Rians Ke70

[B.L.Z.BUB]

Those wheels are cool as.

[rian]

Why thank you kind sir.

[rian]

Just did a diagnostics check, got codes 5 and 9.

 

Which seems to be O2 sensor and speed sensor. Going to get my new O2 sensor now, I'll post up if makes any difference.

[rian]

Also the car is massively down on power about 2500rpm, it has a weird flat spot and sounds really funny. I suspect the catalytic convertor has actually melted so much that it's blocking the exhaust, lol my car is the ~best~.

[rian]

So the old O2 sensor was definitely stuffed. Plugged the new one in, AFR gauge now works (see videos), instead of just sitting on "lean", and the car no longer smells like fuel.

 

This is the AFR gauge at idle:

 

The AFRs jump back and forth as the ECU does it fuel trim thingy.

 

 

 

This is the AFR gauge while driving:

 

If you turn up the volume you'll be able to tell that the AFR is lean under light throttle then goes rich under heavy throttle, whereas it just used to always read super-lean.

 

 

 

 

Sorry about the shitty phone videos.

Edited November 10, 2013 by rian

[B.L.Z.BUB]

 

Sorry about this shitty phone videos.

 

Its always apologies, never 1080P.

[It's_AUDM_Yo]

Nice gauge mount hahehaho

[rian]

So the old catalytic converter is out, and it had actually exploded. There was still a big chunk of catalyst inside that was the perfect shape to block the outlet of the cat, so when the exhaust gases had enough velocity they would push the chunk of catalyst into the outlet and it would act like a plug, I'll get a pic of it soon.

Now that the new metallic cat is in it goes much faster and doesn't rattle, but there is probably still little pieces of catalyst throughout the exhaust system.

 

In other news, I'm about ready to put my 18mm Whiteline swaybar in so I did some quick calculations to figure out how much it will increase the stiffness of the outside suspension.

 

Calculations for old swaybar:

radius = 0.0065 m

yield stress ≈ 300*10^6 Nm^2

polar moment of inertia = (π/2)*r^4 = 2.804*10^-9 m^4

 

Torsion(max) = polar moment of inertia * yield stress / radius = (2.408*10^-9)*(300*10^6)/0.0065 = 129.41 Nm

 

 

Calculations for new swaybar:

radius = 0.009 m

yield stress ≈ 300*10^6 Nm^2

polar moment of inertia = 1.03*10^-8 m^4

 

Torsion(max) = (1.03*10^-8)*(300*10^6)/0.009 = 343.3 Nm

 

 

So by my shitty calculations I should get a 165% increase in torsion with my new swaybar, and if I could be bothered to measure the lever arm of the swaybar I'd tell you what that means in terms of vertical force; maybe I will tomorrow.

 

I'm going to try and go into a bit more detail in suspension properties/characteristics soon, and see what I can learn. I want to make this thread a bit more technical, which may be beneficial if I ever get to the track haha.

 

And for anyone who cares, I found a neat little chart of torsion increases for swaybars of certain sizes: http://www.whiteline...ns/010barup.pdf

Edited December 2, 2013 by rian

[LittleRedSpirit]

Dude has a brain!

 

Cool calcs mate. I can tell you it feels good if you like to slide. Its a much more rigid connection from the rear wheels to the steering wheel.

[B.L.Z.BUB]

A bit different from Altezzas paint can method ;)

[rian]

You guys should have seen how many mistakes I made figuring that out, I'm still not even sure if it's correct haha. KE70Dave or Philbey will be able to tell us ;). The Whiteline technical info I found says I should be looking at about 200% increase in torsion.

[B.L.Z.BUB]

[LittleRedSpirit]

love the ghetto laboratory.

[ke70dave]

Ghetto maybe, but probably the best way to test it.

 

The calcs look fine as far as i can tell, the thing i possibly question is the assumption that the material is the same stuff (yield stress ≈ 300*10^6 Nm^2).

 

Its quite possible the whiteline is made of stronger stuff, which could put your percentage out.

 

At one stage i was considering bolting 2 oem sway bars together, sounds like i might have gotten the same as a white line bar :P

[LittleRedSpirit]

should really be suspended from the mounting points and checked for left to right torsion as thats where the swaybar does its best work for adding oversteer.