Torque Arm on an S197

[csamsh]

Sam Strano is a heavy bar/ light spring kinda guy I thought. He certainly seems to have made it work for the list of national championships he has. Relevant?

He didn't really have any other option. He won his S197 championships in F Stock, where spring changes are not allowed.

 

[sheizasosay]

He didn't really have any other option. He won his S197 championships in F Stock, where spring changes are not allowed.

Yeah that's a relevant point, but he's always saying how his car pulls 1.5 or 1.6g's equating it to what the Griggs car pulls.

I'm not opposed to high springs/soft bars. In fact I have been on a stiff spring/soft bar combo. I just haven't been on a soft spring/stiff bar combo. Just trying to pick up bits of info.

 

[sheizasosay]

"...from steady-state cornering to steady-state deceleration..." Under decel (braking) the car isn't rolling, it's pitching, and the bars are out of the equation. At that point it's all springs.

Ooops. Read it wrong. For some reason I thought that whole "1G throughout" deal was in the corner and breaking while you were in the corner. You were basically saying that "1G" was maintained throughout the entire scenario. My bad.



Started with:

BMR front bar is 35mm also and 3 way adj. Do you know the rate?
BMR front spring is 120-165lb/in progressive

BMR rear bar is 22mm. Don't know the rate, would guess about 150 lbs/in.
BMR rear spring is 140lb/in

Ended up with:
Front spring 350
Strano front bar rate is 472, 547, 642 lbs/in respective to 3 way adj.

Rear spring 300
Strano rear bar is 25mm@ 162, 185, 225 lbs/in respective to 3 way adj.

If we could fill in the BMR front and rear bar rates and come closer to eyeing this thing with all known rates. Also where were the adjustments on the bars in each scenario? I'm going too far with this huh?

 

[SoundGuyDave]

Yeah I'm wanting details of what he did exactly. Dave is a smart guy, he knows how to get his wheel rate. From the sound of his post, it sounded like he got the wheel rate near the same in both scenarios. It might not have been. But if it was isolated out or isolated within a reasonable manner.... that's pretty damn significant. Maybe I'm late to the game. Maybe this is old news. I'm just trying to learn what he has to offer.

The question is if wheel rate remains the same in this ,swap springs andbars around to the stiff spring/soft bar, is there 5 seconds to be had? If that's the case that needs to be on headlines.

Not THAT smart... And no, wheel rate did NOT remain the same, not by a long shot. With the AST setup, my wheel rates were significantly higher in roll than with the BMR setup. The body didn't "float" nearly as much, and while the data points to *similar* peak latG, with the AST setup, I could not only get to that peak latG faster, I could maintain it longer and more consistantly. It's area under the curve in the corner that I think is what really makes the difference. In practice, that means that I could brake a tick later, trail-brake a tick harder, carry more velocity into the corner, and also get on the gas sooner and harder than before.

Basically, the car went from floppy and sloppy in transition to "crisp," if that makes any sense. The car felt like I could put it anyplace I wanted it to be, AND it was a lot more communicative when approaching the limit. FWIW, with Strano's bars, I settled it out at medium up front, and full soft in the rear to get the rough balance that I wanted. From there, it was just one click of rebound or a couple psi to dial the car for any given track.

At this point, with the vehicle weight (and distribution) very different from what it was in 2010, I'm thinking about going up in front spring rate. I like the way the rear is behaving, but I think I'm getting a little more motion in the front than I ideally would like. Not sure what rates, just yet, but my gut is telling me something in the 500-600lb range.

 

[sheizasosay]

Alright sorry for the derailment OP. now back to you regularly paid programming.

 

[Whiskey11]

He didn't really have any other option. He won his S197 championships in F Stock, where spring changes are not allowed.

You seem to forget that Sam also set his 5.0L up for ESP and ran there before getting rid of it because of electrical problems. I'm not sure on the exact specs, never got a word up or down on what all he had but here is what I've gathered so far:

Koni Yellows
H&R Race Springs
Fays2 Watts link
His Swaybars
315 HoHo's on Enkei PF01 18x10.5's

H&R Race springs are somewhere in the 300 range for spring rates.

Not that my experience is really worth noting but I didn't change that much in PAX positioning going from my Steeda Sport/D-Spec setup to my GC Coilovers. Maybe two spots. I changed another 2 with the tires. When the only people remaining in front of you in PAX have either trophied or won at Nationals it's a bit difficult to advance up in the ranks!

I will say though the car got a hell of a lot easier to drive with the coilovers than it ever was on the D-Specs/Sport combo.

 

[Sam Strano]

He didn't really have any other option. He won his S197 championships in F Stock, where spring changes are not allowed.

I have also run other cars... and won ESP a few times too. I was building my 5.0 for ESP but was forced to stop because it had major electrical issues and forced it's sale.

I've also done a *few* other cars... including the fastest Mustangs @ Nationals (and the one that led day 1, and finished 3rd overall this year).

 

[Sam Strano]

Yeah I'm wanting details of what he did exactly. Dave is a smart guy, he knows how to get his wheel rate. From the sound of his post, it sounded like he got the wheel rate near the same in both scenarios. It might not have been. But if it was isolated out or isolated within a reasonable manner.... that's pretty damn significant. Maybe I'm late to the game. Maybe this is old news. I'm just trying to learn what he has to offer.

Sam Strano is a heavy bar/ light spring kinda guy I thought. He certainly seems to have made it work for the list of national championships he has. Relevant?

The question is if wheel rate remains the same in this ,swap springs andbars around to the stiff spring/soft bar, is there 5 seconds to be had? If that's the case that needs to be on headlines.

EDIT- again.....Dave's post was not up when I typed this lol. I think that when Dave clicked "quote" to reply it time hacked where his post would be.

Respectfully, if you found 4.5 or 5 seconds from shock tuning I'd buy beachfront property from you in Arizona. Did you run baseline runs and repeat and repeat them to start with? The thing about test driving is you have to be very consistent, VERY consistent. I'm in the midst of shock testing right now on my Corvette with a set of Motion Control Suspension Doubles (bump, rebound and canister pressure) vs. my Koni Sports, and while the car does different things differently and the greater range of adjustment allows me to do things with bars that I couldn't with Koni's, I can't even see a consistent .5 difference let alone a *5 second* difference.

No, what happened was simple. The course cleaned up. You learned it better, you drove it better. The tires got better, etc. Some combination of the above I'm sure too. Did you then reset the shocks at the end of the day to confirm your 5 second delta on shock changes alone???

I'm sorry, but that's just not realistic. I've won a National Championship, in ESP, with a BROKEN left front shock on my Camaro back in 2001, and not by a little... 1.189 seconds, after my car was wrecked 6 weeks prior, and I didn't realize it broke the front shock too. Here are those results: http://www.scca-milwaukee.org/solo/2006/Nats/2006 Combined Nationals.pdf And there were two other guys there running Camaro's with "big spring, small bar" setups... named Tom Berry and Ken Motonishi, they were 4th and 5th. And if you a serious autocrosser you know both of them too. Relevance to the Torque arm discussion? All those cars had torque arms. 3 different types. My car had the most basic one, and the softest springs of all. And well, the results speak for themselves.

 

[SD_Stang]

Off Topic
I noticed a Certain Terry and Amy Fair in that list finishing 1&2 Respectively in their classes in BMW M3's. Neat!

 

[SoundGuyDave]

Hey, Sam, long time no see! Sheiza wasn't doing the driving being discussed, I was, so I'm just jumping in here...

First off, it wasn't just shock tuning (don't know where you got that from), it was a wholesale suspension change. Out with D-specs, BMR springs and bars, and in with ASTs, Hyperco springs and your bars, so a significant hardware change. The tires used were the exact same set. This was a NASA TT event, so we're comparing the single best lap from each day...

Results of the two days in question:

October 2009: http://nasamidwest.com/docs/2009/Putnam_October_day2.pdf
May, 2010: http://nasamidwest.com/docs/2010/Putnam_May_day1.pdf

To provide comparison, TTA (Bruce Raymond) went from a 1:22.221 to a 1:22.847.
TTB (Nathan Pitcher) went from a 1:18.344 to a 1:18.075.
TTC (Aaron Lichty) went from a 1:18.398 to a 1:19.006
TTD (Michael Alsip) went from a 1:24.166 ti a 1:24.711

So, yes some gained and some lost time, but on balance the days were SIMILAR. No, by no means identical, but similar for a "rough comparison."

Also, I will not argue that I'm the most consistent possible driver, either, unless I'm doing a longer run, like in an endurance race. As you know, TT is all about that "flyer" lap, and it wouldn't be unusual to see my average pace off of the flyer by a full second while I'm experimenting with different lines or doing traffic management to get set for that one clean lap.

All that aside, however, and given that these were back-to-back visits to a track I know decently well, there was a LOT of gain made with that package change. As I admitted before, it's probably not ALL in the springs/dampers/bars, and that at least some of it came from driver confidence in the chassis. Was some of it the track itself? For the sake of argument let's assume that a full one second was. That still leaves a bunch of time to be accounted for.

The course cleaned up: Possible, let's assume that's worth a full second, but the "heavy hitters" in the TT group were all running fairly similar times between the two events.
I learned it better: Possible, but not likely. I had no visits to that track between those two events, and only one event in between, and that one was at a Roval.
I drove it better: Now this is entirely possible, even probable. Was it all me, though, or was it an artifact of the suspension that allowed me to push closer to the edge with confidence? Call that portion two seconds?
The tires got better: Highly doubtful. Exact same set of tires, stored indoors over the winter. Stickers in October, probably had seven or eight heat cycles on them for the "money run" in May.
Etc: Not sure what other factors would be, so no time assessment.

And no, given it was a major hardware change, I did NOT reset to confirm the delta. That level of time change was fairly consistent at the other tracks I ran, though, so I'm not sure what to make of that other than the package change was worth several seconds per lap. I'm in no way saying that the damper tuning alone was worth all of it, I'm merely offering the observation that the package was much more driveable, and as a result, I went much faster.

I'm not trying to say that the "light spring/heavy bar" setup can't or won't work, but for me the opposite DID work. Even if you discount the total 5 second gain (one second for the track, two seconds for the driver's confidence), that still leaves a couple of seconds gain from the hardware, and that on a 1-3/4 mile track.

I know I've posted this before, but here is a vid clip from those two weekends, showing a comparison run between T10 and T1. In particular, look at the differential in body lean as well as in pitch under braking into T1. Also note where I make the 3-4 upshift relative to the timing tower. That, more than anything, shows how much more exit speed I was carrying out of T10 on the 2010 setup.



I've said MANY times that I know next to nothing about autocross, but I do know that the driving techniques are frequently quite different (I've instructed MANY an autocrosser on their first track day, and as a rule, they are VIOLENT with control inputs!), so that would lead me to believe that the suspension setups could be quite different as well. I have no idea how a 0.5 second gain on a 40-second autocross course would translate to a 2-mile road course, or if there even is a valid metric that could be applied.

Anyway, not picking a bone with you, just trying to keep the discussion on the right path, and keeping the tech straight...

 

[NoTicket]

I believe Strano was confused. He quoted someone asking you details, and then responded with csamsh claim that shock tuning alone gained him 5 seconds in an AutoX event.

 

[csamsh]

hmmm...I don't think people fully understand how "off" and bad everything was set up when I "picked up 4.5 seconds." I had no idea where to start with the new setup, so I started with an old "ok" setup.

Definitely- the course cleaned up, I learned the course better, etc. etc. etc. as the day went on. HOWEVER- I usually pick up maybe 1 second through the course of a day, not 4.5. So, maybe the word "alone" was not used correctly. I would LOVE to have the means/pull/influence to be able to be able to throw runs away on repeating runs with a certain setup to baseline the car, do replicates of that later on to confirm positive setup changes, etc. Unfortunately, I can't go do test sessions on a whim

Sam, I don't know your complete history of cars, setup, and racing. All I know is that the nat. championships you personally won in an S197 in solo were in F Stock, where, by rule, you have to like soft (in the grand scheme of things, I realize the Shelby GT has harder springs) springs. That's all I meant to say...not that you had never had any success doing anything else.

 

[Sharad]

random thoughts:

1) My first HPDE was at Putnam. I loved that track. Although I never felt like I ever NAILED turn 8 perfectly.

2) As much as I hate to give Jason too much credit (just teasin' Jason, you know you're my dawg), I'm starting to believe in his "no progressive rate springs" strategy and subscribe to the Hard/Small philosophy described here. I get a lot more suspension travel than I'd like, and that's on the STREET with Koni Sports at full stiff. (I daily drive it that way)

It's not that what I recommend to people is wrong (for their STREET cars). I think it's just that I'm one of those idiots who's dumb enough to run track settings on the street. I don't give a crap about NVH.

I think I'll try a legit set of coilovers next year. Leaning toward either ASTs or Cortex.

 

[sheizasosay]

subscribe to the Hard/Small philosophy described here.

Yeah I could see you being a big fan of that.

 

[BMR Tech]

Ooops. Read it wrong. For some reason I thought that whole "1G throughout" deal was in the corner and breaking while you were in the corner. You were basically saying that "1G" was maintained throughout the entire scenario. My bad.



Started with:

BMR front bar is: 441lbs/in - 506lbs/in - 587lbs/in
BMR front spring is 120-165lb/in Dual Rate (Linear 165 working rate)

BMR rear bar is 22mm 150 lbs/in.
BMR rear spring is 120-160lb/in Dual Rate (Linear 160 working rate)

Ended up with:
Front spring 350
Strano front bar rate is 472, 547, 642 lbs/in respective to 3 way adj.

Rear spring 300
Strano rear bar is 25mm@ 162, 185, 225 lbs/in respective to 3 way adj.

If we could fill in the BMR front and rear bar rates and come closer to eyeing this thing with all known rates. Also where were the adjustments on the bars in each scenario? I'm going too far with this huh?

There ya go Sheiza, I corrected it all for ya.

No doubt that the combo that Dave went to, would easily lead to increased track times, and a huge gain in driver confidence. I can easily see several seconds of improvement there, without a doubt. The components he was using, from us, are the high volume "street performance" components that we offer. We never anticipated our SP009 Springs to be used competitively. I suppose most of his gains were due to the spring rate changes, alone.

That said, we have some really nice "handling-specific" components being tested as I type this. Bars, Springs, and a watts link.....in the shorter term, a new road course inspired UCA that we will be releasing in about 2 months.

 

[BMR Tech]

I have been a vocal opponent of the LCA relo brackets. I just think they open up a can of worms... but with my new car sitting as shown below, I think it's time to make the change. My LCAs have a crazy angle to them now. UPR has a new set of LCA Relos coming out Spring 2014 which I feel will be the strongest on the market. I'm planning to pick up a pair and take my car to a proper chassis shop to have them professionally tig-welded into place. The end goal is just to have the arms parallel to the ground at this ride height.

Interesting.

If they end up looking like ours, I won't be sending you those T-Shirts!

 

[sheizasosay]

Thanks Kelly.

 

[Sam Strano]

Maybe I hit "quote" on the wrong button. I was talking about picking up 5 seconds over 8 runs due to shock tuning. Sorry for any confusion

 

[Sharad]

Interesting.

If they end up looking like ours, I won't be sending you those T-Shirts!

They're not like yours. I mean, there are only so many different ways to make LCA relo brackets, but the easiest way to describe them is that they look just like our original ones, but with back straps. That one doesn't take too much imagination. I think everyone's relo brackets have back straps now.

As much as it pains me to admit it, I think I'm going to grab a set and have Dave install them. My '11 is pretty friggen low. I expect the relos to make a difference. But I won't try to get any crazy AS%. I just want the LCAs to be parallel to the ground on my car.

Anyway, I'll take my BMR shirt in black, Medium.

 

[kcbrown]

They're not like yours. I mean, there are only so many different ways to make LCA relo brackets,

Why hasn't anyone made LCA relocation brackets that work with the stock/GT500 LCAs?

All of the ones I've seen say they require aftermarket LCAs.