MF 7620 Vario engine re map good or bad idea.

[kiwi pom]

I guess if its yours you can do whatever you like with it.

I'm curious, do you guys that chip/remap/delete, disclose what you've done when you move the tractor on?

 

[Will Blackburn]

both 6485 s 130 pto ,6480 115 and 120 pto , 6485 was a waste of time to heavy for the power it had , when we had 2 of them one you could about stand in front and stop it if wasn't in the dealers in bits

6485 s push and pull better than the lighter 6480 size frame models even where they have more hp. They are not a zippy transport tractor or PTO machine.

 

[Cowabunga]

6485 s push and pull better than the lighter 6480 size frame models even where they have more hp. They are not a zippy transport tractor or PTO machine.

In other words they have a lower power to weight ratio in standard spec. That is only an advantage for grip where grip is marginal.

 

[Will Blackburn]

In other words they have a lower power to weight ratio in standard spec. That is only an advantage for grip where grip is marginal.

Useable power on silage clamps and pulling a flat lift. Maybe it’s dynashift advantage over D6. There is a big difference in work rate.

 

[Glaws]

We have got a Massey Ferguson 7620 with a vario transmission, we are considering getting it remap as we are just short of a few hp when towing the drill (non pto drill). I’m wondering if anyone has done it before and if they gained more power or does the transmission just give up under the same amount of load so you don’t gain anything? I’m only thinking an extra 10 -20hp not blowing it brains out.
I’m just concerned about harming the transmission as the last thing I want to do is blow the vario up and end up with a big bill. So any advice/ opinions/ experience greatly received.

There are a few variations depending on build and spec. Whats the serial number of yours?

 

[Tom22890]

There are a few variations depending on build and spec. Whats the serial number of yours?

It’s D172049

 

[Boysground]

I guess if its yours you can do whatever you like with it.

I'm curious, do you guys that chip/remap/delete, disclose what you've done when you move the tractor on?

Ive asked similar questions before, never had an answer! Personally when I buy a tractor I like to know what I am getting, definitely wouldnt buy something modified.

Bg

 

[Bumble Bee]

I was under the impression that the Vario gearbox is set for the horsepower the tractor is supplied with. Increasing the engine horsepower will not increase the horsepower at the wheels as it just blows the pressure relief valve.... and probably warms up the oil more ?

 

[Cowabunga]

I was under the impression that the Vario gearbox is set for the horsepower the tractor is supplied with. Increasing the engine horsepower will not increase the horsepower at the wheels as it just blows the pressure relief valve.... and probably warms up the oil more ?

I doubt it. The PRV only works at under 1400 rpm, above which the thing locks. You can actually set the valve to lock out of 'torque convertor mode' using the menu on the dash. In which case you can pull down the engine to a stall, just as with a fully mechanical transmission.

 

[Timbo]

I was under the impression that the Vario gearbox is set for the horsepower the tractor is supplied with. Increasing the engine horsepower will not increase the horsepower at the wheels as it just blows the pressure relief valve.... and probably warms up the oil more ?

No the CVT (when active) is a closed system - there is no PRV that blows off over a certain pressure (i.e. engine torque input) per sey.

 

[saly123]

I know it’s not a vt but I’ve a 7620 dyna 6 which was as blue delete & remapped. With the better torque and power it pulls a lot better, less revs, less fuel and tractors not working as hard. Was a different tractor after mapping it. Like I said though that a d6. If I had an 18 as been mentioned earlier I wouldn’t do it as it’s the largest in the range.

 

[Frankzy]

No the CVT (when active) is a closed system - there is no PRV that blows off over a certain pressure (i.e. engine torque input) per sey.

Hydrostats absolutely have a pressure relief valve!
If they didn't any sudden increase in backpressure, (such as when dropping into a particularly deep blind furrow), would result in a grenaded pump pretty much instantly.

 

[Cowabunga]

Hydrostats absolutely have a pressure relief valve!
If they didn't any sudden increase in backpressure, (such as when dropping into a particularly deep blind furrow), would result in a grenaded pump pretty much instantly.

Or a stalled engine.

 

[jh.]

Got told years ago about a Massey 7490 or 95 getting chipped . On the dyno it gave 30hp at shaft but out on the road it would do exactly the same speed up a hill chip on or off , with the same loaded trailer on .

 

[Cowabunga]

Got told years ago about a Massey 7490 or 95 getting chipped . On the dyno it gave 30hp at shaft but out on the road it would do exactly the same speed up a hill chip on or off , with the same loaded trailer on .

Well yes it would. Put a ten ton trailer behind 30hp and a hp or two either way is unlikely to make any discernible difference to an abysmal performance.

 

[ollie989898]

My understanding was that generally speaking, you don't need to opt for massive increases in torque or engine power, they can be modest, but the biggest change will be in the shape of the torque curve and the engine will be freed from emissions controls effectively so there will be less restrictions on what fuel can be sent in and when? This makes the machine livelier and easier to live with at the expense of having non-optimal emissions?