.

I can't belive Kubota has not set the pump up for emmisions standards. Most likely retarded pump timing and a bit on the lean side.

KubotaSteve · Feb 5, 2004

It would seem to me that if you want more power or torque, go to a larger tractor. These types of mods. are one reason Kubota is very strict on their warranty which makes it difficult someone who has a legitimate warranty claim. Unless you are willing to accept responsibility including financially for you modifications, I would say leave it as is. I'm pretty sure Kubota has done their homework when it comes to R&D. I imagine Kubota has used up their share of engines testing their product and found the limitations they put on the machine to be the best combination of performance and endurance. Just my two cents.

MadDog · Feb 5, 2004

Henro & Muleskinner: Tsk, Tsk. /forums/images/graemlins/grin.gif There are some things that it is better to think (or even do, perhaps) than to write about. /forums/images/graemlins/blush.gif

After all, representative of the big "K" may be listening. /forums/images/graemlins/wink.gif

P.S. 'K" ,if you ARE listening, I have no intentions of making ANY modifications to my new B7800, until the final millisecond of its warranty has expired. Honest, ..... take my word for it.

Rick Jay · Feb 5, 2004

MadDog,

( P.S. 'K" ,if you ARE listening, I have no intentions of making ANY modifications to my new B7800, until the final millisecond of its warranty has expired. Honest, ..... take my word for it. )

At which time you should head down to your dealer and trade it in for one of the larger L's. It'll probably be cheaper, you'll get 3 more years of warranty and your tractor will gain an additional couple thousand pounds.

For anything I've used my B2910 for, I've never wanted for more power. At times a couple thousand pounds more weight for leverage and/or traction would be nice, but there was always more power than the weight of the tractor could handle.

On the other hand...if we ever do start timing 0-11.9 times, I guess I could see the point. /forums/images/graemlins/grin.gif

~Rick

CTyler · Feb 5, 2004

I dont' know what its' like with tractors but you get a better deal trading in a vehicle before the warrantee expires. Even if its' a day or two before expiration.

MadDog · Feb 5, 2004

Rick: By then, I just may, although I expect to remain satisfied w/the 7800 for some time, and maybe indefinitely.

BTW, where in the Berkshires are you? I am mainly in Randolph, just of Boston, but I have a summer/wkend place in Alford and the 30 acres there are one of the reasons that I bought the 7800.

RobertN · Feb 5, 2004

It's funny, 'cause my Dad would agree with you... He had the fastest car/truck in the Sacramento area for a while back in the '59-'61 time frame. Course, he'd build motors for the Stock Car, run for a week or two in the car, and then build a new one. He drop the old one in his '32 Ford p'up.

Now, he doesn't even like to change to fancy tires and rims. Leave it stock, less problems...

There is soooo much out there in aftermarket for cars, pickups, ect. People have been hopping up anything with wheels on em for years. Guess tractors are a natural extension of that /forums/images/graemlins/ooo.gif

Rick Jay · Feb 6, 2004

MadDog,

You easterners....geeze...everything west of 495 is "the Berkshires!" /forums/images/graemlins/grin.gif

Actually, the town we live in is called "Feeding Hills", it's a part of Agawam (Now famous for "Six Flags New England"), and it's just on the other side of the Connecticut River from Springfield.

I use the "Western Massachusetts" notation 'cause I lump everything east of 495 as Boston. /forums/images/graemlins/grin.gif

Most of us out here aren't too crazy about Boston...or more specifically, the politicians in Boston. /forums/images/graemlins/smirk.gif

I'll wave if I ever see a B7800 on the Mass. Pike. /forums/images/graemlins/grin.gif

Take care,

~Rick

MadDog · Feb 6, 2004

Thanks, Rick. I've generally viewed everything west of the Ct. River as "Western Mass" and everthing between that and 495 as "central" so I guess that we're roughly on the same page.

Looks like will probably take delivery in a couple of weeks. I'm really lookin' forward to it.