Softer springs or not, that is the question

[alexmak]

I like the stiff ride, but sometimes I feel like it gets a little bit too stiff. I've read some threads on going from 350lbs springs to 250lbs springs in the back, and that it will increase amount of understeer. So questions:
1. is this increase noticeable in everyday driving, no track/autoX?
2. what springs to get? the links in other threads to Breeze are dead, so any suggestion for springs to buy or what specs to look for?
3. if you went for softer spring, did you later go back to stiffer ones? Why?

[ggunter]

I'm awaiting anxiously for the answers to your question. When I was young the stiff ride was "cool" but now that I'm old not so cool.

[swwebb]

I thought the default spring rates were 500 front and 750 rear for IRS, which is what you have per your signature line. The rates are 500 front (same as IRS) and 350 rear for the solid axle I believe.

I'm also interested in this answer because Gordon Levy talked me into 600 front and 650 rear. I'm wondering if I should go back to the standard springs or not - how will the ride change? I still have the old springs.

[Jeff Kleiner]

Softer rear will indeed promote more understeer. Noticeable on the street? Around town, no but if you take some highway exit & on ramps briskly you'll probably feel that the car has more body roll and the front will wash out requiring you to keep adding more steering input to get it to turn. You'll have to decide for yourself where your priorities lie and what compromises you're willing to make. I went the other direction and changed to 750# front and 500# rear on a 3 link.

Jeff

[Bob Cowan]

I would consider different shocks before changing springs.

[Jay-rod427]

Middle ground go a good quality progressive spring. soft for comfort first short travel, then firmer the harder you lean on it. And as said good shocks. Preferably with high and low speed compression valving adjustments.

[SDhemmings]

Don't mean to hijack but How do you know which springs you have? I bought my coil overs from another local builder and have no idea what spring they have.

[stacked33]

I realize this is in the roadster forum but I think what I did on my 33 Hot Rod may be applicable. I ordered the kit without springs and bought springs that were exactly 1/2 the rate of what would have come with the kit. From 500# to 250# front and 350# to 175# rear. I also added/fabricated my own anti roll bar in the back to help with body roll. I am extremely glad I did this as it has been a good combination of ride and handling. It would have been too harsh for me the original way. Some may say this wasn't a good idea but it worked well for me. See photo of car on the autocross course, it stays pretty flat on the corners.11722392_10153321770630073_4158422004139761385_o.jpg

[alexmak]

I would consider different shocks before changing springs.

In the threads that I’ve seen, a lot of conversion focused on the springs as a main reason for a harsh ride

[alexmak]

Middle ground go a good quality progressive spring. soft for comfort first short travel, then firmer the harder you lean on it. And as said good shocks. Preferably with high and low speed compression valving adjustments.

Any specific model you have in mind? That would be a bolt on for FFR?

[alexmak]

Softer rear will indeed promote more understeer. Noticeable on the street? Around town, no but if you take some highway exit & on ramps briskly you'll probably feel that the car has more body roll and the front will wash out requiring you to keep adding more steering input to get it to turn. You'll have to decide for yourself where your priorities lie and what compromises you're willing to make. I went the other direction and changed to 750# front and 500# rear on a 3 link.
Jeff

I have IRS, which is supposed to be the most comfortable ride, but I guess it’s just not what I expected. Personally I don’t mind the stiff ride but when I’m with my wife, I feel a little bit sorry for her.

Ok, what about air pressure? I have 15’’ wheels/tires. 25psi or lower?

[Desert Cobra]

I dropped 100 lbs. front and rear and will never go back. No change in handling. Got from Summit Racing made by Eibach. Most springs come with a painted on spring rate. Usually as part of part number (ie B2000-350). I tried a 50 lbs. under but that wasn't enough. You can also adjust some shocks for less compression. Visit their web site for how. I have stock and 50 lbs springs for sale if interested. With softer springs you get more body roll in corners, but full travel on most Cobras is 4-5 inches so is 1/2 inch more roll going to kill you?

[Jeff Kleiner]

.... With softer springs you get more body roll in corners, but full travel on most Cobras is 4-5 inches so is 1/2 inch more roll going to kill you?

Oh heck, just soften it up until it feels like you're riding on a cloud and don't worry about a little body roll or understeer





Jeff



leaning chevy.JPG

[alexmak]

Oh heck, just soften it up until it feels like you're riding on a cloud and don't worry about a little body roll or understeer





Jeff



leaning chevy.JPG

This roll was added when picture was inverted!

[NAZ]

https://www.roadandtrack.com/car-cul...ave-less-grip/

[CraigS]

Concentrate on the rear springs for a better ride. Drop 75-100# because in my experience a 50# change can be one of those 'it must be better because I just spent $ to change it' deals. If you find out that it understeers a little more on the street you are driving too dang fast. Go to an autocross or a track event. Shocks can also make a difference but unless you go to the expense of getting double adjustables you won't get much change and it's almost impossible to know what change you will get before you own them. I like the High Travel springs from QA1. Buy them from Summit.

[rich grsc]

Oh heck, just soften it up until it feels like you're riding on a cloud and don't worry about a little body roll or understeer





Jeff



leaning chevy.JPG

Thats an odd car? Right hand steer, yet it has a USA plate, maybe California?

[CobraboyDR]

Oh heck, just soften it up until it feels like you're riding on a cloud and don't worry about a little body roll or understeer





Jeff



leaning chevy.JPG

That boy makes a good case for a big-a$$ sway bar.

If you're gonna go softer springs on a street car, make sure you also go with sway bars, front and rear.

[CobraboyDR]

https://www.roadandtrack.com/car-cul...ave-less-grip/

That's a terrific video at the end of that article. Thanks for posting.

[Jay-rod427]

Any specific model you have in mind? That would be a bolt on for FFR?

Springs are somewhat universal for coilovers. Just need to know the diameter, length, and spring rate. I don't personally know what the FFR Roadster uses. The shock remains and just gets a new spring on it. Unless you change shocks as well, then they need to match to fit.

[mike223]

I thought the default spring rates were 500 front and 750 rear for IRS, which is what you have per your signature line. The rates are 500 front (same as IRS) and 350 rear for the solid axle I believe.

I'm also interested in this answer because Gordon Levy talked me into 600 front and 650 rear. I'm wondering if I should go back to the standard springs or not - how will the ride change? I still have the old springs.

500 front and 750 rear were default for the older Tbird based IRS, I think this car is the newer Mustang based IRS and I don't know what the spring rates are for that.

I have the older Tbird based IRS and found that I use full suspension travel on launch, so I did not feel comfortable going to a lighter spring in rear.

Unfortunately, with the 500 fronts installed, autocrossing it was an experience in tail happy - completely tail happy.

I generally run 650 or 750 front springs now to keep the rear end hooked up - much better (but a little harsh on the ride).

[NAZ]

That's a terrific video at the end of that article. Thanks for posting.

Folks should know why changing spring rates (front or rear) will affect the handling of the car. Increase the spring rate in the rear on a car that is neutral (handling) and you will have a loose handling car, the bigger the spring change the looser. Reduce the spring rate and you get the opposite effect. Spring rates affect traction, higher rates = reduced traction (again, starting with a neutral car). This is one of the methods chassis tuners have to adjust handling for track conditions. For a street car I want a neutral handling car and I can make a car neutral with softer springs same as I can with stiffer springs, but softer will tend to have more traction (up to a point of diminishing return). Asphalt cars are moving toward softer front springs and more anti-roll bar as it provides greater traction and lowers the front end at speed for better aero. So stiffer ain’t always better.


Also, I see people using stiffer springs as a crutch to limit body roll. There are other ways a chassis tuner has to affect roll, and spring rate is usually not the ideal way as every change you make on a suspension has an affect on other areas so it’s an effort of compromises. Body roll is not necessarily a bad thing as it’s what helps weight transfer and induces camber gain which maintains tire contact on hard corners. But when it comes to chassis tuning, too much of anything can be detrimental (see Jeff’s photo of the 1959 Impala and the reverse camber gain – that car doesn’t just push, it plows).

[JohnK]

Thanks NAZ. That's very helpful. Do mind sharing your thoughts on shock compression/rebound damping? I know a little from my days tuning motorcycle suspensions but would love your insights. One thing I hear sometimes is that folks will crank up the compression damping to try to stiffen the suspension or limit body roll. My understanding is that the correct compression and rebound damping is simply a function of spring rate. You want enough damping to properly limit movement. Too much damping and you end up with problems like jacking the suspension up or down (too much compression or rebound damping).

-John

[Jeff Kleiner]

... I think this car is the newer Mustang based IRS and I don't know what the spring rates are for that...

500 front, 400 rear

Jeff

[NAZ]

Thanks NAZ. That's very helpful. Do mind sharing your thoughts on shock compression/rebound damping? I know a little from my days tuning motorcycle suspensions but would love your insights. One thing I hear sometimes is that folks will crank up the compression damping to try to stiffen the suspension or limit body roll. My understanding is that the correct compression and rebound damping is simply a function of spring rate. You want enough damping to properly limit movement. Too much damping and you end up with problems like jacking the suspension up or down (too much compression or rebound damping).

-John

OK, I don’t want to hijack a spring thread but will briefly give some thoughts to contemplate. Most folks, especially the off-road guys, tend to put way too much damping into their shocks. It’s best to start at the lowest setting and tune from there. We can use damping to control weight transfer during corner entry and during breaking and acceleration. This is in addition to spring rate. We use weight transfer to increase traction – in fact, I’ll submit that the two major “controllable” things that affect traction are weight (static and dynamic) and tire compound. Contact patch and tire size are not directly affecting traction but further explanation of that can be found here: https://www.stevemunden.com/friction.html

Drag racers live and die by traction and weight transfer is of paramount importance. Spring rate and damping greatly affect traction. I run the minimum rebound damping and aggressive bump damping on the front shocks of my drag car. This helps unload the front end faster which transfers weight to the rear quicker. Conversely, I run the stiffest bump on my rear shocks the track will support and tune the rebound to the spring rate. That stiff rear bump damping slows down the shock from the launch and holds rear ride height (weight transfer again) as long as possible. So, shock tuning & spring rates can be used to help tune to track and load conditions.

[CobraboyDR]

Thanks NAZ. That's very helpful. Do mind sharing your thoughts on shock compression/rebound damping? I know a little from my days tuning motorcycle suspensions but would love your insights. One thing I hear sometimes is that folks will crank up the compression damping to try to stiffen the suspension or limit body roll. My understanding is that the correct compression and rebound damping is simply a function of spring rate. You want enough damping to properly limit movement. Too much damping and you end up with problems like jacking the suspension up or down (too much compression or rebound damping).

-John

As a motorcyclist, think of riding a track bike on a forest trail. That thing would break traction constantly, whereas a soft-spring dirt bike will stick like glue.

Yes, the physical forces on two wheels is different than four, but keeping the rubber in contact with the road as much as possible is still the goal.

I have a friend with way more money than sense. He bought a newer 'Vette with a special hard track suspension...and drives on our really bad roads here (Dom. Rep.). He complains constantly how disappointed he is that his fancy, powerful car is squirrely in rough, twisty roads, and bounces all over the place around even the smallest potholes in the city.

[Mark Reynolds]

AlexMak,

I have QA1 9HT650 (13% softer, you will notice it, but the change will be slight) and 9HT550 (27% softer, more noticible, still not super soft) in stock and can offer them at $45 each plus shipping at $13 in a priority mail flat rate box.

Mark Reynolds

[Avalanche325]

Comfortable ride? I thought I was on a Cobra forum.

[rich grsc]

Comfortable ride? I thought I was on a Cobra forum.

Comfortable ride----what handling?

[alexmak]

AlexMak,

I have QA1 9HT650 (13% softer, you will notice it, but the change will be slight) and 9HT550 (27% softer, more noticible, still not super soft) in stock and can offer them at $45 each plus shipping at $13 in a priority mail flat rate box.

Mark Reynolds

Thanks Mark, per your suggestion I purchased springs from Summit, and plan to install them over the weekend to try

[alexmak]

Comfortable ride? I thought I was on a Cobra forum.

Yeah, yeah. I’m sure your energy will be well spent in the threads about power steering and power brakes!

[walt mckenna]

I have thought about this issue since my first go-kart drive. The stock springs are just too stiff for a comfortable ride on roads that are not smooth. I compensate by running my tire pressure at 15 psi, but there must be a better way. I track my car as much as possible, so compromise between comfortable cruiser and capable track car is an important issue. I think that the correct springs, for cruising, coupled with the correct sway bars too increase spring rate, for the track, coupled with the correct shocks to control wheel movement would result in a vehicle with the right stuff. I have not gone down that road because of the trial and error and extra money involved, but would hope that those of you that have, will contribute to this thread.

[bobl]

My car has the 3 link setup. When driving on bumpy roads it would trigger my pacemaker and my heart rate would go crazy. On the advice from this forum I switched to 250 lb. rear springs. I also added some foam in my seat. It made a huge difference. My pacemaker very seldom triggers now, so I've got proof it rides a lot smoother. I preferred the handling with the stiffer springs, but everything is a compromise.

[Avalanche325]

When driving on bumpy roads it would trigger my pacemaker and my heart rate would go crazy.

You, Sir, get an exception. YIKES!

One thing is that you cannot change spring rates without affecting handling. Maybe not in the envelope that you normally drive in, but definitely at the limit (on the street, known as an emergency maneuver). It may also change where the limit is. Unless you are going to do skidpad testing, go with a known setup from one of our resident experts.

[Avalanche325]

Yeah, yeah. I’m sure your energy will be well spent in the threads about power steering and power brakes!

Power steering - You got me there. I'm a big fan. I autocross and track my car. Hydraulic, not electric for me. Gotta stay a little tough.
Power brakes. How dare you! Start taking Wilwoods, and I'm all in.

[alexmak]

Power steering - You got me there. I'm a big fan. I autocross and track my car. Hydraulic, not electric for me. Gotta stay a little tough.
Power brakes. How dare you! Start taking Wilwoods, and I'm all in.

If I keep my standard mechanical brakes, can I get softer springs then, mom? Pleeeeeeease! I’m gonna behave! (Yes, I completely understand the part about springs affecting handling and that’s why I am doing this as a trial and if I don’t like the effect, I can always go back. )

[CraigS]

If I keep my standard mechanical brakes, can I get softer springs then, mom? Pleeeeeeease! I’m gonna behave! (Yes, I completely understand the part about springs affecting handling and that’s why I am doing this as a trial and if I don’t like the effect, I can always go back. )

Exactly the right answer. Try softer springs. Relatively speaking at about $100 it's a cheap experiment. I have also installed the QA1 double adjustable shocks from Breeze. For the street I ran them on full soft in bump and and about 5 rebound. Get to an autocross and changed to a slightly stiffer setting for both. I could change all 4 shocks in about 5 minutes by jacking up one side at a time w/ my handy small aluminum jack from HF. I know that autocross is different than track but another huge advantage of the DAs was I could change handling balance between runs.

[Hoooper]

When I was starting my alignment this weekend and setting ride height my first thought was that the springs seemed probably too stiff to handle correctly on track. The stiffness might be right for an autocross on perfectly flat parking lot but the tracks here have a lot of elevation change and mid corner camber changes that can be problematic for oversprung suspensions. I suspect FFR chose such stiff springs because their kits are sold base without sway bars and needed the stiffness in order to still handle great under the right conditions. With swaybars the spring rates should be reduced, it would be nice if FFR offered the choice of buying the setup for use with or without swaybars, especially for those spending quite a bit to upgrade to the double adjustable konis

[Avalanche325]

I haven't done spring changes on my car. I have added and adjusted my sway bars. A company like FFR would be supplying what works for 99% of their customers.
You might be surprised at how much body roll you get with the stock springs.

OK Alexmak, You can have the springs. It's close enough to Christmas and you have been good all year.

[Jeff Kleiner]

You might be surprised at how much body roll you get with the stock springs.

Here ya' go. Granted, we're running different lines (possibly because his car is pushing) but the photos show a significant difference between my black car with 750# front/500# rear and my friend's blue car with 450# front/250# rear:





Jeff