yesterday at the goodguys show in desmoines i watched a little of the cars run the course, speedway's purpose built three cars were there[all chevys] the course they had laid out the pro cars were running it in the 30 second times,viking shocks had 3or 4 cars with huge wings on the back a couple were vettes if i remember correctly they ran in the 30to 33 sec time . then this 70 lime green challenger pulls up, looks all stock from the outside except for tires and rims of course, lays down a 29 second run
auto cross
- Thread starter Lowcar
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That's a good-looking Challenger. 
yea that would be the one. until you see this car beside some of those pro built clown looking things that resemble chevys of the past,it looks so out of place because it is so stock then goes out and literally embarrasses well they should be embarrassed because of the obvious money spent difference.it was a great thing to see that car kick ***
blunblu after reading most of your replys and first hand knowledge of the mopar torsion bar suspension vs the tubular high dollar coilover conversions and seeing what i saw real world side by side competition, you are absolutely right for a handling car anything but the modified mopar torsion bar suspension is a step backwards not a improvement as some would argue
Both drivers are amateurs with about 8 years of autoX experience now. Not saying they aren’t great drivers at all, clearly they are. But they’re just regular folks having fun and competing with their own car, not anybody with professional driving chops.
And really, it doesn’t matter. If a ‘70 Challenger with a Hotchkis based torsion bar suspension can turn in faster times than a high dollar pro-touring build with an aftermarket chassis, it still shows that the torsion bar system is more than capable. And a megabucks aftermarket chassis does not guarantee you have the fastest or most capable car. Which has always been my point. If you want to install a full coilover conversion, great. But it’s not necessary to have a great handling Mopar. And to date, the best handling Mopars have been cars with torsion bar suspensions.
That car was at moparty last year. Father/son team. Both are good drivers. I think it's all Hotchkis suspension, nothing fancy. I will also say, they take the sport very seriously. He rode his bike around the course countless times prior to us even starting our cars. They checked tire pressures and temperatures after every run. Sometimes its all about your program and a car that just works without any fancy crap.
gzig5
Well-Known Member
That’s a cool story. Hope I can make my Cuda handle well like that. Wonder how much difference a stroked small block at the same power level would make? Should save about 100lbs off the front end?
Great story, I used to run autocross events in the 80s with a fox body Mustang bone stock in every way. Was a lot of fun, I was never interested in anything but having some fun with my car, but I did win my class at a couple of events. Proper preparation is very important, so was staying sober the night before. Lol
gzig5
Well-Known Member
Guess I’m out then.
Lol, that's why I was only in it for the fun.
I know someone has these numbers on the top of their head but I believe a B/RB with aluminum heads, intake, and water pump housing will weigh in at about what an iron LA does.
I have no idea how much weight you can save by putting aluminum heads/intake on the LA but I do know you can easily make more hp/tq than you need on an autocross course with a stroked LA.
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gzig5
Well-Known Member
I believe a small block aluminum head should be worth 25 pounds per side so 50 pounds total. I was under the impression that a big block engine complete weighed at least 100 pounds more than a small block and I would imagine the weight savings are similar on a big block. Maybe the 50 to 100 pounds isn’t that big a deal when the car is really set up correctly as long as the shocks and springs can handle it
MopaR&D
Nerd Member
Talking about big vs. small block, in reality you don't need sh** for power in autocross. I go to track day events (PPIR Track Attack) which are a combination of autocross and road racing where they use a section of the oval track for longer sections but set up cones in the infield for the more technical portions. My 360 puts 290 HP at the wheels and I rarely go WOT at those events, heck I don't use much throttle at all really. The guys (sometimes gals) who run some of the fastest times are in Mazda Miatas and other underpowered but sharp-handling cars. I rode with my buddy once when he did a run in his Miata (he typically places in the top 5 of his class) and he basically had his foot to the floor the entire time lmao. Definitely not my cup of tea and I'm in no hurry to let him take my Duster for a spin he'd probably drive it straight into a wall.
My 360 has a full aluminum top end btw, if I was only going to compete in autocross or other low-speed events like Track Attack I'd seriously consider swapping in a smaller lighter engine with less power because my current engine doesn't help me much tbh. I do plan to step up to open lapping at an actual road course though and that's when horsepower actually matters. And brakes, factory '73-up 10.9" front discs don't really cut it trying to haul down from 100+ MPH... believe me I've tried lol
My 360 has a full aluminum top end btw, if I was only going to compete in autocross or other low-speed events like Track Attack I'd seriously consider swapping in a smaller lighter engine with less power because my current engine doesn't help me much tbh. I do plan to step up to open lapping at an actual road course though and that's when horsepower actually matters. And brakes, factory '73-up 10.9" front discs don't really cut it trying to haul down from 100+ MPH... believe me I've tried lol
autoxcuda
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I see some things of note on the Challenger:
- Tire size is at least 275 up front. (Anyone know exact sizes?)
- Tires are wide enough with increased backspace that there is slight rubbing at full lock turning (see frame rub marks)
- 14:1 Borgensen power steering box with KRC pump
- Can't tell if running Fast Ratio pitman/idler. But E-bodies can fit longer fast ratio arms that would give this car about 10:1 to 11:1 steering ratio. Rough guess: 2 to 2-1/2 turn lock to lock. I know someone that did this on a 71 Road Runner and personally he loved it.
- Looks like there is a channel cap over the front frame rail. Not sure if for strength or rust repair
- Milodon Road Race oil pan
- External oil breather catch can on passenger firewall because hard cornering will load up a valve cover and spit oil from a breather on valve cover
- It needs to have 2 throttle return springs for safety (remember the 66 Barracuda that crashed as a Good Guys event)
- Smaller diameter Tuff Steering wheel with good grip.
- High bolster cloth seat (cloth holds you in better than slippery vinyl)
- Added brake pedal covers for grip and width for better position
- Added "dead pedal" for driving aid
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If I remember correctly, he’s running Advans, 315s square.
I wouldn’t be surprised. I had 275’s on my Challenger and still had some room, and I hadn’t really done much rolling or pushing on the fenders. I think 295’s would be possible with a similar treatment to what I’ve done on my Duster. And if we know they rub a bit, well, 295 to 315 isn’t that much of a jump.
autoxcuda
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I thought they were big, but the article wrote: "Everybody wants us to switch suspensions, run coilovers, cut it up and put 335mm tires on it, but that’s not this car. I think it’s working pretty well this way.” So I figured they were much smaller than just one size smaller.
That said....I'd really like to fit 315's on my A-body Barracuda. Would need to be mini-tubbed and I'm being a wuss about cutting into it.
I bet it handles like a go-cart.....very wide / super low profile tires, lots of camber and that is just what you see in the picture.....not hard to tell this "team" has their **** together. A great race car set-up......but I would be surprised if it would be very street friendly with or without the steering box and torsion bars. The tire bill and trips to the dentist would kill your gas budget.
Thumbs up to the owners / driver of that Challenger.
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Denny, I spoke with them at Moparty. They do not drive this car on the street at all. There was another Challenger there, it was orange dressed as a TA. Same suspension setup only with a 340 six pack. Also, not street driven.
autoxcuda
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I have the stiffer rate Torsion bars in my 68 Barracuda than the Green Challenger if it’s got hotchkis torsion bars. I drive mine on street. Drive 51 miles to track and back.
*edit* Rates from MP Chassis Book. Other manufactures seem to vary a little in calculations.
1.10 Hotchkis torsion bar E-body wheel rate: ~240 #/in
1.12 MP torsion bar E-body wheel rate: 250 #/in
1.14” MP torsion bar A-body wheel rate: 350 #/in
the stiffest e-body torsion bar is a 1.24” that has a rate of about 370 #/in
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that's cool.....and maybe I'm just spoiled, but I like a little "sus"....in my suspension.
No reason they can't be street driven.
I ran Firm Feel 1.12" torsion bars in my Challenger and I put over 70k street miles on it, those are advertised at 270 lb/in, so stiffer than the Hotchkis E-body bars. Hell most of it was with absolutely abysmal KYB gas-adjust shocks. Switching to Bilstein RCD's made that car a completely different animal. I ran 275/40/17's on it, square. So maybe a little more sidewall than what's on that green Challenger but not much.
I have 1.12" Firm Feel torsion bars in my Duster, I've done over 30k street miles with it. The wheel rate on those is 300 lb/in, and honestly with the Hotchkis Fox shocks it rides amazing. I've actually considered bumping the wheel rate up a little, maybe if I can get something in the 320 lb/in range. And I run 275/35/18's on it in the front, with 295/40/18's out back. It's also a 16:1 manual steering car with +6.5° of caster. Sure, parallel parking is no fun but over 10 mph the steering is fine. Heavy, but fine. And above 45 mph it's amazing.
Currently my trip to work is 60 miles one way with over 3k feet of elevation change, I do that about once a week and some of the roads I drive would definitely be considered "back roads" whose surface isn't exactly smooth.
I ran Firm Feel 1.12" torsion bars in my Challenger and I put over 70k street miles on it, those are advertised at 270 lb/in, so stiffer than the Hotchkis E-body bars. Hell most of it was with absolutely abysmal KYB gas-adjust shocks. Switching to Bilstein RCD's made that car a completely different animal. I ran 275/40/17's on it, square. So maybe a little more sidewall than what's on that green Challenger but not much.
I have 1.12" Firm Feel torsion bars in my Duster, I've done over 30k street miles with it. The wheel rate on those is 300 lb/in, and honestly with the Hotchkis Fox shocks it rides amazing. I've actually considered bumping the wheel rate up a little, maybe if I can get something in the 320 lb/in range. And I run 275/35/18's on it in the front, with 295/40/18's out back. It's also a 16:1 manual steering car with +6.5° of caster. Sure, parallel parking is no fun but over 10 mph the steering is fine. Heavy, but fine. And above 45 mph it's amazing.
Currently my trip to work is 60 miles one way with over 3k feet of elevation change, I do that about once a week and some of the roads I drive would definitely be considered "back roads" whose surface isn't exactly smooth.
67autocross
A new iron curtain drawn across the 49th parallel
I ran 1.14s in my 68 Valiant…they are not that stiff…. I’m going to put the same size bars in my 72 Scamp when I swap in the 416 inch small block this year…just waiting on the miladon road race oil pan for 8 months now…
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