T-Bar Merit Badge

[Rasta Monsta]

Giving myself one. DIMED on attempt #1.

I also propose t-bar database. If everyone who installs non-stock t-bars takes one simple measurement, nobody will get it wrong again. . .ever.

Simply measure from the TOP of the banana arm to the CENTER of the hub ("H"), unloaded (off the car).

My contribution:

• TBAR: 22mm, Swapped for 27mm
• "H" MEASUREMENT: Originally 11 inches, modifed to 9 3/8 inches
• RIDE HEIGHT ATTAINED: Freakin' Perfect

Enjoy!

[krystar]

darn..i didn't measure it one mine...but something's better than nothing

Tbar: 30mm
measurement: line up with original scribe mark, then 2 inner splines
ride height: 12" from hub center to top of wheel well.

[SolReaver]

I have no idea what you are talking about. But, IF you were to put a picture in with lines and arrows I would be happy to check it out.

[porsche4life]

Torsion bar...

[Rasta Monsta]

Originally Posted by SolReaver

I have no idea what you are talking about.

Bush voter, seriously considering contributing to Palin 2012.

[porsche4life]

Post of the week!

[slodave]

If this keeps going.... It's going to be in PARF soon...

[smokin_944]

Rasta, how long did the job take you?

[944Spec_bound]

thats a good idea, use a set point of reference for measurement and share it. All the formulas and templates are good tools, but why not simplify it with A to B distances and be done?

1st attempt at mine, car ended up with stiffer bars but exact same height.

My point of measurement was similar to yours. But using the center of the hub had too much eyeballing for me, I wanted it exact. So I used a square, layed it on the inside part of the spring plate, aligned it with the end, and measured to the top of the banana arm.
Like this, I measured where I drew the red line:


My measurement this way:

T-BAR: before 21mm, after 28mm
L-MEASUREMENT: Before, didn't measure it, After 6 1/4"
RIDE HEIGHT: 3 1/2" at rocker with spring plate concentric centered (Raised it to 4" later)

Looks like this now:

[Rasta Monsta]

It took a few weeks of off and on work, my best estimate at this point is 12-16 hours.

Tricky clickie pickies:

[944Spec_bound]

Oh, and the only merit badge I got was this:

[Rasta Monsta]

Hey Spec_Bound, bet your insurance agent LOVES that license plate.

[944Spec_bound]

Originally Posted by Rasta Monsta

Hey Spec_Bound, bet your insurance agent LOVES that license plate.

I hope he never sees it! But I figure I'd call it my Level 1 warning, Level 2 would be horn, Level 3 is #44 comin atcha.
"I warned him," probably wouldn't hold up in court, though.

[M758]

Originally Posted by Rasta Monsta

Giving myself one. DIMED on attempt #1.

By the sound of it you used a little spreadsheet to help out.

Glad it worked out well.

Personally I am 2 for 2 in t-bars.

once from 23 mm to 28

then from 28 to 30.

BTW... my reference measuments are "default" values in the speadsheet.

[M758]

Originally Posted by 944Spec_bound

thats a good idea, use a set point of reference for measurement and share it. All the formulas and templates are good tools, but why not simplify it with A to B distances and be done?

1st attempt at mine, car ended up with stiffer bars but exact same height.

My point of measurement was similar to yours. But using the center of the hub had too much eyeballing for me, I wanted it exact. So I used a square, layed it on the inside part of the spring plate, aligned it with the end, and measured to the top of the banana arm.
Like this, I measured where I drew the red line:

The speadsheet floating around uses the measurement to the center of the hub. The red lines show above are not referenced in the spread sheet and due will not give you the same number due the angle of the trailing arm. Also it is not possible to do a ride height change measurment location at this point without math due to the angle.

That is why I used the center of the hub.

If you want accurace you can used a carpenters square at the hub or use make a piece of cardboard that fit in the CV joint hub. Mark the center of that and use it. I did that when I did my 2nd t-bar job to make it easier. I just never took a picture of it.

[944Spec_bound]

Joe's spreadsheet is an excellent tool, and the pic I used was altered from his original.
So, to clarify, my 1st attempt was hosed because I DIDN"T use the spreadsheet, and tried shortcuts that took twice as long, then had to find a way to make a static measurement.
Sorry, didn't mean to suggest any negative about the spreadsheet.

Do it once, do it right, drop the whole rear assembly, use the spreadsheet!

[M758]

No offense taken.

Im just happy it has worked out. I created that for myself back in 2002.

[Rasta Monsta]

Yep, spreadsheet worked like a charm. . .but like I say, if everyone measures "H" in a uniform way, soon nobody will need the spreadsheet or its multiple measurements.

[M758]

Originally Posted by Rasta Monsta

Yep, spreadsheet worked like a charm. . .but like I say, if everyone measures "H" in a uniform way, soon nobody will need the spreadsheet or its multiple measurements.

Well not really.

The fact is everyone's car is a different weight. The compression of each t-bar is fixed based in the diameter of the bar and a constant car weight. However cars are never the same weight.

My car is 2450lbs or so without driver. Stock curb weight by the book is 2779. So a stock weight car will compress more (requiring a long "H") than my lighter race car.

Not only that I run my car very low, much lower than for a street car. Again my "H" may not bee you "H".

That is why the sheet attempts to determine a baseline spring compression and then figures a delta for the new t-bar. This assumes the weight of the car remains the same pre and post t-bar change.

[krystar]

it would be really nice if the spreadsheet was updated to factor in the 9 and 8.8 degree thing so that u could put in a desired height, and it'd give u how many splines of each u'd have to move to get as close as possible to that target.