Author Topic: rear sway  (Read 5222 times)

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Offline kdogae86

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rear sway
« on: April 22, 2010, 10:59:06 PM »
how do we attach the rear sway bar. do we have to make threads into the unibody any attach mounts to the rear struts?

Offline Sirdeuce

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Re: rear sway
« Reply #1 on: April 23, 2010, 05:35:40 PM »
Are there any rubber plugs in the rail where the sway bar would mount to the frame?
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Offline BigMike

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Re: rear sway
« Reply #2 on: April 24, 2010, 03:41:07 PM »
The bolt holes for the bushing mounts already exist in the frame. They did in my 1987, no drilling or tapping required.

The only other snag is that some struts do not have the end link mount, so we'll need to either swap in different strut housings or weld on some tabs for the end links.

This happened to Bryan when we installed a rear bar on his car: Rear struts missing end link provision.
But on my car, it was a 100% bolt in operation. I just got lucky that my rear struts had the mounts already.

Mike
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Offline Sirdeuce

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Re: rear sway
« Reply #3 on: April 24, 2010, 08:49:47 PM »
Got that covered. The struts I was going to cut for the FX16 have the sway bar tabs. I think we should use the sway bars I took to Kevins. Just paint them black.
"I slept with faith and found a corpse in my arms on wakening; I drank and danced all night with doubt and found her a virgin in the morning."

Offline BigMike

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Re: rear sway
« Reply #4 on: April 25, 2010, 01:15:05 AM »
What bars did you deliver? Do you have a stock rear MK1 bar already?
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Offline Sirdeuce

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Re: rear sway
« Reply #5 on: April 25, 2010, 09:49:06 AM »
A set of Suspension Technics sway bars. The only thing that might give them away is the multiple holes on the ends for adjusting. Not really BIGGER than stock, but suposedly 15%-20% stiffer than stock. I have ADDCO sway bars on my MR2, they're about 60% stiffer than stock, and noticeably larger than stock. The sway bars I took to Kevins are in a weathered box. Yeah, still in the box. Make them look like they came with the car, paint them purple.
"I slept with faith and found a corpse in my arms on wakening; I drank and danced all night with doubt and found her a virgin in the morning."

Offline BigMike

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Re: rear sway
« Reply #6 on: April 25, 2010, 01:36:31 PM »
I run the ST sway bar up front on my car and I believe it is 20 or 22mm compared to the stock which was more like 16mm or so. It made a HUGE difference.

I am sure that we will have plenty of finance room for the ST bars. I'll make up some eBay or Craig's list page and print it out. What is a cheap price, like $50 for the pair?

If we run the ST rear sway bar then I think we don't need a LSD. Remember the car will be much lighter than what these sway bars are rated for.

Mike
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Offline Sirdeuce

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Re: rear sway
« Reply #7 on: April 25, 2010, 03:37:56 PM »
The set I took took Kevin contained both front and rear bars. Check it out before we make any decisions.
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Offline BryanH

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Re: rear sway
« Reply #8 on: April 25, 2010, 11:26:10 PM »
Big sway bars can make the car twitchier at the limit, and less compliant over curbs.  Generally speaking the bigger the rear sway bar the greater the need for LSD.  With an open diff, the big rear bar will pull up the inside rear tire and give us wheelspin.  This is why on my "stock" MK2 NA I run a 15/16" solid front sway bar and the stock rear bar.  I need that just to get the power down, even with the meager 5SFE.  This tends to create understeer in theory, but in part the stiff front bar reduces body roll which in turn reduces camber loss under load, improving my front contact patch.  Also, the rear tires are toed-out a bit to get it to rotate off the throttle.  Probably not a great idea for higher speeds at the track though.

In my experience the stock '87 MR2 sway bar setup is pretty balanced. I went to big bars (ST front, H&T rear which I think was 19mm) for a while and didn't like it, so I went back to the stock front bar and no rear bar.  There was an increase in body roll but the car was much easier to drive at the limit.

'Course, if we run stock springs, some stiffer sway bars are definitely in order to keep body roll in check.

We should add negative camber to the car as well, up front especially as the camber curve is terrible there.  Stock you can get just about -1.0 degrees which isn't enough.  -2.5 or so would be better.  The best way to "hide" this is with crash bolts - much less obvious than camber plates in the strut towers (but also less optimal).

Perhaps for our LeMons MR2 we could run the ST front bar and a stock 85-86 rear bar (or two?). 
« Last Edit: April 25, 2010, 11:31:29 PM by BryanH »

Offline BigMike

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Re: rear sway
« Reply #9 on: April 26, 2010, 01:24:14 PM »
Generally speaking the bigger the rear sway bar the greater the need for LSD.  With an open diff, the big rear bar will pull up the inside rear tire and give us wheelspin.

Good point. I was thinking along the lines of oversteer. Big rear sway bar would give more oversteer as would a LSD (under throttle). Your point with the inside wheelspin is definitely a larger factor than the any additional oversteer.


'Course, if we run stock springs, some stiffer sway bars are definitely in order to keep body roll in check.

For this reason I say we run the stock rear bar and a ST front bar.

The best way to "hide" this is with crash bolts - much less obvious than camber plates in the strut towers (but also less optimal).

Perfect. I can order these brand new from Toyota at a smoke'n price. Sight unseen

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Offline Sirdeuce

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Re: rear sway
« Reply #10 on: April 26, 2010, 07:21:34 PM »
Look at the rear bar in the kit I took to Kevins. The rear bar doesn't seem to be much larger than stock.
"I slept with faith and found a corpse in my arms on wakening; I drank and danced all night with doubt and found her a virgin in the morning."

Offline BryanH

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Re: rear sway
« Reply #11 on: April 26, 2010, 11:11:05 PM »
It's infinity+infinitybillion times larger than stock (which is zero). :P

Offline BigMike

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Re: rear sway
« Reply #12 on: April 27, 2010, 12:51:31 PM »
Look at the rear bar in the kit I took to Kevins. The rear bar doesn't seem to be much larger than stock.

Really? I think the turn signal select lever is stronger than the stock rear bar :o
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Offline BigMike

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Re: rear sway
« Reply #13 on: April 27, 2010, 12:52:25 PM »
It's infinity+infinitybillion times larger than stock (which is zero). :P

Do you mean Eleventy Bazillion?
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Offline Sirdeuce

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Re: rear sway
« Reply #14 on: May 06, 2010, 04:27:05 PM »
If the measurements are correct, the front is a 21mm, the rear 11mm. If I remember the readings right, I mic'd the rear at .84", and the front at .42". Best round #'s come to 21mm, and 11mm. Bothe had multiple holes in the ends to adjust the rates. I believe 2 holes in the front bar, 3 in the rear. The biggest giveaway is the heim ends that came with the set. might want to use stock end links. I'm sure I can find a spot for the heim joint ends! Hmmm.......
"I slept with faith and found a corpse in my arms on wakening; I drank and danced all night with doubt and found her a virgin in the morning."