More racecar, less boat...

My car rocks like a boat. If I grab the front bumper I can easily rock my front up and down. When I grab the roll cage I can rock the car side to side just like my beater Corolla. I have always hated the undulating motion of the front end after a dip in the road.

In comparison every other car at Sonoma Raceway was rock solid when I was trying to shake it until the owner chased me away. Even my S2000 with factory stock suspension doesn't move at all. Granted that most every car at the track had aero as in a front splitter/ huge rear wing and was running stiff springs to compensate.

I think the issue is the Hotchkis pieces. I run their leaf springs, single adjustables and 1.12 TB's. The components work well as its all balanced, but it is a compromise between handling and ride quality. Since single adjustables only control rebound and I think I may need doubles in order to control compression.

Anyone use a set of doubles for dedicated track use only? Road course not drag race haha! Does any company make a custom bolt in set for our cars?
Being the only old school Mopar out there kind of sucks haha!

They aren't custom, but they are supposed to bolt in. Here's my thread. I should be getting them on Monday. There's also QA-1, Vi-king (who offers custom re-valving), amongst others.

Ask Mitch about your 1.12" "beginner" Tb's.
IMO, you could step the TB's up, and if I didn't know about your tire rim package, that would be my first question, but you do have a nice wide /low aspect stiff side wall tire set-up, right?

Get shocks you can dial in.

Just jumping up on spring rate is not necessarily the first step I would take.

I should have listened to Mitch all along. He told me to go 1.24's a while back haha! He's going to post on here "I told you so!"

Problem with stepping up to thicker torsion bars is you have to find that balance again with the rear leafs and have matching shocks to compensate. More money down the drain.

Luckily I did talk to Jon at Hotchkis and he said that you can have their single adjustable shocks re-valved for a small fee.

Yes I have a square setup and will go to 315's eventually after my 295's are used up. I may need to go with a stiffer TB so that my fenders don't get chewed up by the tire when the suspension is compressed on a banked turn.

Good point Goody thats the plan!

With my current setup I am at 2 clicks until full stiffness for the front shocks. Jon at Hotchkis said they were about the same for their car as well. With re-valved shocks hopefully I can have further adjustment. I would rather have singles over doubles anyway for the simplicity

x2 on the spring rate. you only need as munch spring rate to keep the car off the ground and then whatever more to control body roll to keep the tires happy.

it sounds like your issue is all shocks... you likely have one or more that need rebuild and/or not enough rebound valving.

on a side note check your swaybar bushings and endlinks. that will somewhat contribute to wobble after bumps.

"Problem with stepping up to thicker torsion bars is you have to find that balance again with the rear leafs and have matching shocks to compensate. More money down the drain."

I wouldn't make to many changes right now, until you make the tire upgrade, unless collecting switched out parts is the objective. I'm too lazy to go out and test for myself, how much qa1 adjustability can be felt by simply low speed bouncing the car at rest as per the OP's observation of an installed shock. I do know how a stiffer spring/TB will react to the same test. Tire scrub distorts the observation however.

On my daily Dart I've got Hotchkis single adjustables up front and single adj. QA1's on the rear.
1" bars and 7 blade leaf springs on the rear.

The Hotchkis are also about 3 clicks away from full (15?), while the QA'1 are just 3 or 4 clicks 'in' from soft (of a total of 18?).

Obviously a valving issue but,
With the Hotchkis shocks, I can't imagine why/when anyone would need/want the other lower/softer 10 orso clicks (unless you have a very, very lightweight car maybe), while with the QA1's I have a tough time imagining when/why someone would need the rest of the adjustment clicks. Maybe for use on a fullsize stationwagon perhaps.

I have double adjustable Vikings, turning up the compression damping feels just like changing to a stiffer spring, you can balance the car front to back very easily....get some before you buy new bars.

Ariel, have you weighed or scaled the car since the ALL ALUMINUM Gen III was installed? My one and only Autox I have participated in my car was a talking subject for a few observers. They were very impressed with how "flat" my car stayed. I have the biggest T-bars I can get and not ideal rear springs yet. I also have non-adjustable Hotchkis shocks but I also have non bushed endlinks.

if the spring or wheel rate is on the soft side, how much bigger can a guy go up in sway bar size to compensate ? providing the bar sizes are correctly matched front and rear ?

My preferred method would be to get the springs/dampers as close as they can get, then use sway bars as an additional tuning component. Over-compensating with large sway bars usually doesn't end up with the most optimum configuration.

Hey Emil,
Yes the car weighed about 80-85 lbs. less since the engine swap and I recently took out the wiper motor and blades/parts.

The car corners well and flat, not too much body roll.

I have a set of big t-bars you could come up and install on lift to try out. Haven't put them in the AAR yet. Maybe pick a track day at Thunderhill and come up a day early. Mike

Depends on the roll couple of your car's combo. Unfortunately it isn't a universal relationship.

My car can use a .92" t-bar and a 1.25" s-bar and have the same roll couple % as 1.12" t-bar and a 1.125" s-bar or a 1.22" t-bar and a 1" s-bar.

Add a rear s-bar and these all change. Rear bar mounting style also impacts rates as well since there are variations in this configuration as well.

RylisPro -- IMO... since you're intending on the usage of the car more towards track (road course and/or AX/HSAX/HPDE)... then by all means go stiffer on the TBs. The small TBs (~1.12) definitely show improvement over the smaller factory TBs... but for track duty something like the 1.18-1.20-1.22-1.24 will progressively stiffen the car from lifting/diving/leaning... and that sounds just what you're in need of. The bigger TBs (say, up to the 1.24 for example) will make you only wonder, as I've said many times before, why you just didn't install these in the first place so to save the work, experience, labor, and cost, etc... The larger TBs (~1.24) are still very street/hyw-able... they are stiff, but not unbareable. Call FF and order them sooner rathjer than later... 1.24 is the largest physical size that fits in out 1.25 hex opening.

Shocks? Although I have old red "D" Konis, and they were re-valved a little stiffer after a while, today I'd buy dbl-adjust.. QA1, Viking, etc... you can truly tune the ride.... I will be getting these ~the next 1-2 years for my car (still all apart for this year).

Tire pressures can also adjust the ride, etc.

Sway bars are for tuning the lean... they have nothing to do with lift or dive.

When driving hard... real hard, as in track time, and pushing your limits, you want a stiffer suspension. Retail "packages" (Hothckis, example) do compromise the handling... they're far better than stock.. but better for true competition is available.

My car is balanced side-to-side, corners flat, minimal lift or dive when accelerating or breaking, steering reacts quickly, rides like on rails... 1.24 TBs, 225#/5" fiberglass FlexAForm mono leafs, Konis, front sway bar 1.25", rear sway bar 1.0", ~3200# w/o driver and ~1/4 tank fuel... 52% front, 48% rear. A joy to drive and race (forget about "street" as you have to watch the pot-holes, bumps, etc... consider hwy and track as the places to drive).

Your car is awesome and is right up there with the best of them! The "project" never seems to end... time (track time) to make adaptations, etc., \will get you better desired results.

Don't be afraid of larger TBs (~1.24 diameter)... contact FF and they'll make them for you (they may have some in-stock).

Also, yes, a little stiffer rear suspension to balance with the bigger front TBs should be done.

MoPower to ya!

My current setup is pretty good for now and when it is time I need to replace tires for wider ones is when I will see if the need to switch over to thicker TB's. Probably next summer.

The thicker TB's would be the easy part as FF has them. I will have to research Flex-a-Form for the leafs and revalve all the shocks for a higher rate.

For now I will just enjoy the car at the track as much as possible as I still want to make it to the 2017 Spring Fling track event. In the meantime I will get 1.24's, matching leafs and other parts and swap the all at once when I switch to 315's

RylisPro - FlexaForm will ask you the weight of the car, in particular the rear corner weights (lr, rr)... and the intentions of your driving the car. For handling purposes, you want the leaf spring to be relatively flat during most driving... say maybe ~1" arch free-standing ( that's what I have... as setup primarily for AX competition). IF you have rough roads, that's another consideration; flat roads (road course and AX) are typically flat.. so.. that's where you can consider to have a more flat-at-rest leaf spring; bouncing roads would favor more arch, but then handling advantages go away. Compromising becomes the issue.

Hey Mitch,
Yeah I need to get those rear weights and talk to Flex-A-Form. I mainly use the `Cuda on track events but then again I drive my car to the racetrack. I'm too poor to own a trailer haha! 360 miles to Willow Springs from where I live and 360 miles back. Mostly freeway mileage so there are some rough roads.

Question for you, how is the durability of a fiberglass leafspring? It's difficult for me to comprehend replacing a proven steel leafspring with a fiberglass one.

Thanks!

There are plenty of OE that use glass leaf springs, including 'vettes. Not exactly apples to apples when talking about an aftermarket supplier. The material isn't the limitation, the engineering may be.

I've been running the FlexAForm mono fiberglass leafs since the lat 1980s (~1988-9)... never a problem on mine.. never seen aothers fail, etc. these are made by the same company that makes Corvette OE leafs (Flexaform)... they worked with me for the best choice. They do take ~2-weeks or a bit more to initially settle at their flatness (so, I loaded the car down with weight for a cpl weeks as it sat in the garage). they react faster than metal springs (my previous were de-arched hemi springs from a Challenger). They'll save you ~25 pounds per side. I used to trailer the car... sold the trailer ~7 years ago (and tow vehicle ~10 years ago)... began driving the car I've also loaded the car with travel stuff for long distance driving (typically to a race event)... basic tool box, lt wt sizzors jack, spare parts/fluids, tent/cot/sleeping bag/clothes, cooler... brings it down a little for the haul but I spread the load out front/rear... very driveable... no problems. You do want to have the poly bushings installed front/rear (may have to turn down the OD of the fronts bushings a little for installation)... and the bushings might squeek a little... what else is new. I'm aware of some serious national SCCA Solo autocross racers using these leafs... no problems I'm aware of. I've considered the Hotchkis (3-leafs?) IF I'd ever go back to steel, but they're a little too soft for my setup, so, I'd probably add leaf to them and have them de-arched as needed. Weight reduction is important.

I've had my 1.24" bars since they were the only options in about 2007.

No regrets. I've not had them on a racetrack but they ride well with Koni Red's.

The 50 pounds less in the rear of the car due to the fiberglass leafs is very interesting! I would think that 1.24's would only be slightly heavier than 1.12's?

While the weight shift from the rear towards the center of the car kind of sucks it shouldn't that big of a deal.

Firm Feel said that 1.24 TB's = $500
I would guess custom leafs spings = $500
Hotchkis to re-valve 4 shocks = $200
Shipping for everything = $150
Couple of alignments = $180

Not too bad for the cost for everything if I do go for it.

https://board.moparts.org/ubbthreads/ubbt...-Fiberglass.jpg

Whoa! Not good...

Kind of worthless without some context. Any part will fail if abused.

See pic #11 for reference, the other 43? pics will provide some context, low HP street car with less 1000? miles on springs pictured.


https://board.moparts.org/ubbthreads/ubbt...tml#Post1554307

Hypercoil makes composite springs too.

It happens, every process will have defects...ideally they are caught before they get out of the door, but not always.

Since when is this a bad thing? I thought this was the cornering-forum?

I was oversteering way too much at Sonoma particularly at Turn 2 and 11 near the walls haha! Was able to dial it out though.

I'm pretty sure my weight split is still around 55/45 front/rear and want to shift more weight to the rear where it is the lightest. I don't need any more weight in the center as I have a 200 lbs/90 kg roll cage there.

Moving static weight towards the car's CG is almost always beneficial, if your weight distribution is reasonable. But yes, getting it off of the front in these applications is best. If you aren't familiar with it, you may want to look into moment of inertia (polar moment) and further understand how weight away from the CG is like a lever in turns, trying to rotate the car before changing directions. Weight in the center of the car is not as effective at changing weight distribution than in the trunk, but it is certainly better than it being out front.