FSP 1st Gen Protege Project

[FE3-323]

quite interesting.... do you really think the ST bar is needed??? any thoughts about using the 1" 3rd gen escort OEM bar in place of the stocker?

[XelderX]

quite interesting.... do you really think the ST bar is needed??? any thoughts about using the 1" 3rd gen escort OEM bar in place of the stocker?

At this point I really have no idea what to expect once the car is finally driven in anger. The ST bar setup worked well for the previous owner (National SCCA trophy winner), but it may not jive with my personal tastes and driving style. I'll be able to unhook the ST bar quickly in between runs if I needed to test it out without it. Luckily there is a 24 hour event before Nationals this year where I can really play with different setups and run the same course over and over again for data. I'll probably try and find an Escort front bar just to test. I'm assuming it's a direct bolt on?

[FE3-323]

besides some minor bench grinding to the brackets that come with the 1" bar's its a direct bolt in

[XelderX]

besides some minor bench grinding to the brackets that come with the 1" bar's its a direct bolt in

I can handle that. Time to go junkyard hunting again.

[XelderX]

I talked woth the previous owner of the swaybars I'm using and asked him about the 3rd Gen Escort front bar. He did a lot of testing with his EGT and determined that the 1" Escort front bar is actually more bar rate than the stock bar + the ST add on bar. He didn't want to add anymore bar rate to the front of the car. I'm hoping that attaching the stock LX front bar to the strut instead of the control arm will increase the bar rate enough that I can remove the ST bar.

[FE3-323]

i don't know how he came to that conclusion but whatever

[XelderX]

i don't know how he came to that conclusion but whatever

I'm going to do the math on it tomorrow. There are specific equations for figuring out the bar rate. A very small increase in diameter causes a huge jump in bar rate. Plus the ST bar does not add as much bar rate as people think it does due to the huge distance between the pivot point of the bar and the attachment point on the control arms. Hopefully, I'll have something a little more definitive tomorrow.

[XelderX]

I just did some quick math and the EGT front bar is almost twice the bar rate of the stock LX bar. The geometry of the ST add on bar makes it's bar rate very, very small compared to the stock bar. I'll try and get some more concrete #s tomorrow.

[XelderX]

Ok....tons of math. I calculated the bar rates in lbs/in for the front swaybars I could find the diameters of. The stock motion ration on the BG is around .5:1. With my stock front bar hooked to the strut I get a motion ratio of around .75:1. Here is a quick list of the bar rates...

Stock 22mm front bar w/ .5 MR = 109.49
Stock 22mm front bar w/ .75 MR = 246.35
Stock 19.1mm front bar w/ .5 MR = 62.2
Stock 19.1mm front bar w/ .75 MR = 139.96
Susp. Tech 19mm Add on bar w/ .5 MR = 48.89
Escort 1" front bar w/ .5 MR = 194.55
Escort 1" front bar w/ .75 MR = 437.74
The stock 22mm bar plus the ST bar = 158.38

Hooking up my stock bar to the struts means I can get rid of the ST bar. I can nearly make the same bar rate of the stock/ST combo with just a DX 19.1mm bar hooked to the struts.

The Escort 1" bar is 77% stiffer than the stock LX bar and 212% stiffer than the DX bar.

[wheresthericego]

good info is good

[FE3-323]

very very interesting how does one calculate the motion ratio??

[XelderX]

very very interesting how does one calculate the motion ratio??

Its the ratio of how far the wheel moves compared to how far the swaybar moves. I measured the distance from the ground to the end of the control arm and the distance from the ground to the end of the swaybar. After that I just jacked the wheel up 1 " and then measured how much the swaybar moved. Connected to the control arm the swaybar moved .5". Connected to the strut is moved .75".

[therieldeal]

considered making similar calculations for the rear, at all?

[XelderX]

considered making similar calculations for the rear, at all?

I can, but I didn't measure the motion ratio for the rear yet. if I use .5:1 like the front here are the #s.

Stock 20mm rear bar = 203.17 lb/in
Quickor 1" rear bar = 528.54 lb/in

That makes the Quickor bar 160% stiffer than stock

[XelderX]

Not much to update at the moment. I've been working on another project, but I did manage to get the front brake rotors done. I'm happy with the way they turned out. These are Wearever blanks that I drilled and then turned down to .010" over minimum. They started out at 11.3 lbs each and they are now 9.3 lbs.



The Megasquirt and all the associated wiring should be here in a few days along with what I hope is the correct radiator. Next week should be a good one.