SP3CTR0

Hey Everyone,

First post to the forum.

I am hoping that someone on here can help me where the manufacturers have failed me.

A little background: I am in the process of building a 1970 Mach 1 that will be my weekend toy. I am building this car to be as capable as possible on the track while still being something that I can still live with driving on nice days. Performance is very important to me, but I am not hardcore enough to consider a manual steering rack. Ultimate goal is for my car to drive like my 07 Shelby GT, but faster (naturally). If I can get close to that I'd be really pleased.

My problem: I've decided to go with the Concept One complete pulley system in black because I think it stands out the least of some of the other pulley kits. I also need to select a power steering rack. Most power steering racks come as a kit with the pump, but I want to use the kit that comes with the C1 pulley kit for the sake of continuity, fit and finish, etc. C1 has a lot of options for what P/S pump they can provide, but neither Unisteer or TCP has responded to any of my messages trying to determine which of the C1 kits will work, or what their racks require in terms of GPM, PSI, etc. I would very much like to get the rack on order because pushing the car around without a steering rack is a major pain in my butt.

I can't be the only one that has had this problem.... Any advice? I am not 100% sold on TCP or Unisteer, but I've heard that some of the other racks just work OK and aren't really track car suitable.

groho

I'll offer what I know about P/S kits which might fill a thimble. Check with C1 to see if they offer a KRC pump or the bracket for a KRC pump. KRC has a multitude of adapters, pulleys, and pumps to choose from so it looks like you can buy a pump, and order a C1 pulley for it. Why KRC, because the pumps run minimal 1.5-2GPM keeping the pressure down to reduce the light steering feel at speed and increasing road feel, vs stock 4-5GPM pumps that were designed to one-finger the steering wheel. KRC has black pulleys by the way, look pretty good. The pump pressure can be adjusted by spring/check ball change to get the right feel. You also want a lower psi to keep from blowing the R&P seals. Many online complaints regarding leaking R&P seals, most of which caused by a stock pump pressure of 4+GPM and high RPMs. Big diff in pump pricing, max RPM for a KRC cast iron pump is 5000RPM which means you have to increase the pump pulley to reduce the high RPMs, or go with the more expensive aluminum KRC pump capable of much higher RPMs ($800+).

I just picked up an ABS power steering quick steer box (3 turns lock-to-lock) and a calibrated Saginaw pump for a fraction of a R/P setup. Haven't started it yet, but just something to consider.

groho

BTW, add a cooler on the low pressure return side if you plan to track it.

racer_dave

I'll go +1 on the KRC. I run KRC pump on a sweet rack in my racecars. Never have a problem with it and I can vary the pressure to keep the positive feel I like with the racecars so the steering never feels light or soft.

SP3CTR0

This may be a very novice question, but I find no shame in asking... When a rack calls for specific GPM and/or PSI, is this just the maximum the rack can handle for "one finger driving"? For example, Unisteer calls for 3-3.5 GPM, but has yet to provide me with a PSI. If I go with a 2 GPM pump, how will this impact performance of the rack? Will it still operate, just with reduced power assistance?

I very much so plan on taking the car to track days, and a lot of autocrossing, but the car will still see more street time than anything else, so I still want to be able to drive the car without getting a workout, but I don't want the steering to be so sensitive and light that it gives no feedback and would be dangerous at high speed. My front tires will be 295 width, possibly 305 if I can make it work when I am done, so I will need enough assistance from the system to turn these steam rollers.

Per Concept One, the pump is a Delphi brand and is configured based on application. These are the configuration options. As I mentioned before, I can't get Unisteer or TCP to confirm which of these (if any) will work.

Pressure Valve:
Standard pressure 1300-1400 psi (all GM racks & gears) (included in price)
Set PS pressure to 800-900 psi (Mustang 2 rack) +$30.00
Set PS pressure to 1100-1200 psi (Fox Body / T-bird rack & Ford gears) +$30.00

Flow Rate:
1.85 gpm (standard)
2.11 gpm (recommended only for Hydroboost)

Reservoir:
Exclusive Billet Aluminum Mini Reservoir (standard - mounted on pump)
Remote reservoir substituted for Mini Reservoir
Remote reservoir for Hydroboost substituted for Mini Reservoir

groho

you answered your own question, the higher the pressure the more the assist, and the easier the turning, but you loose road feel at higher speed. the lower pressure helps keep the road feel at higher speeds, but looses the assist at very low speed such as parking (just keep the RPMs up to overcome the low power assist). If you're gonna spend the money, get one of the KRC adjustable pumps so you can set it to your personal road feel, or make sure the pump you do get can be adjusted.

racer_dave

On the Sweet and Appleton racks, there are different power assist servos. So you can get the desired steering ratio and then choose the servo you want to give you the right feel. Then if you use the KRC or sweet adjustable pump you can really dial in the feel.

SP3CTR0

I found out by accident that one of the optional pumps offered with the TCP rack is in fact a KRC pro series pump. I reached out to Concept One, and they said I may need to fabricate or modify their bracket to work with the KRC pump, but it should be doable. So far, Concept One has been the only company I have reached out to that has responded promptly and with the information I requested. I believe I can make it all work, but I still want to calculate the pump RPM just to make sure I will be within tolerance on this pulley system. As a 9,000 RPM pump, I'll probably be fine regardless, but it is always good to be confident.