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Volvo 240 body mounted rear sway bar.

Is there somewhere I can read more into 240s suspension geometry and handling, reading elsewhere I saw just a straight up suspension lowering job is nothing more than cosmetic without proper geometry adjustments and I?d like to look more into it so I?m not chasing problems when I start doing suspension work

Whelp you're reading the right forum, look around ...
 
I run a 1" rear bar on my V8 wagon Custom made by IPD 30+ years ago [made to clear the dual exhaust], stock front bar. The rear bar made the car handle much better, remember the car is a wagon, top heavy. The car is very neutral, Koni sport adj shocks at all four corners, lowered 2". As far as mounting a rear sway bar I have seen body mounted bars, and axle mounted bars, they all do the same thing. Body mounts reduce un sprung weight, axle mounts add weight
 
less roll will always make a car feel more confidence-inspiring. Same with more damping.
Too much rear bar on soft springs will lift the inside tire on exit, something volvos gleefully exhibit. Same with too much damping.
Watch an autocross vid of a stock class BMW. The ones with a big front bar and konis cranked full counter-clockwise lift the front tires in an odd way. But they are almost always open diff cars, and they need the traction on turn exits. And early rules only allowed changing the front bar.

Too much rear bar makes the car 'push' or go sideways instead of around the corner.
"push" is understeer in dirt track talk.
 
I thought about doing that but decided i like the way it handles with stiffer springs and less bar.
But for inspiration, here is a corolla with hollow adjustable cobbling action.

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How's it handle (loaded question)?

less roll will always make a car feel more confidence-inspiring. Same with more damping.
Too much rear bar on soft springs will lift the inside tire on exit, something volvos gleefully exhibit. Same with too much damping.
Getting that inside rear to stay down was a challenge
126539684.jpg


here's where I messed with more rear springs (includes tender spring) to get more supported droop travel. I also softened the rear spring rate from, I believe, 325lb to 250lb (main) at the same time. It did help with rear grip(traction)
http://forums.turbobricks.com/showthread.php?p=3296622#post3296622

No rear bar on my car at this time. I pretty much dumped the rear bar when I stopped autocrossing on street tires and got enough camber on the front (at least -2) to get it to turn in. On ~0.8 deg. negative camber with stock-diameter front springs, and street tires, I had a big rear bar and the car was loose, but turned, and was fast when I got it right (fast relative to itself, but I sometimes beat faster cars with slower drivers)

The final iteration never got close to sorted out. Probably needed to look at roll centers or something to try and keep the car on the ground :e-shrug:

152754784.jpg

(this was slightly off camber, so helping the car lift off a bit more than just flat steady state cornering)

Watch an autocross vid of a stock class BMW. The ones with a big front bar and konis cranked full counter-clockwise lift the front tires in an odd way. But they are almost always open diff cars, and they need the traction on turn exits. And early rules only allowed changing the front bar.
Looks like this:
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127210474.jpg



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One comment I still remember from mikeP was about using a big rear bar with a welded diff, to get it to turn. With a locked diff, you're not worried as much about hiking the inside tire because you'll still have drive off the corner. But if you get to the point of overpowering your tire(s), then you'll need to reconsider.

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Drive it first and see what it needs. I made changes based on results & testing, having taken a baseline from other proven setups. Anthony Hyde's page if it's still around had a lot of good info on it about 240 suspension.
 
Thanks guys. Seems like it ain't worth the trouble. I'll just keep the stocker on there for now and see if it'll drift a bit when my lsd arrives.
 
I can't believe Mr Plow neglected to post the pic of me smoking the front tires in the Turbobricks CobbleArt Rapa Scrapple 244 at carlisle. I loved driving that car, even though I took leave of my senses at the time.
And I'm not sure I ever told him, but my dad's number in SCCA was 75. Also Paul Newman's. PLN was nationally ranked, so he bumped us to a different number when he showed up. But I hung out with his crew chief's daughter (we were both 16, same birth date), so ... I guess These IPAs were stronger than anticipated.
 
Not here to throw bombs, but this "super soft/no rear bar" thing is getting to gospel levels on this forum and that's just not healthy at any level of motorsport. One guy at Road America might LOVE a big bar, soft spring setup that Towery can't make work on a 2nd gear parking lot autocross. Another dude who makes time in the fast stuff might need a stable platform with very little travel to get the car to set early so he can get off the brakes and roll speed. The guy next door in the paddock? All about drive off the corner, and a little soft on braking technique, so this car is definitely soft at the rear, but what it's actually just that the LSD disks are worn, or the driver just hangs on to the brakes too long because... reasons. And homegirl over here? She might be like me, who wants a car to always move at the rear so you can steer with the brake pedal. These are incredibly complex and subjective topics that, frankly, most of the posters don't have much experience with. If you are not sliding both ends of the car every corner, every lap, regardless of the speed of said corner (or the runoff), then you really don't have much of an idea of what the car is like, just where your current limitations are. Coming to terms with this is an important step towards getting faster, BTW! It has happened to every single "FAST PERSON" in racing at some point.


Roll is not a simple phenomenon, and if it was as simple as this forum is starting to imply than we wouldn't need so many engineers in the paddock. You can get as kinky as you want here (and honestly, it's just as easy to get a little TOO kinky at times with roll sequences), there are plenty of practical engineers making lots of money doing this, and there are a million different ways to tune a car for a million different outcomes you are looking to achieve. Think about NASCAR or Spec Miata or anywhere in between where the machinery, conditions, and primary purpose are a million times more focussed than "I want my brick to do stuff and it doesn't" and then think about HOW MUCH TIME WE SPEND CHANGING ALL THIS **** ALL THE TIME in order to get the correct balance to finish in front. We often make ride height or toe changes on pit lane without alignment, even though that would be absolutely a dereliction of duty back at the truck between sessions. Are we wrong? Of course not, the target on the sweet spot IS ALWAYS MOVING.

Finally, THIS IS NOT A DIG AT ANYONE HERE. The people who have tracked their cars came up with what worked for them, with their resources and goals, and some have done really good work with good results. However, sort race cars for a living, and I wouldn't ever be so concrete in my bar setting recommendations as this. Hell, what if it's raining? Just really cold? Old tires? Race tires? How much preload? And on and on forever...
 
Not here to throw bombs, but this "super soft/no rear bar" thing is getting to gospel levels on this forum and that's just not healthy at any level of motorsport.

I agree with you because conditions are always changing both on the track and the road and sometimes you need to find a happy medium that works the best in most situations.

At Lime Rock Park where we race at for the most part, just as on the road, all of the corners are different and some have radius changes. One of the corners climbs a hill and another goes down a hill and both are challenging to get thru. Even after finding a good overall set-up you have to learn how to drive the car were it doesn't handle as well, without abusing the tires because once that happens their performance goes downhill fast.
 
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The subject is way to complex to take the time discussing it here. I agree with you 100%. With my Mustang GT, not a 240, yet, it is front engine, RWD and has 4 wheels, I run the stock front bar and a larger rear bar that is adjustable. My car corners flat, exits corners very well and does not oversteer. Someone else behind the wheel might think otherwise. Driving style has a huge effect on how a car behaves. Others I race with are always complaining that their RWD Camaros and Mustangs understeer. I never had that problem with several Camaros I have run. I don't expect a car to corner without transferring weight to the steering tires. IOW, I late brake and get the weight where it belongs and get back on the throttle mid corner to power out of corners. I don't hammer down on the throttle anywhere except when the car is pointed straight ahead and on a smooth surface. My huge, heavy, fat ass GT keeps up with Miatas on tight Autocross courses. It is also still stable at 100+ mph on road courses. SCCA FS class rules allow only one sway bar change, front or rear. I started out with a larger front bar which made the car very precise on steering inputs. Under most conditions I would call it almost neutral handling. On sustained corners, more than 180 degrees direction change it would push to the outside of the corner. I decided to try going back to the stock front bar and installing a larger, adjustable rear bar. The car is now a bit touchy if it is wet out, yet, corners great and doesn't seem to have the push on long corners. If the FS rules allowed it, I would run much stiffer springs on both ends. CAM C allows spring changes and the CAM C cars are definitely quicker through the same courses. They are also allowed power upgrades, wider wheel changes and unlimited camber. IOW, there is no one formula that works across all the conditions a car is operated under.
 
I can't believe Mr Plow neglected to post the pic of me smoking the front tires in the Turbobricks CobbleArt Rapa Scrapple 244 at carlisle. I loved driving that car, even though I took leave of my senses at the time.
And I'm not sure I ever told him, but my dad's number in SCCA was 75. Also Paul Newman's. PLN was nationally ranked, so he bumped us to a different number when he showed up. But I hung out with his crew chief's daughter (we were both 16, same birth date), so ... I guess These IPAs were stronger than anticipated.
I picked the number because of PLN. I also figured it would usually be available in my class. Before that, I used 42. It was the inverse of Jeff Gordon.

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^^ This is why I love having ABS on my “race” car. My friend that has a Fox body Mustang has ruined two sets of Advan A052 tires this season due to flat spots.
 
^^ This is why I love having ABS on my ?race? car. My friend that has a Fox body Mustang has ruined two sets of Advan A052 tires this season due to flat spots.

Be careful what you wish for! Street-based ABS systems are by far the scariest thing I've ever had to deal with in my entire career. **** those Grand Am ST brake rules! They have a mind of their own and the moment you get a "high/hard pedal" in a big braking zone without runoff, you'll understand what I mean!

OTOH, racing ABS is pretty spectacular usually. Often difficult to even discern that it is intervening, watch an IMSA race and you'll see the shift light are used to indicate locking intervention, since with analog valves there isn't a sensation in the pedal (I actually use the pressure on my collarbones as my tell that more pressure isn't changing decel G load!). Anyways, it's the only driver aid other than flatshift that I'm really cool with, since it saves SO MUCH MONEY when you put your dentists and doctors in for their stint.

PS, Towery has good taste in numerology, I've learned!
 
Getting back to stock-mount 240 rear sways vs body mount,
I have a strong suspicion that fat (ipd, etc) rear sways bolted to the long lower arms puts them in a bind and tries to twist them. That long arm also defines the effective sway bar arm length, making it ineffective compared to body-mounted.
 
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