Any ideas on how to make a hydrostatic faster?

[Joe leonardo 164]

I have a charger 12 and wanna make it to quicker 

[ebinmaine 67,515]

Hydros really are limited. You can increase the tire size but that leads into a whole new world of modifications.  

 

 

[Joe leonardo 164]

13 minutes ago, ebinmaine said:

Hydros really are limited. You can increase the tire size but that leads into a whole new world of modifications.  

 

 

Darn

[WheelHorseEnjoyer 25]

The best thing to do would be to get rid of the hydro, put the manual in it and make it a Raider 12.

[Pullstart 62,896]

May I suggest, keeping all your posts on this new machine in one thread?  It’ll help paint the whole picture when we’re working to help you get to the ultimate goal - putting around with a grin on your face!   

 

With that said, the guys above are spot on.  Not much you can do to over drive a hydro, but to see the limitations of these machines, check @Skipper’s big hydro thread out!  

 

[JoeM 7,874]

Is faster as in not up to par or you want a hot rod?

[953 nut 55,246]

1 hour ago, JoeM said:

Is faster as in not up to par or you want a hot rod?

3 hours ago, Pullstart said:

May I suggest, keeping all your posts on this new machine in one thread?  It’ll help paint the whole picture when we’re working to help you get to the ultimate goal -

If the transaxle is sluggish there could be some weak or broken springs on your acceleration valves or a pump that needs to be rebuilt. If you are wanting to hot rod it then larger diameter tires are all that is needed. One thing to keep in mind while seeking a solution to your need for speed is the potential damage you could do to the transaxle. The Sundstrand transaxle has no brakes other than the transmission so the faster you go the more internal stresses are put on internal parts when stopping.

[Sailman 1,291]

If you are hot rodding I can't help but if the unit is "sluggish" especially when hot try switching to 10w40 oil in the transmission. Really fixed the issue in my C-120 doing that. If you have ATF fluid instead then this is not a good option.

[pfrederi 17,739]

Charger 12 is one of the fastest WHs 7.0 mph  faster than the gear drives...  a GT14 is a bit faster at 7.5 probably result of larger tires/wheels

[RJR49 129]

Put a smaller pulley on the pump

[RJR49 129]

You would probably need a smaller belt too but it wouldn't be complicated. 

[ebinmaine 67,515]

Just now, RJR49 said:

Put a smaller pulley on the pump

 

Have you successfully done this?

 

My understanding is that the hydro pump is limited to a certain amount of fluid movement thereby keeping the speed down.  

 

[RJR49 129]

I did it on my snowblower. At nearly 50 years old (1975 C-160) I think putting more stress on the hydro is asking for trouble. If there is a restrictor in the system I suppose you could remove it, or enlarge it. But again do you really want to stress a mechanical devise that old? 

[Handy Don 12,232]

13 minutes ago, RJR49 said:

Put a smaller pulley on the pump

Yes, you can turn the pump faster, but you’ll be exceeding the clearly labeled specifications. 

Extra heat and possibly cavitation may cause internal damage.

Find a 520-HC -- they had higher geared rear ends and went 9+ mph stock.

Edited December 9, 2023 by Handy Don

[ebinmaine 67,515]

2 minutes ago, RJR49 said:

I did it on my snowblower. At nearly 50 years old (1975 C-160) I think putting more stress on the hydro is asking for trouble. If there is a restrictor in the system I suppose you could remove it, or enlarge it. But again do you really want to stress a mechanical devise that old? 

 

Not me, no. 

Just curious.....

I'm the other way around in fact.