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Product Development - Knock Flat IFS Kit - Track Width?

Discussion in 'The Hokey Ass Message Board' started by CoolHand, Nov 30, 2010.

  1. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    OK, for a month or so now, I've been doing development work on a new IFS system that can be bought knocked flat and assembled by the end user (like Ikea, but not Swedish and not shitty).

    I'm getting close to building a prototype, and it occurred to me that I might ought to poll the consumer base and see what track width would be the most popular.

    Currently, I've got it at 60" hub face to hub face, same as the '36 I am building. I wanted a really wide stance, but maybe that's not what most folks want.

    The idea of this kit is to produce a front end with geometry far superior to that of the ubiquitous Mustang II, with bigger brakes, and less (or no) propensity for ripping the lower control arm off the crossmember under heavy braking loads.

    As it is now, we're talking about a front roll center 3" off the ground and a camber change curve that will keep the outside wheel upright through 5 degs of body roll.

    I'm pretty happy with the wheel control and the ease of assembly, I just want to make sure I'm not going to be offering something that is wider than what most folks are looking for.

    The kit could be narrowed fairly easily (split the crossmember down the middle and relocate the rack mounts), but doing so would lower the roll center and decrease the camber gain in bump, so I'd rather hit it right the first time (or maybe offer more than one width).

    I'm looking to offer it as a knocked flat crossmember kit with the control arms already assembled and jig welded. The customer could source the spindles and ream them on-site, or they could be supplied with the kit.

    I'd also offer them fully assembled as crossmember kits as well as fully welded front stub assemblies (firewall forward).

    Right now what I'd like to know is what width(s) you all would like to see.

    So, lay it on me. How wide (hub to hub and/or outside of tire to outside of tire) would you all like such a beast to be?
     
  2. BobPer
    Joined: Feb 15, 2009
    Posts: 284

    BobPer
    Member

    When I designed my C-4 Corvette crossmember, I set it up for 57" hub to hub. For my 36 (Dodge) that works out pretty well with my tires/fenders. I have about the same design perameters as you're describing for your design too. The all aluminum A-arms and uprights can be found pretty reasonably priced, and polish up real nice, and being all aluminum, the unsprung weight is less than steel versions. Another advantage is, it already has bigger brakes/calipers than Mustang II, and all the replacement parts are over the counter. The expensive part is the good coil-overs or airbags. Bob
    [​IMG]
    [​IMG][/IMG]
     
    Last edited: Dec 1, 2010
  3. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    Be truly innovative. Design yours to be easily narrowed to any width. The problem with most every kit on the market is that the cross-members come in a few specific widths. By making the box sides in a manner that permits cutting to width, you create a versatile system.

    I even have the design already that eliminates alignment concerns when jigging the parts up for weld out. I'll give it to you if you care to call.
     
  4. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    The danger of "universal" designs is that in order to make them universal, you have to accept a lot of compromise geometry wise.

    When you change the width of the crossmember, you also have to change all the control arm angles to maintain the roll center location.

    If you've got an idea how this can be accomplished in an elegant manner, by all means, PM or email me and I'll have a look at it.

    I suppose that I could scribe the pieces with several layout lines to allow the end user to cut the parts and align them in that way, but I had planned on doing a tabbed assembly, so that it was basically impossible to put it together wrong.

    It wouldn't be that big of a deal to work up a pattern for every width from say 55" to 60" or 65" (Hub to Hub).

    This stuff will all be plasma cut, so it's not that big of a deal to have more than one program to work from.

    Would one inch increments be fine enough adjustment?

    That way I could retain the tabbed assembly process, and still be sure that the suspension pickup points end up where they need to be.

    What say you on that score?
     

  5. 49ratfink
    Joined: Feb 8, 2004
    Posts: 18,828

    49ratfink
    Member
    from California

    if you narrow the crossmember you need to narrow the rack an equal amount.
     
  6. Francisco Plumbero
    Joined: May 6, 2010
    Posts: 2,533

    Francisco Plumbero
    Member
    from il.

    I worry, you want to sell a flat unit that is fully fitted and not seam welded to the consumer....I would be worried...the number one failure issue with several of the most popular m2 systems is the inability of the end user to either or both not be able to achieve proper fitment, not be economically wise enough to seek out even semi pro help in this regard and or just plain straight assed not really know how to weld worth a shit. I would fear a total ass pinning no matter how well you engineer your stuff, the market is so immersed with a feeling of "it's junk from the manufacturer" in this venue that you could get lumped into a heap. Unfortunately, I say this with respect, you are intelligent, when selling product to less engineering savy people you are at a disadvantage, I think you should hand out a few test flights to some prospect market types and see just how they do with your kit. I don't mean shops, I mean just regular guys. I would venture to guess that of a field of 100 guys you may only get 20 that would buy a unit and have all the skills required to get it built, welded right, dimensioned correctly and have no issues such as cracks extreme warpage or bump steer. I hope I'm wrong but fear I'm not.
     
  7. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    This is not necessarily true. If you don't narrow the actual rack (which is hard as hell to do, BTW) and not just the tie rods, or find a narrower one, you can still get to zero bump steer via other geometric means.

    Managing bump steer isn't as black magic as a lot of folks make it out to be. It's just geometry.

    Perhaps a Fabricating IQ test should be administered before the sale is made?

    I do not hold such a dim view of most HAMB'ers. I see guys on here build shit from scratch and make it work on a daily basis. I'm sure those guys could manage to assemble a knocked flat kit without too much drama.

    For those that can't do it themselves, I'd be happy to sell the kits pre-assembled as a front stub or an entire new frame (if they so desire).

    This should be some of the easiest welding they'll do on their hot rod. The material is very forgiving, and it's thick enough that it'd take a seriously ham fisted fool to burn a hole through it.

    The cracking that a lot of MII systems suffer from is induced by a design flaw inherent to the popular "strutless" designs on the market now.

    You'll notice you don't ever hear of a MII with strut bars tearing the lower control arm out of the crossmember. There's a reason for that.

    Anyway, liability is what it is. At some point, if you're going to be in business, you're going to have to accept some exposure to risk, it's as simple as that.

    Ask the Welder's Series guy how often he gets sued. I'd guess it's not real often, and his entire product line is stuff that the customer welds together.
     
  8. Francisco Plumbero
    Joined: May 6, 2010
    Posts: 2,533

    Francisco Plumbero
    Member
    from il.

    HAMBERS are smarter than others, they have a network, it's the others that will mess up your stuff and blame you for their silliness, it won't be the liability that hurts you, it would be the unfounded blame and chatter that they post on site XYZ, maybe do an off shoot corp to keep the main company clean, the drug companies do that, if your hard on meds cause an ear to fall off the main corp doesn't get hurt.
     
  9. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    Well, since there are like >100,000 HAMB guys, that's a pretty big pool to pull from for the time being.

    I'm down with the compartmentalization of the company. Note the LLC on the end of the name there? Who do you think the Pharma companies learned it from? :D

    As for bad press, from chatter on the internet, it's actually not as bad as you'd think, especially when the scale is as small as mine is.

    When your customer base is in the thousands and not tens of thousands, it's fairly easy to stay on top of problems if they turn up.

    This is also mitigated by being both easy to get a hold of and honest when people run afoul of your stuff.

    I can count on my two hands the number of people who I've dealt with over the years that just couldn't be helped at all.

    The terminally stupid are not as numerous as we've been lead to believe, and the decent but crap-up prone can be managed, especially if you actually talk to people and try to help them out when things go pear shaped.

    When you're a small company, you're in the unique situation where liable or not, there's pretty much no point in suing, because even if they win, our pockets are so shallow that it's a pointless exercise.

    Since most all product liability suits are done on spec by the lawyer (in the hopes of getting a cut from the big settlement), nobody is going to file one against a company that takes in less than a few million dollars a year, 'cause there's nothing there to steal. The lawyers won't work for free, so with no big payout on the horizon, the plaintiff will be out of pocket at $200/hr to win no money.

    I ain't afeared of the lawyers for the simple fact that I'm too skinny to be worth the effort to BBQ.

    Metaphorically speaking, of course. ;)
     
  10. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

    You know what you're doing. You are just facing the one issue every aftermarket designer faces. You can make all the geometry correct for one or two common designs, but then it will undoubtably be applied in a hundred undesireable scenarios OR, you can make a widely adjustable setup knowing the majority of installations will have compromises in geometry. Simple fact is, unless you tailor make each install, you will be delivering a universally compromising product. Which is the better way to go? If you have done much of this, you know that 95% of end users will not even realize they missed the optimum combination. Heck, Most OE installs miss and those that don't are compromised by suspension "upgrades" by the end user.

    I suggest you map out geometry that is in the middle of the range, maybe biased toward the most common track widths. Design in a simple tab assembly that is shortened on the ends of the top and bottom plates and in the center of the front and rear plates. One inch increments are more than adequate. Pair it with a narrow rack that is readily available, but easily widened with rack extensions available to match the finished width. (This may not be the only way, but it is easiest for the end users) Your ultimate success will be in the detail of the instructions. You need two parts. Ordering instructions that simplify identification of the right parts, and Installation instructions that spell out enough detail for a lesser skilled installer. Plain and simple, the fully qualified suspension installers are fabricating their own parts for optimum results. Your market will be the inexperienced that have little experience. Lose sight of this and your tech line and/or your reputation will crumble. You don't have the advertising budget to counter a handful of angry idiots with internet access.
     
  11. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    Come on guys, seriously, I'm not looking for tactical advice here. Like I say in every one of these kind of threads, this isn't my first rodeo.

    What I'm looking for is what width the IFS in your car is.

    I need data.

    The advice is fine, and I'm sure it's well intentioned, but it's starting to sound kinda condescending.

    Don't take this the wrong way, but I don't need the obvious stuff pointed out to me here, this isn't the first time I've done the new product development thing.

    Assume I know what I'm doing business, legal, and advertising wise, and lay the data on me.

    Now, if you've got a specific feature you'd like to see, by all means, post it up.

    Where we're at so far:

    1" increments will be fine enough, that's a good answer for that one.
    57" hub to hub worked pretty good on a '36 Dodge

    That's about it.

    How about bolt patterns? Would 5on4.75, 5on4.5, and 5on5 be sufficient? The stock rotors will be 5on4.75, but redrilling a new pattern isn't that big of a deal, we redrill them to 5on5 to run on our race cars all the time.

    Do the older Chevy pattern wheels still use the 7/16" studs that the newer cars do? I know Ford has been 1/2" for a long time, but I'm not sure on the Chevy stuff.

    The dia doesn't really matter (per se), they're all readily available, just gotta install the right ones for the application.

    Anyone else got a hub to hub width they'd like to share?

    It looks like most aftermarket guys offer them between 56" and 60" hub to hub, in what looks to be about 2" increments (so three iterations total).

    A lot of variation can be made up with wheel backspacing, assuming the wheels you want to run are available with different backsets. The dreaded wheel spacer could be utilized if the studs were switched out for hardened versions.
     
  12. scottybaccus
    Joined: Mar 13, 2006
    Posts: 4,109

    scottybaccus
    Member

  13. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    Not offended, just don't want the thread to veer off point too far.

    I found the Crankshaft Coalition page about a week ago, but as you say, very little pre-1950.

    The distinct lack of cars with 60" or greater hub to hub before the middle sixties is what got me to thinking that one width would simply not be sufficient.
     
  14. Kato Kings
    Joined: Aug 22, 2006
    Posts: 707

    Kato Kings
    Member
    from Minnesota

    I would say 1 inch increments from 56 inches wide to 62 inches wide should just about cover most projects. Are you going to allow the use of junkyard a-arms, spindles, etc. or just offer tubular ones that you build?
     
  15. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    The control arms will have to come from me (nothing stock will fit), but the spindles, rotors, and brakes will be junk yard items that the user can modify to fit.

    The spindles I have in mind are the '81-'89 big Impala spindles with the 11" rotors. They'll have to be reamed to fit the ball joints, and maybe the tie rod ends, depending on what application the rack ends up coming from.

    Obviously, if the user can't (or doesn't want to) modify the spindles themselves, they can be provided with the kit ready to go.
     
  16. Sjiefaa
    Joined: May 18, 2009
    Posts: 168

    Sjiefaa
    Member
    from Holland

    I'll test the first prototype for ya :D ! 57'' width please, 1937 Dodge sedan.
     
  17. BIG-JIM
    Joined: Jun 13, 2009
    Posts: 1,374

    BIG-JIM
    Member
    from CT

    Don't be so shy.:D
     
  18. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    Ha! :D
     
  19. Hey, neat stuff. I've been pondering the same type of setups, though as of late i'm taking a different road for a bit. We install prob 4 or so a month here, all different so i've seen quite a few. Couple thoughts for you...

    first, to answer your question on widths; think about the types of vehicles you are going to target. model a's/32s/34s - early 30's cars? they are all going to be fairly narrow 54-56 inches should do. mid to late 30s are going a big bigger, 56-58 depending, and the fat fenders are pushing 58 depending on the wheels. We put a 59.5 on a 48 ford and its got skinny smoothies right out to the end.

    I like wheels with big offsets. I was thinking of putting a 60 incher on a model a. I'm weird. Most guys like at least a neutral backspace, if not a heavy backspace. What is your audience? You knock down the scrub radius a lot if you can push the spindles out and get the right angles with the uppers.

    What do you want the cars to do? Most guys dont care how they handle largely. You want a good comfy ride that is safe in all conditions. (heck, how many guys drive around with stock solid axles!) you want to hit the curves hard, that negitive camber gain is going to be your best friend. if your designing one or the other, fine. but make sure you are clear which one. That figures into your "universal" bit a touch, cuz if you have to keep changing roll center angles and king pin inclination, etc... maybe have a "sport" option?

    also, dont forget about fender clearances. sure, you can get great geometry by pushing those upper control arms up, but will they clear the fenders? Take a model a for example... tricky little buggers. But, it can be done. and with the racing/impala stuff. (got a mock up and cross sectionals if your interested)

    oh, and maybe you might consider doing something to utilize the racing stuff; most front ends are heavy as all get out. on these rods that dont weigh what the land whales do, taking some of that unsprung weight out of there would be most beneficial. using the adjustable upper control arms gives you much better control and personal alignment specs options too.

    good luck with your project; sounds like it could be a good one!
     
  20. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    Very good insights. Most of what you've said, I've been thinking about for some time now.

    The segment of the hobby I want to target is the group of guys who want to build a rod for road racing or auto-X or just want a car that points and cuts when you ask it to.

    The ride will be totally dependent on how you spring and damp it.

    The control arms will be fabricated, non-adjustable lowers, 100% adjustable uppers. It's going to be hard to get the unsprung weight much lower. Fabricated spindles and aftermarket hubs would be the only ways to reduce it further. Wilwood sells LW alum calipers that will fit the Impala spindles, so the brakes are already pretty light (or can be, if you're so inclined).

    The package I have in mind will be significantly lighter than using all the stock components.

    I'm leaning toward making the system revolve around the coil over damper type spring system, as that is the lightest option, and the easiest to mount and deal with.

    The fender configuration on cars up to about the late 1940's, makes optimum mounting angles for the CO's hard to obtain because of fender clearance.

    The CO angle on the front of my '36 chassis is damned near 45 degs, and that is entirely due to fender clearance issues.

    Early body styles make for quite the challenge when it comes to retrofitting performance suspension.
     
  21. bobnier
    Joined: Oct 24, 2009
    Posts: 13

    bobnier
    Member

    You have to produce a 56 1/2" kit. If you can figure out a 22 1/2" inside frame rail to 29 1/2" outside, I would be interested.
     
  22. CoolHand
    Joined: Aug 31, 2007
    Posts: 1,929

    CoolHand
    Alliance Vendor

    How about 56" hub to hub and two 1/4" wheel spacers? :D
     

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