Consensus on big bar/soft spring?

[craig510]

For a "big bar setup" the effective spring rate of the bar needs to be greater than the effective spring rate of your coils. This pulls the inside tire up and will compress the suspension due to cornering loads. Unless you have a silly light spring rate 1.125" bar ain't gonna do it. You will need a 1.375"+ diameter before you get into big bar territory.

[DBasher]

Originally Posted by GregWeld

I have lots of video of MY HOOD.... I have lots of video of MY DASH.... My car is faster than I am. LOL

Fixed it for ya buddy!

Lots of talk about what works best for the individual, different driving styles and what not. What about the guy building a car with zero experience on a road course?

Greg you've got three track cars and I'm sure they're all set up different. The mustang with Ron's secret sauce, the Lotus I'm guessing is stiffer and lighter with more aero and then the Miata....which is, um...a Miata. Which do you feel the most confident in?

[Che70velle]

Originally Posted by craig510

For a "big bar setup" the effective spring rate of the bar needs to be greater than the effective spring rate of your coils. This pulls the inside tire up and will compress the suspension due to cornering loads. Unless you have a silly light spring rate 1.125" bar ain't gonna do it. You will need a 1.375"+ diameter before you get into big bar territory.

Craig, don't get excited over the actual sizing of the bars. Pay attention to the actual rate of each bar. The 1 1/8" bar on the front of Rods car is rated at 1532 lb/in.(wow!) For comparison sake, my "bigger" 1 3/8" DSE bar on the front of my Chevelle is rated at something like 820ish. The larger 1 1/2" splined bar setup, offered by DSE, is rated at just over 1000 lbs.
I ran the BBSS setup on my asphalt late models, and understand what is needed as a fine tuned system to make this setup fast. Shock valving is the most critical. I posted on my build thread a couple years back that I was going to attempt a BBSS setup on my Chevelle, and wondered then what people would think, so this thread is interesting to me, to say the least...can do without the bickering though.

[Sieg]

Originally Posted by Che70velle

Shock valving is the most critical.

BINGO!

[GregWeld]

Originally Posted by DBasher

Fixed it for ya buddy!

Lots of talk about what works best for the individual, different driving styles and what not. What about the guy building a car with zero experience on a road course?

Greg you've got three track cars and I'm sure they're all set up different. The mustang with Ron's secret sauce, the Lotus I'm guessing is stiffer and lighter with more aero and then the Miata....which is, um...a Miata. Which do you feel the most confident in?

Great question Basher!! Not really relevant to this particular thread but here goes it:

Let's discuss before and after....

The Mustang was a complete disaster for handling... it was outdated... worn out... had cracked suspension parts - bushings that were frozen... shocks that were the worst worn out crap many people had ever seen. It's a track car... it's a few years old... stuff wasn't up to snuff. I didn't know any better. I only knew that I couldn't keep up with similar cars.

Enter the forensic teardown and measurements of what was... and a fresh sheet of paper and calcs by Ron Sutton...

The car is now a pure joy to drive -- videos of before and after confirm that the car works and works really well. Everybody used to pass me.... now - about the only people that pass me are guys with way fatter tires (Big Mikes Cup Car for instance). He used to pass me and I'd never see him again... now I can hang with him and do so without driving hard. I have the Sutton Low Roll High Travel design on my Mustang. The car is amazing. I have complete confidence in the car off line or any line... It's allowed me to work on driving skills rather than my life saving skills... with a series of linked recoveries. It's just flat planted.

I bought the Lotus 2 11 as a back up car... driving it is what tipped me off to how BAD the Mustang was. I USED TO describe the Mustang as "the pissed off bull"... and the Lotus as an adult GoKart.... That description would NOW be - the Mustang is WAY MORE FUN than the Lotus. I drive both with almost the same lap times. The Lotus used to be WAY faster. I may now sell the Lotus - because it's just too much fun to wheel the Mustang. I used to "get thru" the Mustang -- and happily stepped "up" to the Lotus... Now I drive it (the Lotus 2 11) because I have it and it should be driven...

The Lotus has double adjustable Ohlins.... weighs nothing... has plenty of power... steering is quick and light - and it's surgical.... the set up is exactly what the factory specs say to run it at.... the only big changes for handling are the mono ball bushings that replaced the rubber bushings.... and the Camber - and ride height and rake for downforce. The Ohlins are set to factory recommendations. It's an IRS... It runs grippy Yokohama A001 Softs (similar to Hoosier A7's).

The Miata was set up by Hobaugh for his daughter -- and he has auto crossed it and tracked it. With 100 more HP it would be a hoot... it's a "momentum car"... don't lift or you loose any momentum you had. It has some Falkens on it I think... It has adjustable shocks - different springs -- a roll bar... And the only guys that make fun of it are the ones that haven't had a chance to drive it. It's a hoot - sticks like glue - and a guy can really get after "the lines" with this car! YES -- the other cars can pass it... it lacks HP and TQ.... it does not lack FUN or confidence. You can toss it around in the corner - evoke mild oversteer and then just point it where it needs to go and ZOOM ZOOM... like I said - a total hoot! The cheapest, most fun, track car ever. Put some sticky Yoko's or Hoosiers on the little brat and it would be faster... but then I couldn't drive it to the grocery store after tracking it all day.

The Lotus 2 11 is by far the most dangerous to drive... huge rear weight bias (63%).... needs speed to get the aero working... snap oversteers.... and I mean SNAP. I've learned to drive it and catch the oversteer - but it will bite you big time! It's every fast - and is not a beginners car. You go into a corner and lift, or touch the brakes - you're history. It too is a momentum car -- but the momentum is far higher because it's fast. Don't make any mistakes in this car. It needs to be well driven at speed. Over correct as I did from T8 up to T9 at Thunderhill and you have a "tank slapper" on your hands. There's a series of "S" black marks up in that section - just before I spun it. LOL I simply missed the apex at 8 and then tried to correct my line.... and it was Katy bar the door! Bring on your fat tired 600+hp ZR1 and I'll drive by you like you're standing still. It's really well engineered and light as a feather.


I'll take the Mustang any day. NOW! I wouldn't have said that pre "Sutton". That's the answer to "which do you feel most confident in". It's the most neutral handling - glued to the track - predictable - no fuss - just "punch it! I know the road" of all three cars.

[Matt@BOS]

Greg, that is a great endorsement for Good Ron (Sutton)! Sounds like he setup your car so YOU could drive it fast!

[WSSix]

People have touched on this but I think it needs to be specifically pointed out. Everyone drives differently. You have to set the car up for your driving style. That, or you have to retrain yourself how to drive. It might ultimately be a combination of both. However, there's also more than one way to go fast. Combine them all together and figure out what works for you. I still think it's best to listen to lots of different people and decide for yourself what will work for you and your car. This has been a good read after skipping over the bickering. Let's keep the tech up.

[GregWeld]

Originally Posted by Matt.A

Greg, that is a great endorsement for Good Ron (Sutton)! Sounds like he setup your car so YOU could drive it fast!

That was baked in the cake. He (Ron Sutton) was brought on to help me... in the most basic ways. Tire pressures... etc. Running two cars, I wanted to LEARN basic car/track management. i.e., if the track is hot - what do I do with the tire pressures etc. When are my tires "hard" (Durometer). Teach me how to measure tire temps and what they are telling me. BASICS.

The point is - that HE was able to watch the car - and ask me questions and listened to ME and what I was feeling etc.

I think by the end of the first day - he'd taken 15 or 16 seconds off my lap times.

Fast forward... "Why is everyone passing me in the Mustang? But I can pass them all in the Lotus?" And "The Mustang just wears me out..."

All of the discussions we had were not about being .10 faster. They were solely centered on making the car more fun to drive. Making it predictable. Improvements that made the weekends fun and safe for ME... at whatever level I was capable of driving. I will NEVER tell you I'm fast or that I'm a good driver. It's never been my goal. I just wanted the car to work so I could stop having "oh crap" moments 6 out of 10 turns. The CARS are fast. My guess is - the Mustang would be 4 or so seconds a lap faster with Brian Finch or Hobaugh or Mary Pozzi behind the wheel. I think they'd really like the way the car is set up.

I've gotten the car to understeer (tight) once or twice now.... The minute I let up on the brake - she gets grip and off I go on around the corner... I had very minor oversteer (loose) on exit under power. Mentioned this to Ron and with a minor adjustment on the shocks (triple JRi's) that disappeared. The car is happy. The understeer was induced because I'm so much more confident in the car that I can hammer the entry harder - brake later - and explore late apex lines etc that I NEVER would have attempted prior to the "fix".

I was going to name my "team" - Tasmanian Devil Racing - I spun every track event. Now my lap times are faster than the group I run with and I don't spin or even come close to it. I did go off track at T3 at Sonoma on exit - kept it in the dirt until I could feather back on track for T4 - and I hardly even lifted on the throttle... I was WAY off line into the turn (3) - which had me exit wide - I knew this was going to happen when I entered the turn... I just got lazy on a pass and didn't bring the car back to where it should have been. In the old car - I wouldn't have made the pass - and had I gotten off line I would have been in the wall at T3 instead of a "ho hum I have two in the dirt". When flagged for my indiscretion - the President of the club asked what happened - I told him - (he's run nose and tail with me) he waves me back out and says "GO GET 'EM".

[mfain]

Originally Posted by bergers59

I'm trying to make a decision whether I want to go big bar/soft spring, or soft bar/stiff spring. From the research I've done, I've mostly found articles pertaining to late model asphalt cars rather than autocross. From what I can understand, soft springs are good for rougher surfaces(parking lots for autocross?) and making the tires work. I intend to run c prepared(slicks) and maybe a few 200tw events. Car will be 80% at track, so ride quality is of little concern. It seems as though BBSS requires different geometry(less camber change) to accommodate increased dive, and more testing/tuning to setup, is this true? I understand its a subjective question, but which setup is best for my application?

I've been watching this thread some, and I decided to throw in a couple of cents worth. OP, you are right in that the BBSS (high travel/low roll) works because of the geometry changes the high travel produces - for example, caster gain that results in correct camber movement for BOTH tires, not just the outside tire when they are turned. After studying Ron's posts (and many other sources on the subject) and talking with Ron personally, I made the move and cut several thousand dollars of C6 suspension out of my unfinished project track car and started over. To make a long story short, there isn't a piece of the car forward of the firewall that wasn't cut, moved, or massaged to accommodate big tires traveling 4 inches in compression (with proper geometry) and still being able to turn without hitting something- frame rails, front cross-member, sway bar mounts, inner fender wells. etc. I guess I'm saying that your decision on whether or not to go BBSS should involve careful analysis and preliminary design work to see the extent of the changes required and to see if all of the effort and expense is worth it to you. It is more than changing the springs and sway bar on a production-based vehicle. Good luck with your project.

Pappy

[Ron Sutton]

Originally Posted by WSSix

People have touched on this but I think it needs to be specifically pointed out. Everyone drives differently. You have to set the car up for your driving style. That, or you have to retrain yourself how to drive. It might ultimately be a combination of both. However, there's also more than one way to go fast. Combine them all together and figure out what works for you. I still think it's best to listen to lots of different people and decide for yourself what will work for you and your car. This has been a good read after skipping over the bickering. Let's keep the tech up.

Trey, I totally agree.

When I was in racing, we didn't set-up cars to suit the driver. We set-up the car to be fastest & taught the driver how to drive it optimally. Every 1/10 of a second mattered. Our joke used to be, "Do you care how the car feels or how winning feels?" But in sportsman racing, track days, pro touring, etc ... I take a different approach, because the top goal is often having fun, more than winning. In that case, we do want to set-up the car to fit the driver. At the end of the day, we want the car to inspire confidence, be fun to drive & be fast. So we're not worried about 1/10 of a second.

Some may think I only do high travel/low roll set-ups today. But that's not accurate. In the initial consultation, I explain the pros & cons of the 4 common set-ups.

1. Conventional low travel/high roll (around 1" travel & 3° roll) - provides more grip & confidence on corner entry under braking. Allows the driver to drive in deeper & brake harder. But carries less mid-corner speed. Provides moderate corner exit grip.

2. Modern high travel/low roll (around 3" travel & 1° roll)- has less grip on entry. Requires the driver to brake earlier & softer. Provides more grip & confidence through the corners & carries more mid-corner speed. Provides superior corner exit grip.

3. Moderate travel & roll is an in-between set-up of the #1 & #2. Typically around 2" travel & 2° roll. Achieves a balance of the traits from #1 & #2.

4. Low travel/low roll (around 1" travel & 1-2° roll) - provides high grip on corner entry under braking. Has narrow sweet spot where the car turns well. If under driven, tends to push. If over driven, car is loose or free. Requires top notch driver feel & control.

After they understand these options & their traits ... then my client guides me on what they want. Most of my clients choose #2 or #3. But regardless, I know how to calculate the spring & bar rates ... if I have all the key info on the car ... to achieve whichever strategy my client wants. The choice doesn't matter to me, because I'm not driving it. All I want them to be is happy with their car. My joy is when they call me after running it & say the car handles amazing.