mazda oem power steering pump on ls1

[orion4096]

Several people are running the Mazda oem power steering pump on their ls1 with good success.  I've never driven a rotary powered FD to compare, but I prefer the mazda pump on my ls1 swapped car over the ls1 pump with turn one fitting/restrictor.  People suggested starting a new thread about the different ways to do it.  It's straightforward if you have the resources to fab a simple bracket(s) and spacers.  Some of the choices you need to make are:

- Decide which pulley you want to run (Mazda ~4.6" vs aftermarket 6,6.5,etc).  All the pulleys I've seen that weren't designed to replace the Mazda pulley have different offsets which needs to be designed into the bracket.  Depending on which pulley you pick and how you design the mount, you may be able to re-use the Mazda high pressure line.
- Design a bracket that mounts the front, back, or both ends of the pump at the proper offset from the head.  KRC has some good diagrams of the ls1 offsets on their website.
- Fit an aftermarket reservoir.

If you want to run the Mazda (or aluminum aftermarket equivalent) pulley then here's an example bracket from wickedrx7 and a similar one that I 3d printed but never made out of aluminum:







KRC makes a 6.5" fbody offset pulley that bolts onto the Mazda pump.  The offset moves it much closer to the pump body which requires a smaller bracket.  I chose to re-use the GM bracket as a base and make two smaller brackets to sandwich the pump between with various sized spacers.  I was hoping to make their y-body offset and 6" pulley work with the same setup, but the bracket would need to be redesigned and the fittings wouldn't clear.  This is what's on my fd right now:







KRC also makes a 6" SBC offset pulley which is a lot closer to the Mazda pulley offset.  I'm trying to (so far successfully) convince them to make me a 6.5" version.  This would be a much simpler bracket like the first one, would allow you to run any pulley on fbody accessories, and might also work with the y-body offset using shorter spacers and an aftermarket pulley.  At least, that's the plan...

[orion4096]

Other, reasonably priced aftermarket pulleys would be good.  I couldn't find any details on how big the various Mazda replacement pulleys are.  Since I'm running a stock size damper, having a 6"+ PS pump pulley makes me sleep better at night knowing it won't be at 10k+ rpm at the 6600 rpm limiter.  Although, people have run it this way without problems.

The reservoir placement is also not ideal.  I'd prefer a much shorter feed line to the pump and a reservoir mounted over it.  This may require a new inlet fitting.

[quinns]

So wicked's with the factory rx7 pulley is being over driven? This is the reasoning for the bigger pulley right? I'm considering tackling this during the winter want to line up some parts. I'm running gen V Camaro ls3 accessories though so mine would likely need to be spaced even further out.

[orion4096]

Ya, it depends on the crank damper size.  The oem FD crank pulley and PS pulley are about the same diameter.  My ls1 damper is 7.53" diameter which is about 64% larger than the FD crank pulley.  Not sure it matters, though.  A timken PS pump bearing replacement is rated up to 12k rpm and the pump stops adding assist (internal bypass?) at a much lower rpm so it's just the bearing, shaft, pulley, and whatever else is spinning that has to deal with the higher speed without additional load.  Not sure what the plastic pulley is capable of.  That could be the only real problem at the higher speed.  In theory, it also takes more HP to spin it faster, but that's probably negligible.  It's also going to provide more assist at the same rpm with smaller pulley before it saturates.  Not sure that you can tell the difference.  The ls1 power band is so different than the rotary it's hard to compare assist at various rpms.  Basically, lots of small things that bothered me which is why I went with the bigger, aluminum pulley.  The only thing I don't like about the bracket I'm running right now is it's complicated and I wasn't able to get y-body accessories work with a pulley swap.

Spacing out further should be easy to do.  I ordered the 6" SBC offset pulley and should have a bracket for it in a week that works with the mazda pulley, too.  The 6.5" SBC offset version is going to take a few weeks (months?) to hit the next pulley production run at KRC and I didn't feel like waiting.

[halfspec]

Thank you for the information. I've been lurking in your fabrication thread with much interest
I think the only reason you aren't getting more replies is that more than a few minds have been blown 

I wish this knowledge had been available when I got started years ago. As it is, it's going to be a while before I can even think about tinkering with this idea as breaking down anything on my FD. It is becoming more and more challenging because in my wife's eyes, I'm not moving towards completion when I keep breaking things down and redoing it lol!

Thanks again
Lane

[orion4096]

Made a new setup this weekend.  Not sure I like it, though.  It can fit all reasonable diameter pulleys, but now the pump sits high.  I thought moving one of the spacers to another hole on the head would be better, but now the pump has to be where it's in the pic because it has little clearance in any direction.



Another option is going back to the leftmost bolt holes on the head and trying something like the following.  This is where the bracket I'm running now puts the pump and with a 6.5" pulley it can use the same length belt as the ls1 pump.

[Mik3ymomo]

I am really interested in converting to one of your designs when it looks to be a clear
Path to do so. It's still a little bit of R&D for this to work with particular accessories.
For instance I have LS1 accessories on my LS3.
So that puts me in the Fbody camp.
Sounds as if you are running the Ybody?

Is it Possible a solution would be metal
Stanchions for using Fbody vs Ybody as seen with the Katech Tensioners?

They sell the exact same tensioner to Ybody or Fbody customers. Only difference is the Fbody guys get the metal spacing stanchions to go behind the tensioner for proper belt alignment.
As seen here next to the tensioner.
[smg id=7081 type=preview align=center caption="DbkP1fk jpg"]

[wickedrx7]

I think I am going to redo mine this winter to accommodate the larger pulley. So if you need to buy (2) to help convince them, count me in.

After a few spirited drives, my ps pump was making a little whining noise.  I do have a small oil cooler (going to go bigger on this as well) but fluid seemed to get pretty hot after some high rpm driving. I am sure this will be true even with the bigger pulley but I think it will help to save the life of the pump. 

It is important to note that I think I remember my pump doing this back in the day when I tracked the car with the rotory.

I just think the design will be better with a larger pulley.

One thing I haven't done is measure the stock ls3 pump pulley, I will do this tonight.

[orion4096]

My FD has f-body accessories.  The Miata has y-body accessories, but no PS - useful for testing fitment and belt alignment, but not much else.  Different length spacers (stanchions) was the plan for y-body spacing, but now I'm not sure it's going to work without a new bracket and a pulley that sits closer to the pump.  For y-body, there's not enough room between the head and the back of the pump using the Mazda pulley offset, but you also can't change the offset too much on the pulley before it starts interfering with the the bracket or pump fittings.  Most people aren't running y-body accessories so I might just give up on it.

The 6" SBC offset pulley is showing up later this week so I'll find out this weekend what fits.  I tried a few other pump placements and ended going back to the first cad drawing I posted above ... I just need to make it out of aluminum.  Drilling the bolt holes is easy.  Drilling out the center hole for the pump with a cheap hole saw and drill press is not fun.

[wickedrx7]

Clamp the piece down and keep spraying with wd-40 to keep cool while drilling. 

And let me know on the fitment of the 6" pulley.  I might have to get one.  It "might just clear with my current bracket...

I am running y-body so I do care!

[orion4096]

How did you get your pump to fit with y-body accessories and the mazda pulley?  My pump would be sitting inside the head if I spaced it back another ~.7".

[wickedrx7]

I am running ls3 accessories... they sit farther out than f-body.

[orion4096]

Oh, like the truck style.  That makes more sense.  The y-body stuff from the c5, c6, and cts is the hard stuff to fit.

[wickedrx7]

Ah, for some reason I thought that was ls3... No biggie.  Can't wait to see how that pulley works.  What did they charge you for it?

[orion4096]

It's $80 on Summit if you can find another $20 to get there for the "free" shipping.  http://www.summitracing.com/parts/krs-krc20017600

Once I'm done bolting it on and running it this weekend I can mail it to you to try out.  It looks like it needs about .15" (two washers?) worth of spacers on the pulley to get it to line up with the Mazda pulley.  I'll check it this weekend.