Sure thing Ron, the current front sway bar is from an F-body 36 mm dia, 0.220" wall tubing.
The new Ridetech MuscleBar will be 1.5" dia (38.1 mm) and 0.250" wall tubing.
I'm running a 1" solid rear bar and 162 pound springs.
Okie Dokie Lance ...
When I worked up your current suspension package, we decided to run it a tick on the free side so there was no push (unless you turn in & apex too early).
For those following along with us, TRS (Total Roll Stiffness) is an accurate calculation that takes into account front & rear track width, roll centers, CG, spring rates & sway bar rates to provide a total roll resistance number.
The TRS number ONLY tells us the car's average roll angle at specific G-force numbers ... not front & rear roll angles. That's where the FLLD & RLLD percentages come in. These acronyms stand for Front & Rear Lateral Load Distribution. That's an engineering term for how are we splitting up this roll resistance front & rear ... stated in a percentage. We need more roll in the rear than the front for neutral/balanced handling.
We worked out your current FLLD as 54.0% FLLD & 46.0% RLLD. That's with:
Front Springs: 600#
Front Sway Bar: 36mm x .220" wall
Rear Springs: 162#
Rear Sway Bar: 1" Solid
If you just changed to the XHD Ridetech Muscle Bar with no rear changes, the 1.5" x .250" wall sway bar alone would change your FLLD/RLLD to 56.6%/43.4% and tighten the car up. You'd have more rear grip and when the track is really grippy from proper temp & good rubber laid down, it would be tight. Tight means harder to turn, but not pushing ... but borderline. That would be ok for road courses ... as long as you run big sweeping corners with wide entry & exit lines ... but it wouldn't like tight corners & it certainly wouldn't autocross well at all.
So you'll want to change the rear springs at the same time you change the bar. Ridetech sells the rear springs you need, so I suggest you get them with your new sway bar. You'll need 250# rear springs.
So with ...
Front Springs: 600# (Same)
Front Sway Bar: 1.5" OD x .250" wall (Custom XHD Muscle Bar)
Rear Springs: 250# (New)
Rear Sway Bar: 1" Solid (Same)
Your new FLLD/RLLD will be 53.9%/ 46.1% ... within .1% of your previous set-up. But of course the whole car will run flatter ... less roll angle ... and work the inside tires better.
__________________ Ron Sutton Race Technology
Last edited by Ron Sutton; 08-01-2014 at 03:26 PM.
Lance, I just read through your whole thread, great stuff. I really like what you've done with your Monte Carlo SS and look forward to seeing more, great write-ups.
Good luck the rest of the season.
Hey Lance, just read through, great thread. I'm anxious to see how things go with the new parts. I'm always trying to read up on serious G bodies so I can see how my car compares.
To compare, my set up is-
weighs 3550 without me in it,
600# S10 front springs
Factory wagon 1 1/8 (28.6mm) G body front sway bar
front Varishocks set on 7 of 16
no rear sway bar at all
CPP C10 1/2 ton 3" drop springs, don't know the spring rate, I bought them used and just slapped them in.
rear Varishocks on 6 of 16
17x9.5s all the way around with 255 and 275 40 Nitto NT555s
Last SCCA event I went to my best run was 76.8 and a 2009 Vette that was there was in the 75s so it was running respectfully around the middle of the group on times. I was driving a bit conservatively just to ease into things as this was my first "real" event so I think as I gain more driving skills the car will get faster.
What's odd, my car doesn't seem to roll near as much as yours. Maybe I'm not driving hard enough, lol! I have a much smaller front sway bar than you and no rear bar. What might be making the difference is the 6 pt cage (which is only welded to the floor not the frame), I boxed the frame in the middle, I built a frame connector that ties the middle frame rails together and ties into the rear lower control arm mounts, a brace connects and triangulates the rear shocks, and a trailer hitch connecting the rear end of the frame rails. Up front I have 73-77 A body firewall to rad support braces, the Regal brace that triangulates the radiator support, and I built a heavier wall larger tube triangle brace that goes under the front frame rails. In my videos I see the fender gap flex maybe 1/8"+ so my next step is down bars connecting the firewall to the front frame rails. Not sure that is what is making my car roll (read twist) less, but these frames are ridiculously flimsy and bracing can only help. You mentioned early on a roll bar, have you done that? If you custom build one you can design it to be out of the way and easy to get into. It may not be NHRA 9 second legal but who cares. I have lots of pics in my build thread link below in my signature if you want to see what I'm talking about.
Other than the bracing, I wonder where the big difference between our cars could be? Again, I'm anxious to see how the Monte acts with the new parts. Good luck!
__________________
-Ben, Creative Director
Last edited by Ben@SpeedTech; 08-01-2014 at 03:34 AM.
Here's a link to an outside view video- does it seem to roll less than yours? It's kinda hard to tell unless both cars were on the same track, but best I can tell yours rolls a little more... It looks ok embeded here but if you watch the youtube link it's a little clearer and larger.
__________________
-Ben, Creative Director
Last edited by Ben@SpeedTech; 08-01-2014 at 03:19 AM.
Ben, the pictures you see of my car when it's really rolled hard are possibly more a product of the courses we typically run on. Instead of large open sweeping type of corners like you showed in your video, we have mostly short chutes, hard braking and super tight corners.
This picture was taken in the middle of a large high speed sweeper at Gateway.
And this picture was taken at the end of the course at Gateway under a hard braking tight type of corner.
It might just be that it appears that my car has more diagonal roll once the back is up in the air under braking.
__________________
Lance
1985 Monte Carlo SS Street Car
One key reason Lance's car rolls more is we raised his ride height to achieve more front suspension travel. You can't make a car "high travel" if the suspension runs out of travel and something binds or hits.
All too often guys lower their production car a LOT for appearance sake and or perceived better handling ... without taking into account how much suspension travel they have left. I forget Lance's numbers, but shock travel was limited to somewhere in the 1.5" range ... IIRC ... and we raised the car to achieve over 2" of travel measured at the shock.
Lance's car still travels to the same spot it was before. We just start from a higher position. What this does is increase the dynamic rake of the car in "dive" and shifts more tire loading forces from the rear tires to the front tires.
Of course in purpose built suspensions ... especially in race cars ... we build the cars so they will sit as low as the rules allow & travel the front suspension until the front spoiler or splitter grazes the track. That is hard ... if not impossible ... in most production cars. So in the quandary of, "do I lower the car in the weeds or run it a little higher to make sure I have travel?" ... travel wins for handling purposes.
Those are great examples of different situations. My next SCCA event I'll have to see if I can get my son set up on a tighter part of the course for some shots of harder cornering.
Again, I'm trying to see how my car is doing compared to others with cars like mine. As far as I know, I'm the only one in this SCCA region that even runs CAM class, so trying to compare to lowered Hondas and 350Zs just doesn't help me much, lol! By watching and talking things out with folks like you is helping me get a better car and driving style together. After all, somebody, with maybe a G body or other "different" car needs to whoop up on all those Camaros once in a while, right?
Yeah, I suppose it's hard to tell/ compare unless we could see both cars on the same track. I watched my video a bunch of times last night, particularly the quicker turns before the large sweeper. It seems like I have decent roll range, but I guess I just need some video/ photos from some areas with tighter turns to see what's going on there too. I've tried to pay attention to different cars and folks like Ron, and I realize that some roll is good to help plant the tires, not enough or too much maybe isn't so good.
It seems there's only a handful of us G body guys that are serious about autocross, it would be way too cool for me to meet up with some of you guys at an event and compare notes. Maybe one day... I'm totally changing my entire suspension in August so I can sneak in a couple of SCCA events before the Hotchkis autocross at Fontana in October. Maybe there will be some other G body guys there, hopefully. Next year I'm going to try to get out to the Heidts challenge so maybe that's where I'll see some of ya.
Thanks for sharing that Ron. One of the reasons I'm deciding to go to Coilovers is so that I can play with/ factor in easy ride height and spring rate changes. The most recent mod to my car was cutting a bit of coil off the front springs and it went lower than I had wanted. In a world like this to me dealing with coil springs is a lot bigger pain than just swapping to coilovers.
Lance- Sorry to hijack your thread a little, just trying to learn from the things you're trying to sort out.
Ron- so in a car like Lance's or mine, being a daily driver that's "purpose built" and will see more track time than the average car, what type of range are we looking for in shocks? 2+ inches?
If I'm understanding you correctly you're going with a stiffer sway bar so he can maintain the height but lessen the roll, correct? Do you feel like the car is close to where it needs to be other than that?
No problem Ben, that's why I do these threads...to share with others about what we've done and plan on doing and to share how it's worked.
Before we started, my front shocks had about 1/2" of compression travel before bottoming out, static fender height was 25.5". One of the first things Ron had me do was put zip ties on the shock shafts and make a few autocross runs to see how far the suspension was traveling. That was eye opening and started us on this journey of making the suspension travel more to obtain the handling we wanted. A suspension bottomed out on the shock body in a turn is not what you want, trust me on this.
We now have enough travel built into the car that under full bump the fender height is 23.25" and full extension is 27.25" (this extension measurement was done before the longer Ridetech Shocks and LCAs were added and may be even higher now) and we have the current ride height set at 26.25" (25.5" tall 275/40/17 tires). We have the 3.6" travel Ridetech shocks on the front and they bottom out at the same time the tie rod ends hit the frame and sway bar (all at the same time). I don't have the exact shock travel numbers with the Ridetech shocks here at work, but you can see we are traveling the front suspension a LOT for a G-body. It took work to get that all to play nice together, but it is certainly worth it with the way the car turns in now.
__________________
Lance
1985 Monte Carlo SS Street Car
Thanks for sharing that Ron. One of the reasons I'm deciding to go to Coilovers is so that I can play with/ factor in easy ride height and spring rate changes. The most recent mod to my car was cutting a bit of coil off the front springs and it went lower than I had wanted. In a world like this to me dealing with coil springs is a lot bigger pain than just swapping to coilovers.
Lance- Sorry to hijack your thread a little, just trying to learn from the things you're trying to sort out.
Ron- so in a car like Lance's or mine, being a daily driver that's "purpose built" and will see more track time than the average car, what type of range are we looking for in shocks? 2+ inches? The short, smart azz answer is "More." If someone is going the high-front-travel/low-roll-angle suspension route, the more we can travel the front end ... to a point ... the better we can make the car turn. Like lance said, his shock was traveling under an inch before. Depending on the shock mounting location, it's about twice that at the wheel in most production cars. So he was traveling the wheel under 2" in dive. Now we're traveling the shocks over 2" & the wheels over 4" ... and it turns a ton better. Of course there is more to it than that. A lot more. But your question is about travel.
In my cars that have a real world ride height ... the best handling, meanest cornering machines are traveling the outside wheel 5"-5.5". The closer you can get a car to that, the better it "can" corner ... providing everything else in the package is right too. The farther you get away from that, the less cornering speed we're capable of carrying.
If I'm understanding you correctly you're going with a stiffer sway bar so he can maintain the height but lessen the roll, correct? Yes ... correct. We're not looking to travel his car farther. His car handles amazing for a production G-body. It's because we got the front geometry right (including high caster), balanced the front to rear roll angles with spring & sway bar selection ... and went the high-travel/low-roll suspension route.
Because when we did this, the biggest Bar Lance could budget at the moment was a 36mm Camaro bar ... we matched the rear springs & ran it. It works "well" ... but it rolls too much. That means he is not getting the inside tires to work & grip as well as they could. So, by increasing the front sway bar size significantly ... and keeping the FLLD/RLLD the same with the correct stiffness of rear springs ... it will still handle balanced ... but utilize all 4 tires better & have way more total grip. Grip is cornering speed.
Do you feel like the car is close to where it needs to be other than that?
Oh boy ... that's pretty subjective. We can always go faster. The questions come down to each person's personal budget, goals, planned usage, etc.
I'm saying this slightly tongue in cheek ... but we can shave about 10 seconds off his lap times by cutting that body off his production chassis & putting it on a cutting edge, Track-Warrior tube chassis. But where does it stop? I think each person has to make that decision. Sometimes money makes that decision for us.
As far as Lance's current package goes ... without making any major modifications (cutting up) the car ... it only needs a few things:
* Bigger front bar & matching rear springs
* A little more caster & a little less camber
* Scaled to be balanced with just the driver
* New tires to replace his current shredded ones
* Once he get's it running flatter, he may be able to reduce the ride height "a little."
You'll notice I didn't mention more front travel. He can't get more without making major mods to the car. Plus how far it travels now ... around 4" ... is pretty sweet.
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
Linear Mode
