I'm in the initial planning and parts collection phase of my first hot rod build - a 28' sport coupe. I've decided on a traditional build... I love the look of a 28/29 cowl on 32' rails. That being said, I want this thing to handle the best I can make it using "traditionalish" components. I want it to sit low... probably lower than a car would have in the 50s, but not stupid rat low. I'm thinking a 32' frame, pinched and bobbed, with kick ups (3" front and 4" rear?). I like the look of transverse springs front and rear. What can I do to accomplish my handling goals? I know vintage rubber in small widths will limit traction... I just want to find a happy medium. I've done some searching, and have been unable to find builds that focused on handling prowess. Any help or insight would be appreciated. Thanks!
That's sort of where I started (http://www.jalopyjournal.com/forum/showthread.php?t=374184) but it tends to run away from you, and before you know it you're thinking about DeDion axles, Mumford linkages, and weird hydraulics ...
Sirhc My unit is a 28 on duece rails. It has a 6in Zeeeee in the rear with a 6in Super Bell up front. The bottom of the duece shell is 1/2 in above my tennis shoe. It uses a Model A spring up front and A modified Model A rear spring over the axel in the rear. I use P&Js shocks front and back set at about 40 degrees. It handles like a slot car sort of . I can overdrive the front tires in a hard corner. I use radials instead of the Traditional Bias ply because I need all the traction I can get. I am not sure how other folks do it because i can still lay about 75ft of rubber in 1st as it is. If I was using Bias ply tires I would still be at the last stop sign I left. PS My unit is as close to perfectly balanced as you can get without building it on a scale! Left to right - right weighs 13 labs more than left front to back - Front weighs 9 lbs more than back Total weight full of fuel 2308 LBs
Can do, But I don't believe it has to, Depends how fixed you are on certain ideas, Hotchkiss rear and beam front with forward wieght bias and skiney front tyres is not an ideal recipe. But with enough set back to get a better split and IRS ( if not IRS & IFS ) no reason why 'traditional' should not corner like a dream, without getting into strange linkages There are always going to be limitations to the effective chassis stiffness of anything built on a ladder frame, so unless you go full space frame it's never going to have the same cornering as things with better torsional stiffness, but depends on how far you want to go away from 'traditional'
Set your engine back as far as possible, and drop it as low in the chassis as is prudent, to start with. Remember you're thinking can am here and not 1320. The cross leaf on the rear won't hurt you a bit but your are probably going to have to play with spring rate a bit. One Won't corner if its bouncing, but you want to keep it stiff enough to control body roll. A little flex in the chassis won't hurt you a bit you need to keep your tires planted. Shelby said that when they built the first AC Cobras (the small block cars) they did almost nothing to stiffen the chassis just played with the spring rates and put good shocks on 'em to limit rebound. His theory was that if the frame flexed a little you could keep the tires planted you could out corner anything on the planet (they won in Europe against the high dollar sports cars). I would probably use a panhard bar on the rear but you may want to look into a sway bar (they had 'em back in the day) something like say for a '40 ford or so, I've always done well with a panhard bar myself. You'll want it to set pretty close to level with the car at ride height. Mount your shocks a close to the wheel as possible (but still be able to hide them). Can get a wide track without ultra wide tires by running reverse wheels,try and keep your unsprung weight down. You may coinsider aluminum drums (Buick)all the way around. Mount the rear spring behind the axle it takes less spring to control the axle if it behind the axle as opposed the infront of the axle. That's why a daytona mount puts the spring behind the axle. On the front I would look at a drop axle and a cross leaf again, and just like the rear you'll probably need to play with your spring weight. I might avoid major rake and try and match tire diameter if not width. They always handle better if the axle centers are the same height. Panhard bar or sway bar again on the front. I have a tendency to lean towards a gas shock, its not totally period but if you take the labels off no one will be the wiser, avoid friction shocks like the plague. They just don't work that well and you want to build one that handles, right? Make sure that your control arms (radius rods) are up to par IE pretty stout. Spindly looks kool but stonger is better when your not building a show car. That should get you started. Leme know if you get lost.
This the general idea of my most recent project. I want the look and feel of an old racecar, but want it to ride OK and handle decent. My biggest unknown in pulling it off are the tires. I want bias ply firestones for the look, but really don't think they are going to handle worth a darn. My other problem is forcing myself to stay in one particular era visually. I keep bouncing between 20's, 30's, 40's and 50's http://www.jalopyjournal.com/forum/showthread.php?t=339315&highlight=roofus
I set my 32 up with good handling in mind. The engine sits low - 6" pan clearance and the same on the trans. The car is a little higher in back than I like, but it should have been C'd and I didn't do it. It has good ground clearance and I can and do go many places with it. This is the other side of a rough dry lake near L.V. Standard 4" dropped axle, Vega cross steer with panhard in front, originally a Posie's Slider front spring, now a Durant mono-leaf. Both worked well. Coilovers support the 9" rear with a panhard and a Deuce Factory sway bar. The owner of the D.F. - Roy Fjastad - stated that they'd found a front sway bar wasn't necessary. Parallel 4-bars front and rear. Radial tire diameters of 24" front and 30" rear are ok, but a better match front and rear would perhaps improve things. Regardless, no problems in keeping up with the factory level sporty cars on winding mountain roads. The big engine helps there as well. The 31 on 32 rails roadster project has the same front end with the Posie's slider spring and a frame notch. Rear 9" is supported by transverse cross spring with D.F. sway bar and a panhard bar. Some feel that a panhard is not necessary on a transversely sprung rear, but a suspension discussion here on the HAMB about running a dry lakes roadster deemed it a necessity on the car. Gas shocks on the back. Home-made radius rods up front and a Chris Alston ChassisWorks 4-link with 1 1/4" bars on the rear. The rear 4-links will start off parallel, but will be tuned for a proper instant center. Tire sizes on this car are 25" front and 28" rear. Tread widths are narrower than the 32, that due to liking the looks of the narrower tires on this more traditionally styled car. I think it will corner as well as the 32. Chassis/engine etc. setup is identical to the 32 vis a vis where stuff sits so it'll make for a good comparison. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~` A little food for thought. Some years back a now defunct hot rod type magazine tested a Whale Tail Porsche, Jaguar suspended (front and rear) highboy roadster and a traditional highboy roadster on a skid pad. The Porsche with it's wide and sticky tires did the best. The Jag suspended roadster with its narrower and not quite as sticky tires did almost as well and the thinking was if it would have had wide and sticky tires it would have equalled the Porsche in G ratings. Surprisingly, the trad roadster did very well. It had radials as I remember, but not very wide ones. My opinion was that the trad roadster may have been able to run away from the Porsche on a big road race track due to it's strong running SBC. Provided the brakes were up to the task. It wouldn't have lost that much in the corners. Helluva sleeper deal if you think about it. The sporty car gang see's a hot rod roadster and thinks about how Model A's and the like sway on the corners. Build the right car, no need to go overboard with exotic suspensions, and most times you can hand the sporty car guys their hat. I can hear the gears starting to turn within the sporty car crowd, but if you have a hot rod with twice the torque and 2/3 the weight . . . well . . . ya don't need the math police to figure it out....
research some of lee osbornes or steve "the greek" paranies (sp?) setups. ive driven an osborne car and man i couldnt make it NOT handle. insane. as for the bias tires id say run em. that probably will be your limitng factor, but if all else fails, check out those diamondback radials they are making that look similar to the firestones using shaved and regrooved yokahama tires. they might hold pavement a lil stronger than the firestones.
Roger Lund's (I don't know his HAMB name) gold '30 coupe sure was impressive going around the auto-cross in Des Moines at last weekend's GoodGuys. It's a channelled car with a flathead on bias-ply tires. Anybody know his handle, or more info on the car?
Why not contact a local historic racing club? Those guys know there stuff. if they have a track day get down there and start aking questions. I noticed that many of the older engish sport cars (lotus, caterham, MG etc ) use fairly antiquated live axle rear ends, and still manage to embarass my brother and I in a track prepped mitsubishi evo. As previosly mentioned good weight distribution and decent radial tyres is half the battle won.
Thanks for all of the replies guys... Simple is good... i'm thinking a low CG and stiff suspension will get me pretty close to where I need to be. I'll be running a buick 215 with a four speed, should be able to get that little thing pretty low and far back in the chassis. This sounds real close to what I had in mind, thats for the run down.
Mine handles. Very well ( ask some of the HAMBers that have rode in it ). I even responded to a couple of Magazine Editors that seemed interested in Testing it, and really put it though its paces. But in the end, they both blew me off ( one of them even had me install seatbelts and other crap in it, for the upcoming test ) So I guess you'll just have to take my word for it. ( and the people who rode in it... )
Had a pal in the Rocky33 with me one night that asked if these old cars could corner. Not too long after shutting his yap he was peeling his self off the passenger door from the rather abrupt left turn........
A factor on roadster type cars is always going to be unsprung weight. The car can easily be built down below 2,000 pounds, especially with stuff like the aluminum 215, but it is hard to bring down running gear weight to match. Perhaps current versions of V8 QC made for midgets that have been discussed on here would be a way...semi traditional rear with lots of aluminum and magnesium. What's out there in brakes?? There must be some kind of circle track stuff suitable for a really light car with calipers and discs lighter than any of the normally used drums or passenger car type discs. Buggy springs can do the job fine on roll and sway, but with the type of car you are laying out it would be really easy to get grotesquely horrible unsprung ratio with normal hotrod components.
Here's one discussion... http://www.jalopyjournal.com/forum/showthread.php?p=4078661 What is the 8 3/8 stuff? That would be about size of earl Ford R&P, but never actually measured. One of those looks a good deal like a V8 QC with a lot of attention to weight.
Unsprung weight is a problem. But not more than, say, in a Lotus 7 or in a car like my Mallock U2 Mk6. And those were extremely succesfull racingcars ( that did battle with much more sophisticated machines in their day )
Here is another handeling Hot Rod nipping at the heels of some Italian Exotic. Ol' Yeller #1. That is the sistercar to this one, that I still have to restore. I beam in the front, live axle in the back. ( OY1 had a V8 60 front axle and torsion springs, instead of the buggy spring on mine )
But the Lotus could start out with what, Anglia-Cortina type parts for a rear lighter than anything good in our junk yards...we have to get way outside our normal boxes on that issue, look at alien types of racing or nearly extinct older furrin cars. The 215 engine's size and low torque give some extra latitude. That little QC looks like an inspiration. Our normal gene pool for brake parts is also way too heavy here...need to look at sporty car and midget stuff there too.
Yes, a 9" is stupid heavy... But the whole thing is scaled up. My Mallock weighs ( if I remember correctly ) about 450 kilograms, with fenders, steel wheels, lights, a passenger seat, and other street equipment. My '28 must be easely twice that... ( i'll have to put it on some scales someday )
6 X 16 and 7.50 X 16 Firestones from Cooker. Bias Ply. They break away early, but very controlable. You can hang the tail out, or go for a neat controlled 4 wheel drift. At some point I would like to try some Dunlop Racings or Exelcior's on it... I dont mind Bias Ply's. I've done most of my Racing on them. ( but those were fat, low profile slicks )
Talking about unsprung weight, I really dont understand why Quick Change Rears are so popular... Those extra gears, shafts, bearings, bigger housing, etc, seem to be at the worst place possible. I think I'd want all that at the back of the gearbox, so its sprung...
I'll be running a buick 215 with a four speed, should be able to get that little thing pretty low and far back in the chassis. I was just about to sugest that. If you want Buick 215 HIPO parts you might try seaching for ROVER V8 parts. They should bolt right up, but have a more european performance.
My Track T with a 289 Ford, aluminum bellhousing, glass body and an 8" rear end weighs 1650 lbs. It is a springer in front with coil overs in the rear. The tires are Firestone 5.00-16's in front with 8.20 Firestone's in the rear-both bias ply. With the three link in the back with an adjustable panhard bar, it handles really well. The engine is also set really far back, and the wheelbase is 114".
I've been building something like this in my head for quite some time. I'm wondering if you could gain any advantage by running fully independent (one of those split I-beam kits to keep the trad. look), with quarter elipticals. For the rear maybe a Jag, or independent Ford 8.8, with coils. if you can hide it, or I remember seeing a really cool old article where a guy built his own independent rear out of a banjo rear, keeping with the trad. theme. Low CG, even weight distribution, maybe four bars?
Its funny this thread came up now. Im gonna try running my truck (400+ HP @ 2400 LBS) in a little SCCA parking lot deal Sat at a local show. I know my times will suck But I assure you it will be entertaining.
I'm building alot of adjustability into mine. Not very traditional, but maybe you could make it look so.
Take some pics and post some times in a separate post when you can. I'd like see how you did and how the truck compares to the sporty cars. I'm hoping some sportys will be close to stock, but the ones set up for autocross would be tough to beat. Oft-times I wonder how the autocross set up sporty's would do on a longer track. ~~~~~~~~~~~~~~~~~~~ Years ago, there used to be a Go-Kart track next to Mandalay Steam Generating Station in Ventura, California. Impressive little cars they were, but the most interesting was when the local Corvette gang decided to take on the Karts on the Karts home turf. A major ass-kicking ensued and the Corvettes suffered mightily at the hands of the Karts....
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