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Question about Speedsource front bar

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Old Jun 4, 2010 | 09:57 PM
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dieselsdad's Avatar
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Question about Speedsource front bar

Can anyone tell me the diameter and the end to end distance of the Speedsource front Sway bar? If you know the measurement (length) of the drop arms that would be nice too.

Thanks,
Michael
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Old Jun 5, 2010 | 10:24 PM
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Lots of lookers but no takers? Anyone out there, anyone......
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Old Jun 7, 2010 | 05:15 PM
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From: MA
The bar is a 1.25″ OD with 0.250″ wall thickness.
http://www.mazdaspeeddevelopment.com/news/?p=95

Not sure on the second question.
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Old Jun 7, 2010 | 07:30 PM
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Just measure the OE front bar and all will be revealed

be forewarned that with this style bar that the further inboard the front inside wheel lip and the smaaler the wheel diameter that there is a possibility of contact with the swaybar at full lock. This is why the arms on the OE bar have the offset bend in them.


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Last edited by TeamRX8; Jun 7, 2010 at 07:36 PM.
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Old Jun 8, 2010 | 01:01 PM
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Thanks a ton for the replies. I didn't know if the bar used straight arms or offset arms and the picture helped a bunch. I had been searching for it on MazdaSpeed but couldn't seem to find it.

Thanks again.
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Old Jun 11, 2010 | 09:20 AM
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I have all the specs if you want them. The bar was designed in conjunction with the rear Mazdaspeed bar and about 400F and 350 rear rates with a Hoosier tire. If you are adding more grip you can go to the solid bar (avail at Speedway Engineering) and go up about 50-100 lbs in Spring rate both fr and rear. This would be for something like a 245+ R Hoosier or equivalent. Remember---it's the TIRE that determines spring/bar setup. Less grippy tire = the need for softer suspension.

I would not run this bar unless you were running at least a high performing, larger footprint tire(s).

This bar also has a unique number of splines (not the standard #). It is one spline more or less than the standard roundy-round/Nascar bars. 47, 48 or 49 are the numbers I recall.
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Old Jun 11, 2010 | 05:04 PM
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My version of that bar (same specs) with 500# F and 250# rear is major loose. I don't see how you can run 400#F/350#R with even a solid 1.25" bar. Filling in the center doesn't add much. Seems to me it would require a larger diameter center section. That's on 265 width street tires. It was looser still on 400#F/250#R.


.

Last edited by TeamRX8; Jun 11, 2010 at 05:11 PM.
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Old Jun 12, 2010 | 04:47 AM
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Your spring rate gap between F and R is huge compared to what we have found to work in road course environments. Typically we have a 50 to a 100 lb delta max. Any more than that (for us) results in ovrstr.
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Old Jun 12, 2010 | 07:14 AM
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From: Caput Mundi
Originally Posted by EricMeyer
Your spring rate gap between F and R is huge compared to what we have found to work in road course environments. Typically we have a 50 to a 100 lb delta max. Any more than that (for us) results in ovrstr.
I believe that Team only autocrosses his car. What differential are you running Eric? I believe that the lock-up rate of a dfferential should also put into consideration when picking up spring rates.
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Old Jun 12, 2010 | 07:09 PM
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Originally Posted by EricMeyer
Your spring rate gap between F and R is huge compared to what we have found to work in road course environments. Typically we have a 50 to a 100 lb delta max. Any more than that (for us) results in ovrstr.
That seems counter-intuitive, especially since by your own admission the front swaybar size has been upped to ginormous stiffness with no rear swaybar using those quoted rates

WRT road race vs autox if anything the autox setup is typically preferred to have more rear rotation than a road race setup.

400/325 is the closest pairing I have (250/500/600 are the other rates I have in possession). If you want to discuss setup privately I'm willing to give it a shot.


.

Last edited by TeamRX8; Jun 12, 2010 at 07:20 PM.
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Old Jun 13, 2010 | 05:23 AM
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We had an alms suspension Engr plot our entire car and I've since abandoned the single big front bar concept.
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Old Jun 13, 2010 | 07:55 PM
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Based on my experience over the last several months that seems like a valid conclusion
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