4000 Twenty power questions

[timb]

The injectors appear to be the same but there IS now a difference showing up in the pumps and turbochargers.

Pumps: The 4120/4320 use "RE526495". The 4520/4720 use "RE526494".

Turbos: The 4120/4520/4720 list "RE523753". The 4320 lists "RE523756". (weird)

 

[rockyridgefarm]

you are the guy.

 

[Bulverde]

Someone must know...I checked on the parts and there seems to be no difference. I am trying to get the actual shop manuals. Maybe they will tell a story. Will get back to all but one would think that a certified mechanic would have to have some idea or he may make your 4520 a 4120 with the wrong part (or turbo boost).

Interesting???

 

[Bulverde]

By the way...How long has the 4x20 series been out? Long enough for the bugs to be worked out? Lastly, I read in here that compact sales seemed to be off and we were expecting increased incentives. Any word???

 

[firtol88]

My guess is combine timb's #2 & #3 with slight part variations and ignition tuning.

anyone say chip it.

 

[Bulverde]

I called JD yesterday and asked the question about the differences. They said that only the dealer can call JD technical support.

I called my dealer who a technician just return from the training school. This is what I am told:

1) There is no difference between the tractors in any respect (from a parts standpoint).

2) The added power comes from ignition timing and injector timing. He suggested that this mod could be performed at a local injector house. My only question would be...How do you know that the HP has been bumped and to what?

3) JD had a similar HP increase on some of the 5xxx series tractors a while ago. This was done mostly with injectors and turbo. JD's position was that a customer could make the change but could void the warranty.

4) I asked the sales rep to verify exactly what would make a 4120 into a 4720. I committed that I would purchase if he got the answers. He is checking on this and is supposed to call me today or Monday.

I also wonder if anyone makes power upgrades for the 4120. With autos, you can get a new mapping chip or intercooler, etc. I don't think that the deere's have the computer control modules yet but are there other power mods?

Will check back when I hear from The dealer.

 

[Bulverde]

Tim,

Interesting findings. I wonder if we could obtain spec sheets on all four components.

 

[Sparkeee24]

Howdy!! In my interests in finding the same information, I registered with John Deere's online parts catalog info page, and it shows many interesting things. I can't make it all out, since I'm not knowledgeable on the inner working of newer diesel fuel injected turbo charged systems. But it does show diagrams of ALL the internal pieces along with part numbers. It is somewhat tricky how to get there, I stumbled across it myself. But information is there! This may or may not be correct... BUT, here is the page for the Fuel Injection Nozzle to fit the 4320 tractor http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets Hopefully that takes you to the injector page... Maybee this will help re-kindle this thread! I noticed about 18 different washers, that placed behind a spring and piston assembly within the injector nozzle, adjusts the amount of fuel flow through the nozzle. I THINK...These are each in 2 and 3 thousandths thickness differences. Sparkeee24

 

[Sparkeee24]

Howdy! Allrighty... Evidently they have made 2 models with the 4320 designation. The washers I mentioned show up on the 4320 model, not the 4320 CUT... I too am seeing no difference besides these models besides turbochargers. This you can tell exterior under the hoods. take care folks. Sparky

 

[wkoukios]

I would think it all boils down to computer calibration.
These are direct injected engines requiring computer control, thus the variables are not hardeware but software driven. However, if the computer program calls for more fuel than a specific injector can provide, you must change that as well.

The turbocharger sizing is more related to Displacement(Engine size) and at what rpm boost is to be optimized for. Many other variables come into this area, Is it waste-gate controlled? Is it a variable goemetry turbo housing? Or is it simply designed to be optimized at pto engine speed?

I just bought a 4120 and did not go with the 4320 because of huge cost for 5 hp.
I believe the added cost to be the expense of keeping emisions unchanged. So the cost is not parts, its R&D.
I hope to boost mine up after warranty expires. That gives me 3 years to research.