Starting w stock '68 RoadRunner - First steps? what shocks?

Hey guys, thanks for looking.. this has prolly been asked a million times, right?

My brother loved track racing his bone stock '68 RR last year and is coming back this year for more... I've got a European sports car I track race, so I'm all set.. but I'm helping guide him in his first basic steps to improve..

This is a 2.1mile road course with 18 turns and 450ft elevation change. Lots of braking and turning. I don't know his budget, but I know he has limited time to install the improvements before track day (his RR is in storage til two days before track day.."What Could Possibly Go Wrong?".. ).

Please share your thoughts on the following "low hanging fruit" to improve his RR, I think it's basic enough to be pretty solid, but running it by you Mopar guys in case I'm missing something...

Not looking for "Full on" racecar, just some good incremental improvements that won't degrade street-ability too much.

1. Tires. Currently 14" street radials.
- Buy a new set of 15" steel rims, he has decided on a set of grippier Cooper tires.

2. Brakes. Currently stock drums, manual.
- He'd like to go with front discs, but with limited time to install and troubleshoot, I suggested a shop that offers high-perf linings for existing drum shoes. We can swap them in quickly. It'll put more heat to the drums, but willing to try it out.... See how it goes.

3. Suspension. Stock torsion and new OEM rear leaf springs.
- So far, just a slightly stiffer front sway to reduce oversteer. He's found a front sway he likes from Hotchkis (I like the FirmFeel front & rears on my '65. We each have our druthers).

4. Shocks. No idea what he has now, but definitely plain street spec.
- I'm going to suggest he go with stiffer shocks, but I have no experience sourcing or spec'ing anything (I upgraded my '65 to Monroe GasMatics fronts and I forget what I put on the back, but they were yellow Monroes, a little stiffer). Any suggestions? I found Koni has a search function that lists some shocks for the RR.

5. Seating. Stock bench seat.
- We get thrown around a lot. I'm not sure what will help without changing out the bench. Are there belts that will hold us in better, that bolt in?

Am I steering him OK? Anything else that might be easy, quick and reliable?

Thank you,
- Art

OK, a number of you have looked at this post without comment, so I gather we're on the right track (ha ha, get it?).. and I'm not being sarcastic when I saying Thank You for looking at this.

Cheers,
- Art

Honestly it reads like a joke post. There isn't a single point that indicates an effort to make the car even marginally safe on a track. Disk brakes, big ones, all around- Talk to Cass, otherwise known as Doctor Diff He sells cost effective brake kits for our old cars and is an upright guy.
_When a 3000 lb Toyota Corolla comes with 11.5" front disks and 10.5" rear disks can you really think that a 4000 lb B body is gonna stop from speed with drums. My 68 barracuda had 10" drums and the brakes were garbage. Not worn out, not mis-adjusted, just not up to the task even in commuter traffic.
_ I'd suggest Hotchkis or Firm Feel for sway bars/springs and shocks. Hotchkis has a 4 door B body they beat on auto-X courses and runs circles around newer sports cars, the Firm Feel guys have years of racing experience. You won't go wrong talking to them and their products work.
_ You can get a limited number of 15" tires that will work on a track, if you must. You are really limiting the brake sizes for stopping a big car, I'd get 17" or 18" wheels and tires. There are retro looking wheels in those sizes if the look isn't to your liking.

#1. Change the brake fluid. Valvoline's 'synthetic' is pretty good stuff.
#2 Check everything else over. Brake shoes, oil, tires, oil, etc.
#3 Have a good time.


That's doable. Not sure how much difference in grip there will be. If it shortens the sidewall, gets more tread width, and maintains the load rating it should be a plus.
Package may weigh more. You should note that Scott Harvey recommended doubling up on the spiders of steel rims, at least for rally. There's a classic photo of the Chrysler France Hemi 'cuda with a broken ralley rim. A circle track rim like Basset makes might be stronger and lighter.
An aluminum rim with lots of cross sectional strength is worth looking into. ie styles torque thrust, mini-light, mag star, or 'ansen' slots.

Since he owns the 14s, maybe the new set of tires is dedicated to track rather try to make them dual purpose.


Bring some method of checking drum temps. See how much wear is on the ones on there from last outing, and if visible, the edge code. Rochester Brake and Clutch is worth talking with about linings and they can arc them too.
Tricky part is the car is inbetween street and track. Linings for racing with front drums will generally not be great for street. With the street tires, not sure the speeds and loads will be there for all out race linings. Besides the temperature range, how the linings feel to him - the release and grabbyiness - will be important to how comfortable and confident he feels with them.


Save and measure the original leafs. Important reference point and those may end up being better than a repop.
On track, definately increase that front roll resistance. If there had to be a choice, do that over the leafs. Use polyurethane end link bushings with heavier washers and sleeve.

Does the car have the optional shoulder belt? That's not a quick and easy if not installed but would be good start.
Scroth claims to have a safe, DOT approved, 4 point harness. I've never felt fully confident in that claim, especially as a retrofit into one of our cars. But they've had it out for over 15 years so could be worth writing them.
My concerns are (a) riding up off the hips while driving. (b) no cross strap for the shoulder belts during a crash situation.

I think so.
A cheap freebee is to drop the nose a little and align for a little more agressive camber and caster. Use shoe polish if you don't have a pyrometer or time to use it at the track. The best specs will be dependent on the tire, and to some degree the car and driver.

Keep an occassional eye on the oil pressure. If it seems to keep dropping (relative to rpm) after water temperature has stabalized it may be getting hot enough during the sessions that a heavier grade will be needed to maintain viscosity. or it just may be oil return and pan control.

1. Tires.
Forget those Coopers. They are a cheap tire with matching cheap performance.
With a good 'brand' tire like Goodyears/Michelin, traction will be improved greatly.

2. Brakes. Currently stock drums, manual.
I've heard about improved drumbrake linings but this will mostly put more heat into the already inadequate drums.
I would at least look into fabbing ducting to direct/route fresh air onto each wheel/brake.
Brake-fade might put a quick end to the fun after just a couple of rounds.

3. Suspension. Stock torsion and new OEM rear leaf springs.
- So far, just a slightly stiffer front sway to reduce oversteer. He's found a front sway he likes from Hotchkis (I like the FirmFeel front & rears on my '65. We each have our druthers).

4. Shocks. No idea what he has now, but definitely plain street spec.
Bilstein, QA1, Hotchkis/Fox all make good shocks which will be a league above the 'cheaper' stuff out there.
Adjustable shocks would preferred. This will also greatly improve regular driving and are easy to install.

5. Seating. Stock bench seat.
How about securely fabbing/mounting a temporary sheet of rubber to improve grip on the seat.

I wouldn't piecemeal it since everything really needs to be setup together. I would call Hotchkiss and inquire about one of there complete kits and then call Doctor Diff for brakes.

If you absolutely have to do it in pices then brakes first, rims and tires and next sway bars.

And buy Andy F's book on updating the b-body suspensions. Lots of great info in there.

That is what I was thinking. Why would I type a reply when I already typed a whole book?

Thanks guys, for the well crafted advice, including Skeptic who lived up to his name but still offered advice. I tried my best to write a "bump" comment that showed I took encouragement, and not offense at not having gotten any comments yet.

Thanks for the time you put into your advice. Our goal is to read it and select some or all of the incremental upgrades without "losing control" of the many variables of the RR's dynamics.

I know my own car well enough from tracking it for 4 years , gradually improving it, and I've learned the lesson that can come from making modifications without enough consideration, without documenting the baseline, or without thinking of the 'whole package'. Then you have to undo what you did to understand what went wrong. Been there done that. Trying to avoid it for my brother's RR.

Skeptic, "There isn't a single point that indicates an effort to make the car even marginally safe on a track.".. may I suggest you are over-thinking this.? This is an entry level amateur driver effort looking for incremental improvement.. read on for more explanation..

Last year my brother was an amateur driver, out for his first track day ever, with the motorsports club I belong to. They are a group of track racing enthusiasts who welcomed him and his RR.
.. Our type of club racing takes place at road courses all over our area every season. Our club rents the track and the staff. Club members are the drivers who pay a fee that covers the track rental cost. Drivers bring whatever car they have, have it pass tech inspection, and see what it'll do. We race against the clock, not "door-to-door". Drivers are given a thorough orientation. New drivers are coached. Car/driver combinations are assigned Groups according to performance and ability. Groups go out in Sessions. Cars are cleared onto the track by the Stewards at timed intervals to reduce "traffic jams". At our track, the track stewards can be relied on to perform diligent tech inspections, watch the drivers and cars carefully during track sessions, and flag drivers or cars they observe are behaving too hazardously. Rules are enforced. Violators are ejected from the track day.

This is how safety is handled so that any car that passes tech can participate, and drivers are kept in check. For a newbie driver and car combo, this gets them a controlled, coached environment in which to establish their baseline, and gets them feedback. Tech inspection found nothing to keep my brother or the '68 RR off the track, and as competitive as I am with my brother, I'm actually proud to say he got praised by the stewards and club organizers for how well he handled the beastly RR.

I wonder how this compares to the way your club or race track handles safety with cars and drivers of greatly varying or even unknown performance sharing the same track.

Best,
- Art

Skeptic needs to go back to the straight line race forum. I love advice from people who have never cooked their brakes on a road course.
Lot's of regular cars pass tech and do laps.

OP I have years of road course time and obviously so does Matt!

Great advice by Mattax who has cooked several sets of brakes

Seat belts are a deal breaker. Put a real set belt [race belt]in for the lap belt. A real seat would be extremely beneficial

High performance brake shoes are required
DOT4 NOT 5 fluid
Rochester Clutch and Brake for the shoes
585-924-3717

Tires tires tires be square with the sizes - same size.
If you have $$$$ try 16's 255-50-16 works well in just about everything and there are great tires n that size.

Shocks are critical

Seat belts

Tires

I would not worry about cooking the brakes as a novice.

Wheels with cooling slots will be beneficial

A '70 Satellite wagon I had was really transformed with up-sizing the front swaybar and adding a rear one.
The thing about brakes, besides fade, is that the better you buy, the deeper you can carry speed into a turn; also, braided lines help with feel.
As much wheel & tire as you can get in there, and given the car, yeah a "square" dimensional setup is most likely best. Power & gearing play into that a bit, and understeer/oversteer preference too. As far as Coopers, their Zeon RS dry tires have been great on my Mustang, and tires will be a consumable item on a RR.
I'd be inclined to put a proper oil pan on it for improved pickup & added capacity.
Stiffening the structure will make the car more predictable and separate flex from suspension response. Makes changes & tuning less confusing.
The seat & belt deal means at least 4 or 5 point, then bolstering, so the stock appearance thing is gonna suffer. Midpoint in that would be OEM-looking buckets with added bolstering, like what's available for early Camaros but not to my knowledge for Mopars, meaning a talk with a good upholsterer.

What can be better than a spontaneous, unsolicited recommendation? Thanks!

I've ordered two copies - one for each of us - didn't know it was authored by our very own AndyF - do we Moparts folks get a specially autographed version?

(I looked at it on Andy's website some time ago, but I misunderstood the emphasis was on building a stroker.. with brake options, then weight savings, steering box, and some suspension advice thrown in afterwards.)

Cheers,
- Art

Thank you all again. Quick summary to date:

1. Tires/Rims.
Yes, since he plans keeping the 14" OEM Magnums for street use. The new rims/tires could be dedicated to track use. I'll ask him if that's his thinking. If so, look at 16-17-18", with an eye on whatever disc conversion he is thinking about in future. 255-50-16 are pricey, how about 225-50-16's? I'll ask him to scrutinize his Cooper choice just so he's sure on his decision (maybe the Zeon RS in 225-50-16 for $102/ea?). Tire size: Square. Select rims with good ventilation.

2. Brakes.
Flush DOT 3 out and upgrade to DOT 4. Valvoline synthetic. I have a laser to measure brake temperatures (we also use the laser to adjust tire pressure by measuring temperature spread). He did get brake fade last year. Source upgraded shoe linings from Rochester. Look into steel braided lines and ducting cool air.

3 Suspension.
Front sway from Hotchkis, w polyurethane bushes and HD seats and sleeves. Plan is to leave the OEM rear leafs as is. No rear sway. But we'll 'review w Hotchkis and be clear our goal is a bit more oversteer. Discuss shock recommendations w Hotchkis.

- Alignment? I've never tweaked my Mopars but will search here, see what you guys are operating with. My track car is dropped 30mm front, 1.5 degrees added camber, 2 degrees total toe-in, and little caster. I'm really not tempted to mess with the RR's alignment much (I can't understand those offset cam bolts for our UCA's)... unless I can get two days scheduled w a shop. We'd need to get the new alignment, then road test and back to adjust it as needed. That's cutting it close to track time, and if alignment ain't good he's going to be hating it all day. ..although I'll see what I can find on YouTube to teach me.

4. Shocks.
I'll talk with Hotchkis, see what they recommend to go with their front sway, and whatever we decide for the rear - just the stock rear leafs or add a mild sway.

5. Seats & belts.
His RR has the factory option 3-point harness. He didn't complain last year, but I'm trying to anticipate with more grip he'll stay comfortable. I'll ask him what he thinks. Possible Scrotch harness. Thanks for the idea of the rubber seat pad, we have those wicked grippy pads under some furniture cushions - that should work really well. The other drivers will love this.!

Other:
- Should've mentioned that we are not blinded by improving just the car. Developing driving skill ranks topmost in improving lap times. So, coaching will happen before and during track day.
- Monitor oil pressure. Possible new oil pan for proper pick up.
- Monitor body flex.

Looking down the road I'm not sure where he'll want to draw the line between OEM appearance and racing it. I know the more you make it track car, the less it is useful as a street car. Neither of us have truck & trailer, so driving to and from track limits us to mods that are street legal. Just one of those things.

Cheers,
- Art

If "our goal is to increase oversteer" (in other words, less understeer) = add a rear bar.
I generally run as much caster as I can (most ever has been +7.2), which improves bite, feel, and tracking. Seems universal so far (Mopars, Camaros, Mustang).
Dual-purpose road course & street in mild to medium efforts has always given me a better street car. Different from dual-purpose drag cars I've had.
For a separate track tire & wheel, not only ventilation but lighter weight will help: less rotational mass & unsprung weight.

Few quick thoughts.

Don't worry so much about brand, but rather specific tire.
If the car currently is shod with F70r14, then the tire diameter is roughly 26" with a Load capacity of 1500 lbs. and weighs about 24 lbs.
So that's the current baseline.
then start looking at different possible combinations available.
The simplest is going to be the same type of tire in larger rim with shorter sidewall.

Watch out for the so called streetable DOT competition tires. This is code for 200 TW tires designed to meet various competition rules. The ones I've looked are unsuitable for northern climates with warnings about use or storage below 50*F! In contrast you can buy a relatively tough regular competition tire that's usable down to freezing temperatures and will by inference be less sensative to heat cycling. Some of these are far cheaper too!
For example Toyo Proxes R888R
https://www.tirerack.com/tires/tires.jsp...R&tab=Specs
Similar overall diameter, higher load rating, weighs 27 lbs. and is not too camber hungry for a competition radial.
These would be an investment of $650 or so with shipping.

A Piralli P600 has 'only a 180 TW' rating, but is truly streetable tire. It's not cheap. Be a good $1000 but your brotehr could use it for more than just track days. It is also a 27 lbs, 26" tall tire but in 15" with a taller sidewall.
https://www.tirerack.com/tires/tires.jsp...romCompare1=yes
If mounted to the same model rim, in the same width, the 15" combo will weigh less in total.
So these are the things to weigh, so to speak.



Fred Puhn has a few pictures and diagrams discussing brake cooling for drums.
Try to get any braided stainless hoses from a company that's done their homework - maybe even got them DOT certified. Just a little too little strain relief and they can eventually break. That's not just theory.


?? I thought it already was a little loose at times?
Discuss with Firmfeel too if you want to see if perspectives are different.
Rear bar changes will be more noticible. A light bar, with adjustability maybe something down the road.


Not many shops are competent here.
Smartcamber is a relatively cheap digital gage. I like bubble gages better myself. The shop manual has a good intro to the adjustments.
If you take a turn or two out of the torsion bars, that might be enough change for this upcoming outing. That alone will do slightly increase negative camber, postive caster, as well as slighly lowering roll center and center of gravity.

Too much to digest here, but two items jump out to me, both are related, and both will put you into the guard rail and/or hospital.

Contrary to another's comment about not to worry because driver is effectively a novice, from my track experience, novice class abuses both below the worst, and don't yet have the skill set to know they are doing it.

1. Tires, air them up, worry about grip later, novice driver needs lower grip levels to keep speeds low, to learn traction circle before they get too far in over their heads.
2. Brakes, drums should never see the track, unless on parade lap, brake fade sucks, the crudest temporary brake duct will do wonders , any other mentioned previous suggestion can't hurt, changing day before(?) to fresh fluid high temp is a must.

\

Thanks JC, long time, trust you and yours are well, almost came to visit you, what some 6 years ago now?
Anyhow, thanks for the concerns, legit for sure.. and we aren't not worrying. He's had 6 hours on track with me in the car, and he's well disciplined. Never say never, but we are in good position to keep things under control, novice and drums included ... reading my reply to Skeptic will shed light on safety..

I've gotta run my kids to sports, cheers!
- Art

Good to see you've gotten some more feedback, I'll third Andy F's book, I've got two copies myself, I misplaced the first one and bought a replacement, it's that valuable. I'm not even a B body guy, but most everything still applies. I'll also say track time is good time, it's easy to build-or buy, a car that is far more capable that the driver.

Bilsteins.

for a cheaper alternative with a higher boiling point(500) I buy this at the local canadian tire store:

https://www.ace-canada.ca/en/product/synthetic-brake-fluid-ford-dot-3-450-ml-02635075

I would suggest a HT racing fluid, like: https://www.wilwood.com/BrakeFluid/BrakeFluid

it's a lot less expensive then most alternatives for brake fade.
You have many similar choices available.
Ducting Drums properly is a lot of work/modification, almost easier to install discs (you need to also get cooling air inside the drum), and if you run normal sized & TW range tires, on a heavy car (RR is in the heavy range IMO)), you will be very close to brake fade. It's not a lot of fun or learnful to drive at the edge of brake fade.

Best book I have come across on this topic:

https://www.amazon.com/Think-Fast-Racers-Why-Winning/dp/1451558759

It's more about the approach and why, not what.

Best very important concept stressed:

"everything effects everything else"

Thanks for the brake fluid follow up.. I know we just won't be able to get discs on it for this season - which is only one track day, June 22nd at NYST. We'll get through it...

I'll also look at that racing book - I def advanced my skills with the lessons taught in Skip Barbers 'Going Faster', but nothing wrong with more info.



Just received my copies from Amazon (wanted to buy directly, but got redirected).. starting to read tonight..

Best,
- Art

Just be careful the wet boiling points are appropriate for the situation. Wilwood's HT 570 wet BP is better than it was 10 years ago. Prestone doesn't have theirs posted on that particular link but I'm sure it can be looked up.
If the fluid will be changed before any outing,then wet BP isn't nearly as important as it is for vehicles where it may only be changed once a season or less. The Valvoline I mentioned early has a dry BP of 527 F - far above the minumum required but much lower than the Wilwoods. But the Valvoline's wet BP is higher.

All very true, but anybody serious about track time, does fresh BF every weekend outing or at first sign of fade as the fluid likely has already been cooked. Wet boiling point in this application is irrelevant IMO.

I'll second this.

Andy,

Do you answer messages? I was looking for your extended water neck with a port months ago, tried to reach you through this site and e-mail to no avail. Luckily they are on your site now!

I've got the following on my 68 RR.

6.1 Hemi with a cam and ported heads 475 crank hp easy
Megasquirt 3 EFI gold box
23 spline 833
2.94 8.75"
Battery in back
Mopar 1.22" t bars
Hotchkis 2255 sways
Mopar XHD leaf springs (both RH)
Hotchkis shackles
Mancini Lowering spring front hangers
braced stock lower control arms
RMS strut rods
Koni Red shocks
Firm Feel stage 3 steering box
Stock UCA with problem solver bushings
14.25" LX rotor with a viper caliper
18x9 Mustang wheels with 6.18 BS and a 1" spacer for 5.18" BS
275/35-18 tires all around.

I'm going to get a set of 18x9 5" BS torq thrusts to get rid of spacers.

The work is in progress. I still need a set of wheels without an adapter and a rear disc kit, plus I need to install the sway bars. The car is getting a bunch of rust repair from the vinyl top issues, but it was destined to be a grand touring and amateur road course car. I've also got Corbeau buckets for the seats and I'm going to 3 point belts.

Thanks fr sharing your 68 RR build Alex, looks great and there’s lots of information for my brother to reference and consider.

And a huge Thanks to AndyF, your B-Body Perf Upgrades book is absolutely as helpful as you guys all said it would be. Also gotta add it’s really well written, which can be lacking in many similar books. A lot of the advice also applies to cars across the board, with the added bonus of featuring a bunch of Moparts friends’ cars .. What’s not to love?
Well done.

Cheers,
- Art

Guys,
Thanks for your input.. We had a perfect track day June 22nd, sunny, dry and 78F... my brother did great and dropped his laptime from 2:08.10 to 2:04.55.

He arrived with his whole family the day before track day.
With the limited time we stuck to the very basics:
- He had ordered a set of Firestone Firehawks, 235/55-17's mounted and balanced on mag rims, got them delivered to my house, mounted them and test drove.
- Flushed old DOT3 brake fluid, replaced with new Ate Typ 200 DOT4.
- Checked alignment, it was adequate - no time to tweak.
- Checked all the systems we could; fuel system, carb adjust, brake drums & liners.
- Monitored tire temps for optimum pressure.

Then we reviewed strategy;
- GOALS: Conserve brakes, use HP and grip to advantage.
- Therefore: Manage the approaches to turns such that he carries momentum, minimizes braking, and then maximizes exit speed.

I rode with him one session halfway through the day.. the Firehawks appear to have fantastic breakaway characteristics, as far as I could tell from the passenger seat: Very gentle onset of throttle-induced oversteer and the transition *out* of the throttle induced oversteer was smooth as silk...

Showing a lot of lean here, but we are very happy with the improvement with so little effort... He made it through the entire day in one piece, had one spin but stayed on track, nothing broke, all good.
Thanks again..
- Art

awsome!

so the only thing replaced was the wheels and tires?

no new shocks?
any idea what torsion bars are in the car?

Said it still had all the stock stuff under it, so t-bars of .88 and a sway bar of .93

A set of 235/55-17 tires is going to be a huge improvement over the stock rubber on one of those cars. Once you're ready to step it up a notch it will be fairly easy to lower the car an inch the add new springs, torsion bars and good shocks. For about $1000 investment you'll have a car that rides a little firmer and goes around corners a whole lot better.

Thanks guys,
Sorry took me a while to come back and check here - Yeah - his RR is all stock, so whatever it got from the factory is what he's running it on..

Thanks for the pointers for further improvements next time Andy. I bought us both a copy of your book, so we have that going for us.

..My brother is not the most observant Mopar owner.. He had some bad tire wobble on his drive to my house, some 3 hours of highway driving. He felt he needed the tire balanced and an alignment. I took one look at his tires and nearly crapped. He was on old bias-ply tires, must 've had some strands broken, worst wear pattern I've ever seen.. (Photo attached). ..and he had his whole family with him for the trip, 4 kids and wife. Crazy.

..He is back on new street tires, storing his track tires at my house, so I'll try them out on our '65 Satellite in the spring.
..Of course this kind of driving transfers a lot more stress to the frame, and a post-trackday inspection I found two cracks in his K-frame, at welds where the folded steel flanges return around the front bolts.

The saga continues.

One question I have is about the rear upper shock mounts:

How much stress/racing can that area tolerate before you gotta strengthen that mounting bracket?
I mean, it looks pretty weak - just stamped and folded sheetmetal spot welded to the underside of the trunk panel?

- Art

Not a lot. We've blown out the holes in a couple of cars and torn one cross member completely out of a car once. Easy fix is to weld the ends better and then make some spacers and bolt the center rib to the trunk pan. You can also reinforce the bolt hols a bit by tacking in some williams washers.