Stock vs coilovers...worth how much time on a track?

[Jimmy Pribble]

Actually, it does. I'm talking to Ken Brown about his JRZ coilovers and as part of their service offering they will provide specific tunings for specific tracks. Some tracks are right turn, some left, some with more turns than others, etc. Tunable suspension is very important to winning races and are shown to do just that.

I will have my coilovers tuned per track. However, that's more for winning races than just personal lapping. So if lap times are important, and perhaps winning races with better times, having the proper rig is part-and-parcel to doing that. No question!

I thought that is what I said.

The question had to do with absolute lap times. In absolute terms, I claim there is negligable difference in a tuned coilover suspension and and identically tuned standard suspension. In most cases (and certainly for anyone asking this question), neither will be tuned for any track. Spring rates will be a best guess for the car and maybe driving style.

As I said, the advantage to a coilover is in it's flexibility to be adjusted to different tracks, something that typical track drivers can't be bothered with. Most coilover users that I have ever known have run a set-it-and-forget-it setup. Maybe it's better or maybe it's worse than a standard suspension upgrade. Neither is generally tested so...

I have never known a non-racer to change springs on coilover setup.

Anyway, sorry if I was unclear, but it looks to me like we are in complete agreement. Sorry if my post was confusing.

Jimmy

 

[JScheier]

One more element that a 'good' suspension system (note I said 'system', not coil-overs) can add is confidence.

A good set of dampers, with proper spring rates, proper alignment and proper settings can increase your confidence in the vehicle. As an example... with OEM dampers and springs, my Boss would bounce, skip, etc over bumpy portions of the track. With my current dampers, I can adjust them at the track allowing them to absorb more of those imperfections at a higher rate, making the car more stable and thus more predictable in those areas of the track. As such, I have increased confidence in that area of the track... much more so than my competitors who are skipping along, not sure where the rear of the car is going to end up.

^also very important in bumpy braking zones.

 

[DD GT3 RD]

Can you just put high spring rates on the stock damper then? That doesn't seem right

 

[Jimmy Pribble]

Can you just put high spring rates on the stock damper then? That doesn't seem right

There are guys here running Ford Racing 'P' springs (I think) with stock dampers. That will most likely be my "Stage 1" upgrade, as well. Without some data from a shock dyno, it would be hard to say at what point the dampers become ineffective.

 

[Zquez]

Can you just put high spring rates on the stock damper then? That doesn't seem right

No, the valving won't handle the high rates. The car will handle and ride like crap because you'll be bouncing all over the road. Also, the piston inside of the stock suspension will not blow off fluid as quickly as a high end monotube. Everything has an efficiency range, and the stock suspension pretty much maxes out at around 200 as far as spring rates are concerned. Even though the boss motor is out of a race car, the suspension is wholly street car.

 

[Zquez]

Also, lowering the car reduces the suspension travel. The stock stuff is designed for stock height +/- a few inches. Coilovers allow you a greater range of travel while being lowered than just springs on the stock style struts.

 

[JScheier]

Can you just put high spring rates on the stock damper then? That doesn't seem right

Can you? Sure.

Should you? Only if you enjoy crappy rides. Think of it this way... put a 10,000lb spring in the car. Is the damper doing the work, or is the spring doing the work? If your shock is rated for 500lb springs, putting a 600 lb spring in there is effectively taking the damper out of it's zone where it is effective.

Most higher-end damper (re)sellers will work with you on spring rates, and may even re-valve the dampers to ensure that they can handle the spring rates.

Beware of vendors that just tell you to 'turn the knob' to deal with higher spring rates. For the FRPP springs, most of those are low enough rates (and are progressive) that they will 'work' within OEM spec. As you get into specific rate springs, 400+ and up, you can probably imagine how well those would work with OEM dampers.

As Jimmy mentions, shock dynos and spring rate machines are good friends to have.

 

[JScheier]

Also, lowering the car reduces the suspension travel. The stock stuff is designed for stock height +/- a few inches. Coilovers allow you a greater range of travel while being lowered than just springs on the stock style struts....

and in some instances are shorter than OEM dampers just to regain that travel (or even longer in off-road type scenarios).

It should be noted that a 'coil-over' suspension is what your boss already comes with, ie: coil-over-strut/shock. An adjustable ride-height coil-over system is what most of us are discussing (not directed at this poster... just in general).

 

[Zquez]

and in some instances are shorter than OEM dampers just to regain that travel (or even longer in off-road type scenarios).

It should be noted that a 'coil-over' suspension is what your boss already comes with, ie: coil-over-strut/shock. An adjustable ride-height coil-over system is what most of us are discussing (not directed at this poster... just in general).

Good post. I think you articulated what I was trying to say better... lol

 

[fuhrius]

if you're building a track car and want to go fast, take weight out of it...that helps in all areas.
is a better track-oriented suspension going to improve you lap times? yes. you're skill? no. what are you looking to achieve? win races or be a better driver?

10% improvement is hard for me to believe.

my most quantifiable data point is more similar to Gary's...running a boxster s (first gen) with slightly modded suspension (adjustable drop links and bars, tons of camber via plates, semi-solid engine / tranny mounts, stock springs and shocks / struts....all day long at Laguna Seca in the low 1:48's on dunlop star spec steet tires. same tires and everything else...added PSS9's (bilstein) to complete what was then, essentially, the identical suspension to the boxster spec stuff...mid 1:46's with consistency.

One thing that might not have been emphasized yet is setup. One of the big reasons I saw improvement is that there is a well-worn 'recipe' for setting up that suspension...thanks to the spec guys. If not for that...and me 'tuning' my suspension...I may have lost time.

 

[ArizonaBOSS]

Can you just put high spring rates on the stock damper then? That doesn't seem right

Depends on what you classify as "high", 200lbs-in, sure...350-500+, forget it. The stock dampers won't be able to control that motion.

 

[Sesshomurai]

and in some instances are shorter than OEM dampers just to regain that travel (or even longer in off-road type scenarios).

It should be noted that a 'coil-over' suspension is what your boss already comes with, ie: coil-over-strut/shock. An adjustable ride-height coil-over system is what most of us are discussing (not directed at this poster... just in general).

That's news to me! I thought coil-over meant the spring is coiled-over-the-strut/shock. The boss springs are definitely not that. They are separate entirely.

 

[DD GT3 RD]

I agree that the shock wont handle it, I was kinda reinforcing that...it seems some think suspension wont make the car faster?! Obviously if you cant drive well enough then maybe so...more practice

I have it on P springs and its still pretty soft

Im looking at AST 4150, JRZ RS1, Eibach Multi Pro R2 and KW V3

AST and JRZ being the best but worried about maintenance

Not sure about the Eibach

KW being reliable but not sure how good

 

[Sesshomurai]

I agree that the shock wont handle it, I was kinda reinforcing that...it seems some think suspension wont make the car faster?! Obviously if you cant drive well enough then maybe so...more practice

I have it on P springs and its still pretty soft

Im looking at AST 4150, JRZ RS1, Eibach Multi Pro R2 and KW V3

AST and JRZ being the best but worried about maintenance

Not sure about the Eibach

KW being reliable but not sure how good

I'm in the same phase of study. If you haven't take a look at what Cortex is offering (extreme grip system). You can upgrade the dampers to penske, ohlins, etc. It's a big step and I want to get it right, same as you.

 

[JScheier]

That's news to me! I thought coil-over meant the spring is coiled-over-the-strut/shock. The boss springs are definitely not that. They are separate entirely.

exhibit A

Front of a Boss has coil-over setup. Rear does not.

 

[Sesshomurai]

exhibit A

Front of a Boss has coil-over setup. Rear does not.

Ok. In a very loose interpretation maybe, but no one I know would consider a strut with spring seat a "coil-over" the way its typically meant. Good to know i now have coil overs!

 

[Zquez]

In case some of you were wondering who the best was....

 

[ArizonaBOSS]

Ran into a World Challenge driver at my last event that said JRZs are great dampers but an absolute PITA to get serviced since they have to go back to Belgium or something near that area.

I have Roush/KW coil overs on my car and they work well, but I don't have enough experience with other brands first-hand to judge how good or bad they really are compared to anything else. I would like to get a set of AST 4250s (rebound and compression) in the future, or if I was really on a spending spree, a set of the Multimatic Dynamic 3-way dampers that are optional on the 302S.

The CTSCC Mustangs run AST 5200s.

 

[Zquez]

Ran into a World Challenge driver at my last event that said JRZs are great dampers but an absolute PITA to get serviced since they have to go back to Belgium or something near that area.

I have Roush/KW coil overs on my car and they work well, but I don't have enough experience with other brands first-hand to judge how good or bad they really are compared to anything else. I would like to get a set of AST 4250s (rebound and compression) in the future, or if I was really on a spending spree, a set of the Multimatic Dynamic 3-way dampers that are optional on the 302S.

The CTSCC Mustangs run AST 5200s.

I know of the Roush/KW dampers and have heard good things about them. I, like you, don't have a whole bunch of experience with top shelf dampers but ask me again in a few months. I have the 4150s that I just put on and they are a work of art. The nice thing about the 4150s compared to other single adjustables in the price range, is that they can be upgraded to 4250 doubles down the road. I definitely don't feel like coilovers are overkill for track toys like so many people say, but I do feel that unless someone is actually competing for money and sponsorship's 10,000 dollar dampers are just stupid. As far as servicing, AST USA is located in texas so no overseas shipping.

 

[ArizonaBOSS]

Yeah I am following all of Vorshlag's stuff on S197forum and corner-carvers; I love what they are doing and all the info they share.