courtesy of www.plaftaphto.com

What's it Got ? A '67 Barracuda Set-Up for Autocross & Ralley:  The Nitty Gritty of What Worked and What Didn't.

courtesy of www.plaftaphto.com

GOALS

  The key is to choose components that work well together.  There are two approaches to to take.  One, copy what someone else has successfully done. The Mopar Performance books are a good example of advocates of this approach.  The second method is to understand what ought to work together and try to put together your own package.  David Vizzard's books are a good help for this route.

ON THIS PAGE:

SUMMARY 1. SUSPENSION - Springs & Shocks 2. BRAKES 3. STEERING 4. WHEELS - Rims & Tires 5. POWER TRAIN - Intake to Axle 6. ELECTRICAL

Summary of Set-up:

Induction:

  Carb.: Holley 650 cfm vacuum secondaries, center hung bowls, rear metering block.

  Intake:  Edelbrock LD340 Dual Plane plane manifold.

Exhaust:

   340 cast-iron manifolds.

   2.5/2.25 dual system from Accurate Ltd. with X cross-over and 2.25" turbo style mufflers.

Transmission:

    Torqueflite 727 with Turbo-Action/MP shift kit, and medium stall Turbo-Action torque converter

Axle & Differential:

    3.23 gears.  8 3/4"  with  limited slip (Dana clutch style "sure-grip")

Brakes:

   Kelsey-Hayes 4-piston disks, front.  Cycleweld (OEM) pads

   10 x 1 3/4 drums, rear. Pennsylvania Brake, Red Streak shoes (went out of business in 2001)

   Non-assisted dual resevoir master cylinder.

   Adjustable prop. valve.

Springs:

   Front:  1.09" diameter, 240#/in wheel rate.

   Front Sway Bar: Saner adjustable 1.125"  dia. in the softest postion.

   Rear:  Landrum 200#/in 4 leaf.

Weight: 3210 lbs. without driver.  57% on front

 

Shocks:

    SPAX adjustables G480, G481

Steering:

    Manual fast ratio (16:1)

Wheels:

    small bolt pattern, 5 bolt - 4" circle. (A-bodies through 1972 used this Small Bolt Pattern for wheels.  The factory never supplied anything but 14 (and 13) inch rims for this pattern.  The factory apparently pulled large bolt pattern parts from other production lines for some of the A-body race cars. There also was a special run of 5X4.5" K-H disk brake rotors and hubs.)

   Street:    215/70-14 BFG Radial T/A     14x6 & 14x6.5  Cast aluminum slotted rims.

   Autocross:     225/50r-15  Toyo RA1        15 x7.0"  Circle Racing alum. racing rims

 

Suspension Bushings:

  Polyurethane and "polygraphite" all around.

  except...Moog "problem solver" Upper Control Arm bushings (installed August 11, 2001) for more caster.

SUSPENSION

Springs:
Spring rates were chosen with the objectives that they be soft enough for use on rough roads, and that a rear sway bar would not be needed. Why no rear bar? Two reasons. The first was that a good rear bar was not available. The second was that many road racers have found that the rear bar makes the car too twitchy. However, autocrossers might benefit from having a good adjustable bar. It is likely that the next change in rear springs may be accompanied by a rear sway bar. Availability is getting better. Firmfeel is starting to make them and Saner can probably make a custom one if design it.

It is important to keep the balance between the front and rear springs. The handling line discovered emperically by Direct Connection (Chrysler) is a useful tool once you grasp it. The main difficulty in calculating the roll rates is in getting the spring rates for the sway bars and the leaf springs.

For a long time the car was set up with 1.04" torsion bars ( about 200 lbs./in. wheel rate), a 1.125" diameter front anti-sway bar, and 6 leaf 'heavy duty' rear springs made by Triangle Spring (160#/in).  Result was as follows.  The leaf springs were a little too stiff and had a little too much arch when new.  Over time, the rear spring rates went down and the front/rear balance got better.  However, after 80,000 hard miles, the right rear spring was worn out.

The new set up is with 1.09" torsion bars, 1.125" diameter sway bar, and Landrum asphalt track springs (200 #/in).   The Landrum springs are on the crude side and we had to send one back to get a matching set.  Also the second leaf does not come as far up and under the front eye to give good support.  The main leaf is nice and thick. (The Direct Connection Chassis book recommends minimum main leaf thickness.) Overall, I am very pleased with the car's balance. At autocross speeds and in the dirt, very controllable throttle oversteer an be fed in. Wheel hop is present though, and is being investigated. With the earlier set up, wheel hop was controlled mostly with the pinion snubber. Our goal is not to use that method anymore as it compromises some of the cornering dynamics.

One WARNING about Swaybars.  Chrysler only put sway-bar tabs on cars that came with sway bars.  Mine were welded on afterwords, but tabbed lower arms can still be found. Note that there were several changes made in K-frame and sway bar designs over the years.

 

Shocks:
    I've installed the SPAX shocks. They are relatively cheap (for adjustables) and have proven to be far better than the KYBs on the street in terms of ride quality and provide similar if not better control.  However, the SPAX shocks are designed for Australian valiants and need some minor mods to fit the US & UK A-bodies.  Front shocks need the bushing sleeve opened up very slightly with a drill or reamer.  SPAX  ran out of bushings for the rear shocks, so you need to install your own bushings now.  Model numbers for the SPAX shocks are G480 & G481.
    For the rear shock bushings, I used polyurathane Chrysler 5/8" Shock Bushing (Energy Suspension #9-8112G).  Apparently the 11/16" inner diameter is not available.  However all of the other dimensions are correct, so its "just" a matter of drilling out the center.  Although easier than drilling rubber, the bit still wants to tear rather than cut the soft material.  Freezing helps make it stiffer.  After drilling, I cut the bushings in half with an Xacto razor saw and a sharp utility knife.  By making two halves, the bushing does not need to pressed in.
    The KYB Gas-a-justs were a cheap non-adjustable shock.  I hear bad things about the ones made in recent years, but mine served fairly well.  I had one leak after about 6 years and it was replaced for free.  Photos in the Fall of 2001 showed the car has a lot of roll.  I suspected some of it is transitional, which meant that the low frequency shock damping was insuffiecient.  (The stickier tires and other improvements also are a factor in the increased roll).
    SPAX Features: The SPAX shock is single adjustable, but each click effects the compression only about 1/3 as much as the extension motion.  This is good.  Adjustment is also external.  Price is about $80 to $100 each (US).
Credit for discovering this application of the Aussie Valiant shock goes to Dave Mapes who tried them out on his '66.
 
 

BRAKES

    Kelsey-Hayes 4 piston calipers work very well, but with a car that sits alot, brakes need to be bled every year.  The
power booster was not liked by me, and was sold, along with the stock proportioning valve.  (Stock - but not from this car -it was a drum brake car originally).  Kelsey Hayes calipers are readily available, rotors are not.  The Bendix replacement rotor is not balanced and the "hat" section taps the caliper piston boots every rotation.  I returned them! I see another brand (Borg-Warner ?) now makes them too and it looks better.  Mitchell's Motors claimed they had 2 NOS ones, but only sent me one, a lefty; and that was after waiting a month but charging my credit card immediately. (two thumbs down on their business practices) The money was straightned out by my credit card company.
    NOS Cycleweld pads work very well up front for street and autocross, and Pennsylvania Brake's Red Streak shoes are the best I have found for the rear drums.  Drums are plain, although a ribbed drum may have been made, thats not clear, and I haven't found them.

STEERING

Original K-frame:
    The '67 A-body has a weak idler arm.  I should have swapped the K-frame when everything was out!   Every 2 or 3 years the idler arm wears out.   The '67 idler hangs down from a stud (same design as the earlier A-body idlers, but the idler for '67 is a one year only part).  In 1968 Chrysler changed the design to a through bolt.  Lesson. Don't autocross or rally with the '67 design if you can help it!  The car finally got a '68 K-frame in 2003.

Steering Gear:
    A manual steering box with the p-part 20:1 ratio worm gear was used for quite a while.  This is a relatively streetable ratio depending on - how much parallel parking, how big and heavy the wheels are, and what the scrub radious is.  Once you are moving its fine.  However, this ratio is a little too slow for the slaloms.  Finally, this 20:1 gear was installed in the original 6 cylinder steering box.  These boxes used a bushing on the output shaft, while the boxes that came with v-8 cars used bearings.  In 2003, a 16:1 steering box was installed.  It requires significantly more effort to parallel park the car.  A big steering wheel for leverage helps.

Why manual steering? There is a good weight savings using the manual box over a power unit.  In addition, the stock power steering units lacked road feel.  Two companies sell firm feel units today, as well as fast ratio manual units.  Some who have used power steering in competition report the need for a cooler.

WHEELS
   This car is using the original 5 lug - 4 inch diameter bolt pattern. For the record, some of the race prepared cars had a 4.5" bolt patterns with various combinations of parts pulled from the bigger cars and special run part.  For the average joe, only 14" diameter rims steel were offered by the factory for the small pattern.  The widest width was 5.5" which was OK for the E70-14 tire size, roughly the same dimensions as a 205/70-14. In 1969 a 14x6 cast aluminum rim was introduced, but then recalled.

Rims:
 Options for aftermarket 5 on 4" bolt pattern rims.
1 - Centerlines. Two reasonably priced rims styles, but one is really for drag racing only(no air vents to help cool the brakes).
2 - Crager SS. Look nice, but are at least as heavy as stock rims.  Available both new and used.
3 - Used American Racing Equipment (or copycat) cast aluminum rims which are fairly common. aka "slots". These are what I use on the street. They are light and strong, and came in 14x6, 14 x7 and maybe other sizes. Watch the front fender when running 215/70 tires on the 14x7. The backspace isn't quite deep enough, and they sometimes touch. The shouldered lug nuts are a pain to install on stock length studs.  14x6 cast slots about 12 lbs.  14x7 cast slots about 14 lbs.
3b - You might also find other style used rims such as torque-thrusts, or the recalled Kelsey Hayes.  The latter actually being a relatively sought after piece (unlike most small bolt pattern rims) will usually have a very high asking price.
4 - Custom Steel. Several companies will put a small pattern centers into ralley style or stock style 14" and 15" diameter steel rims.  I did this for my first set of autocross rims,  15x7 ralleys, about 19 lbs. each. Relatively cheap.
5. Custom Aluminum.  That's what I'm using now. Circle Racing is probably the cheapest.Whether they would do well for street and ralley use I do not know, but are certainly fine for autocross and track days.  For more money there are Bogart rims (also aluminum, but a stiffer construction).  13 lbs. each.  for 15 x 7.5" Circle rims.  A lug nut with larger outside dimensions is a help. A fellow on e-bay is now offering 17" rims with a vintage SS look. I don't know anything else about them.

   With the 15" diameter spun aluminum or steel rims, 4.4" back space is about the limit before hitting the upper balljoint.  Going to 16" rims would probably clear the balljoint.   A 7.5" width will just carry the 245/45-15 tire decently.  There appears to be room to go outward to 8", but this will also move the centerline out. This will increase front track. In general this is a good thing, but it also increases the scrub radius, which especially with a manual steering car, is a bad thing.  Stock offset was about 0.7", and 7.5" rim with 4.4" backspace is about 0.2" and with an 8" rim would be about 0.75" away from stock.
 

Fall 2001. BFG R1 245/50r15 tires on 15 x 7 Ralley Rims (photo courtesy of Steve Claymen)

June 2002  Hoosier TDs on 15x7.5 Circle Racing Aluminum Rims

 Tires:
    The tallest tire I've run (to gain ground clearance for the headers) were 225/70r14 BFG Radial T/As.  These tires easily fit, but under extreme conditions (full jounce-turned hard), the fronts just touched the fender trim.  With the headers off, I've returned to 215/70-14s which serve fine.
     Now to seriously autocross, the street tires don't cut it.  Sticky tires are more fun (once they're on) and save the street tires for what they are better at doing.   In my opinion, 225/50r15 are not wide enough to make the car truly competitive in Solo 2 autocross competition, but its a fairly available size, and keeps the ride height low, while happily fitting on 7" wide rims.
    In 2001, I squeezed 245/50-15 BFG Comp T/A R1s onto a set of 15x7 'ralley' rims.  This made the shoulders round and  not all of the tire could be used effectively.  Steve Wall had this size tire rub on his car during manuevering (see link to autoxcuda).  I ran a little less backspace on my rims (4 3/8") and had only a little rub on the rear leaf springs and on the front sway bar and none on the sheet metal.
    After deciding I liked the 245/50s, BFG basically got out of the market.  This left Hoosier the only manufacturer of 245/45-15 competition tires.  (well Avon did also, but...anyway)  I went with the Hoosier 'Street TD'  bias ply and what I thought were 15 x 7.5" aluminum rims.   It turned out the rims were only 7.0 inches wide. Oops!  Also, while the Street TD very hard to break loose, it provided less directional feel than the radials.   Fast forward to 2006.  In a back to back test,  Dave Mapes and I found the 5 year old TDs were still fun, but significantly slower for autocross than a somewhat old set of 225/50r15 Toyo RA1s.  Guess what tire I'm running now.

Wheel & Tire Weight Comparison:

( mostly weighed on a bathroom scale )

DRIVETRAIN

Engine Bay, September 2001:

 

Thats right. OEM air cleaner (repro) hides the 12" K & N.  At least theoretically, that was a little on the small side.  Two breathers and one PCV valve (the d/s PCV valve is not connected).  MSD boxes taking up the fender and horns back in original location (compare to earlier picture with the Mecca coolant set-up)

Intakes I've experimented with both a Holley 650 and 750 vacuum secondary on a Holley single plane Street Dominator, and the Holley 650 on an Edelbrock LD340
The 650 cfm 4150 model, smooth idle was obtained without any carb mods (unlike the 750). With a 750 the throttle plates had to be drilled and idle air bleeds restricted to obtain good idle on the same engine and intake. So the smaller carb on the single plane manifold IS a much better combination than the larger carb on same intake. Gas milage with the 750 was fair; good for a 340, but much worse than a 318.  The 650 brought no measurable improvement.

The Holley vacuum secondary carbs are a little tempermental.  They seem to have a penchant for flooding out during severe braking. (The 750 is worse).  The cure is to use the screw in style jet extension in the rear bowl and notched float.

Exhaust: So far the winner has been the 340 Exhaust Manifolds, and 2.2.5 to 2.5" duals exhaust. An X pip has been installed but no evidence once way or another yet on whether it was an advantage over the H pipe. Only Accurate Exhaust offered a tailpipes to clear the '67 cas tank strap, so we went with them this time. The front tubes came a little low, and I don't know why since the engine sits on an original '68 cuda K-frame. We flow tested the 2.25" mufflers Accurate supplied vs. the 2.5" Dynomax Super Turbos. The Accurate muffler was very good for a 2.25" muffler, but the 2.5" Superturbos clearly out flow them. Resonance with the Accurate muffler is much less than with the SuperTurbos.
Headers Headers by Ed just hung too low for the roads of NJ and Pennsylvania, otherwise they were great.  True equal length and sized for the application, plus they fit together perfectly and go in hassle as hassle free as headers can.  They came back off when the car got repainted and the crazy looking 340 manifolds went back on.  The 340 manifolds weigh more, and make spark plug access awkward, but ground clearance is not a problem. Recent tests by a popular magazine show that even a less than ideal header is better than even the 340 manifolds except right around 5400 rpm, where the 340 manifold does quite well. A 1968 Hot Rod test of 340 engine mods suggests the same thing.

Header options for LA engine A-bodies has been very limited. To give up the least ground clearence, best bets seem to try Doug (Thorley), TTI, or make your own.

Waterless coolant:
     The Mecca coolant was rather expensive and was not all that practical on the street.  I will admit the engine never pinged with the stuff (at least that I can recall).  I lost all of it a couple of times, like when the cluthc fan went into the radiator.  I stopped using it about the time I went from a 6 cylinder radiator to a larger, high flow unit.  Not sure if the stuff contributed to the recent failure of a majority of the steel expansion plugs or not. The theory behind the Mecca system is that better cooling and less corrosion is possible with a properly formulated propelyne glycol than a water- glycol mix.  The system runs at atmospheric pressure because the heat transfer is very efficient, using nucleate boiling to cary heat away from the cylinder walls, but it never turns to steam (no water in it).  The system runs at atmosphereic pressure.  (The reason for a  pressurized system is to increase the boiling point and prevent the coolant from vaporizing, eg. turning to steam.  Steam or vapor does not circulate very well although it does absorb a tremendous about of heat when it initally turns from liquid to vapor).

Engine bay in 1991
Aluminum valve covers replaced the ones supplied by RHS that were too short.
Mecca prop-glycol waterless coolant system still in place - later removed.
Remote oil system still in place - later removed

Current cooling system is simply a standard high flow radiator and good old green stuff with distilled water.  Unlike the oil temperature.  There has never been a problem with the cooling.  (Except the fans self destructing - a Chysler flex fan I picked at a junk yard to replace the cluthc unit subsequently sent half a blade through the battery outside of Fredricksburg Virginia)  I now am using a new, Mopar Performance clutch fan, and no shroud. <

 Remote Oil Lines, & Accusump:
The accusump was great.  It was located behind the rear seat and connected with a braided -10 line under the carpet.  Unfortunately, the lines coming out of the engine were a recurring problem. The small block mopar oil adapters are a poor design in every respect.  They are not great for flow, like to leak, and tend to rotate when the external lines are being attached to them.  The recomended way around the adapter is to tapp right into the block.  This could not be done with the engine in the car, I tried!  Additionally, the rubber inside the aeroquip hoses would start to get real brittle from the heat, and after about 12-18 months they would begin to seep oil.  Therefore both the accusump and the remote filter were eventually removed.
 

ELECTRICAL
Ignition: MSD 6T with rev limiter, adjustable timing control, blaster 2 coil, Taylor Wires, Champion RN9YC .045 gap
    Three voltage regulators and one chrome box later, it is my opinion that the Mopar Performance electronic ignition items leave something to be desired.  I keep one orange box as a back-up, and run the MSD 6T instead.  Since switching to the 6T, the electronic voltage regulator has not failed.  Talking with others, if it does fail, the original points style regulator will work fine in this application.  The MP mechanical only distributor was great, but gas milage suffered.  I rigged an advance mechanism that switched the MSD timing retard box on and off .  That worked OK, but found it simpler to simply use a MP distributor with vacuum advance.  My thinking is that it probably improved part throttle response as well.
The Taylor wires got overheated sitting in traffic for an hour with air temperature of 95F. What happened was the insulation at the crimp failed when one of the wires was removed. These were replaced ASAP with a better protected wire..but it wasn't really a better wire. I'ld go back to the Taylor's or try the MSD which are reputed to have a slightly higher heat resistance than the Taylor's. I've made a comparison chart of wire resistivity and more comments.

Charging & Lighting:
    After suffering many years with a headlight system on the brink of failure, a major upgrade has been completed. The addition of an "60 amp" Tuff-stuff alternator from Hurst Auto & Truck has mostly solved the low rpm charging problems.    A March underdrive pulley on the crank stopped the tendency of throwing the fan/alternator belt at high rpm shifts. But alternator output at idle was too low. A bunch of calculations later showed that the underdrive pulleys could not be the main culprit - alternator speed at idle was over stock speed because of the high idle is now around 1000 rom (stock is 500rpm).  I've been using H4s headlights, which draw the same current power as stock, but light the road far better than even halogen sealed beams. The Hella Vision plus is a good headlamp, and passes inspection in NJ.  Recently, I installed Cibie E-code lamps in my Grand Wagoneer, and I must say that the Cibies provide a more even light, and less annoying cutoff than the Hella Vision plus, or the regular Hella H4. In fairness, the lenses on the Hella's are now chipped up, mostly from truck stones driving down south a few years ago. Time to replace I'm afraid.
    Page with Details and Links on Improving the Forward Lighting
 

SITE INDEX:
Intro:'67 Barracuda..one curve to another
The Story of the Restoration
Grand Wagoneer Page
Pictures from Autocrosses 1989-92 in NJ, Other cars including my old  '74 Nova 250 cid 6 that I ran in H Stock.
 

More Tech:
Fuel Delivery Facts and Figures
Ignition Wire Comparison
Improving Forward Lighting & Electricals
Handling Theory for late-'60s to mid-'70s Mopars
Strut-rods and Bushings

Disclaimer:
    If you take advice, or copy something I have done, you are on your own.  I'm just trying to be helpful. You need to make your own decisions, and know about or discover the risks before barging ahead on any endevour.
Claimer:
    If you steal something I have written, or a picture I have taken or drawn, you are a thief.  Plain and simple.  If you wish to quote something, you are free to do so.  All I ask for is proper credit.  If you wish to quote or copy more than a couple of lines, then you must get my permission.

 e-mail: M. Grubel

mgcudat rev7 Oct 2006