Posted By: moparmikethree
converting 70 Challenger to a rack and pinnion - 07/13/12 12:04 PM
Has anyone every changed the 70 Challenger from a gear box to a rack and pinnion? Is there a kit, how much? or can you piece one together from after market parts. Did you like the outcome?
Posted By: Devil
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 02:57 PM
There are no good kits out there right now to convert a 70 Challenger to R&P. The one mentioned above is for drag racing. But you can do some work to you stock setup and make it work awesome.
Check out the Hotchkis setup for some ideas.
Posted By: moparmikethree
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 03:17 PM
like what, give some details. tired of the play in these gear boxes
Posted By: DJVCuda
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 03:52 PM
QUICK!!!
Someone tell Jon Clark ( formerly of Mopar Performance ) that he CANNOT run his 68 Plymouth in an Autocross event with the RMS AlterK!!!
Wait!!! He did...must have missed the memo as well...
Too late! He already did. 
Posted By: savoy64
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 04:54 PM
back to your question----the stock K member will not allow the use of a rack and pinion set up without drastic removal of metal----but if you have the money the above setups look good---if you are handy you can make your own---i did----bob
Posted By: abodyjoe
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 04:57 PM
i have the alter-k on my street car (dart in my sig). its been flawless and these jersey streets suck. i have close to 10,000 miles on it. wouldn't think twice about putting the system under a daily driver. not sure where the "its for drag racing" thing came from but thats not accurate at all.
Posted By: Silver6Pak
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 09:16 PM
I have an extra complete front end dropped from a 1971 big block Challenger. K member, control arms, spindles, discs, torsion bars,sway bar, tie rods, etc etc Complete, ready to bolt in. Why? Because the dude I bought it off of converted his to R&P and drives it daily.
Posted By: ahy
Re: converting 70 Challenger to a rack and pinnion - 07/13/12 11:51 PM
I don't believe there is any good way to mount on the stock K. Simple bolt on efforts result in crazy bump steer.
If you choose not to go the Alter K route, a Firm Feel box, gusseted K and suspension re-build with good parts will tighten things up consideraby. Big improvement.
Posted By: AndyF
Re: converting 70 Challenger to a rack and pinnion - 07/14/12 12:30 AM
There are a bunch of different kits that can be used to put a rack into an E-body car. Most of the the kits are designed for drag racing, but there are a couple that are aimed more towards the GT crowd. They are all fairly expensive ($3000 or so).
You didn't say what you were trying to accomplish so it is hard to help much. If you just want to make the steering a little better then get your box rebuilt by the guys at Firm Feel. There is a ton of stuff that can be done to tighten up the stock steering system. 11/16 tie rod ends, bracing the K-frame around the steering box, etc.
I covered this topic in my B-body book so maybe start there. There is also information in the old Mopar Chassis book as well as various out of print Mopar suspension books.
Posted By: Challenger 1
Re: converting 70 Challenger to a rack and pinnion - 07/14/12 12:58 AM
Thanks Andy for your input and DJVCuda for all the pictures.
I have question about the above setup, how heavy is it compared to stock?
It looks heavy and would be more geared to auto cross racing more so than drag racing?
To the OP I'd recomend FF upper control arms along with one of there boxes and I sure you would be happy. The postive caster that you get with the upper control arms is great, I mean huge.
Posted By: Chally426
Re: converting 70 Challenger to a rack and pinnion - 07/14/12 02:29 AM
I also have been on the fence about this....The alterkation is probably O.K and believe me I wanted one until a friend pointed me towards Hotchkis...The big difference...Cost Hotchkis complete front and rear is like 2500.00 plus a good box from firm feel...another 500 or so.
The RMS...4500 for the front and another 2500 or so for the back, I took a ride in the Hotchkis 70 Challenger a Carlisle and COULD NOT BELIEVE how good that car handled...The 70 Challenger ran a better time through that course that a new SRT8 Challenger and a new SS Camaro...Bottom line, Save some money and go with Hotchkis...
Posted By: cogen80
Re: converting 70 Challenger to a rack and pinnion - 07/15/12 12:24 PM
the point is your prices are $500 off on both units. also when you break it all down and really look at what you get with both kits its obvious that either the Hotchkis is way way over priced or the RMS is way way under priced.
Posted By: cogen80
Re: converting 70 Challenger to a rack and pinnion - 07/15/12 03:49 PM
no arguing at all here.. just pointing things out. call it a debate..
Quote:
My beginning problem with the RMS was cost, 6 - 7000 is a lot of money (and you still need to stiffin the body) especially after riding in the Hotckis challenger and thinking you could get that for half the cost of the RMS.
stiffen the body? in what way? frame connectors? heck you can do that for dirt cheap.
you ever driven or ridden in a RMS equipped car?
there is no denying that either system is a lot of money. but at the same time a lot of people just look at price and not what they are actually getting for that price.
Posted By: AndyF
Re: converting 70 Challenger to a rack and pinnion - 07/15/12 05:53 PM
It all depends what you're trying to accomplish. There is a lot of information available on the subject if you dig a little. Start with the tech articles on my website.
www.arengineering.comTim and I have spent a lot of time with his '68 Valiant. It runs a stock style suspension but has had a ton of tweaks to it. That car works pretty well and it would be fairly simple to duplicate.
I also covered the topic in my B-body book. E body and A body cars are similiar enough to the B-body cars that the information translates okay.
Posted By: Vert
Re: converting 70 Challenger to a rack and pinnion - 07/16/12 07:37 PM
There was a purple 71 Challenger in Crofton, MD. Owner had retrofitted a rack&pinion setup. Still had factory k-frame. Car was for sale at local service station. Someone there told me that R&P never worked well.
Posted By: Dan@Hotchkis
Re: converting 70 Challenger to a rack and pinnion - 07/16/12 08:30 PM
Not to add fuel to the fire, but a quick search on Amazon netted this:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=hotchkis+mopar+TVSThat said, there are various improvements that can be made over our kit, but as far as bang for the buck, there isn't a better deals on quality, made in the USA components out there. Our list price on the Hotchkis site is to ensure that we do not undercut our vendors, but that doesn't stop us from offering show specials at events we go to as well as extending HUGE discounts to our military members and dependents. That taken into consideration, our parts are also capable of being done piece by piece as the stock components wear out, which many customers like to do. That coupled with the ability to use your stock brakes, wheels and other components, has made our entry into the Mopar suspension market a formidable kit, with numerous victories at autocross, HPDE, and hill climbs around the country.
Posted By: Rick_Ehrenberg
Re: converting 70 Challenger to a rack and pinnion - 07/18/12 01:50 AM
My 2¢...as published in Mopar Action:
I have found a couple consecutive negative remarks about RMS products published in recent issues of Mopar Action and I am seeking to understand why. This came as a surprise to me because I can find no negative data on any RMS product no matter where I look. Many builds, including my own, that are pursuing handling related performance upgrades often include RMS. A much smaller percentage use XV (due to cost and mods) and even less Magnum Force. Bill at RMS really seems to have his heart dedicated to building quality products capable of improving street and road race performance with more than 10 years of product application to support it. If you have experience with RMS quality problems, or data to support the “questionable” status, please share it with us enthusiasts seeking to get our Mopars onto the tracks. This way we can make the necessary improvements, mods etc. to appropriately benefit from these kinds of upgrades. There should not be fear, uncertainty and doubt between fellow enthusiasts. I understand how the RMS system distributes cornering forces on our car’s infrastructure differently from the T‑bar but is there data of failures resulting from this? I can’t find a single case of failure of any kind. If you know of any please share and help us understand what is “questionable” about these products. Maybe together we can make the perfect solution.
My ’71 Challenger is using XV in the rear and RMS in front with all XV bracing products including rad support, inner fender bracing and connectors.
Thank you for your help and expertise.
—Daniel Niclas, San Jose, CA
Dan—
On a drag car, the RMS AlterKtion stuff is great—takes out lots of weight, makes more exhaust room. But there’s a laundry list of potential problems with using this on the street and/or road course. In no particular order...
> Heim joints—anybody’s heim joints—just do not last on the street. Even with added boots, they still don’t come anywhere close to OEM tie rod end durability. And, as an artifact of their construction, they are much more prone to total failure than an OEM tie rod end.
> The cantilevered outer tie rod end, spaced up with a stack of shims and spacers (for bumpsteer correction, no doubt out of necessity, because the rack could not be installed correctly due to interference, and a “generic” steering arm is used), is a scary potential catastrophic failure point. The loads on that bolt, should you be in a hard corner and hit a pothole, are astronomical. Some photos I have seen show the spacer tube welded to the steering arm, which may offer partial mitigation.
> The suspension (spring) loads are now taken by the front rails. They were, in the OEM Chrysler design, primarily, imparted to the torsion bar crossmember. On a drag car, where you’ll have a roll cage tube passing thru the firewall and tied into the top of what was the shock tower, the problem is pretty well mitigated. But on a street car, where you seldom see that, you’ll be inducing lots more chassis flex. Just hook up a small video camera and watch how the steering shaft telescopes over bumps. The Chrysler OEM system had a lightweight front structure with springs (T-bars) mounted low and rearward, damn near “Formula One” technology. Why give that up?
> The K-member is no longer a “K”, drastically reducing its ability to prevent the front rails from “parallelograming”. This would significantly reduce crashworthiness (especially in an offset frontal crash) as well as reducing overall chassis rigidity.
> I believe that the spindle diameter is smaller than stock. In 1973, Chrysler increased the spindle diameter as weight, tire size, wheel width, etc., were all increasing.
> The frame thru-bolts will crush the frame as the bolts are tightened. There should be tubes welded into the frame, EG: stock transmission crossmember, etc.
> Every pix I have seen shows brake hubs that have no way to pilot the wheel. ESPECIALLY road racing, hub‑centricity is paramount.
> There’s near-zero compliance—nothing to replace the OEM tension-strut bushing. Instantaneous impact loads are sky-high, exacerbating the above negatives. And the effective footprint of the LCA, which, in the OEM design, included that tension strut, is greatly reduced (nearly 50%) in the RMS design, further reducing its ability to safely handle impacts.
> The steering column’s pot coupling is eliminated. The pot coupling is what compensates for chassis flex; deleting it means that one of two things will occur over time/abuse: Either the nylon shear pin on ’67-up non-E-bodies will break, or the upper column bearing will fail (possible on any Mopar).
> You’ll note that there is not one weld in the factory suspension components. By design. That’s not to necessarily say that welds are always bad, but, if they can be avoided, you’ve eliminated one area where, unless each weld is X-rayed, you just don’t know what to expect over the long term.
Mr. Reilly has always thought I’ve had it in for him. That’s simply not true, I think he has designed a very good drag-race suspension conversion. It’s just when you take a drag race front end, sell it for street use, with nothing even close to factory durability and stress testing, that I worry. Lack of reported or known failures isn’t proof of anything: Space shuttles made many flights “before,” the Silver Bridge carried tens of millions of cars safely, then one day it simply vanished into the Ohio River, killing hundreds, to cite just two well-known examples. When a fleet of test cars have spent 250,000 miles each being hammered at a PG, then get back to me. This applies to the competitor’s products as well. If I didn’t point these things out, I’d be complacent. Reilly, in fact, does point this out, go read the disclaimer that is in the RMS documentation:
“....By purchasing this product, the buyer/end user assumes all risks associated with its use and agrees to having the proper skills for it’s [sic] installation. Reilly MotorSports Inc. and its suppliers will not be held responsible, liable or accountable for any injury, damage, loss, penalties, or fines that occur from using this product in any manner.”
For my dime, upgrades to the basic T-bar system are the way to go. Firm Feel, XV’s level one, and even Hotchkis have parts and packages that get the job done, although Hotchkis’ swapping (giving up) brake anti-dive* for more camber gain doesn’t thrill me either. If you’re building a straight-line-only drag car, your opinion may vary.
Guys often confuse “race” parts with “durability.” Often the opposite is true. EG: Aluminum con rods and rocker arms, “race” axle shafts and gears, tiny radiators and fans, super high-lift cams, and many more. A lot of guys, of course, do get by with race parts on the street. How? Simple: The car sees 10 cruise-ins or 300 miles a year, smooth roads, 40 MPH, etc.
If I don’t take care to see that there’s some kind of disclaimer in articles featuring cars with these suspension conversions, we could be seen (legally) as endorsing them—which we are not.
To boil this down: Again, I’m sure the RMS setup has good geometry (even has anti-dive) and drives just fine. On a drag car, the extra header and oil pan real estate, and reduced weight, would be the hot ticket. It is the specter of sudden, catastrophic failure in “real street” use that worries me.
*—See p. 35 for more on this. {Aug 201 issue}
Rick
Posted By: torqueaddict
Re: converting 70 Challenger to a rack and pinnion - 07/18/12 04:02 AM
Jeez I was going to start a thread about this but I'm glad I looked before I posted. This really makes you wonder whats safe and what isnt. I really want to upgrade my suspension like the rest but I am more concerned about safety. The Hotchkis stuff looks promsing too and for 2600 bucks on Amazon you cant beat that. I guess he has some major points. How "in the know" is Rick from mopar action anyway guys?
Posted By: torqueaddict
Re: converting 70 Challenger to a rack and pinnion - 07/18/12 05:10 PM
Is the xv kit more safe than the alterktion set up?
Posted By: Pool Fixer
Re: converting 70 Challenger to a rack and pinnion - 07/19/12 12:00 AM
I actually made a spread sheet over the winter comparing TVS vs RMS. You are right it's hard to compare the two because RMS is more complete than the base TVS. RMS front and rear, about $6300.00
Base TVS w/new rear shackles from Summit (2559), then go over to firmfeel for shocks (400), 1.06 Tbars (325) , bigger tierod sleeves (225), sector support kit (135),stage whatever box (330), fast ratio idler and pitman (285).. still under 4300.
As Dan said, the hotchkis website prices are what they are. Much better prices can be found at Summit or Amazon. I was able to pick up the TVS rear springs for my charger for $385 with free shipping from amazon in May 2012
