Sterlingfire
ignant
So enticing at that price. I just worry that they can't handle much over a 33 without the portals.
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Ifs 101
- Thread starter patooyee
- Start date
So enticing at that price. I just worry that they can't handle much over a 33 without the portals.
Isdtbower
In for Tech
Interesting information on the top arm breaking. A group of us were concerned about this, but didn't know how to put a number to it. Portals definitely put more pressure on the top arm. Both from accel torque and braking. Do you think the breakage was from braking? As that has traditionally been the maintenance issue with IFS. The longer lever arm must change the anti forces also. I have not seen anyone take on those numbers. We were almost there with Thin Air but he left us too soon. I'm too far away in years from being able to crunch those numbers.
mdogg
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It started breaking once we stiffened up and braced the bulk head, something had to give. Broke the 1st upper last year under acceleration at Koh clipping a rock on hub in qualifying, a few months later again bouncing up a waterfall. I don't think it broke when braking but broke from small impacts with the extra leverage and no give anywhere. I was having issues with the front upper arm mounts cracking before this. I went back and forth with a few builders and general consensus was with it being a true a-arm with mounting points so far apart it was not able to take the load especially with the portals.
We also have gone back and forth on what material is best and if heat treating can make chromoly too brittle as a possible failure cause as well. So we are switching things up, my friend is finishing up replacing the front clip and changing it to a J-arm style setup similar to armada/triton ifs. Not making KOH this year with the border closed so have a lots of time to get this setup working right.
Ben, Tim, and others in this thread, thank you for being here discussing this stuff in the open so everyone can gain more understanding. Its helped me understand better changes we made and why I actually liked or disliked them at the time!
mdogg
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This is what I consider the bulkhead, basically the structure where the diff and arm mounting points are located
Tech Tim
Your AD Here....
Ooops, have been neglecting this thread.
$40K... LoL. That's a bargain. The Wild West PRO IFS set-ups would cost more than that fully built.
For trail wheeling I would look at two different IFS suspensions, the Toyota 1st gen IFS and the GM 3500 IFS. Both are great starters for a couple reasons. One is aftermarket support for gears, lockers, half-shafts etc. Another reason is because people cut it all out to do a live-axle swap. So you can always find parts.
For those wanting to run big tires, go straight to the GM 3500 IFS. The spindle uprights (knuckles) have decent geometry, 8 lug UBHs, big brakes and a one ton size cv/halfshaft. Great starting point. Now you don't have to run the GM center, if you don't want. Hell, swap in a Mustang 8.8 IRS or a 9" from Spidertrax or Currie or come up with one of your own.
Looking on Craigslist (here in WA), you could get a pair of spindle uprights/UBHs/brakes/shafts etc for $500.00-600.00.
The Currie F9 center w/ stubs at $2600 (they used to be a lot less $$$ when they first came out)
Price-wise, run the Kartek 934.5 (35 spline) CVs at $400.00 ea. Center shafts are just double splines shafts, match up what spline you are running and order up a set. Dutchman will get you $500.00-ish for a set of double splined shafts. To make it real easy, run the OE outer stub on the cheap or the RCV outer CV/stub for bigger budget.
Steering, there are a few different avenues. You could go full hydro ram, if you are used to full hydro in a live axle, not much difference. You could go rack for big money or look at mirroring the GM horizontal swingset set-up. it really isn't that tough to figure out and you could save some big bucks over running an aftermarket rack. This is Irate... figure the stuff out.
What would be fun is to figure out how to run a factory rack (or circle track rack) with a double ended ram.
For geometry, just mirror everything factory and lengthen the a-arms. The geometry isn't all that bad. Move the inner pivots inboard, until they match whatever flange to flange center section you are running. Extend the arms out until the outer flange (WMS) matches the width you want. If you think you understand 4-link set-up, stretching out factory IFS geometry isn't all that hard. Is it KOH race level? No, but it will still work very good.
Don't get caught up chasing big travel numbers. Geometry starts going stupid when you over travel an IFS. Long a-arms is the key to good travel (again just like a 4-link). Get the center as narrow as you can, then stretch the arms out as wide as you can for your desired WMS to WMS measurement.
For those wanting to run smaller stuff, look at the first gen Toyota stuff. There is a ton of long travel kits already out there and being Toyota quality, stuff can handle pretty good abuse. I ran a 1986 IFS 4Runner, 3-1/2" wider per side, factory center, ARB air lockers both ends (of course), 5.29s, Marlin doubler, RAD triple sticks and 35" MTRs. Wheeled pretty much everything in the PNW, hit the Hammers a few times too.
Some of this might sound like gobbled-gook, I'm tired and just typing off the top of my head, sorry.
Isdtbower
In for Tech
Basically yes.
Most Rack and pinions only throw about 4.5 inches. There are plenty on the used market for $1000 generally. The smaller ones can take a smaller, less cortly, pump. For BIg turning and strength there is the 7" throw model for about $3500 plus a $1000 pump.. The mechanical link gives you the "precise" steering for 60mph+. The same can be had with swingers for less but it takes a good designer to know the off angle forces that tend to destroy them.
In straight axle steering. the forces on the inner heim connection is in-and-out and slightly front-to-back. With IFS you have the same PLUS the up-and-down from articulation and mainly from BIG HITS. That increases loads on everything! There are generally 4ea 1/2" grade 9 bolts that attach them to the bulkhead, but those have been known to break! Racks are now keyed into the bulkhead so the bolts are not in shear.
Something to consider is that the rack can be positioned with the pinion pointing up or horizontally back. Racks are generally designed to absorb the most hits with the pinion horizontally to the back. But this presents packaging problems within the "bulkheads". So most design with the pinion pointing up and then have issues with wear and getting the steering shaft to that vertical center location. If you want to see funkeyness in a front engine IFS..It will be there. (Along with the driveshaft of course) Guys work it out. Not impossible, but part of the expense and experience.
I think we could relate to that force by placing your steering shaft at a down angle of about 20* and then hitting it with a small sledge hammer to simulate the car landing and the front tire exploding ....LOL.
If you went full hydro, the forces on the shaft and mounts will be substantially more than you were used to with a straight axle. (2 - 3X ???) With the advances in more precise hydro, it is a relatively current option as Tim said.
All of this threads comments are not meant to discourage just to be informed when designing and understanding the "why's." And we continue to learn..........
AgitatedPancake
Frobot
That's basically how I'd interpret it. It's just there to provide the mechanical connection needed for the servo to actuate the hydraulics, but while the hydraulics are operational it shouldn't be needed from a strength perspective. In the event of failed hydraulics or a dead engine though, I suppose you want that mechanical connection strong enough to be able to force the steering to do what you want. It looks like the slide just rides in guides, I bet keeping grit out of that is pretty important.
I was thinking more about the steering box conversation earlier in this thread, and had an expanded thought process. One of the ideas that appeals to me is running a power steering box on one rail with an idler arm on the other rail, and a center link which the tie rods down to the knuckle tie into like traditional setups. Obviously pretty beefy. But then I got to thinking, instead an idler arm run a second power steering box. Cap the ports, plug the servo, and leave the input shaft free floating. Drill and tap both boxes like you would for standard hydro assist, and plumb them together. Now both boxes are powered via one input shaft and one servo. More force available than a 2.5" ram with 1.5" shaft, nice dispersed loading, and a pretty simple system
Provience
Kill!
this was done with a toyota setup for a...????? class legal system. whitetrashfab? DWT? DirtyWhiteRacing? can't remember who the heck it was now. but basically tough truck type stuff and kept ripping up idler arms, added a RHD steering box to the frame rail and problem solved, on that front.
they weren't both powered, just one. small tire class
Wilson
Newb
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I do not recall it being mentioned earlier and I don’t think that she has come here, but “Bebe” on the other site built a d44 custom mid travel under her h2. It had an early d44 narrowed, with custom stub axles. Fab’d arms (and uprights, iirc). D44 spindle and a gm rack
Tech Tim
Your AD Here....
Pretty much all it is, a high performance rack and pinion with a hydraulic assist ram.
Unfortunately they are also one item that really drives the cost of a custom IFS up.
michael.gonzalez
Banned
Let's not forget that the 9.75" IRS diff from a 2002 expedition is another great option. Can use factory CV axles, hubs, rotors, calipers, knuckles etc.
Or the 8.8" IRS from the smaller 2002 explorer.
Much more budget friendly.
Or the 8.8" IRS from the smaller 2002 explorer.
Much more budget friendly.
The only advantage being the mechanical connection? I'm totally fine with full hydro personally. I used to bomb around forest and empty ORV park roads in my last buggy at 60+ mph with full hydro. No issues to me. Is this an issue that you would say is "racer-exclusive?"
Stephen
HMFIC@ORD
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Thanks for checking in Tim.
Since we can fab around a-arms, knuckles and steering, the big place to figure out how to spend money is the torque transmitting stuff. We're all exploring diffs more but I thought I'd jump on the axle shaft thing since Tim refined the solution a little more here. We need to be pretty careful looking at CV alternatives if we're comparing to RCV. If we spend $800 on a pair of inner CVs and $500 for shafts, we're halfway to a set of RCV shaft assemblies configured for a stock-ish GM3500. If you can run stock GM outers then we're winning. If you need D60 chromoly strength outers then just ordering a full set of RCV shafts for $2500 is probably the right way to do it. This is where finding out just how bad the empi inners are could be of value to us. A pair of double splined shafts and some cheaper inner CVs with stock GM outers is looking like the cheap way to get our feet wet. That's not a 40" tire solution because 40's need 35 spline 4340 strength. An even cheaper way is to cut a factory shaft and weld an extension tube into it. Obviously it's not going to retain full torque capacity but it would make a good mockup shaft system and you could drive with it. Just not real hard.
I wonder what torque capacity is for a stock GM shaft assembly? Someone with an axle breaker needs to break some of those.
Using the new GM diff (2011+) has come up a couple times and we've looked at it and determined that they aren't very aftermarket friendly. The carrier bearings are backward so it's going to be a long time if ever before we see an aftermarket carrier (locker). It might work if open or welded is OK for your use but that seems to be all that is available. So the cream of the crop for a GM diff option is going to be the '01-10.
I'd like to play with the new GM wheel bearings also since everything has become huge but the 8 on 210 bolt pattern is likely going to limit wheel selection somewhat and I don't know if they can be re drilled to 8 on 6.5. Again, the bang for the buck solution is going to be in the '01-10.
TRINDU
PBB Orphan
Want to expand on that? I posted that idea on the other site and was basically told the second box wouldn't be powered, without any force on the input shaft. Would the tapped ports be tied together in mirror image?
Right now I'm just looking at packing a RHD box with grease so it's a robust idler. If I could make it hydro assist-esque, I'd definitely go that route.
AgitatedPancake
Frobot
You're not feeding the second box via its standard pressure ports, and essentially locking out its servo. So at the basic level you're simply using it as an assist ram via the piston it has in there. The first box is providing all of the fluid and control via the 1 servo and 1 pressure line. Then both boxes are drilled and tapped for hydro assist, and connected left to left, right to right. So just like with your standard hydro assist setup, when your box sends fluid to help you turn right, fluid gets sent to the other box to turn right.
That seems like an awful lot of extra weight to pack around for an idler. I think the powered idea would work, you would just not use the servo side at all. There would be a little trickery to figure out if you need to put power to the same end of the idler box or not. Mirror image boxes usually put the sector shaft on the opposite side of the piston gear which reverses the direction of action. That gets corrected inside the piston by the direction of cut on the worm gear for the re-circulated balls.
I briefly looked up gears and lockers for that. Selection was even worse than the gm 9.25.
TRINDU
PBB Orphan
So the act of sending fluid to one side of the piston, or other, will assist steering. Without the need for any mechanical input.
youre probably right for a racing application. But 86-94 toyota idler arms are junk. The aftermarket solution is $400+. If I can outfit a RHD box, manage to get some sort of power assist, then I'd say it's well worth the weight penalty.
I was originally debating on a assist ram, but if this works, I'm ahead in packaging, simplicity, and cost.
Yes. A power steering box uses almost all hydraulic power to do the steering. The mechanical connection is tiny spindly and pretty minimal.
I could build a bad ass idler with two pillow block bearings 1” shaft stock and flat bar for less than $100 bucks.
I would rather have it powered though. That’s a pretty sweet idea! It would be way easier to package up.
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Tech Tim
Your AD Here....
iirc the Gomez Brothers KOH cars were using full hydro ram steering in their first cars. They still might be.
"racer-exclusive"? No, how about driver choice and budget capabilities? We design our race IFS with the big race racks because budget is not a concern, winning is. The trail IFS' we've done were with P/S boxes and idler arms, because they are less expensive and they work.
I'm not a fan of full hydro except in a cone dodging crawler. I'd rather have a mechanical link somewhere to give me some feedback to the steering wheel. BUT that is me and why I said if you are already used to full hydro steering, go for it.
arse_sidewards
Contrary to everything
- Joined
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- 8,209
9.75 has shit selection. Gear options for HP are pretty limited but the 8.8 has anything you could ever want in terms of the carrier.
Isdtbower
In for Tech
I can't do screen shots for some reason but check out Kibbetech on their site and Instagram. They just posted a swinger/power steering box solution on Iinstagram that they are selling. In the chassis section of their website they are selling a "Jeep" IFS for $35k without the 9" drop out but includes the 9" pumpkin. Premium parts. Lots of Spidertrax. You final fab probably. Pretty good stuff there. I am just having multiple "issues" with my desktop!!!!!
Edit: I might add that the Dez guys have been using swingers for years so know the design needs...for 2WD. That changes some when you add the resistance of the center section. More than one swinger set have been re-designed after the first testing with 4WD. Do some homework around that If you are thinking that route. Those rigs are heavy with big articulation and minimal turn angle. Which might be overkill for some of you. Good news is that most all will be a welded design so rebuilds are "easier."
Edit: I might add that the Dez guys have been using swingers for years so know the design needs...for 2WD. That changes some when you add the resistance of the center section. More than one swinger set have been re-designed after the first testing with 4WD. Do some homework around that If you are thinking that route. Those rigs are heavy with big articulation and minimal turn angle. Which might be overkill for some of you. Good news is that most all will be a welded design so rebuilds are "easier."
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Tech Tim
Your AD Here....
Here is the link to the Kibbetech Jeep suspension: https://www.kibbetech.com/products/ifs-jeep-front-suspension?_pos=1&_sid=10908e913&_ss=r
The pictures offer lots of good ideas.
The pictures offer lots of good ideas.
TRINDU
PBB Orphan
Alright then, sounds like a have a new project to waste money on.
Drawing like a child on a napkin, you look to be right having to swap A -> B, and B -> A on the lines. On the new tapped holes fore and aft of the piston the fluid would need to be on the opposite side if you're using a mirrored steering box.
Next, how does one "lock out the servo" on the assist/idler box?
AgitatedPancake
Frobot
Dang, that is an awesome system. I've daydreamed about offering an IFS kit for solid axle jeeps, I'm glad to see manufacturers realizing the potential. Relateively clean high clearance frame rails from the start, couldn't ask for more. I really like that system.
AgitatedPancake
Frobot
What are the proper search terms for finding inner CV stub axles for these narrow diffs? Most that I find while searching for "stubs" are outer stubs with threaded ends, versus the basic splined inners with their own pressed on bearings. I'm just looking to grasp the off the shelf options, but I can't tell if there are many
I found 35 spline curries for 934's at 8.0625" length, and 5.625" length
https://www.currieenterprises.com/CE-4305B2
https://www.currieenterprises.com/CE-4305B1
I found 35 spline curries for 934's at 8.0625" length, and 5.625" length
https://www.currieenterprises.com/CE-4305B2
https://www.currieenterprises.com/CE-4305B1