Power or Manual Steering for CSP Miata
 

Folks, I am in the middle of a dedicated autocross build to SCCA CSP specs. The power steering seals are leaking badly. My question is, should I replace the power unit with a manual rack (I already have one) or rebuild/replace the power unit. At least one accomplished driver recommends keeping the power unit for the quicker ratio. However, many of the top cars have the manual rack to save weight. I am curious about what everyone thinks. FYI a depowered rack is not legal for CSP.
The build so far:
‘90 B spec Miata
’94 differential with RX7 LSD
Delrin differential bushings
JIC Magic FLT-TAR monotube shocks
700lbF 450R springs
Energy Suspension urethane bushings
ISC offset Delrin front upper bushings
AWR adjustable upper rear control arms with Delrin bushings
1.25” NB “Big” Racing Beat Sway Bar, rear bar removed
SuperMiata end links
’03 motor
Megasquirt
949 Racing 15x10 wheels
275-35-15 Hoosier Tires
Autoconnexion fender flares

Saving weight is everything in autox, so go with what is the lighter option.

Also, cheat and dont get caught. But you might need the extra mechanical advantage with 8" wide meat-hooks on the front. start working out.

You can run the non powered rack with thirteens but with the big fifteens you need power. The top runners run PS.

How do you guys run Power Steering without the AC compressor?

Shorter belt!

I would run the power. I think only one car in the top 5 in csp doesnt have it, and I had to step over the pile of PS parts they just purchased way too many times in their garage last weekend. Honestly you only need it for steering speed or bumpy lots. The car will turn in faster than you can physically turn a manual rack. But unless its really bumpy I didnt feel the need for the power assist from a strength perspective. That car is actually easier to drive around in paddock than my car with only 225's so maybe its got magical steering geometry from the factory.

Oh yeah, add spare hoses to your kit of spare parts because 275s like to blow up rubber PS hoses.

Use the 2001 subframe and system. Much better.

Yes with the 275A6 you NEED p/s, maybe even 255 13".

I drove a competitive CSP car at Nationals a few years ago and it was on 275's with non PS and I never felt it was a problem (finished 5th with a bent subframe). I am digging back into my head, but I don't recall any of the top CSP guys Nationally run PS (that was 2010 though).

I think it really comes down to how much the weight matters to you. The steering ratio is quicker, but of course there becomes the issue of "feel" and "perference"

I know sheniker does now. And I'm almost certain that fraser does. Pretty sure most everyone else copies what they do. It weighs 6 pounds more than the manual.

Sheniker wasn't back then, but things change in 2 years. It does make the build a little easier though since you don't have to source a golden NB non-PS rack. I know when I drove the ex-Darby CSP car, it was a close copy of Sheniker's car at the time (minus some details that were added in 2011). Now if someone can just figure out a way to keep the hoses intact.

The car Fraiser is driving isn't even a 100% car. Last I heard it was still using a Torsen. By all accounts his a machine. Some people can just flat out drive. I co-drove with Jason Collett a for a few years in ASP and he is one of those guys. I could never catch him in many features.

OK, I’ll be repairing my PS and buying some extra hoses!
Are the top cars all running the NB subframe?
I was considering installing R type outer tie rod ends to help the geometry, an opinion on that would be appreciated.
I should probably jump in here with the build goals. The car is intended to be a budget CSP build, everyone hold your laughter. I picked up the car with the 03 motor already in it. The guy who swapped it could not get it running so the car was bought as a project (cheap). I’ll leave questions on the motor setup for another thread.
Most of the parts came from Craigslist or other autox cars. For instance, I realize the JIC’s are not the best setup but they came off a regionally successful SSM car. I could use a winter project so I might consider the subframe.

I know a national prep CSP car is on NA subframe, I dont think it matter much, use the lighter one?

In my car, with 10" wide slicks or 275 a6s, I want to try ps... running a looped rack now and its a damn workout that sometimes distracts from the necessary precision, IMO. I think it could really make a diff for most drivers, and I think it'd increase my abilities... feel through the wheel becomes less important when you're yanking that hard in slow corners.

I just put my PS system back in the car today.. Tossing the thirteens.
It was not needed with the smaller tires but after driving Kubo's car with manual and fifteens a few years ago...

lol, small world. That car rides a trailer with my old hardtop that I sold to Darby.

I wish I'd had the money to buy that car when he sold it. It was the most fun car I've ever auto-x'd over the years. Makes me want to build one of my own.

Its up for sale again. The guy who bought it just wasnt into it (and wasnt nearly as good enough of a driver to compete in CSP).

Haha. I am still in the "I wish i had the money" phase of my life. Out of curiousity, how much is the owner asking for?

The car has it in it in the right hands. I am not a great driver by any stretch, but I finished 5th in it. That was before he found the rear subrame was tweaked (we knew something was wrong, b/c of the rear camber) and before Brian Johns retuned it for the 2011 season and it picked up a lot of mid range power. Put it on a corn diet and a few minor tweaks and should be right there at the top.

I dont remember how much. But national level CSP isnt something to get into lightly. IMO its the most prepared SP class and has the largest amount of talented drivers. Put it this way, CSP was the fastest SP category at nationals this year, and even 5th in CSP was faster than Junior (evo school guy) in his SSP corvette. And the top 5 CSP cars were in the top 11 in pax(out of around 1200).

Ah the old Power vs. Armstrong steering debate in autox.

You have the guys that swear by power steering and think anyone who gives it up is crazy. Then you have the guys that like the "feel" of a manual rack.

Then you have the guys in the SM classes that don't have ROOM for power steering, and then end up depowering their power rack on top because they don't believe anything. Don't do this, don't be like me.

Either way, if the difference is 6lbs, just keep it and remember to take a pre-race dump.

I'm already trying to figure out where to stick the mr2 PS pump that will go in at some point in the future at the same time as an NB subframe and power rack.

I'm trying to figure out what sort of workout routine i need to adopt to deal with the 275 A6s on the front of a FWD Macstrut car using a depowered quick ratio rack.

I agree CSP is a fast class, that is why I'd like to be there. Plus my only other option is SSM and a lot the fast SSM cars are in the Southeast. Rather run in CSP in the southeast and maybe walk a way with the some tires from Tours.

I think the biggest advantage to PS in a CSP is the quicker steering ratio. With the new found power in CSP, the extra drag of a PS isn't as a big a hit as it used to be.

I choose CSP because, like all of us, I like Miatas. This is my first car build, despite the fact that I am well on the high side of a half century. Information and parts are readily available. I am no alien so getting a trophy at national is not in the cards for me. The CSP sure will be fun on our parking lot courses though.

Leafy,
Google cheap autocross car sometime. The answer is always Miata of course. How wrong that assumption can be :)

I put a spreadsheet to estimate the cost of a competitive CSP car. Based on parts alone, it would be around $15,000-17,000. That is assuming you pick up a cheap 90-93 and that you don't sell and of the components you swap out. Almost 1/3 of that cost is the dampers/coil overs.

I am curious if anyone has tried to under drive the power steering pump to decrease the pressure and reduce the number of hose failures.

Thats a pretty low cost. Figure 3500 for head work (what an e-stock spec head costs in labor, so an estimate) + what it costs to get the bottom end re-built to spec, whatever penskees or tripple adjustable xidas. 2 sets of 15x10's with 275 A6, 1 set of 15x9 with h2os, aero, seats, flat top, ecu, custom intake, rb header, custom header back, tubular control arms, that air craft alternator that some people run, a light weight battery, the voodoo that you do to the power steering to make it last, swisscheese brakes, getting the correct fd and tranny combo, big front sway bar. That'll get you mid pack with some good driving.

Blah. You are talking about 100% car, which only a few exist. The driver counts for a lot more than that last 5%. Fraiser is an example of that. My estimate was to make a competitive car, not a 100%

Built motor: You're going to get 90% of your power on a stock motor. I can tell you Darby's car on 93 was within 15whp of Schenker's now.
Dampers: I agree that, that's why 1/3 of the budget is there.
15x10's: Why do you need two sets? At most you need one extra mounted in case of a catastrophic flat mid heat.
15x9's: Not that expensive from Tire rack.
Aero: I built an ASP spoiler from aluminum scrap for less than $100. Assume the splitter is around the same, maybe a little more.
Intake/Header/Exhaust: That was in my estimate (though I used a Honda IM in my estimate with some DIY work from friends)
Control Arms: Not as important, I'd only replace them if the stock ones were damaged
Stock alternator works fine.
Battery: Give me something that starts the car every time. I hated carrying the jump box for Darby's car just in case it didn't start. Puts too much stress on the driver before the run.
PS pulley wasn't in my estimate.
Brakes: My estimate was just 1.6 brakes and FM Little BBK.
Transmission and Final Drive: Just talk to people ahead of time.

Darby's car didn't include many of the items above and I finished well into the trophies. I've been around auto-x for years and I've seen drivers with less prepared cars win over 100% because of the driver.

15 HP is a lot in csp. You need the control arms to get enough camber. The pulley isnt the way to fix the ps (not sure its even legal). And yeah the aero parts are 100 for the big items but stays and mounting add up to almost as much as the big pieces. You also need a trailer and a hard top. Hard top only for transport and monsoons.

My estimation was based off what I already own (like a tow vehicle, trailer, hardtop, and certain spares). The spoiler was less than $100 with the stays. You can get enough camber without control arms. The only benefits to the arms besides the weight is a being able to control the camber without changing the tow and without increasing the track width.

Well no. The arms let you get more camber than the ~2.7* that you can get at that ride height normally.

Ok. You race on paper and I'll just drive.

Now why not take this a step further and improve the power steering? Imagine steering with 2 fingers?

Because you still want some steering feel, you're not driving miss daisy in a Lincoln town car.

you just want the feel to tell when the tires are slipping?

your whole body should be able to feel that.






Driving newer cars that dont feel as connected as older cars you learn to drive it and it is a lot easier physically on you over a weekend.

gtfo, where do I get this mystical belt that fits?

I measured with a piece of hose! I was off a bit though...

Grassy ass.

+1 for keeping ps. I run 15x9/275's in csp with ps but no ac (just use the no ac belt) and it's the way to go. You can focus on your driving and not slug it out with the wheel on sweepers.

I just drove my car on 275 purple crack yesterday. I got the wheel ripped out of my hands only once, when I got late in a slalom and tried to just hoosier magic force my way through it and ended up getting all sorts of sideways. After that run I came in and went. I want power steering.

Isn't a PS pump a supply only as much as it demands kind of deal?

Well i'm guessing most people go with a different power steering pump because its the easiest. I'm thinking how about redoing the fittings and all that with bigger diameter ones?

A different ps pump isnt legal.

Read section 15.1.a.

But a different pump pulley is.

The answer to burst ps lines is in 15.1.a and that is as much as I'm allowed to tell you.

Sounds more like driver error than not having PS.

I got late because I tried going faster through the slalom, the car had the ability to make it I didnt have the ability to muscle the wheel fast enough.

My build inspiration is the John Becker car. I started with a ‘90 that has a 03 motor (with headers) that the owner could not get running. I traded a buddy a set of wheels and tires for the Mega Squirt. Being a 90, some of the back date stuff won’t be necessary to add lightness. Gaining 2.5 negative camber is attainable with ISC offset bushings at a reasonable expense. The seats are a combination of new and used Kirkey aluminum, light and cheap. You get the idea this is a budget build. There is no escaping the tire cost for running CSP though.

Well not exactly, if you win 2 scca regional events a year and have a hoosier contingency you'd get 4 free tires a year. Not easy to pull off, but it's not impossible.

they paid tires for regional event too?? i am confuse.

I think he means tours.

correct, my bad I meant national tours that come to your region.

How do you guys swap the pulleys?

Off topic but while we are on the topic. Ever so often, while I am sitting in traffic, if I try to rapidly turn the wheel to pull out from behind a car, it feels like the power steering stops working for a second. Is this just pressure building in the system or a problem?

22x10 hoosier road race slicks in R35 compound on 10" wheels. Depowered rack. The only time I notice having to make an effort to turn is under 10mph and even then it's not exactly an issue.

Currently recessing as necessary to go to 23.5 by 11.5 on 12" wheels.

Swap the fluid to Redline Power Steering anf that goes away.

I have not tried it yet but adding a power steering fluid cooler with the Redline ps fluid is supposed to take care of the problem of blown lines. Does anyone want to share specifics on this?

If you saw this in the email, think about it.

Is it as simple as sucking it out? I haven't looked but I do not think there is a dedicated drain for the PS system?

Thanks for all the insight. I appreciate it.