[stretch]

Thanks guys. So who wants to take all the individual graphs and plot them onto one big high-res uber-chart?

Someone wants to see a t2 dyno graph, then someone remove a coilover and take it to your nearest race shop. There are two within 20min from me that charge $50 for a shock dyno, and that will tell us for sure.

Its been a long day, and I'll read more of the links tomorrow for sure, thanks strech!

Aye, that's why I completely don't understand why a company would consider their valving "secret". It's like if Cobb kept the dyno gains from their ECU reflash a secret so nobody could copy the torque curve. I mean, could you image that? The shock dyno curve IS the bragging right of the manufacturer. It's not just RCE; most manufacturers seem to keep this stuff private. It's their choice to do so, but why not brag about it?

I too am cautious about buying products without a dyno. I mean, look at the DMS dyno above. They're a big brand name, expensive, lots of rave reviews, so you'd expect an impressive dyno, right? But the dampers are totally progressive, and that'd be awful for a street car (my purposes). Are they progressive because they're designed for rally cars? I don't know. And Whiteline's then-popular Group-4's, another favorite prospect that a lot of people used to cross-shop, shows almost no digression at any firmness- maybe it's comfortable, but is that really optimal for daily drivers that see track time, too? I doubt it. Still, Kudos to Whiteline for publishing the information so I can make an informed decision- it's given me respect for their company.

One reason I really like Koni is that they usually send the original "test-fit" owner home with a dyno to post online. Koni dyno graphs are usually easy to find. Get one revalved, and you'll get a dyno showing what it's been revalved to. Their valving generally looks to me, at least on paper, to be excellent. (And it usually feels good, too.)

so those pss-9's aren't looking too bad now, huh?

Well, we still don't have an STI-specific dyno of them, just a generic one. It shows more digression than a lot of competing units (all except Zzyzx), diminishing as they're turned softer, which I think is great. If it weren't for the Audi forums dyno, I'd have no reservations about them. Also, it appears as if you keep your Bilsteins at a medium firmness level, then you're valving might not be far off from stock. (Again, though, that's not a car-specific Bilstein dyno, so it may not be even close to representative of the actual product.)

Someone's been busy - great job and research Stretch!!! This is what a technical forum should be about!!

I see you're playing with some AST coilovers- sounds like you're going to bring back a TIC variant of the Whiteline's discontinued (but popular) kit? I'd be curious if you can get a little more digression in the curve; AST uses some pretty big pistons for their price range, which should allow the necessary piston control if they use the right valves.

Has anyone ever used a 3-way or 4-way damper where high and low speed piston movement can be adjusted independently? I'd love to hear your thoughts on what settings worked and why- where low speed and high speed movement was most commonly felt in real world situations. Is there ever a reason to add more high-speed bump? I would think the less, the better, whereas you take as much low-speed bump as possible for a given ride quality.

 

[RaceComp Engineering]

Ooooooh.....you guys are pushy :lol::lol:

Myles will be out most of the day, but maybe I can persuade him when he gets back in. We'll see. No promises.


- Andrew

 

[KarlSTI]

Good thread. :tup: Look forward to the T2 plots.

 

[stretch]

Ooooooh.....you guys are pushy :lol::lol:

Myles will be out most of the day, but maybe I can persuade him when he gets back in. We'll see. No promises.


- Andrew

Well, I talked to Myles- he wanted to talk to me directly to avoid any confusion. Basically, Myles doesn't want to open up their coilovers to undo criticism. (As if that happens on the Internet... ha.) Posting a dyno chart is like opening up a can of worms. Anyway, RaceComp knows their valving works, and Myles doesn't want people to over-analyze what the graph looks like.

That said, I still asked for him to put up the dyno- my interest is in seeing why the T2's work as well as they do. But it's not gonna happen. RaceComp feels they have little-to-nothing to gain by putting it up (except props from a few people reading this thread). Anyway, it was nice to finally talk to the man, the myth, the legend: Myles.

 

[spazegun2213]

Has anyone ever used a 3-way or 4-way damper where high and low speed piston movement can be adjusted independently? I'd love to hear your thoughts on what settings worked and why- where low speed and high speed movement was most commonly felt in real world situations. Is there ever a reason to add more high-speed bump? I would think the less, the better, whereas you take as much low-speed bump as possible for a given ride quality.

you might want to pose that question on a forum like rennlist, or another higher end racing forum.

oh, and I'm still reading! damn you strech for linking 11ty billion articles!

 

[KarlSTI]

Well, I talked to Myles- he wanted to talk to me directly to avoid any confusion. Basically, Myles doesn't want to open up their coilovers to undo criticism. (As if that happens on the Internet... ha.) Posting a dyno chart is like opening up a can of worms. Anyway, RaceComp's valving works, and Myles doesn't want people to over-analyze what the graph looks like. After all, and I agree with him on this, more of this and less of that on a chart doesn't mean squat next to seat time.

That said, I still asked for him to put up the dyno- my interest is in seeing why the T2's work as well as they do. But it's not gonna happen. RaceComp has little-to-nothing to gain by putting it up (except props from a few people reading this thread), so I guess I understand his position. That doesn't mean I won't stop asking for a dyno though, cause I think seeing the charts are really educational for us car nerds! I just hope Myles doesn't take my (our?) persistence personally.

uh.....OK.

 

[Rootus]

Well, I talked to Myles- he wanted to talk to me directly to avoid any confusion. Basically, Myles doesn't want to open up their coilovers to undo criticism. (As if that happens on the Internet... ha.) Posting a dyno chart is like opening up a can of worms. Anyway, RaceComp's valving works, and Myles doesn't want people to over-analyze what the graph looks like. After all, and I agree with him on this, more of this and less of that on a chart doesn't mean squat next to seat time.

That's his choice, but it won't stop someone else from putting a set of the T2's on a shock dyno and posting the graph themselves. Hint . It also turns away some folks who care about disclosure. I do not like putting things on my car that work by voodoo. And I think seat time is horribly inaccurate for judging performance unless you are driving at 10/10ths on a track and timing the results.

 

[RaceComp Engineering]

Ok, so my guys brought this thread to my attention Friday.

First I would like to say that a couple of our clients that are very happy with the T2's, who have a successful time attack car are asking for ALOT more spring rate and so we are making a special version for them that will be revalved for a 800/?? rate. Prior they will be testing the current set up as a baseline, so no worries you dyno freaks will get a plot. As for us posting, well the unspoken word has to do my agreement with my co-branding deal. So there is your reason. Same thing when we have worked in the past to develope 2 other brands out there that we dont get credit for.

As for the remarks about VOODOO and such, I take them personal. When you make those remarks there is no other way for me to take it, since I pour my heart and soul in to this company working 18-19 hr days for the last 4 years almost, to develop products for this relatively small niche market, (why) because my heart is here. But certainly my long sometimes crazy post and threads have declined because of remarks like the VOODOO thing and all the other jabs and stabs at RCE and myself for not entering the T2's in to the circus fo a select few idiots to over analize and or criticize a products that we developed. Developed from ALOT of track time ,.yes at 10/10th. I have been doing this for 20 years on the driving side and the crew side and the marketing side and alot of those remarks were out of line. I have done nothing but try to bring to market as many products that this community can benefit from as possible. With the end use in mind first...and our pockets second.

I have instructed, raced( regional and semi pro level), autocrossed ( to the national level), and tested ( pro level) many different types of cars with many very good teams and worked with some GREAT engineers. So sometimes the remarks by a few people on these boards really get to me.

So no worries, my 2 clients will be posting very soon, as I am sure anyone else with T2s. We asked for small changes to accept a wider range of rates and those changes based on testing have proven to be a good choice. Nothing top secret, but man did this thread turn into a semi bash fast ONLY because we wouldnt post a plot. I dont see you guyts knocking Ohlins for not posting fixed perch plots or TOkico, or KYB..etc. So yes, I took it a little to heart.

We thank the people who have purchased our products in the past. Look for 2 more coilovers in the very near future as well as for the new 2008 cars.

Myles Williams

 

[Rac10000]

Myles, I completely agree with you. Some people have a tendency to immediately jump down someone’s throat without knowing all of the underlying facts of the decision. Having met you and speaking with you on multiple occasions, I know first hand how much time and effort you dedicate to RCE. I appreciate all your hard work and it definitely shows in the overall quality of your products.

Let me know if you need anything.

BTW, I am really looking forward to testing out your springs this upcoming track season (yes, I'm finally swithcing out my Tanabe's).

-Alex

 

[RaceComp Engineering]

Ya know I DO really understand WHY people get that way....I just wish sometimes they would think about all that we do-do and not harp on it. I guess I could understand more if the reviews came back BAD, or horrible ,.or people complained about the same thing. So far the only issues have been that some have not tightened the rear main bottom bolts and they have lost their alignment settings. I also dont think we( or I ) are above approach in asking for the plots.

Myles

 

[RaceComp Engineering]

Myles, I completely agree with you. Some people have a tendency to immediately jump down someone’s throat without knowing all of the underlying facts of the decision. Having met you and speaking with you on multiple occasions, I know first hand how much time and effort you dedicate to RCE. I appreciate all your hard work and it definitely shows in the overall quality of your products.

Let me know if you need anything.

BTW, I am really looking forward to testing out your springs this upcoming track season (yes, I'm finally swithcing out my Tanabe's).

-Alex

Thanks for the support, thanks alot.

Mw

 

[stretch]

I just wish sometimes they would think about all that we do-do and not harp on it. I guess I could understand more if the reviews came back BAD, or horrible ,.or people complained about the same thing.

It's because everyone loves your coilovers that I want to see the valving.

Myles, I don't think anyone attacked RaceComp directly, but instead just the general reluctance of the industry to post dyno graphs. That would put Racecomp in the same company as Ohlins and Moton, so that's not bad company to be in. I understand why you wouldn't want to post dyno graphs and open up a can of works. There was no insult implied, just wishes to see this stuff.

Hell, I wish intercooler companies showed thermal imaging and data logs (with lots extra sensors hooked up) when they released a kit, too, but I only know of one company that does. I wish spring rate manufacturers would always disclose their spring rates (usually happens), sway bar manufacturers would list their spring rate (rarely happens), and intake manufacturers would supply new MAF calibrations when the readings inevitably change (never happens). Heck, there have been some turbos for which I couldn't find an efficiency chart for!

So, I wish a lot of things, and it's nothing to take personal. No malice was implied towards any product. Posting a graph doesn't make a product better or worse, it just helps us understand why it is what it is. Understanding why a product works is every bit as important to me as how well a product works- I've just got that engineer mentality. I'm sure Rootus feels the same way, hence the "voodoo" remark. Again, it's nothing personal.

That's his choice, but it won't stop someone else from putting a set of the T2's on a shock dyno and posting the graph themselves.

Well, for a prospective customer, it's $50/shock plus the $1900 for the coilovers to test! You can't test something you don't already have, and once you've bought 'em, is seeing the graph important anymore? You might as well just throw 'em on and see how they feel. Even my curious mind probably wouldn't go through the hassle of dynoing something I've already bought unless I thought I had a problem.

 

[RaceComp Engineering]

Its funny how you sleep on things.............and so I agree with you on the company we "might" be in. But you know alot of people arent thinking that way......and I should have said that I enjoyed talking to you the other day, so you didnt think I was firing back at you. ( OT: ROSS....I parked next to you at HIN last night,.your car was dirtier than a 86' F150 at a rodeo in Texas after a hurricane...(lol).....yes that was my wife's Boxster S next to you. Oh and I diverted those thugs from stealing your S204 wing at the last minute also.....(wink). )..ok back on topic.

If its because of us being in that company then I back WAYYY off,.but you know how it is....people are always 6'8" and 400 lbs on the internet..........when they start yelling from the back row....." YEAH" with a deep voice.

Yes I went to HIN, left home at 9 when the wife fell asleep and got home at 12. Today I am dad and husband and Bob Villa. When they go asleep, I will work on the "Tarmac" spec entry level coilovers......(devils face).

Myles

 

[stretch]

I'd like to steer this conversation back towards it's intended purpose, which is to discuss the graphs themselves, not the availability of graphs. So, here comes another overly lengthy post to brew up some discussion.

In my limited experience, dampers with lots of digression make all bumps feel roughly the same size. By having lots of low-speed bump and rebound, small bumps feel bigger then they are- a lot of people would consider this having good "road feel". But, if the damper has lots of digression in the curve, larger bumps will feel not much more harsh then the small ones, so the chassis never gets upset.

Now, OE dampers typically have just small amounts of digression in order to prevent small bumps from being felt, but this is at the expense of car control, since body movements typically happen at low piston speeds (below 5 inches per second). In fact, this is basically the only part of the curve that matters in determining the car's handling bias and behavior. More resistance below 5 in/second will slow how quickly body roll occurs, so more low-speed damping is generally desirable for a track car. Anything above 5 inches per second is going to come from bumps in the road, which we want to absorb as much as possible (thus have little resistance).

Digression can be seen much more in bump resistance than in rebound. I'm not totally sure why, but my guess is that this is the most comfortable way to critically damp a spring regardless of how much force it is generating. It's the springs job to push the tire back towards the ground as quickly as possible, but we don't want to push the tire back so fast that the strut extends too far, creating a second oscillation. Perhaps a somewhat linear rebound curve is the answer to this? I don't know. The Zzyzx coilovers have lots of digression in the rebound chart, so maybe other manufacturers go linear because it's cheaper. Again, I don't know. I would think digression in the rebound would be a good thing- the quicker a tire rebounds off a bump, the better- we don't want to slow the rebound movement down until the spring has unloaded.

So, with a product like KW V3's, I'd guess that the bump adjuster tends to adjust "road feel" and handling more so than it would alleviate potholes and other major bumps in the road. KW shows their bump adjustment adjusting low-speed bump resistance only, leaving high-speed bump resistance constant. So, bump can be made extremely digressive by firming up the bump adjuster, adding tons of car control without increasing the harshness from potholes.

Compare this to a single-adjustable product that adjusts bump and rebound simultaneously (like Bilstein, Tokico D-specs), and you'll see high-speed bump get adjusted too. I don't know that adding high-speed bump is ever a good thing, but you're stuck with it. On the other flip side, high-speed bump and also be reduced to pretty low levels for the ultimate in ride quality (at the expense of handling, since low-speed resistance disappears with it).

In the KW V3's, rebound is adjusted across the entire curve. It becomes more digressive as it is firmed, but is progressive at full-soft. The ride quality and handling differences will be across-the-board and drastic. To get much low-speed resistance, though, one may end up adding more high-speed resistance than desired. But again, this just might be the best way to make a system critically damped for a given firmness, I just don't know. That said, I suspect neither full soft or full firm is very useful- too much rebound will prevent a tire from returning to the road after a bump, which results in traction loss.

I think the primary use of rebound adjustment is for making a damper work with different spring rates. Firming up rebound really requires a firmer spring to prevent traction loss. So, since KW's (and I would assume RCE T2's) become more digressive as they're adjusted firmer (which in turn requires firmer springs), I would think that those using KW's on increased spring rates would have the best overall ride/performance compromise. Those with soft springs running soft rebound are going to be stuck on a progressive rebound curve- good for isolation from the road, but bad for performance.

Actually, having too much of either bump or rebound will result in traction loss since your tires will not stay planted as well as they would on a softer setup. To an extent, ride quality can be good for performance.

So, with KW's, it seems as if the bump adjustment primarily tunes handling whereas the rebound adjustment has a more profound effect on ride quality. Any KW (or T2) owners want to chime in and share their experiences with the adjustments? Am I accurate at all?

Since Bilstein's PSS-9's (and Tokico D-specs, KYB AGX, etc) adjust add high-speed bump and high-speed rebound as they firm, I suspect their firmer settings hurt more than they help on anything other than a totally smooth road course. In this respect, KW's bump settings are more useful, since the entire range of adjustment looks useful (in fact, full firm might be the way to go at the track). However, Bilsteins can ultimately lower bump resistance everywhere which will provide the much better ride quality (at the expense of handling). As far as rebound resistance goes, both are in the same ballpark of full-firm and full-soft looking too extreme to be useful, with Bilstein perhaps showing more digression across its range.

Again, I'd love to hear from owners and their experiments with adjusting their struts.

 

[Splash]

Sure,

Ohlins FP struts and RCE springs...

25-positions and the bottom 15 seem to be useless.

Not a slam on Ohlins, more an observation of the range of the struts vs the springs used.

The RCE springs lower too much for soft valving, which is predictable, given that they were designed for STi OEM struts. Any less valving than stock and the bumpstops are a frequent visit, and it can be disaster if the bumpstops are shorter than stock.

Initially, I did not like the combo with the Ohlins set to 15. The rears are fine, but the fronts crashed easily, even on mild bumps. However, when set to 24, they take on a new firmness yet still won't punish the kidneys.

Our lot has a nice ridge/bump that is usually either on a corner exit or entry (depending on direction). Aaron's SM STi has Tarmac 2's, and is working on his settings. His rear was sorta bouncing around on that same bump. I'm sure he'll figure it out, but mine set on kill aren't disturbed by it.

Then again, I run STU, and don't generate the same grip to need the stiffer springs/valving.

So, IMO, the Ohlins, while adjusting rebound and bump at the same time, make minimal changes to the bump curve while making bigger changes to the rebound curve. They have a wide range, but that range assumes soft springs. Stiff springs remove the lower ranges from usefulness.

 

[spazegun2213]

Its funny how you sleep on things.............and so I agree with you on the company we "might" be in. But you know alot of people arent thinking that way......and I should have said that I enjoyed talking to you the other day, so you didnt think I was firing back at you. ( OT: ROSS....I parked next to you at HIN last night,.your car was dirtier than a 86' F150 at a rodeo in Texas after a hurricane...(lol).....yes that was my wife's Boxster S next to you. Oh and I diverted those thugs from stealing your S204 wing at the last minute also.....(wink). )..ok back on topic.

If its because of us being in that company then I back WAYYY off,.but you know how it is....people are always 6'8" and 400 lbs on the internet..........when they start yelling from the back row....." YEAH" with a deep voice.

Yes I went to HIN, left home at 9 when the wife fell asleep and got home at 12. Today I am dad and husband and Bob Villa. When they go asleep, I will work on the "Tarmac" spec entry level coilovers......(devils face).

Myles

Yes, my car was dirty as fook, but i washed it today... only to have 2 birds **** on it and pollen all over it... oh and i hate you for driving a boxter, but i did get your card.

And as for harping on RCE. We do that out of love, we know that there is no voodoo with you and you cant pull winning springs, coilovers, camber plates out of a hat with NO testing. I know you are a perfectionist and spend hours, days maybe even weeks just thinking about one aspect of the coilovers. And so far 100% of the users love them... (uhh yea, so good luck for people trying to find them used), I cant stop hearing about the build quality and the price, and the adjustability from all the people i know that got them (and if i had the money, I'd throw it your way).

We want to see what a winning combo looks like on the dyno. We want to see why its so good. Even though 90% of the users could care less, us "bench-racers" want to know.

You all know i love RCE, and you all are always the first people i talk to about suspension for any of my cars.

 

[Rootus]

As for the remarks about VOODOO and such, I take them personal.

Ummm... yeah ...

a select few idiots to over analize and or criticize a products that we developed.

I don't need to read any farther than that .

I do like your camber plates, they are serving my needs well. You were straightforward about what they did and how they did it. I'm too much of an idiot to go for T2's, though :wave:.

 

[BoostJunkie]

Ummm... yeah ...
I don't need to read any farther than that .

I do like your camber plates, they are serving my needs well. You were straightforward about what they did and how they did it. I'm too much of an idiot to go for T2's, though :wave:.

I don't think he directly called you an idiot, but if you are that concerned about it why don't you get your hands on a set and get them dynoed? Nobody is stopping you, and I can guarantee that seeing a dyno plot will not help you develop an accurate opinion about the dampers. Your comment about seat time being an inaccurate judge of performance couldn't be more wrong. I can geek out over statistics all day long, but when it comes down to it, if it doesn't feel good on the track (or the street) I don't want it. Seems to me that it's a lot more useful to develop something based on what works in a real situation, rather than in theory.

 

[stretch]

Oye.

but if you are that concerned about it why don't you get your hands on a set and get them dynoed? Nobody is stopping you...

Playing devil's advocate here-

Because that's hella expensive for a customer to do but free for the manufacture to supply. That's enough to stop me, anyway.

...and I can guarantee that seeing a dyno plot will not help you develop an accurate opinion about the dampers.

Of course it will help- it's just not as important as seat time. It'll help because we're not all shock tuning experts and need to visualize what cause-and-effect relationship occurs when adjusting our dampers. An expert can do it all based on feel, and to become an expert, I need the tools to learn how to develop that feel. Maybe others don't feel that way, but I do.

Seems to me that it's a lot more useful to develop something based on what works in a real situation, rather than in theory.

If I were to buy coilovers based on what other people said works in a real situation, then I'd think Megan coilovers were awesome. After all, isn't some dude winning autocrosses despite using them? Hell, even I've been duped before by thinking lowering springs felt much faster (but the timer said otherwise).

Some handling traits can originate from several sources; a damper dyno is useful in revealing which it is responsible for. People said the Whiteline coilovers were great street coilovers but there were better choices for the track. Until seeing the dyno charts, I made the assumption that this was due to the low spring rates (fixable with large sways), but they have a lack of low-speed resistance in the dampers, too. Without a dyno graph I wouldn't have seen this design choice. Or what about KW and their bump adjustment only altering low-speed bump? Normally I'd never even try setting bump to full stiff, but after seeing KW's dyno chart, it looks like a good idea.

 

[BoostJunkie]

Oye.


Playing devil's advocate here-

Because that's hella expensive for a customer to do but free for the manufacture to supply. That's enough to stop me, anyway.


Of course it will help- it's just not as important as seat time. It'll help because we're not all shock tuning experts and need to visualize what cause-and-effect relationship occurs when adjusting our dampers. An expert can do it all based on feel, and to become an expert, I need the tools to learn how to develop that feel. Maybe others don't feel that way, but I do.


If I were to buy coilovers based on what other people said works in a real situation, then I'd think Megan coilovers were awesome. After all, isn't some dude winning autocrosses despite using them? Hell, even I've been duped before by thinking lowering springs felt much faster (but the timer said otherwise).

Some handling traits can originate from several sources; a damper dyno is useful in revealing which it is responsible for. People said the Whiteline coilovers were great street coilovers but there were better choices for the track. Until seeing the dyno charts, I made the assumption that this was due to the low spring rates (fixable with large sways), but they have a lack of low-speed resistance in the dampers, too. Without a dyno graph I wouldn't have seen this design choice. Or what about KW and their bump adjustment only altering low-speed bump? Normally I'd never even try setting bump to full stiff, but after seeing KW's dyno chart, it looks like a good idea.

I agree that for SOME people (very few), a dyno plot can be helpful as a supplementary resource. However, I think what Myles was trying to say is that too many people base their decisions on statistics, when it's really a lot more helpful to find someone in their area who has the setup they want and asking for a ride. We have encountered many people who have asked for dyno plots in the past who had no clue how to read them. As far as settings, IMO it's much more effective to get out on the track (or auto-x course, whatever you do) and test as many different settings as possible. Even if it sounds like it would never work in theory, I'm sometimes surprised by what does and doesn't feel good on the track. Watching an interview with the chief engineer of the Subaru WRC team the other day, he said something that stuck with me. He said that they could analyze data to death trying to figure out what setup is fastest, but in the end if the driver isn't confident with the way the car feels, it's worthless.