Sway bar size, what do you recommend

denpo

denpo

Carburated Nihilist
Joined
Jul 14, 2010
Messages
2,522
Location
Montreal, QC
I have also finish my shopping session for my suspension rebuilt. Here is what I have so far :

-Complete energy suspension poly bushing kit.
-Bilstein sport front and back
-470lbs rates front coil
-New set of Moog balljoint
-Johnny joint for the trailing arm.
-Spreader bar
-Homemade modifications similar to dragvette's basic drag kit.


I plan keeping my 15'' "turbine" style rims, 275 rear, 245 front, I just love their style.

First question: is about sway bar, what size do you guys recommend?

Now, I've been looking for a rear composite spring, kind of pricey for my budget. I could have deal on a TRW 340lb one, but heard complains about the ride height.

Second question: How stiff should be the spring for my configuration, and is there a regular metal spring that should match such specs?

Thanks
Denis
 
Break with the bread and get a 330? or 360 VBP plastic spring....your ass and neck will thank you in the morning.....

seariously as Rowbuck.....:thumbs::smash: AS I RECALL it was only 250 bux, but that was long time ago too, then again the economy being in the dumpster, maybe they keeping prices lo too....

:surrender:
 
denpo said:
mrvette said:
AS I RECALL it was only 250 bux
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330$ now, plus shipping to Canada (ouch), not THAT expensive, but still...
I guess I'll have to wait a couple of paychecks.
Thanks MrVette.
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I think it's a huge improvement, and well worth the bux, hate to think about the import crap on top of it...maybe someone up there can lend a hand for you to pick it up here.....

sway bars....I have a stock 7/16? bar in back and a thinner bar in front...maybe 7/8? but with my 460 lbs front springs, I just removed the truck suspension to my ass rides better on these shitty roads....we are a sand bar, and have pot holes galore everywhere in site.....

:surrender::smash::thumbs:
 
denpo said:
mrvette said:
we are a sand bar, and have pot holes galore everywhere in site.....:surrender::smash::thumbs:
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Ah ah, nothing, I say nothing can beat Montreal/Quebec roads in term of pot holes quality.:rofl::rofl::rofl:
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Yet another reason I hate the thought of anything larger than 17" wheels....

anything larger than 18 and I see/feel a disASSter in the making....

:flash:
 
BBShark said:
The Chevy Power book recommend a 15/16 dia. bar.
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:clap:

That size/diameter spec stuff is what I can't make sense of....15/16ths....

why not 1" and just alter the steel hardness? whatever spec??

I can see 1/2-5/8-3/4=1"=1.5" even...but 15/16??

why?? serious engineering question....
 
denpo said:
kind of pricey for my budget. I could have deal on a TRW 340lb one, but heard complains about the ride height.

Second question: How stiff should be the spring for my configuration, and is there a regular metal spring that should match such specs?

Thanks
Denis
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The rear spring can very easily be changed later, if on a budget I would not worry about it right now... better get the car on the road so you can enjoy it.... then change the spring later... just my 2 cents...

ride height IS an issue.... previous owner got a 9-leaf re-arched spring somewhere, probably some scrap metal yard in southern Orlando.... what a piece of junk, raised the car about 2".... TRW springs have about the same reputation....

again, if your budget is the main concern.... live with what you've got until you have the funds to buy what you want.... maybe you're happy with the steel spring as it is right now....
 
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Depends on what you want to do. For drag racing the bar isn't significant. For handling, modern theory is to use soft springs to keep the tires in contact with the pot holes and use big bars for roll stiffness. Of course the basic chassis isn't all that stiff in torsion (or bending for that matter).

As to bar size - the rigidity of the bar is a function of the material shear modulus (all types of steels are about the same on this measure) and the 4th power of the bar radius. A 1" bar is about 29% stiffer than a 15/16 bar so 1/16 makes a bigger difference than you might think.

Grampy
 
I've never understood why anyone would get anything less than the biggest sway bar available, assuming you're going to get a rear bar. Sway bar does not affect ride quality, so the bigger the better, the front bar if big enough will cause understeer however. So, get a rear bar too. I have a Fast Corvette 1 1/4 bar.
 
enkeivette said:
I've never understood why anyone would get anything less than the biggest sway bar available, assuming you're going to get a rear bar. Sway bar does not affect ride quality, so the bigger the better, the front bar if big enough will cause understeer however. So, get a rear bar too. I have a Fast Corvette 1 1/4 bar.
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Bullshit, my ASS tells me different.....I had a stiff VBP 3/4? rear bar and a 1.25? front bar, and the car got to my tolerance level on these crappy roads here, full of more pot holes than a Mexican forest.....

So when replacing those bars with a stockish rear 9/16? and a 7/8 front...the ride quality was greatly improved.....even just simply pulling in/out of a driveway or shopping center.....

then to go for the Bilstein shocks later on ...instead of the KYB's....

the largest change I found there was that my ass was more comfy over the local 3.5 mile long bridge, it don't bounce like a NBA star anymore....

:crap::nuts:
 
Well, think about it. If you're running into potholes and one wheel is moving significantly more than the other, the sway bar is going to pull on the opposite side. But for someone like me that lives in CA with perfectly paved roads everywhere, most of the time my suspension is doing the same thing on the left as it is on the right (when I'm going in a straight line of course), and under these conditions, the sway bar is passive and not increasing the effective spring rate. So... it's like it's not even there.

Really, you should only feel a sway bar on uneven roads and in a hard corner. But 90% of the time, it does not affect ride quality. At least where I live.
 
enkeivette said:
Well, think about it. If you're running into potholes and one wheel is moving significantly more than the other, the sway bar is going to pull on the opposite side. But for someone like me that lives in CA with perfectly paved roads everywhere, most of the time my suspension is doing the same thing on the left as it is on the right (when I'm going in a straight line of course), and under these conditions, the sway bar is passive and not increasing the effective spring rate. So... it's like it's not even there.

Really, you should only feel a sway bar on uneven roads and in a hard corner. But 90% of the time, it does not affect ride quality. At least where I live.
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Florida sand bar has no stones, we have to import landscaping stones, it's so pathetic....and EXPENSIVE, some streets in/out of my hood here have not been paved since WAY before I moved in...'97.....sand is a lousy foundation....

:clobbered:
 
One would think that the biggest sway bar available could be the way to go except for the fact that a Corvette can easily have too large a rear bar. This will cause an oversteer condition that can only be described as dangerous. That is why mid years were never offered with rear bars by the factory for small block cars. BB cars car use a rear bar if it's not too big. Finally the early 70's LT1 cars got a tiny 7/16 sway bar which belive it or not actually does have some effect despite its miniscule diameter. I had 7/16 bar on my car with a stock 3/4 dia front bar and it was dangerous with the oversteer. That was my first experience with a rear bar - I was supprised that the little bar had any effect at all but it sure did. I have the same 7/16 rr bar on now with a 1 1/8 fr bar and am happy. Knowing what I know now I would never install a large dia rear bar on a sb corvette and I would be very conservative using a large rear bar on a bb Corvette. Companys that offer large bars for these cars frankly are not doing anyone any favours. I had this conversation with Dick Guldstrand [again] last week. He usually recommends no rear sway bar at all on C2 -C3 Corvettes
 
Bar sizing is about balancing front and rear roll stiffness. These factors influence understeer/oversteer. As others has explained too much rear roll stiffness can promote an interesting ride experience. A good basic rule would be don't add a rear bar without increasing the diameter of the front bar. The factories design in understeer as a more forgiving basic handling trait. Oversteering cars from the factory attract lawyers. For Denpo sticking to near stock sizes may be the best medicine.

Grampy
 
Grampy said:
Bar sizing is about balancing front and rear roll stiffness. These factors influence understeer/oversteer. As others has explained too much rear roll stiffness can promote an interesting ride experience. A good basic rule would be don't add a rear bar without increasing the diameter of the front bar. The factories design in understeer as a more forgiving basic handling trait. Oversteering cars from the factory attract lawyers. For Denpo sticking to near stock sizes may be the best medicine.

Grampy
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Ooo, scary lawyers out for no good. Except that there is this thing called superseding intervening negligence. And if you slide your Vette into a poll and try to sue GM, the judge will kick you out of court like the moron that you are.
 
Btw, with a bigger bar you should close up the welds on the sway bar brackets. I ripped mine off the control arm. :smash:
 
If you're really sticking with 245-60 and 275-60 15" tires then forget about the sway bar discussion for now....

you're saying you're "on a budget' like many of us - don't feel bad about this... I still run 295-50 on my '79 :D

My opinion or advice: drive the car first and then make your changes based on what you've got and what you "feel"....
 
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