PSC steering box question

[rdelling]

Anyone running the 621-MR steering box from PSC on their TJ?

I just installed it and a new 1200x pump and 4.5 inch pulley. At RPM's above 1500 it is great, at idle and when I have my foot on the brake (Vanco hydro boost brakes) It is still tough to turn the wheel. I was hoping this box and pump would cure my lack of steering with 37's and full width axle.

I just got the pump back from PSC, because I was concerned it was not putting out enough pressure. They assure me the pump is working.

I have an auto tranny and my engine idles at about 800rpm's..The smaller pulley was to get the rpms up on the pump to help with the low idle...

I bought this set up to add ram assist. Will the ram assist help with the low rpm steering or will I still need to bump up my RPM's to get the ram to work too?

[Jerry Bransford]

If you don't get an answer here soon enough, PM 'mrblaine' on either www.jeepbbs.com/ or www.jeepforum.com/ He helped me get my steering worked out and he's a guru at figuring out various steering issues.

[rdelling]

What steering ar you running on your rig?

[steelman]

If you don't get an answer here soon enough, PM 'mrblaine' on either www.jeepbbs.com/ or www.jeepforum.com/ He helped me get my steering worked out and he's a guru at figuring out various steering issues.

You can PM him right here on MJR as well. :thumbs_up

[blkTJ]

I run PSC steering components but with a "P" pump and without hydro boost, so I'm not gonna be much help.

[mrblaine]

Anyone running the 621-MR steering box from PSC on their TJ?

I assume it's a ported box for adding ram assist, but is there anyway you can tell if it's the 800 series or 808 series box? 800 is direct replacement for the TJ OEM box with the same size piston.

I just installed it and a new 1200x pump and 4.5 inch pulley. At RPM's above 1500 it is great, at idle and when I have my foot on the brake (Vanco hydro boost brakes) It is still tough to turn the wheel. I was hoping this box and pump would cure my lack of steering with 37's and full width axle.

What GPM at what pressure and RPM is that pump putting out? I've been less than impressed with the output of PSC's hot rodded TC pumps and I doubt yours is that stellar if it's a TC with a 4.5" pulley. That diameter pulley will usually smoke a TC pump that been boosted up too high if you run it at freeway speed very long.

Also, do you know if the booster has been high flowed by Van?

I just got the pump back from PSC, because I was concerned it was not putting out enough pressure. They assure me the pump is working.

It's more than just pressure. Erik is running a KRC set-up I adapted into the Early TJ and late YJ that puts out 3.17 GPM at 1450 psi at 1100 shaft rpm. With a 4.25" pulley, the pump is making full flow and pressure at engine idle.

I have an auto tranny and my engine idles at about 800rpm's..The smaller pulley was to get the rpms up on the pump to help with the low idle...

Yeah, but I'll bet it's only been tweaked on the pressure relief side and is close to smoking itself at freeway speed.

I bought this set up to add ram assist. Will the ram assist help with the low rpm steering or will I still need to bump up my RPM's to get the ram to work too?

Adding the ram assist places more demand on the pump. If it can't keep up now, the ram will make it worse.

All ram assist does is add displacement to your pistons which may require a bigger pump or high flowing the hydroboost or a smaller box and the ram, or, well, there are a few ways to fix it, but without knowing what you have, it's hard to know where to start.

What brakes do you have?