Shock Tuning Question for the Experts

[RacerX10]

I'm about to have my first set of DA shocks (Integra IDA), always ran straight valve stuff before.

My question is this : can you tune a car from a "heavy" all the way to a dry slick setup just in shock adjustments ? I guess specifically I'm wondering if it's still necessary to change springs, etc on a typical race night when you have the shock tuning available.

So, just to restate it, can you take a "average" (chassis builder recommended) set of springs, let's say
500LF 450RF 250LR 225RR to start with, and just in shock adjustments / bar angles / panhard bar changes tune it from heavy to dry slick over the course of a night ?

Just trying to find out what are reasonable expectations.

Thanks !

[let-r-eat]

I would expect to see some good tech coming out of a thread like this.My short answer is "NO". Mainly due to the later G force being less on the slick track. You can't transfer as much on the slick track and the shock is only controlling the spring rates you have. So a heavier spring that's needed on the tacky fast racetrack is not appropriate on the slower slick racetrack and this can't be overcome with any shock. Lowering the compression or stiffening the compression on the right front with the stiffer spring installed for the tacky will never obtain the travel necessary for the slicker race track.Flame away?

[RacerX10]

No flames from here, sounds pretty reasonable to me. Wonder if somebody will disagree ?

[LM14]

A shock is only a timing device for the spring/suspension action. You should change springs to suit the conditions and shocks to fine tune that setup.

The shock is not meant to replace the proper spring setup.

JMO,
SPark

[hucktyson]

The only one who can answer that question is the legendary Lockheed Martin rocket propulsion engineer Brian Gray !! Results speak for themselves and if you have set up questions there's only 1 man to ask !! Lol if you don't believe me just ask him and I'm sure he will tell you .

[hpmaster]

A shock is only a timing device for the spring/suspension action. You should change springs to suit the conditions and shocks to fine tune that setup.

The shock is not meant to replace the proper spring setup.

JMO,
SPark

Good post...... maybe a great post....... the best shocks in the world are not going to make up for wrong springs.

[MasterSbilt_Racer]

I keep spring changes to an absolute minimum. IMO, you can get away with changing none or 1 spring and stay good from tacky to slick on the same track.

Our cars are very adjustable and there are plenty of ways to keep handling consistent.

[Brian Gray]

The answer is sometimes yes and sometimes no. Depending on how the shock was built it is going to have a range for the lower speed rates and the higher speed rates. The adjustments are usually only within a few hundred pounds. If your high speed control is within the range needed on your slick setup for a heavy track you can control the wheels in the tack but usually your going to have specific low speed controls you won't be able to adjust out of. Everything is always a give and take. People get mad at me for promoting here but it sounds like you might need more explanation on what the shock does . most cases you will not have enough adjustment or will be valved out to one side or the other. Just because your shock is adjustable doesn't mean it will work in everything. It needs to be taylored to what your car needs. There is no one size fits all. I can help if you'd like more info.

[Brian Gray]

This relates to shocks . Mr park is exactly right in his post.

[hpmaster]

I keep spring changes to an absolute minimum. IMO, you can get away with changing none or 1 spring and stay good from tacky to slick on the same track.

Our cars are very adjustable and there are plenty of ways to keep handling consistent.

I agree once a car has the proper springs under it the number of spring changes are few. What I have seen is too many people spend more time and money on shocks when they are in need of proper springs.

[zeroracing]

If your going to drop the coin on new IDA shocks, get with a true shock guy, spend about the same amount of money or a little more and get the info to tune your car with. No sense in spending all that $ and getting limited info.

[Matt49]

My opinion:
For a particular track size/banking/configuration (regardless of conditions) a single set of springs should provide a balanced setup 95% of the time. Tune with bars and shocks from there.
Personally, I think the mindset of "shocks are only for fine tuning" is old (and flawed) thinking. There is huge adjustability in today's shocks and you can tune a car from heavy to slick with shocks alone if you know what you're doing.
There are many things that used to be "fundamental" setup logic that are no longer AS applicable today. Many concepts (e.g. heavy spring gets the weight) are overshadowed by other things today. 20 years ago, there wasn't much rear steer, there wasn't much dynamic wedge due to bar loading, and there certainly wasn't as much front roll center migration. "Heavy spring gets the weight" still applies but there are other things going on that more than cancel out the effects. Example, SOFTER RF helps cars of today turn into the corner (for many reasons). This is the opposite of what was true 20 years ago when the spring rate itself was the main contributing factor to grip. Stiffer LR used to create more drive...the opposite is true today. These are just two examples.

[D.E.K.]

Go to brian daugherty at port city he is awesome with info and the shocks r awesome we dont have to change anything from heats to feature.

[hpmaster]

My opinion:
For a particular track size/banking/configuration (regardless of conditions) a single set of springs should provide a balanced setup 95% of the time. Tune with bars and shocks from there.
Personally, I think the mindset of "shocks are only for fine tuning" is old (and flawed) thinking. There is huge adjustability in today's shocks and you can tune a car from heavy to slick with shocks alone if you know what you're doing.
There are many things that used to be "fundamental" setup logic that are no longer AS applicable today. Many concepts (e.g. heavy spring gets the weight) are overshadowed by other things today. 20 years ago, there wasn't much rear steer, there wasn't much dynamic wedge due to bar loading, and there certainly wasn't as much front roll center migration. "Heavy spring gets the weight" still applies but there are other things going on that more than cancel out the effects. Example, SOFTER RF helps cars of today turn into the corner (for many reasons). This is the opposite of what was true 20 years ago when the spring rate itself was the main contributing factor to grip. Stiffer LR used to create more drive...the opposite is true today. These are just two examples.

True, but the soft right front spring is only half the truth in many cases. I like many others seem to forget or at least not tell what else we have done to get that right front shock set up to work, with that I shut up.

[Matt49]

True, but the soft right front spring is only half the truth in many cases. I like many others seem to forget or at least not tell what else we have done to get that right front shock set up to work, with that I shut up.

Very true. Here to "help" but not give away information I spent many weeks and many $$$ acquiring.

[hpmaster]

The answer is sometimes yes and sometimes no. Depending on how the shock was built it is going to have a range for the lower speed rates and the higher speed rates. The adjustments are usually only within a few hundred pounds. If your high speed control is within the range needed on your slick setup for a heavy track you can control the wheels in the tack but usually your going to have specific low speed controls you won't be able to adjust out of. Everything is always a give and take. People get mad at me for promoting here but it sounds like you might need more explanation on what the shock does . most cases you will not have enough adjustment or will be valved out to one side or the other. Just because your shock is adjustable doesn't mean it will work in everything. It needs to be taylored to what your car needs. There is no one size fits all. I can help if you'd like more info.

Brian seriously, I mean SERIOUSLY? Please read what you wrote and admit this was the longest non answer in 4M history. I avoid reading most your posts for this reason. Rather than hide your self promotions in volumes of nonsense just start out with your quote "most racers are scum bags", most of us can judge from there.

[Brian Gray]

Your living scumbag proof of that comment. Most doesn't mean all douche wagon.

[RacerX10]

I keep spring changes to an absolute minimum. IMO, you can get away with changing none or 1 spring and stay good from tacky to slick on the same track.

Our cars are very adjustable and there are plenty of ways to keep handling consistent.

Maybe an example ? As driver / crew / sponsor / daddy / husband / etc I'm constantly looking for ways to minimize my work load :)

[RacerX10]

If your going to drop the coin on new IDA shocks, get with a true shock guy, spend about the same amount of money or a little more and get the info to tune your car with. No sense in spending all that $ and getting limited info.

Agreed. However, I have been running on *literally* 16 year old shocks and I've decided it's time to upgrade if I'm going to be worth a (not a nice word)(not a nice word)(not a nice word)(not a nice word). Going to splurge and buy new tires, too. I've never had a new tire on my car :)

[RacerX10]

Stiffer LR used to create more drive...the opposite is true today. These are just two examples.

Ack .. I'm running on 20 year old info then. Stiffer LR doesn't tighten up exit / create more drive any more ????

[LM14]

Matt49, I totally agree this is old thinking. I also agree this thinking came from pre "hiked up" days, but I feel it still holds true.

Yes, there are many adjustments to choose from. Yes, shocks have changed drastically and you can do things with shocks you didn't dream of a few years ago. I still believe you can mask spring issues with shock adjustments. You may be able to make it work in most instances but it still isn't right. Maybe that spring change would have made your car even faster than the shock change you are using to mask spring issues.

Once shock technology took off, everyone is shopping for the magic silver bullet shock setup. Who is best, what brand is best, what do I need to buy? You need to buy what you can get serviced, buy from somebody that you can talk to and what is best for driver "A" may not wok for driver "B". Shocks are not the end all of chassis tuning, they are merely a piece of the puzzle.

We, as racers wanting to go faster every time out, tend to rely too heavily on the latest trend and forget why we needed to improve that piece of the puzzle in the first place. As chassis dynamics changed (improved?) we out-ran the ability of the shocks to control movement IN THE TIME WE NEEDED THOSE MOVEMENTS TO HAPPEN. Movement didn't change, interaction of chassis components changed and we needed to move these events to a time they best suited the chassis needs. It's still 4 tires on dirt, we just have a newer way of planting those tires. If the newest technology is really so great, why have we not seen times drastically faster than they were 10-15 years ago. They are faster, usually, but not really that big of a change. Monkey see, monkey do?

That's why I still feel springs need to be changed to match the track/driver/HP/ and shocks need to be used to fine tune.

Now if you are soft enough on the RF to run on bump stops, the shock is totally different. The part that is the same is it still controls the timing of the spring/bump stop event. It's still a part of the tuning puzzle, not a replacement for a proper spring.

JMO,
SPark

[Matt49]

Matt49, I totally agree this is old thinking. I also agree this thinking came from pre "hiked up" days, but I feel it still holds true.

Yes, there are many adjustments to choose from. Yes, shocks have changed drastically and you can do things with shocks you didn't dream of a few years ago. I still believe you can mask spring issues with shock adjustments. You may be able to make it work in most instances but it still isn't right. Maybe that spring change would have made your car even faster than the shock change you are using to mask spring issues.

Once shock technology took off, everyone is shopping for the magic silver bullet shock setup. Who is best, what brand is best, what do I need to buy? You need to buy what you can get serviced, buy from somebody that you can talk to and what is best for driver "A" may not wok for driver "B". Shocks are not the end all of chassis tuning, they are merely a piece of the puzzle.

We, as racers wanting to go faster every time out, tend to rely too heavily on the latest trend and forget why we needed to improve that piece of the puzzle in the first place. As chassis dynamics changed (improved?) we out-ran the ability of the shocks to control movement IN THE TIME WE NEEDED THOSE MOVEMENTS TO HAPPEN. Movement didn't change, interaction of chassis components changed and we needed to move these events to a time they best suited the chassis needs. It's still 4 tires on dirt, we just have a newer way of planting those tires. If the newest technology is really so great, why have we not seen times drastically faster than they were 10-15 years ago. They are faster, usually, but not really that big of a change. Monkey see, monkey do?

That's why I still feel springs need to be changed to match the track/driver/HP/ and shocks need to be used to fine tune.

Now if you are soft enough on the RF to run on bump stops, the shock is totally different. The part that is the same is it still controls the timing of the spring/bump stop event. It's still a part of the tuning puzzle, not a replacement for a proper spring.

JMO,
SPark

I agree with 90% of this. The 10% being the lap times. Shock technology (and today's setups) don't necessarily come through when the track is fast which is when qualifying times and consequently track records are being recorded. But when the track is slick, we're probably running 1 to 2 seconds faster (depending on track size) than we were 30 years ago. The big builders (i.e. technology trend setters) sell cars to the big money teams. The big money teams race for big money on slick tracks. Every builder today is trying to build a car that will turn AND have forward bite in the slickest of conditions. The roll center movements and anti squat are what achieve this and shocks getting the car where it needs to be and holding the car where it needs to be in most cases to make it happen.
Take the guy running up front at any given track and put a set of straight 4 or 5 valved non adjustable shocks on his car and he'll go to the back when the track isn't fast.

Good discussion.

[let-r-eat]

I will render another opinion I have regarding shocks that some will flame away at me for sure.A shock is designed to keep the tire in contact with the racing surface.I find that many compromise this basic principle when they try to control suspension travel with shocks. We see this all the time on rough race tracks.If shocks were all that is needed then they wouldn't even make springs of different rates.

[LM14]

Good point on the slick, Matt. There is a drastic difference in the slick from what we raced 25 years ago.

SPark

[MasterSbilt_Racer]

I will render another opinion I have regarding shocks that some will flame away at me for sure.A shock is designed to keep the tire in contact with the racing surface.I find that many compromise this basic principle when they try to control suspension travel with shocks. We see this all the time on rough race tracks.If shocks were all that is needed then they wouldn't even make springs of different rates.

Your shock has a spring in it, if mono tube. Your cars mass, the springs, and dampers all have to work together. Technically, if you change spring rate, dampers need adjusted too.

[RacerX10]

So to go off slightly on a tangent, is everybody running that soft RF spring setup these days ? I've never run under 450 on the RF.

[Matt49]

I will render another opinion I have regarding shocks that some will flame away at me for sure.A shock is designed to keep the tire in contact with the racing surface.I find that many compromise this basic principle when they try to control suspension travel with shocks. We see this all the time on rough race tracks.If shocks were all that is needed then they wouldn't even make springs of different rates.

Definitely. This is where the importance of dampening control at different shaft speeds come into play. The low speed dampening (or lack thereof) is what we are using to control car attitude but we still need to understand the high speed dampening characteristics that help us control contact patch integrity. For example, you want the RF to tie down but not "ratchet" down, if that makes sense.
This can be achieved through proper shimming but quadruple adjustable shocks (rebound and compression in both high and low speed) are coming to DLM racing soon. Integra showed some off at PRI but I don't believe they are available to the public yet.

[Matt49]

Your shock has a spring in it, if mono tube. Your cars mass, the springs, and dampers all have to work together. Technically, if you change spring rate, dampers need adjusted too.

Good points. Wheel rate is what's important, not spring rate. The same spring on 5 different cars will produce 5 different wheel rates which is why the shock/spring package that works on a Rocket won't necessarily work on a Masters, Barry Wright, etc.

[let-r-eat]

I agree with Matt49 and Masterbuilt_Racer, LM14 and others here. You can get yourself all jumbled up with the use of both speed and position sensitive adjustments especially when you're using a shim stack to control high speed and a bleed for low speed adjustment. You still have to be able to determine the threshold for the breakover of the low and high speeds.This stuff isn't plug n play.

[let-r-eat]

To elaborate further the rebound sensitivity is where the action is. The spring only stores so much energy and no matter the rebound combination used if the spring doesn't have enough energy stored to create the speed allowable by the damper then you are just losing the ability to keep the contact patch planted. I like these type threads. We could dive into the details or proprietary information but that isn't really necessary because we are discussing principles. Think about what the stacked right front is placing on the demands of the shock? This is why it is so difficult for people to get it to work properly, along with utilizing the spring outside of its design limits. I'll quit there.

[PushinTheLimit]

RacerX10, that is something that I've been wondering lately myself. I've been running mostly on a 375 RF spring and going to a 350 RF spring when it slicks off. Some of the local racers have told me to go down to a 325 RF spring and see how that feels in the slick. But then some I've talked to haven't went below a 450 RF spring (for a crate). I was following the Rocket book on what it said spring wise, but found that the setup for a Rocket with a crate was different.

[fastford]

To elaborate further the rebound sensitivity is where the action is. The spring only stores so much energy and no matter the rebound combination used if the spring doesn't have enough energy stored to create the speed allowable by the damper then you are just losing the ability to keep the contact patch planted. I like these type threads. We could dive into the details or proprietary information but that isn't really necessary because we are discussing principles. Think about what the stacked right front is placing on the demands of the shock? This is why it is so difficult for people to get it to work properly, along with utilizing the spring outside of its design limits. I'll quit there.

just curious, did you mean stacked right front or two stage right front?

[Matt49]

There isn’t any magic in a softer RF spring by itself. It complements the roll center migrations of many of the new front end designs but also needs to be complemented with other setup changes to make it work correctly.
Back to the “old logic” thing for a second. Old school thinking deduced that a stiffer RF spring would free the car on entry. But new front end design and LR spring behind setup dictates that we change our thinking. A softer RF spring is allowing for more RF suspension travel which does two things: 1) lowers the dynamic roll center and 2) allows the LR to decompress. Lowering the dynamic roll center increases the front end’s side bite which makes the car steer better. Allowing the LR to decompress induces rear steer which lets the car rotate better. So winner winner chicken dinner we’ve got a car that steers more positive on corner entry with a softer RF spring. But the problem with the softer RF spring is that it reduces dynamic wedge which has a negative impact on forward drive coming off the corner. So you have to do something (if not many things) to get drive back in the car or you’ll be slow in the slick coming off the corner. What those things are is beyond this discussion and more than I’m willing to disclose :-)
Dual stage RF spring setup and RF bump stops are another story and there is a lot more going on there from a shock perspective than meets the eye.

[let-r-eat]

stacked OR 2 stage.Sorry I wasn't more precise in clarification.

[hpmaster]

So to go off slightly on a tangent, is everybody running that soft RF spring setup these days ? I've never run under 450 on the RF.

RacerX10, running older shocks and set ups are not conducive to a softer RF spring alone, alone being the key as stated in the points outlined by matt above. Newer more adjustable shocks when added to a car with help of a competent shock guy will get you on a path that will have you seeing overall benefits that most likely also include your using lighter springs on the RF. As for everybody running a soft RF spring in a word NO. As stated by matt other changes to your car and set up will determine how soft of a RF spring you need and can effectively run for a positive overall performance benefit. With out these other set up and equipment changes it is safe to say if you were to simply add a 300 lb RF spring to your car today you would be completely dissatisfied with the cars performance, as I found out when I first tried a softer RF spring alone. JMHO

[RacerX10]

Those were some really helpful replies without giving up any trade secrets and I appreciate it very much.

I thinks for the time being I'll stick with my old school 450 RF setup and experiment with the soft configuration on a test and tune day.

With my known 450 setup, I'll play around a bit (one change at a time) and learn how these DA shocks affect he car.