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The 4500 steering that won a national points Championship

120K views 443 replies 97 participants last post by  a1racer 
#1 · (Edited)
I know there is both a go fast steering thread and a recent thread inquiring about our steering. We have been hounded about our secret steering all this year so I am about to drop the secret, but first. In previous years racing we were breaking 1 to 2 steering boxes and pumps per race with a traditional ram assist steering setup. After racing a season with both Ultra4/DirtRiot and getting on the podium 6 times in 8 races. This year we did all that on the same parts we started the year with at KOH.

I am going to start by giving credit where credit is due, this thread is going to be long winded so if you don't like it hit the back button now. I have waited to do this because there are going to be people arguing against what I am saying despite the fact that I can prove what I am saying works. I wasn't willing to start this thread until I was good and ready to field such retarded comments as "but so and so said this" I don't care what any one has ever told you, it may very well have been wrong. The most important information I got in all of this came from Hydrodynamic right here on pirate. I have had long conversations with Jeff from Howe, Tom Allen and Lance Gilbert with PSC. Hydrodynamic (name is Jeff) was the one that could explain to me what I needed to understand. The thing I couldn’t wrap my head around was that a servo is not an orbit valve, but provides the same hydro service via a differential pressure between mechanical input and mechanical output forces.

The class we race in requires a mechanical connection between the steering wheel and the wheels, no full hydro. Our very first desert race ever was the 2012 KOH Every Man Challenge. While in 3rd place in that race the Scrambler broke its first of about 15 steering boxes with hydro assist that lead me to the end of the earth and back on all things steering. I have been working on a solution to regular hydro assist for about 4 years. We were at the Ultra4 Reno National Finals last year and broke another box on the front row in our prelim destroying our chance at a podium. Later a friend of ours Clay Gilstrap ran one of the fastest qualifying laps in 4400. Where he hit a rock so hard as to explode a tire, the tire balls, and a forged Method wheel. Without damaging any of the rest of the car. His is a Tribe4x4 built IFS rig with a Howe trophy truck rack. It occurred to me that the IFS rack is literally just a different configuration of ram assist. I began by reading the whole go-fast steering thread and anything ram assist related I can find. After talking to all the big steering manufacturers I decided to abandon traditional ram assist for our race car. There are people racing and doing well racing with regular old ram assist but for us it had to go. I wanted to figure out how to get the power of full hydro while staying class legal with a real mechanical connection. The willy’s race truck had been built around the steering in the first place so we kept our box and just modified it.



A power steering box is a small ram assisted rack & Pinion unit all by itself. The rack doubles as a ram shaft as well, the pinion being the sector shaft, the box having its own steering servo on the input side of the box. There is a tiny little port that runs the length of the bottom of the box from the front of the piston to the servo. For the piston to move forward all the fluid in that cavity has to return to the servo through about an 1/8th inch hole several inches long. This hole cannot be adequately opened up where other ports in the box can be. In an event where the vehicle plows into an immovable object at speed the wheels trying to move the internals of the of the box faster than fluid can evacuate the small port leads to a momentary hydrolock event and leads to the sector shaft twisting off, or breaking the teeth off the sector shaft.








The secret is don't bother calling sweet. Call Howe. Sweet specializes in circle track and street setups meant to run a maximum of a 1 ½ inch rams. Howe buys servo's from sweet and modifies them. The whole trick is three parts that are volume matched to each other, the pump servo and the ram. These 3 part numbers are all the right size for perfectly smooth 2 1/2 turn lock to lock steering. I use PSC for the pump but Howe sells an equivalent one, we have ran both. But the modified PSC pump in this application is $200 plus the pulley and works fantastic. With this pump and servo the Howe ram requires more fluid displacement while creating the same pounds of steering force on the steering knuckles. Howe's 2 1/2 inch rams have smaller shafts which means more fluid displacement. This is the servo that Howe uses on the trophy truck rack. A friend of ours bought a stock servo straight from sweet to run in conjunction with a cable setup similar to the poison spider 4500 rig from the first EMC, and it doesn't work right. So even though its 200 more dollars from Howe than from sweet it really does matter. This is what we won the national points championship with and I insist it’s amazing. You will have to figure out the pulley size you need for yourself. We run a ford engine and our crank pulley is about half the diameter of an LS crank pulley.

Pump part number SKU #: PSC-SP1200X-8-12
TC series Extreme Duty PS Pump-SP1200X : Pump Systems and Components, Universal Pumps | PSC Motorsports - performance steering components

Ram part number SKU #: SCX2212K1
XR Series 2.5" Double Ended Race Cylinder | PSCMotorsports.com performance steering components, power steering

Servo part number P# - 725 with a 200# torsion spring
Control Valves | Parts Categories | Howe

 
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#220 ·
From Matzell's thread:

EMF did this a while back and posted about it a few years ago with stock boxes:
Hydro Assist The EMF Way - Steering Tech - EMF Forums - 403.935.3540
Dealing with the internets Hydro Assist - Steering Tech - EMF Forums - 403.935.3540

Willyswanter has an old thread from 2003ish posting a hydro assist with drag link and stock-ish pump. He did this on his giant chevy truggy with a ~4gpm pump and ported box. Not sure if it was quick enough for what we do, but it looks like he left us some tech :)

http://www.pirate4x4.com/forum/gene...0085-double-ended-hydro-assist-questions.html
http://www.pirate4x4.com/forum/general-4x4-discussion/236132-double-ended-hydro-assist-results.html
 
#221 ·
Shawn/Kevin,

What type and size cooler are you running? I got mine together and working yesterday. I am hoping the cooler I have now will keep it cool, just wanted to compare to what you have.

Thanks again for going through the trouble and pain to make your system work. I know mine is not the exact same as yours but it came from your ideas!
 
#222 ·
I've got a funny question for you guys that is comically simple compared to the rest of this thread, but I feel it applies due to your experiences :D.


In steering boxes that begin to get worn out and develop slop (common situations, not necessarily single event impacts), what is it that is wearing to open up those tolerances, and cause excess backlash until you to tighten via the adjuster screw? Are the teeth between the sector shaft and piston actually wearing into each other causing slop? Is it the bore of the piston getting stretched eggshape actually letting the piston push away from the sector shaft?

I know there was mention of the cylinder bore stretching, though I don't know if that is the common failure? I'm just curious if the "core" of the box is usually toast once slop develops, and can't properly be rebuilt.
 
#226 ·
Nice, I sincerely appreciate the input guys. I've got a worn out steering box in the WJ, I'll probably be pulling it apart entirely to do some inspecting and measuring. It's starting to seem like just about any individual component within the box could be a factor, so I'll be curious to see what is causing it in my particular instance.
 
#227 ·
The race of the piston and the worm can be trashed too or the balls get worn. Most "rebuilds" just add fresh balls to the worm+piston. Really just depends on box type, use, etc. Those little recirculating balls take all of the stress from input and leverage absorbed from the sector shaft. They are the only "mechanical" link between you and the roadway.
 
#228 ·
Nice, I'll inspect there as well. What I think honestly caused the issues with my steering box right now - death wobble. I've had the shakes a few times on the road and I can just feel it beating the steering box to death when it happens, even if only a couple seconds before I can get things under control. I'm really curious to see what I find inside, but it will probably be a bit before I get around to it.
 
#229 ·
I have been following this thread reading it several times and Matzell's because it is good tech and I would like to apply this to street/trail Jeep. The part I have been fuzzy on was how the Sweet valve is mechanically connected from the input to output, and what would happen if you lost a pump or hose.

I contacted Sweet and this is what they told me "If hydraulic power is lost there will still be a mechanical connection. However the connection is not a strong one, it's a 3/16" pin and slot."

Does anyone know if the PS gearbox is setup just like this with a 3/16 pin or is it a more solid connection? I cannot tell from the cross section views or the first pics in the thread to mod the box and I do not have a box and I can take apart to see how it works.
 
#230 ·
Does anyone know if the PS gearbox is setup just like this with a 3/16 pin or is it a more solid connection? I cannot tell from the cross section views or the first pics in the thread to mod the box and I do not have a box and I can take apart to see how it works.
Its the same inside the sweet servo as it is in the PS box. The torsion spring with that pin you mentioned are captured inside of two interlocking pieces of metal. The torsion spring can twist but when you twist it to far the two pieces of metal contact maintaining a connection. Even if the pin sheared (never seen that happen) it would still maintain a mostly solid mechanical connection to the wheels.
 
#235 ·
Kevin started 37th and got 4th in mod with this setup after spending an hour at the top of chocolate thunder fixing a sticking throttle pedal. Matzell and Lindsay Gilstrap finished with it as well.

I still say that if you're not breaking boxes you've no need for this. For whatever reason we can't get a full race out of traditional ram assist where others can.
 
#240 ·
So Tim Diekman (timmay) of Liquid Iron Industries built a street able trail buggy using this steering and ran around Moab for EJS for about 2 weeks with it. Timmay wont talk much about it but here are some pics of his Commando buggy. Vetteboy79 got to spend EJS week running around with his TTB buggy with Tim. For the facebookies there are lots of pics of the build. https://www.facebook.com/tim.diekmann.370?fref=ts



 
#241 ·
Love that rig, glad to see it back in action :smokin:

Any reason this steering shouldn't be used on a leaf sprung rig? Overkill I know but may get linked someday. The parts are around the same cost if not less than the PSC hydro assist "kit" for my LS YJ but I like this set up much better. Thanks for putting this thread out there for all to see.
 
#245 ·
Still messing with my own version of this system...

You can buy smaller ratio boxes, 6:1, 8:1, 10:1, and 12:1 from PSC, Sweet, and other street rod places. They're the same saginaw bolt pattern. These are $200 to $800 depending on ratio, I'd like to get one around $300 and see if it can keep up with a smaller ram.

You'd still have to gut the box if using the external servo, but I've been putting together a similar kit that would use a modified TJ pump that flows ~3.4GPM vs the 2.4-2.7 stock. I would run a DE ram with assist but leave the servo in the box. $280 for a 10:1 or 12:1 box, I am thinking I'll try it. Going with a ram from Dean at Kickass Offroad. I just need the box to flow enough to keep up with the ram, so I won't be using a huge 2.5" unit.

Based on my calculations with the volume needed and the pump, it would take approximately 1 second for the fluid to flow fully in the system I've designed. All I need to do now is find the maximum time and/or volume a box can flow in a faster ratio, such as 10:1, and I can find out if a hydro-lock condition would occur.

So...anyone have some data they'd like to share?
 
#246 · (Edited)
I am getting closer on mine... Saginaw box with 14:1 gear, TC pump, 2.5X10 double ended ram destroked to 9.5625"...

Everyone tells me I am under pumped, If so I'll switch to a CBR pump. I'll post back once its done, give my thoughts...


I have been wondering the same thing, how much flow is needed for which ratio, keep in mind Howe racks are 1.5:1 and have ram volumes that are much larger than what is common on most solid axle cars. In theory we should need less pump...
 
#247 ·
In theory we should need less pump...
It is my opinion that you are correct, a TC pump can move 4.5 gpm. Our rig runs the pump at a 1:1 pulley ratio off the crank AKA 5 3/4" crank pulley to 5 3/4" pump pulley 2 1/2 turns lock to lock. The truck runs 90* fluid temp and has flawless steering from idle to balls out. The steering doesn't get twitchy at high RPM's as can happen if you over pump your system.
 
#249 ·
Thread update time.

We have just completed the second full season on the same parts that were installed on the terminator in 2014. While some in our class are still arguing whether or not the effort is justified others are embracing it having great results like we did. Jimmy's4x4 with has their turn key 4500 buggy package dialed in with a mix of a DE ram and Sweet servo, with a bell crank system so that a triangulated 4 link can be used. No panhard no bump steer no flex steer.

This is Tom More's 1982 Toyota bodied Jimmy's 4500 rig powered by a turbo'd 3RZ Toyota 4 cylinder. Driver Marty Mann drove it to win the Ultra4 nationals at its very first.


 
#253 ·
For the bell crank steering i've seen it discussed that it needs to be a 1:1 ratio going through the bell cranks. with that I would assume that the drag link on the axle needs to attach at the same point as the mini tierod off the ram. so then would you take the distance from that mounting point to the pivot of the knuckle say its 7". then would you make the arms on the bell crank the same 7" and control the speed or throw via the pitman arm alone.
 
#250 ·
After one year of racing and trail riding, mine is still working great! I am not sure this is for everyone but it is working great for me.

Thanks guys for helping to get this to market.

Rob
 
#251 ·
Glad this is back to the top. I started collecting parts for mine, using the box for controlling hydraulics. Going with an AGR box that's 3.5 turns lock to lock instead of my variable PSC box. Already have a PSC 1200x pump and 2209 double ended ram. Based on my calcs, I think this ram is too big for the box but we'll see. Designing my ram mount now, will check in once it's done.

If anyone would like to trade rams, this would be much better for someone that wants to use a Sweet servo or full hydro. I am looking for a 2.0 bore DE ram with a 1.125 or 1.25 rod. Thanks!
 
#252 ·
I'll be throwing this set-up on my DD Dodge. I've already picked up a Scout II box, and the 3 turn Worm gear from PSC.

I know having this on a DD has created curiosity in some so hopefully I can give that input sometime in 2017.
 
#256 · (Edited)
So its done and it works. While it is not as effortless or as fast as V-1 that we put on dads 4531 rig (seriously his is the best of the best) it is a simpler install and is much better than a normal ram assist setup with a powered gear box and tiny assist ram. I'm going to run the next EMC with this modified junker box.





This pic is at full bump and full lock to the right. Its close but clear is clear and I can't imagine the event that I could get it to bottom out at full lock so not concerned. Took the pic to show my dad.
 
#265 ·
What do you feel makes it better than normal ram assist? Because it doesnt have to share the power with the r&p? Because you tapped directly into the servo and eliminated the small return channel from the piston? Or simply because you opened up the ports some for the ram?

You mentioned that this was slower than V1, which I understand, but where have you noticed it being slower during use? Using a smaller ram should speed it back up some?
 
#257 ·
The way you were writing I figured you tried it and it wasn't good enough. I hope it works out for ya - thanks for updating and I look forward to your results!
 
#258 ·
Yeah, I'm still a little defensive about why I insist we need a $600 dollar servo when the steering box a foot away already has one in it. You would have to drive dads car at speed and in the rocks to understand though. I rode with Wayland Campbell in my dads car this year and it took even him a minute to get used to how quickly and easily it steers, that coming from a guy that's used to driving an IFS car with a Howe trophy truck rack.

I had two rigs with the exact same PSC ram assist setup. Both are the variable ratio boxes both with good TC pumps and both run through hydroboost brake boosters. For some reason the race car took more effort at the steering wheel to steer as my jeep. Now it takes less effort to steer than the jeep, a lot less. So its an improvement for sure, but a modified box still has its limitations that an aftermarket unit was built to address.

The analogy I've come to use on this particular subject. There are guys we race with that have steering issues and still bring it up for what ever reason, that what we did for our steering is unnecessary. These same guys have $8000 dollars worth of shocks and have spent time tuning them, or custom race engines with time spent tuning them. So they understand the value of buying custom race parts and then spending further time perfecting them. Yet just want to run off the shelf steering that was meant for a street legal trail rig.
 
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