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Old 08-11-2018, 09:43 PM   #380
DET17
Reformed SAABaholic
 
Join Date: Nov 2009
Location: NW Georgia
Default Ever closer to back on the road.....

Well it's been a good while since an update.... vacation along with wife's honey-do list work slowing things up a bit, but finally completed some jobs today.

For the first time since April 2017, the car is back on 4 wheels:



All of the rear suspension "torque points" have been waiting for the car to sit on the springs at normal ride height. With all these connections just snugged, I rolled the car forward and backward in my 2 car long basement shop..... this to get everything "familiar with each other" before again elevating the car rear back to ramps for torque application.

Since the rubber suspension bushings torsion as the suspension travels, one must NOT torque them until total weight is back fully on springs & dampers. Once in that "normal ride height condition" the bolted connections are torqued so that the torsion as the suspension articulates is +/- the same amount of torsional strain; that is to say each rubber bushing is neutral at normal ride height. If you make the mistake of torquing these points with the suspension at full droop, you will over strain these bushings resulting in failure. I retained the original VOLVO rubber bushings at the 4 points in the dog bones; Hopefully the added torque doesn't destroy these....and I won't ever run poly joints. We shall see how they do.

For 7/9 Posterity, the front thru bolt on the damper/sway bar (along with pan hard bar) torque at 63 lb.ft, the small rear sway bar flat head bolt is at 35 lb.ft, and the dog bone torque arms which control the rear end reactions are torqued at 103 lb.ft, all 4 points.

Here you can see the various torque points:





Here a picture of the "progressive rate" rear spring, loaded. Note the 4.10 ratio tag on the axle..... looking forward to that +10% torque to the tires!




One of the longterm annoyances for me has been the TME exhaust.... the CAT back 2.5" stainless system. I've always loved the exhaust note.... I think TME nailed that part. The issue I've always had with it was when attached to the pipe exiting the CAT, the rear tip of the muffler was never horizontal, but pointing down toward the road. With the experience TME has in making exhaust, they can't have screwed this up as found. While the guy who sold me this used insisted it was for the 7/9 cars, I wonder if he was given the wrong front pipe (axle forward). Regardless, with the last hurrah it is time to fix this properly.

I elevated one of the rear hangers to level the muffler L-R with the bumper, and customized the front of axle U-clamp with extensions, so that the muffler tip is level to the road as it passes under the bumper:





Of course, the remedy for the muffler created more work at the CAT back area. What I've done is purchased a couple pieces of stainless 2.5" pipe, and will buy a mandrel bend that I plan to section up and then butt weld it all together. Looks like the old man will be learning how to MIG stainless...... skills that will be needed in my future 242 Whiteblock build.

Here's the section that will be modified for a nice smooth flow to that IPD tip:

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Project "cheap thrills" build thread: http://forums.turbobricks.com/showth...67#post4211467

Feedback thread: http://forums.turbobricks.com/showthread.php?t=198746

Last edited by DET17; 08-12-2018 at 08:15 AM.. Reason: coffee edits the morning after
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