Maximum Motorsports S197 K-Member

[Tob]

It isn't easy. The idea to get the tie rod and the control arm to be in parallel planes (I know I'm simplifying here) isn't overly complicated though. The issue is that you can't see the axis of the ball joint (if you have a fairly adept mechanical understanding you ought to be able to come pretty close though). However, if you follow some of the writeups on it you see that some rather small spacer changes can have a fairly large impact on it. As much as I tried to be pretty exacting when I did the alignment I'm pretty happy so far just following Maximum's general recommendations for bumpsteer. Here's a look at where I was vs where I am now.

And Roger, while cleaning up the memory card on my camera I noticed some files I had never processed. Here's a few of the GT500 engine mounts fastened to Maximum's billet blocks.

 

[Catmonkey]

Tob, is your car lowered or sitting on the original springs?

 

[Tob]

FRPP 5300L springs.

 

[Catmonkey]

That makes sense. I wouldn't have expected the tie rod end to be lowered as much for stock springs. My front end is still sitting on the SVTPP springs.

 

[Tob]

Remember, the inboard LCA pivot elevation was changed with Maximum's K.

 

[Catmonkey]

Yes, I'm just not sure what that does to the suspension geometry. If your car wasn't lowered, there's not much more adjustment to lower the tie rod. Does the revised pivot location affect ride height?

 

[rdanzy]

Tob,
Thanks for the pics. If I decide to put the motor mounts under the brackets I will also use a safety bracket to retain the mount in the event of bolt failure. Thanks for bringing up that FME.

And Roger, while cleaning up the memory card on my camera I noticed some files I had never processed. Here's a few of the GT500 engine mounts fastened to Maximum's billet blocks.

 

[Tob]

Yes, I'm just not sure what that does to the suspension geometry. If your car wasn't lowered, there's not much more adjustment to lower the tie rod. Does the revised pivot location affect ride height?

Tire/wheel combinations aside, the springs are what is driving the ride height, not inner pivot location.

When you lower an S197 up front you are essentially shortening the distance between the wheel axis and the strut tower top. The front control arm is rotating upwards at the spindle but the axis it rotates on (at the K-member) stays the same which causes the camber to become more negative. Among other things, it also has an impact on the front roll center. Take a look at the following sketch (disregard the "Fox" style spring location for a moment) and note how the slope of the front control arm changes after lowering the ride height via a spring change, etc.

As the spindle is moved upward the instantaneous and roll center deviate from the stock location. By raising the inner pivot at the K-member (in this case either 5/8" or 1-3/8" higher than stock) on a lowered vehicle you better optimize the camber curve as well as the roll center. Read the following link through a couple of times. You'll see the importance of roll center height(s) by the last paragraph and better understand what happens up front as well as where you would be with a panhard bar or a Watts link and how the front and rear are related.

http://www.miracerros.com/mustang/t_rollcenter.html

Tob,
Thanks for the pics. If I decide to put the motor mounts under the brackets I will also use a safety bracket to retain the mount in the event of bolt failure. Thanks for bringing up that FME.

You got it Roger. I figured you'd have a plan in place...

 

[Catmonkey]

Got it. Thanks!

 

[Jack Hidley]

To add to what Tob posted on bumpsteer, see my post linked below.

The bottom line is that if the car is lowered, and then realigned back to the original alignment, there will be virtually no difference in bumpsteer.

http://forums.corral.net/forums/8565296-post36.html

 

[SCGallo2]

The bottom line is that if the car is lowered, and then realigned back to the original alignment, there will be virtually no difference in bumpsteer.

Thanks for confirming that Jack. After reviewing your bump steer kit installation instructions and graph on page 11 (link below), I came up with the same conclusion. You also get less suspension travel on a lowered car, which reduces bump steer in itself. I performed a DIY alignment over the weekend, using stock specs and all is well, though I have not pushed the car hard in the twisties yet. I doubt that I could feel the difference on the street anyway. I have pushed the car hard while on the stock suspension, and it had just enough understeer to keep the back end from rotating around during high speed cornering, which is good for rookie road course drivers.

http://www.maximummotorsports.com/Assets/install/pdf/steering/Mm5TR-2.pdf

 

[OsirisGT]

I know it's been a bit but I got up to see the car. Took two pics.

 

[Tob]

Are the welds to repair damage or simply to strengthen the chassis? And are you going to pull the sheetmetal back into place?

 

[OsirisGT]

Seam welded the entire car for road race. I' not sure exactly what they are going to do but I was told they were going to plate it before the k member goes on

 

[BMR Tech]

Tob, check it out

http://www.svtperformance.com/forums/showthread.php?1002387-I-can-t-find-the-rattle

 

[Tob]

How the hell did I miss that thread?!

 

[Bad Company]

How the hell did I miss that thread?!

LOL......I thought the same thing after seeing Kelly's link to the thread. I think it has to do with the thread title and your mind saying I don't need to read about an annoying rattle and skipping over it

 

[Tob]

I think it has to do with the thread title and your mind saying I don't need to read about an annoying rattle and skipping over it

I totally agree with you. Wait...I'm not supposed to do that. Profiling thread titles infers assumption and stereotyping and that would make me a thread racist!:-D

 

[RedVenom48]

SICK looking build there osiris! Thats awesome... that shop is like a mile away from my dads house. Seems to be alot of great race shops here in SD. I like it!

 

[OsirisGT]

Swing by, check it out, give them money!