818Rasmus E Modified

[Rasmus]

Got an idea in my head to build my own bump-steer correction kit. Apparently, the 818 bumps steers when you install the suspension in "R" ride height.



After days of thought on the imperial vs metric debate, I decided to go with imperial size rod ends. Two reasons. 1. The majority of the suspension in the rear will run imperial rod ends and bolts. 2. Price. M16 rod ends run about $65 and 5/8" rod ends run $20 for similar ratings. Next you get in the price of Metric Grade 10.9 hardware vs Imperial Grade 8. Anyway, I cut the end off some old OEM steering rod ends. Drilled and tapped them for 5/8"-18.



Notice the spacers. FFR's recommendation to correct the bump-steer is to space the rod end's 2 7/16" down from the steering arm. Or 2 13/16" from bottom of steering arm to center of pivot point. I, intentionally, included a 0.128" washer and cut my main spacer short. Just in case I need to adjust something in the future by running thinner washer, no washer, or more washer.



Drilling out the steering arms to accept 5/8" bolts. Ridiculousness.


The full set of hardware that went into it all. I found some nice rod end boots from Jegs. The stainless steel washers in the boots are 0.047" thick. So my full spacer kit is ---> 0.128" washer ---> 2.263" big spacer with bevel for range of motion ---> 0.047" stainless steel washer with boot.


Installed.


Other side.

[Brando]

Yesterday I also installed my bump steer kit. I was not able to find grade 8 5" 5/8" bolts however. I opted for regular bolts. Those bolts are HUGE and there really isn't that much strain put on the steering rack in contrast to the size of those monsters.
Do you think that grade 8 is critical for those bolts or is it just to be safe?

[Rasmus]

Do you think that grade 8 is critical for those bolts or is it just to be safe?

I don't know if it's critical. I didn't do an engineering stress analysis. I, personally, use only grade 8 or 10.9 hardware in the suspension and braking systems. Especially anything in single shear, like what I did above. That 5 inch bolt will see stress from steering and also under braking.

[Jaime]

It's not so much shear as tension from levering the end of the bolt using the spacer-knuckle interface as a lever. Probably 5:1 lever ratio on the bolt, times the approximately 20:1 ratio of pinion radius to steering wheel radius. This means the 50 pound of steering effort on the wheel turns into thousands on the bolt. However, back of the envelope calculations say that the wheel should be ripped out of your hands long before the bolt yields.

[Brando]

Sorry for the thread jack on this subject. The more I read the more convoluted I feel about this subject. I think i'm sticking with grade 5

which is stronger grade 8 or grade 5 bolts

Many people state they discourage grade 8 when shear force is concerned due to being more brittle and snapping as opposed to grade 5 which bends.

[Frank818]

Rasmus, you are amazing and will never stop surprising us with your awesomely smart ideas. It's nice you share with us part of your brain!

[Jaime]

Sorry for the thread jack on this subject. The more I read the more convoluted I feel about this subject. I think i'm sticking with grade 5

which is stronger grade 8 or grade 5 bolts

Many people state they discourage grade 8 when shear force is concerned due to being more brittle and snapping as opposed to grade 5 which bends.

You can tighten grade 8 bolts more, so the static friction between the surfaces is much higher, keeping shear off the bolt. Also, once a bolt permanently deforms, it's usually only a matter of seconds before it breaks, unless there is a secondary support mechanism. I don't buy the "grade 5s are better" theory. I'd guess that most grade 8 failures are due to improper installation, or on poorly designed joints.

Always make sure to tighten high grade bolts to their recommended torque value.

[Rasmus]

It's nice you share with us part of your brain!

Thanks for the compliment. I like giving back to the communities that give so much to me. Plus if I do something boneheaded the interwebs will point it out.

Always make sure to tighten high grade bolts to their recommended torque value.

Just looked up the torque spec for 5/8"-18 Grade 8 bolts. 240 ft-lb dry, 180 ft-lb lubed. Yikees Shaggy! My 1/2" drive torque wrench only goes to 150.

[D Clary]

I would prefer grade 8, but in this case a half inch bolt would be big enough so a 5/8 is kind of overkill.

[Jaime]

Just looked up the torque spec for 5/8"-18 Grade 8 bolts. 240 ft-lb dry, 180 ft-lb lubed. Yikees Shaggy! My 1/2" drive torque wrench only goes to 150.

Them's some big bolts. A common problem with under torqued bolts is that they don't stretch enough and then are prone to vibrating loose. Since you have a lock nut on there, that won't happen to you. Like you, I always use high grade bolts for suspension, and I always use lock nuts or lock washers. You can tell a real hardware geek when they always put washers on upside-right.

[Rasmus]

You can tell a real hardware geek when they always put washers on upside-right.

Guess I'm not a real hardware geek then. What side goes where? The rounded side or the sharp side toward the work?



Now you'll see why I debated on the Metric vs Imperial Rod End question. At $65 per M16 ($65 x 10) vs $20 per 5/8" ($20 x 10). I set my lateral links at Wagon width. 400mm center-to-center. Sedan links are 410mm c-to-c. Pictured above is my low-tech way of getting all four links to the same length. Having set one link to 400mm c-to-c I clamped down some metal angles to just touch got the rod crowns. Set the other three after that. Easy.



Thus allowing me to hang the rear suspension and knuckles.



Right Rear. The sweged rods I used are Allstar brand. About $13 per. They're an inconsistent gun-metal color. Some have a slightly more yellow tint, some more green, some more black. I went with 12.5" lengths instead of the FFR recommended 13" because I wanted Wagon width in the rear and I didn't want to screw the rods all the way down, only to come up long trying to get to 400mm. So 12.5". You can see how much thread is exposed.



Left Rear.



Drilled out the knuckle's lateral link suspension points to accept a 5/8"-18, 9.5" grip length bolt. Beefy.


The amount of clearance between the coil spring and the rear upper lateral link is worrisome.


If you fellas see I've installed anything incorrectly please let me know. Thanks.

[metalmaker12]

Lol, looks good!

[AZPete]

Anything wrong? Those alum panels in your tank bed!
Other than that, you do nice work!

[Rasmus]

Anything wrong? Those alum panels in your tank bed!

Great. Now I've got 120 1/8" holes to fill in my frame.


Again.

[Scargo]

Ras... That's some nice work. Obviously a machinist or ex-machinist (like me).
I have to ask why you didn't consider just moving the steering rack up? I will be doing that.

About the bolts: To everyone, Please... I know I am always sounding like your mother, but this is important! Exclamation point.
Racers turn loose of their steering wheels when they are about to have a front-end crash. Why? Because everything in the front suspension, which includes the steering, is built hell-for-stout. They do not want to break their hands or wrists. Likewise, you do not wanting anything breaking on your suspension. It sees huge loads (like when you run over a six~eight inch curb).

You do not want low-grade bolts in anything in your suspension. Just assume I put exclamation points at the end of all my sentences from this point on, OK? In the first place, if you go to Home Despot, or similar, you may be getting inferior, cheap, Chinese bolts. Second place: You do not want common grade bolts in your suspension. You also want to torque everything and use Locktite.

I'm fascinated that Metric is so expensive compared to SAE. I will keep that in mind when I shop for my end links, etc.
Where did you buy yours? I have many bookmarks for places to buy this stuff from, but find that there always seems to be the same item for cheaper, hiding under the next rock. And, then there is the other OEM brand of car parts that fits or interchanges that can be had for cheap, IF you know what you are looking for.
I like: Chromoly tubes with 5/8" ends. Chromoly End links. About $60 for a thin-wall adjustable chromoly lateral link.
Aluminum and all that yada-yada. Heim ends with load specs. Joe's aluminum hex tube in 3/4 thread.
These might be what FFR is supplying.

[Rasmus]

Ras... That's some nice work. Obviously a machinist or ex-machinist (like me).
I have to ask why you didn't consider just moving the steering rack up? I will be doing that.

Thanks for the compliment.

I did consider moving the rack. I even created a thread asking just this question: 818R Suspension and the Steering Rack.

Inspired by a question in another thread:

"Running the low ride height requires the use of a bumpsteer kit because the steering rack stays in the same chassis location." Does this mean that the steering rack can't be moved up to stay in plane

Rather then install a 25mm bumpsteer kit to make up for the drop in height, could we not just move the steering rack up 25mm to correct the geometry?

You could do that but the steering geometry will be better if you leave the rack where it is and move the outer tie rod. Getting the long tie rods closer to the plane of the longer lower control arm (longer than the upper) is what you want.

So I didn't do that 'cause Jim Schenck said to not to.

[Rasmus]

I ordered my rod ends and hardware from McMaster-Carr.



Link to my exact rod end.
Static Radial Load Capacity: 17,955 lbs.

[RM1SepEx]

I like speedway motors for these rods and links... I've used McMaster too

[Frank818]

Rasmus, you didn't have any issues when installing the front LCAs' tabs (rearwards big bushings)?

[Rasmus]

Rasmus, you didn't have any issues when installing the front LCAs' tabs (rearwards big bushings)?

Oh, I did. That was not fun. I eventually just went by the FFR manual and installed the Lower Trailing Link onto the the knuckle first thing, while it was on the bench. Helped to smear a dab of grease on the bushing and tabs then "walked" it on. Next came the Lower Lateral Links. Easy. Then I used a pry bar to open up the tabs so the Lower Trailing Arm's front bushing would slide in there. After that it was easy. After setting a rough alignment, coilovers go on last.

[mentatbashar]

Guess I'm not a real hardware geek then. What side goes where? The rounded side or the sharp side toward the work?

Rounded off side of washers to the part. Sharp edges to the bolt. You don't want the sharp edges "digging into" the material of your part.

[Scargo]

I like speedway motors for these rods and links... I've used McMaster too

Some sources say they can be had with grease fittings. Does anyone feel this is a plus? How do you lube yours?
Along similar lines, I have looked at 1 inch swaged aluminum tubes (using 5/8" threads) for use in the rear suspension. Are they going to be strong enough for lateral links and trailing arms, etc? I have calculated that I can save over a pound in partially unsprung weight by using these aluminum tube links.

[Rasmus]

I understand I'm building a kit car. I know there will be issues I have to work though. I've worked through several already. It's not a Toyota and stuffs gonna need a little tweaking to fit. But this:


The throttle pedal. That's how FFR's designed mounting bracket makes the throttle sit. And because it is made of from thin 16ga metal it flexes when you press on it. That is, it twists to the side under any load. It's just a bad design and poorly engineered. Like it was an after thought, "Guess we need to mount the DBW throttle some how. Hey, have the intern design something. Perfect. Where we going for lunch?"

[Frank818]

You did not receive a pedal box thick metal plate to bolt on the chassis?

[Rasmus]

You did not receive a pedal box thick metal plate to bolt on the chassis?

I did. The clutch and brake pedal assembly bolts to that. The throttle bracket is separate.

[RM1SepEx]

The cable setup flexes too... I eliminated it and mounted the pedal right to the firewall

[Jaime]

The cable setup flexes too... I eliminated it and mounted the pedal right to the firewall

Any details on what you did? The cable pedal mount is one of my backordered parts and something I'd like to get finished.

[Bob_n_Cincy]

Rasmus
I reshaped the bracket to bring the pedal to the proper angle.
The pedal still has some flex.
Don't forget to put in the pedal stop, like oem.
Bob
See pictures.
gas pedal.jpg250px-Pedal_Locations_in_2007_Subaru_Legacy.jpg

[Pearldrummer7]

Hey, have the intern design something.

Hey, their intern Frank did some great work on that car, actually! :lol:

But seriously, that's so poorly designed. Why isn't it mounted to the firewall, anyway? Wouldn't that be the easiest solution?

[RM1SepEx]

Any details on what you did? The cable pedal mount is one of my backordered parts and something I'd like to get finished.

details are on my thread, just line up the cable hole and drill holes through the aluminum. Take the thin steel mount bracket and toss it. I also found that I didn't have enough cable free play using the supplied bracket. It is quite a bit "stiffer" w/o the bracket. Wayne did his car and the GRM car w/o the bracket

[longislandwrx]

Wait the rear knuckle Subaru long bolts are M16?

Also what did you use to space the rod ends off the knuckles?

[Rasmus]

Thanks for the help on the throttle position fellas. Might just put a spacer in there. RM1SepEx, mines DBW but thanks for the thought.

[Rasmus]

Wait the rear knuckle Subaru long bolts are M16?

Also what did you use to space the rod ends off the knuckles?

No. The rear knuckle Subaru long bolts are M14-1.50 x 240mm. The reason I mentioned M16 rod ends are the 5/8" upper holes FFR designed into the frame's lateral link tabs. 5/8" is 15.875mm which is just about the width of an M16 bolt shank. 15.80-15.85mm. So it's tight with the powercoat on but it could work.


Spaced off the knuckles with this neat part I found on Jegs for $2.59 per pair:


JEGS 555-64255
Its comes in 1/2" and 5/8" diameters and widths from 1/4" to 1". I used two 3/8" width ones for the knuckle side and four of the same for the frame side. Or twelve for the whole system, (i.e. six packages).

[C.Plavan]

Been there, done that on the throttle. I used a spacer. I then welded a brace up top to stop wobble. I plan on just making a throttle stop so I don't break the pedal off when racing.

http://thefactoryfiveforum.com/showt...l=1#post129042

[MrDude_1]

Even welded it back together with the weird ~20 degree offset the two opposing universal joints had originally. I don't know why Subaru welded it together that way but I didn't care to research why and just duplicated it.

They're at an angle so all the needle bearings roll when rotated. If they were straight, they wouldnt move enough and would wear a pit in the shaft, like the bearings did on your bad CV-joint.. You end up with this "clicking" feel in the steering.

[wleehendrick]

Thanks for the help on the throttle position fellas. Might just put a spacer in there. RM1SepEx, mines DBW but thanks for the thought.

I also have a DBW throttle (06 donor) and wasn't happy with the position. I bent the top flange of the FFR bracket and added a spacer on the bottom bolt, I think I ended up ~1.25". This puts it in a great spot for heel-and-toe operation, but it's still a bit flexy, so I'll probably beef it up at some point. But, being DBW, it's easy to move it around since you don't have to worry about routing a cable!

[Rasmus]

But, being DBW, it's easy to move it around since you don't have to worry about routing a cable!

There's the positive I needed. Thanks man all things considered at least it's DBW and I can "easily" make a bracket to suit.

[wleehendrick]

Ha! in the grand scheme of building a kit car... yes, this was an easy one

[Rasmus]

Made a 22mm spacer out of HDPE. Sits the throttle pedal back just a bit behind the plane of the clutch and brake. Which is how Subaru mounts it.


Bolted the steering column in. The seat's on 25mm wood blocks so I could have a sit.

[Scargo]

Great find on the JEGS spacers. Now, who has all the grade 8 bolts in onesie-twosies?
PS: I'm trying to do as much Metric as I can when cost is not totally prohibitive.