Well. That was interesting.

First race of the year. First time on the track this year. First drive on my new Dump Truck setup. Back in ITE where I haven't a prayer of victory unless it rains.

Several very late nights were spent trying to finish up the car, to the point that I was pretty rummy for Fridays practice session.

I gotta tell you what I was driving and how I got there first.

Last year I ran a pretty standard setup: Mugen N1 dampers with 900F/1100R, stock front bar, and Mugen 26mm rear bar. Camber typically around -3.5F and -1.5R, zero toe in the rear, and no more than 1/8th total toe out in the front.

On fresh tires that setup was pretty good. A bit loose on the first few laps, then pretty neutral thru the middle, and finishing pushy. Especially pushy in old T3 - a bottom of 3rd long turn. It's not generally considered one of the important corners on the track, but I regard it as very important. You can waste alot ot time there, and I've never turned a fast lap when I was plowing thru it. I've been looking to both car and driver for a consistent answer for this corner with little success. You should know that this is a nearly universal problem - everybody has trouble with T3, and that includes very good drivers who've worked on it for decades.

I didn't really have much complaint with the old setup. Maybe I'd have liked a little quicker response. And of course, with the limits imposed by our FWD weight distribution, the only way to increase speed is to find more front grip.

Which leads to the new setup. The idea is to run minimal ride height to minimize weight transfer, and run maximum spring rate to reduce roll and dive allowing minimal static camber settings to put down a better patch with lower unit loading on the inside wheel.

Another idea was the elimination of the front sway bar. This is also part of improving the contact patches in all modes. I've mentioned before the fact that our wheelbase exceeds our track. We transfer more weight to the outside front in roll than we do to either front under braking. Using sway bars to get our roll resistance means we're getting more camber change under braking than if we had used only springs. Why do this if we don't have to?

So the new setup is 1400F/1600R, with no front bar, and my own Speedway 1.25/0.095 rear bar. I started out with about the same toe settings, and camber set at -2.5F and -1.2 rear. Ride height was around 26.5 average to the fender lips on 23 inch tires (R3S04's - 225/45-15F and 205/50-15R).

I set the cornerweights to "split the difference". The DC2 chassis is typically balanced decently Without the driver. Add driver and now you're heavy on the left. Where you gonna put it? I've generally put some of the front differential off onto the right front, but not all of it - being somewhat ignorantly fearful of carrying all the differential on the rears. And I did the same on the new setup to start, without rethinking it seriously.

I asked Scott Z's advice on damper settings, and he suggested full hard on the rear and start at the middle on the fronts (3.5 turns out) and go from there. He at no point encouraged me to go this far on rates and said he'd never seen any clear benefits this far out. I was concerned that I'd be out of the design sweet spot on the dampers. The rears are effectively rebound adjustable only, with pretty light compression damping. But the front adjusters have significant effect on both compression and rebound. I anticipated that I might want more rebound and less compression - but I got what I got, and so I'd just have to find a compromise.

I spent about six hours on the strings and scales, and had to abandon my own advice on setting damper body length. With these rates you really can't crank in very much preload, and I don't like helper springs and I don't like letting springs flop around. So I used the damper body length to set the ride heights. And I ran out of time and didn't use any packers to space the bumpers.

I've decided I really like adjustable length bodies. They give you flexibility with respect to tire diameter and spring free length. If only it was as easy to adjust extended rod length.

BTW - on a DC2 with stock a-arms, if you bottom the arm on the inner fender, on 23 inch tires, there's still more than an inch clearance to the seam we all beat over. The Skunk arms bottom about 1/2 inch of wheel travel sooner. With the Mugen N1's set at the practical max body length (minimum purchase), the arms still hit first. I put small dents in mine when I went off one of those times at last years Rose Cups.

First Impressions?

Discomfort and anxiety.

The car was fine on the flat. But the curbs seemed to throw the car off hard. I gradually snuck up on old T7 at the end of the back straight, and was rewarded with some serious flailing. When the car let go, it happened fast but was catchable. I didn't find it to be any more prone to major drop throttle oversteer, and it was still maddeningly pushy in T3. The car was also bouncy upon curb landings and in the exit zone of T2. Unofficial lap times were about average for last year.

I had to try something. So I spent most of Saturday afternoon and evening (no sessions) changing out brakes (I'd used practice to burn up the last mm's of some leftovers). I used my usual HT-10's on the front, and installed some Blacks on the rear. I jacked the left rear and right front till I had equal front cornerweights. I put some more camber into the right rear thinking it might cut my grip in T3 by going past the sweet spot, and increase grip in T7 because of the lift of the curb. And I added a turn for the stiffer on the front dampers.

I was more comfortable going out to qualify on Sunday morning. I was more rested, and less rusty. And I had a theory.

And the car drove...About the Same! Except for the half second slower I was going.

I had about 5 hours to come up with a new theory. I took off my tires and carried them over to Fred the tire guy. He thought the outside front could do with a little less camber, and both rears could use more, based on wear and buildup. Taking that kind of advice would depend on 1) whether I believed that necessarily had anything to do with grip, and 2) whether putting more contact patch down at the rear was going to do anything good - which it wasn't.

I took off a half degree from the left front and reset the toe the same, and after alot of thought took both rear camber settings to -1.0. And I went the other way on the front dampers - to 4.5 turn out - pretty soft.

The Race:

I qualified somewhere in the middle, between the Porsches in front and the Miatas in the back. I was surrounded by AS, T2, and SPU. Greg was on my left just 0.2 sec slower in the Golf. I thought I got a good start, but it really wasn't. I got boxed in on the entry to the chicane, and then missed an opportunity to move over on the exit and had to pass a couple of cars on the first lap to get behind Greg. He was working on Scott Culbertson in the T2 350Z going into the chicane on lap 2, and I took the outside and pulled up about even heading for the left hander. He went a little deeper and squeezed over on me. I put my front end into his quarter ahead of his rear tire. I backed off for a second till it was clear he was recovering, and then we resumed racing toward the right onto the main straight. I left room on the inside for Greg, but didn't know an AS Mustang was trying to squeeze inside Greg. He hit Greg in the rear and spun him to the inside. And that was about as good as it got. I shook off the AS car, and closed on Scott's Z while he tried to get around an AS Camaro. I thought I had a shot, but then it took me a while to get around the Camaro and Scott was gone. His fast lap was about two tenths faster than mine (1:29.889 vs 1:30.126).

Later as either my tires got greasy, or I'd lost some interest or focus, I let the two AS cars by so as to not interfere with their race. I nearly lost the car in T2 while following Scotty B as he lapped me. I got sucked in and thought I could hang with him thru the back section. Not. The rest of the race was boring. Marshall in the other 350Z hit the wall hard exiting old T9 and dumped coolant and debris, so the last few laps were perfunctory.

I was very aggressive on the first lap, and I wasn't going to waste any time. Bergers photo's clearly show my missed opportunity on the first lap. They show the post apex contact with Greg - but not the pre-apex part. People in the stands said it looked like a straight racing incident. Greg and I talked in impound and we didn't have a problem. The Mustang driver kinda did - thinking that he was going to be blamed for his contact with Greg. It was funny hearing his perspective. He thought Greg and I were racing too aggressively and beating on each other, and that he was the victim.

I'm not too happy about it, but I'm glad my damage isn't any worse. I still have to check out the front end. The car drove ok after the hit, but it seemed to be getting unstable under braking toward the end of the race and it was spooky.

The effects of my pre-race changes were positive. That 1:30.126 fast race lap was my fastest of the weekend by about a half second. Still not as good as my best in the high 1:29's, but at least I was heading back in the right direction. The car was still bouncy in T2, but I was able to throw it across the curbing in T7 pretty hard, and even over the gators it wasn't too bad. I think with some more sophisticated dampers (and more $$$) I might be able to make these rates yield some more meaninful speed. One of the local yardsticks - Neil Shelton in his Crossle - said the track was about a second slow this weekend. A slightly comforting thought, but nothing more. This testing for speed stuff is alot of work.

So, back to theory. You get the car this stiff and your camber settings are everything. The rear barely moves. You select a rear camber setting for the terminal roll your front roll stiffness is going to give you. You've traded a lower flatter curve for a taller steeper curve. A narrow little window that charges you heavily for failure to pay attention to conditions. When you reduce the camber change effects in the dynamic envelope, and you're left mostly with weight transfer, you've got in some senses a more docile and less responsive chassis. I think that's more good than bad, but it could depend on the driver. I found myself sawing the wheel more than I normally do, but once I calmed down my inputs I found it pretty easy to drive the setup smoothly. I also found the chassis to be more placeable and predictable. The overall philosophy really seemed to pay in the braking zones. I was able to push deeper on the front straight, and I'm sure I can on the back straight too once I extinguish some lingering uncertainty in the turn in for T7.

The thing about these kind of rates is that over major surface irregularities, the tire force variation is greater - more change in grip. But nothing come for free. Is the total compromise worth it? I turned you on to Rennie's posts on the DSR board regarding rates and methods, and I've had that very much in mind thru all of this. Putting it into perspective, depending on tires of course, many race cars run wheel rates up to 2 times the cornerweight. My current setup is still less than 1 time at the front, and still less than 2 times at the rear. So it's not crazy, but some work in the damper department is clearly needed.

I ran wingless and really couldn't say I noticed from behind the wheel. The Lobak muffler really delivered - my readings were 90-92 dba. I still haven't been on the dyno and done any reasonable testing, but they're reported to be pretty benign and I'm prepared to believe it.

Another thing - my opinion is that 205's are plenty of tire in the back. I'm not even using all of them, and I've still got all the rear grip I need.

Well, that's it. Another year, another Rose Cup. It wasn't the greatest ever, but it was interesting, challenging, exciting, and rewarding. It wasn't epic. And some important people were missing and missed. I'm almost melancholic about it, and it's an odd feeling. I really didn't have as much emotional investment in this one. Is that because I didn't have a reasonable shot at the win? I can't help but think about contrivance and spontanaiety. I can love driving and racing, and at the same time know that it's a silly business. When I see how wrapped up people can get emotionally, and how that spending of ones life energy is relatively inconsequential in the small picture, let alone the big picture, I kinda want to pull back a little. It's just a game. A great game, played with many great people. But it's just a game.

Scott, who's looking forward to the next game....July Double Regional...how am I going to get solidly into the 1:29's without spending a wad?




Modified by RR98ITR at 8:29 AM 6/16/2004

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote"> ... many race cars run wheel rates up to 2 times the cornerweight. My current setup is still less than 1 time at the front, and still less than 2 times at the rear. </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">So the new setup is 1400F/1600R, with no front bar ...[/i]</TD></TR></TABLE>

... so you corner weights are something like 1400# for each of the fronts and a little less than 800# for each of the rears?

Hmmmm ... don't think so.

 

Wheel Rate != Spring rate (at least on a car w/o struts)

 

cool write up scott.

 

Front motion ratio is approx 0.7, rear is approx 0.74.

Wheel Rate = Spring Rate X (Motion Ratio squared).

Front springs are actually 240 N/mm - which I describe as 1400 lbs in conversation.

1370 lb front springs give a wheel rate of approx 670 lbs.

1600 lb rear springs give a wheel rate of approx 880 lbs.

Front corner weights were set at around 800 lbs.

Rear corner weights were set to 515L and 407R.

Scott, who isn't afraid to be numerically incorrect when it comes to insignificant digits...and wouldn't want to be accused of providing too much information...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">Scott, ...and wouldn't want to be accused of providing too much information...</TD></TR></TABLE>

Thanks for clearing that up Scott!

Often times there's no such thing as "too much" information, ... unless its completely irrelevant!

 

Nice write up Scott. Too bad the schedules conflicted and sent some of us chasing points north of the border.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">
Especially pushy in old T3 - a bottom of 3rd long turn. It's not generally considered one of the important corners on the track, but I regard it as very important. You can waste alot ot time there, and I've never turned a fast lap when I was plowing thru it. I've been looking to both car and driver for a consistent answer for this corner with little success. You should know that this is a nearly universal problem - everybody has trouble with T3, and that includes very good drivers who've worked on it for decades.</TD></TR></TABLE>

The only answer I can see for this corner starts with a bulldozer...

Rick

 

I love reading your posts.

 

As far as running 205s on the rear I reached the same conclusion a couple of years ago. You're only using about 1/2 of whatever tire you choose, so it really doesn't matter very much.

I run the same size on all corners for the practical reason... Rotation. Tire rotation that is.

Oh, and you're still fuggin batshit crazy. More driving, less thinking and cranking.

 

&lt;Willie Wonka voice ON!&gt; WRONG.....WRONG SIR! &lt;off&gt;

More Thinking - More Driving - More Speed.

Uh,...more money too.

The new 225/45-15 R3S04 doesn't really fit the rear of a DC2 with rolled fender lips and a 5mm spacer without running more negative camber than I want to run for the sake of maximizing rear braking traction.

Scott, who knows about tire rotation...that's what they do in those rare instances when I drive the car...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Catch 22 &raquo;</TD></TR><TR><TD CLASS="quote">

Oh, and you're still fuggin batshit crazy. More driving, less thinking and cranking.</TD></TR></TABLE>

from the little that i have seen of his posts im starting to think so too.

and as far as the dampers go give advanced design a call see if they can work something up for you. they are expensive but this might just solve the damper problem

 

Did I get this right? So all this thinking (plus work and money$$$) and you are slower than last year!!! I just got all my parts on and I ran 2.03 seconds faster at Mosport last weekend than I had run in the fall of 2003. Of course I am making the seocond set of gains which are a lot easier than gains from your n-th generation changes. Must be something wrong with the theory. And I thought those new Hoosiers were supposed to be better than the old ones. What happened? I would have been very disappointed if all my work and $$ had led to slower lap times than last year's. What is your explanation?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote"> What is your explanation?</TD></TR></TABLE>

Must have been that "magic" Mugen wing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">&lt;Willie Wonka voice ON!&gt; WRONG.....WRONG SIR! &lt;off&gt;
</TD></TR></TABLE>

OK.
But I've picked up a whole bunch of time in the last year. Went from being 3 or more seconds behind the frontrunners to being right up their asses, sometimes beating them, sometimes turning fastest laps of the race.

During this time I've pretty much changed the oil and washed the car. Wait... I did make a rear bar adjustment for CMP. So there was *my* "thinking and cranking."
Is my car optimally developed? Of course not. But I'm finding time, and fun, by spending my limited time and money behind the wheel instead of underneath the car. &lt;shrug&gt;

Of course, your changes might have actually been wonderful. But how would you even know given how long its been since you've danced out on the edge. Dont tell me you went out in one weekend and completely regained 10/10ths form... I respect you, but I won't believe you.

Scott, who thinks the other Scott needs more seat time more than he needs new dampers.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote">What is your explanation?</TD></TR></TABLE>

Ouch, a little harsh!

It sounds like Scott really tried to re-work his car for this year. Going out and doing some of your own thinking can lead to tremendous breakthroughs... sometimes not. Scott is doing something very respectable and something that everyone should do: engineer your own setup!

I would rather dream up my own setup and be just as fast, and maybe faster with a few minor tweaks than go out and just dump lots of money into parts.

Good work and good writeup Scott! Keep thinking!

Also, for those of you who hate on Scott for his thinking... I guess you haven't seen his in-car that he posted up last year. My first comment was, "Damn you are smooth for such nerd!"

Nerds rock

 

I really hate to engage in defensive bench racing, but what the hell.

By my 5th lap of Friday practice I was within a half second of my best ever race or qualifying laps.

By the end of the weekend I was within 2 tenths with a car that was still bouncing up and down on the tires like an empty dump truck.

I could definitely benefit from more frequent seat time, and if it weren't for life getting in the way I'd be there.

And all I've really put into the car since last year is a couple pairs of springs, some relatively inexpensive swaybar hardware, and a bunch of labor that I took pleasure and pride in.

I'd call it a bargain in entertainment. I'm happy enough with the progress I made thru the weekend.

Explanation?

&lt;shruggs&gt; "I dunno - I'm working on it". It could be that what I've picked up in contact patch quality and reduced weight transfer was offset by suboptimal damping and/or simply being oversprung. I'm pretty sure that a precise answer is beyond my abilities and resources. I will however converge on a reasonable approximation of an answer.

Scott, who has enjoyed glovelike intimacy with his ITR...what a trip to turn those first uncertain laps on a new setup...




Modified by RR98ITR at 11:28 PM 6/16/2004

 

Scott...

You mentioned the removal of the front bar. With all things being equal, can you isolate your imressions of that change. I would figure old T3 (new T6) would have been easier and faster w/o it??? Better rotation or more more nuetral... why the push?

Greg ~ alignment and corner weighted-free since '02

 

Greg,

I didn't just omit the bar. I tailored the spring rates to maintain the approximate front/rear roll stiffness balance. So I can't "isolate" that change.

If you were to simply remove your front bar and leave everything else alone, you'd have more body roll, need more static camber, and likely feel the car was slower in response. Whether it felt any looser would depend - it wouldn't be guaranteed.

Scott, who thinks this is all getting so complicated...Spec Miata looks better and better all the time...but I'm either too smart to do that, or not smart enough...I've thought about it and I can't figure out which it is...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">By the end of the weekend I was within 2 tenths with a car that was still bouncing up and down on the tires like an empty dump truck.

</TD></TR></TABLE>

Having completely stripped off the entire suspension front and rear this winter on my ITR, I too can relate to the entertainment value of a complete suspension rebuild and I too engineer my own car. I ran hundreds of simulations in LapSim to get a feel for what changes would be most beneficial. I went through in detail and worked through all the examples in the new book "RaceCar Engineering" to learn a little more about suspension setup and contact patch management. I looked at my data logger print-outs to see where I was fast and where I was being a little shy with the throttle pedal. I measured the whole suspension in 3D for future analysis in Susprog3D while I had everything apart. I took what I learned and thoroughly enjoyed re-building the whole suspension on the car for the second time. I bought a set of scales and alignment tools, and built some to adjust corner-weights and alignment.I researched this board and others to find ways of adding reliable power with headers and intake and some ECU/fuel changes. Plus I got that magic Mugen wing. And now my car is a whole lot faster, based on my first outing, and that made me feel like my hard work over the winter wa worth it.

Issue is that I am at least one or two generations behind Scott in the pyramid of speed, and I have learned a great deal from Scott. So I am wondering what it is that did not make make his car faster, when of course the idea was to improve speed with those mods. I am certain I could not yet drive a car as stiffly sprung a Scott's. So I am looking for a gut feeling. Is the ride rate too high? Have too many changes been made at once to an already highly tuned car? I ran on same tires as last year, since they weren't worn out. Scott stiffened up the car a bunch, and changed tires, and changed the sway bar contribution at the front and maybe more than he thinks at the rear. Or is it just a case of learning to rive the new setup. My driving buddy has moved up to a Toyota WSR, and is now driving on Dunlop slicks. He is having a hard time adjusting to the peaky nature of the very high grip curve of the slicks compared to R compounds, and lack of warning when they are about to let go, and this problem is only going to be solved by more seat time.So are Scott's new shoes any better or is it that they are bouncing off the track too much and he can't use them, or will a little more seat time and adjustments bring the lap times down. Questions, questions and so little time to test.

Claude who wonders about too many changes

(oh and I forgot to mention that I added NSX front calipers and Legend GS disks, and changed from Hawk Blues to Carbotech XP9 front and XP8 rear!)


Modified by descartesfool at 7:17 AM 6/17/2004

 

If you're getting satisfaction from what you're doing... Great. Keep doing it.
But many of your writings here suggest that you are in fact not satisfied with your current path. &lt;bigger shrug&gt;

I'd take the spring rates back down to what your current pimpy dampers can handle and leave the front bar off. That may not work out on your dogeared yellow notepad, but I think you'd be surprised.
Or is that approach just to easy for you to even attempt?


Scott, who remembers how his old car handled with 1200lb springs on the rear... Great... Until I hit a bump or a curb.

 

Hmmm, well, I'm satisifed with the process in which I'm not satisfied with my progress - though I'm satisfied that I'm making progress. I could be more satisfied with if the rate of progress were faster, but then the final satisfaction might be less since the task turned out to be less of a challenge.

Racing is a big PIE. You like the Driving slice. I like that slice too. But I also like the Engineer slice. And the Philosopher slice. I'm not interested in easy. I'm interested in interesting.

One of my friends had a conversation with a crewman on an Atlantic team. You know the kind of team - large transporter, uniformed crew. Running SCCA Nationals. The conversation revolved around dampers, and the crewman invited my friend to peek at some of his algorithms. You know - FFT's and stuff like that.

I am truly a Caveman by comparison. But a happy one. And I trust in the simplest rules and relationships in the physical world.

I don't intentionally set out to do anything the hard way per se. But I do seek understanding. What you frequently suggest I would characterize as abandonment and retreat. I simply have no interest in such a course. As for the destination - the path will lead where the path leads.

I know you're mostly just poking at me, and I don't mind. I've surely invited it, and it too is interesting sometimes.

Here's the big philosophical hook in all of this for me: let's say each progressively faster setup is harder to drive, less forgiving, and more work to maintain - But it's FASTER. Where do you stop. Where do you say "Yeah, I CAN drive that, but it's too much"?. Or does the Real Racer push ahead into infinity and beyond (or untill the cash runs out)?

Scott, who has thought of alternative configurations assembled from parts already in his growing pile...but why give up on this one while I'm still making progress - there's more to learn here before moving on...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">I'm not interested in easy. I'm interested in interesting.</TD></TR></TABLE>



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">FFT</TD></TR></TABLE>

*wakes up in cold sweat after punching Fourier in the nose for doing too much crack*

I truly enjoy living your races vicariously, Rinde.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by maxQ &raquo;</TD></TR><TR><TD CLASS="quote">



I truly enjoy living your races vicariously, Rinde.

</TD></TR></TABLE>

What he said. Very good stuff, Scott.

Casey, once again finding commonality with Andy.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RR98ITR &raquo;</TD></TR><TR><TD CLASS="quote">
1600 lb rear springs give a wheel rate of approx 880 lbs.

Rear corner weights were set to 515L and 407R.

</TD></TR></TABLE>

I think that the fact you pretty much have 1760 lb of spring supporting 922 lb of car might be contributing to the problem. Rather than compressing, it could be that the springs are just pushing the whole rear of the car up in the air over the bumps.

You mentioned earlier that the Sports Racer guys talk about a 2 to 1 spring to weight ratio, but if that's set static, then you might have to consider that a C or DSR car has a better aero package than an Integra and lots more downforce. I wouldn't be surprised if there was also more compliance in their other suspension components (besides the springs), to absorb the bumps.

I haven't seen a SR race in a while, so I'm not sure if they pound the gators as much as us stock-type guys do.

 

Nerds.