.boB

My V8 car needs to have PS. Old military injuries make it difficult to drive without it. So leaving it off - although that does have some advantages - is not an option.

I purchased the LS1 complete, including the front accessories. And I have a Miata power steering rack to use. The question is, how to mate them up.

I also saw this cool bracket. Flyin' Miata : Projects: The V8 Miata Project I could make the bracket, and buy a new pump. But I already own the LS1 part. And I would have to do a PS delete on the LS1. Both installations require custom hoses, so that's not an issue.

The LS1 PS pump moves about 2.5-2.8 GPM, and makes about 1250-1350 psi.

The Miata pump specs at 1102-1209 psi at idle.
-- What is the maximum pressure the Miata pump makes? (which would tell me how much pressure the stock rack can take)
-- How much does it flow?

charchri4

Bob I have no idea about pressures and never looked at it but I can tell you this, I've run nearly 10,000 miles using the 96 Miata rack and the GM pump from the 2002 Camaro and it works great. The rack has about 200,000 miles on it as far as I know and no problems yet with it. The Camaro track guys have problems with cooking the pump so I used a oil cooler from a jeep I got in a bone yard that is much bigger than the Camaro PS cooler was. The pump has about 60,000 miles on it and so far so good.

The power steering kit from Flyin Miata is designed for a CTS pump and it's a total waste of money. It's 130 bucks for 50 dollars of parts you can get from Summit. The return line is easy I just used the Miata one and it clamps to the GM pump just like did to the Mazda pump. It is tight down there against the pan so it's ideal to plumb that part up before you have the oil pan in the way.

For the pressure side I used this guy http://www.summitracing.com/parts/rus-658530 which is either a tad long or way too long depending on how you route it but works fine. The fittings on the rack and pump is the only thing I used from the $130 kit and I'm not sure what they are but it should be easy to figure out since you have both the rack and the pump. You could probably take it all down to AZ and come up with what you need for a couple of bucks.

.boB

Well that's encouraging.

Do you race? This system will see a lot of time in the upper rpm ranges. I don't want to overpressure the rack and blow it up; makes a mess and ends your day.

charchri4

I haven't had it on a real track yet but have bumped the rev limiter doing stuff like this plenty of times...

The key is keeping that pump cool. I'm using a trans cooler from a full size jeep on it. This 2 row job was way too small.



This is the jeep one and it is about 2 inches taller than what you see here.

.boB

Sweet. Just the info I was looking for.

Do you happen to know the fittings sizes for the pressure side?

You're right. Keeping the pump and rack cool is pretty important. Especially on the track. I'm not sure how I want to approach that, though. My first thought is to use only AN fittings and hose, and a stacked plate cooler. But that might just be overkill.

For this car, rubber hoses and hose clamps would probably do just as well for half the money.

I'm also considering using a 25% underdrive balancer. That would slow the pump down, and that might put less strain on the rack and pump. Also makes a little bit more power (which is never a bad thing).

charchri4

Don't have a clue Bob but it is quite a bit bigger than 6 an and I think it used about a 22 mm wrench size. It should be really easy to figure out though if you have the pump.

Underdrive for a track car is a really good idea.

titangts

Just to back up. My miata had ps using stock rack with ls pump. Zero issues. 212k miles on rack. I have though removed for more engine bay space and better feel. But I can understand your circumstances.

Meierznutz

The Stock Vette balancer has a rear grove for a 4 rib belt. The same as the Miata pump. For Nadine I used the entire stock Miata system with the pump mounted off a bracket that I made from 1/2" 6061 sheet. The pump mounted to the plate with the stock bolts but I slotted the plate to give belt adjustment. It sat low on the block at the seam of the oil pan. If there is room there with your set up I think I still have the pattern, I could make you one.
The great thing about this system is that the only mods I made were to remove the factory cooler and reverse the elbow on the pressure side of the pump for clearance. Later NA's have an outlet that is retained with one screw and you just flip the elbow 180* The larger Balancer actually ran the pump slower so I wasn't worried about cooling.After that everything is a stock part fro any NAPA if there is a failure. Nadine's PS had more than 10k on her without issue last I heard.

.boB

Interesting. At the moment, I'm going to use the stock LS1 pump and bracket, because I already own them. I did install an underdrive pulley. I seriously considered a Miata pump, and mounting it in place of the AC compressor.

Meierznutz

This is the shot of the one time the car saw a lift during the build. I had to drop the front cradle to clearance the Bell housing bolts to avoid rattles. If you look close in the first pic the PS pump is low on the block. The Idler is sill mounted and the Alternator was removed. The bracket used existing holes in the block to mount.
In the second shot the PS pump is way down there. The belts are both installed. In the third pic DO NOT run the PCV line from the valve cover to that rear port! It pulled full manifold vac to the crank case and caused the rings to chatter! LOL
I can send you more pics so you can blow them up to see clearer. PM if you want them.

523-LSX-NB

We use the Miata PS pump w/ a 6 rib pulley. Originally, used the 4 rib pulley mounted low, but was throwing belts occasionally (7K RPM). So, modified to 6 rib set up mounted up high. Discussed this a couple of months ago w/an as mocked up pick in the M.net thread regarding PS, posted in the engine conversions section.

LS John

I realize this is an old post, but ,,,,
I used the stock LS-1 pump with the Miata rack, and my steering was very twitchy. Little steering wheel movements would move the car around on the road. I ended up getting a power steering regulator. Its a small block, with a screw in bolt. as you screw the bolt in, it bypasses more fluid, and lessens your power steering pressure, and makes the steering manageable.
Still looking at larger tire/wheel combos, so haven't been out under hard acceleration yet, but hoping this helps keep the car stable.

.boB

I'v been racing the car for 3 seasons now. Using the stock LS1 pump in the stock F-body location. The Miata rack is also stock. It's all connected with AN at the high pressure end, and rubber hose and clamps on the low pressure side. There is a large tube and fin cooler mounted in the low pressure side.

I find the steering to be easy, and predictable. I don't think it's twitchy at all. But I am running a 275 Hoosier. Here's a video taken earlier this year at La Hunta Raceway, La Hunta, CO. It's a short and very technical track. You've got to be quick on the wheel here.

LS John

Thank you Bob.
I still have the stock 14" tires and wheels on my car, so may be the reason the steering is so touchy/twitchy.
I have a wide body kit from Monster Miata. I am going to purchase 6UL wheels and tires for the car, but was hoping to find out what size tires I can safely use, without rubbing issues. The Monster wide body kit flares the fender lip, and makes the fenders 2- 2.5 inches wider, but does not make the opening higher.
I'm wanting to use 17X9 wheels, and not sure what size tires will fit. 40 series sidewalls will probably be needed, but hoping not to go to 30 series sidewall tires.
If 17" won't fit practically, I'll go with the 15", and see what the largest tire wheel combo will work.

The knowledge on this site is exactly what I needed to find. Thank you all.

02-VIVID

I'm also using a stock F-body pump with the Miata rack on my car. Mine works great. I'm running 245/45-15 on 15x8 6UL wheels.

.boB

3 years ago, I searched everywhere for some 17" wheels. Couldn't find any. And they would be heavier. I am told the Miata chassis is very sensitive to unsprung weight.

Dave Tibbitts