What did you do to/for your 1er today?

[Suprgnat]

Originally Posted by chris_flies

Sorry, your explanation, and how I read it seemed to indicate that it would be taken out of effect as soon as pressure was built up to a sufficient level in the hydraulic system, and that the higher pressure piston would be responsible for the rest.

Sounds like it just really doesn't matter...

Exactly. As soon as a whole bunch of fluid quickly fills the "extra" volume created by the larger pistons and "takes up" the pad to rotor gap, the pressure builds and the valve closes and allows the extra fluid and pressure to continue to build equally, in a linear fashion, in both brake circuits.

I'm sorry I'm not explaining this well.

Let's say a 57/42 system with a 1 mm (round numbers) pad-to rotor gap with a 22 mm master cylinder.

The volume of fluid required to close the gap is:

Vfront = 28.5^2*PI*1 = 2551.76 mm^3
Vrear = 21^2*PI*1 = 1385.44 mm^3

Amc = 11^2*PI = 380.13 mm^2

That means it requires 1385.44/380.13 = 3.64 mm stroke to close the gap on the 42 mm cylinder before it starts building pressure.

Meanwhile: the front gap has only closed 1385.44/2551.76 mm = .543 mm.

So now we're building pressure on the rear and the MC piston still needs to move another 2551.76-1385.44 = 1166.32/380.13 = 3.068 mm until the front pad contacts the rotor (remember: round numbers) and the front brakes start to build pressure.

Soft pedal, because the fronts which provide the bulk of the braking aren't engaging fully, and long travel.

The take-up piston quickly fills the 2551.76-1385.44 = 1166.32 mm^3 volumetric difference between the front and rear brake caliper piston displacements allowing the front and rear hydraulic systems to build pressure equally.

[chris_flies]

Originally Posted by Suprgnat

Exactly. As soon as a whole bunch of fluid quickly fills the "extra" volume created by the larger pistons and "takes up" the pad to rotor gap, the pressure builds and the valve closes and allows the extra fluid and pressure to continue to build equally, in a linear fashion, in both brake circuits.

I'm sorry I'm not explaining this well.

Let's say a 57/42 system with a 1 mm (round numbers) pad-to rotor gap with a 22 mm master cylinder.

The volume of fluid required to close the gap is:

Vfront = 28.5^2*PI*1 = 2551.76 mm^3
Vrear = 21^2*PI*1 = 1385.44 mm^3

Amc = 11^2*PI = 380.13 mm^2

That means it requires 1385.44/380.13 = 3.64 mm stroke to close the gap on the 42 mm cylinder before it starts building pressure.

Meanwhile: the front gap has only closed 1385.44/2551.76 mm = .543 mm.

So now we're building pressure on the rear and the MC piston still needs to move another 2551.76-1385.44 = 1166.32/380.13 = 3.068 mm until the front pad contacts the rotor (remember: round numbers) and the front brakes start to build pressure.

Soft pedal, because the fronts which provide the bulk of the braking aren't engaging fully, and long travel.

The take-up piston quickly fills the 2551.76-1385.44 = 1166.32 mm^3 volumetric difference between the front and rear brake caliper piston displacements allowing the front and rear hydraulic systems to build pressure equally.

Ok, now THAT is making sense to me. Thanks!

See, I'd have never known about this little design feature.

[Skotcoop]

Originally Posted by chris_flies

Not for a 128i. The Delphi coils are the latest iteration of the part for our cars.

Oh gotcha.

[Skotcoop]

Originally Posted by ShocknAwe

Coils I recommend sticking with the most up to date OE coils or going with the Precision Raceworks kit.

Extensive testing of all the coil options hasn't shown a difference or need for anything else. wish I could link to the forum where the data is.

Check out Eldor as a compnay and read about the company itself and you'll want Eldors. Its a pretty cool story. They're all about top notch quality and I believe they are made better than the others. Plus my brother recommended I get those when I replaced all mine.

[ShocknAwe]

Originally Posted by Skotcoop

Check out Eldor as a compnay and read about the company itself and you'll want Eldors. Its a pretty cool story. They're all about top notch quality and I believe they are made better than the others. Plus my brother recommended I get those when I replaced all mine.

It's just another supplier. Same as Bosch and Delphi. Story doesn't matter.

Much like lemforder meyle corteco Debi Bilstein and all the rest...

[BMWWorld]

Yesterday I took the rear seat out. It's fun when you forget that the bolts on each side of the brackets has to come out. lol

[schmidtp]

Finally got new RB turbos on along with a bunch of other engine goodies, lowering springs, and M3 control arms. No wastegate rattle and car feels brand new around corners.

[BMWWorld]

Putting the finishing touches on my reshaped forged carbon fiber steering wheel. I'm also working on a forged carbon fiber e-break handle.

[Petro135]

Replaced auc sensor. Weird part is I removed that months ago when i changed to bms cabin filters never threw a code. Hit 4th gear at high rpms, went into limp mode. Next day my a/c was warm. I figured I had a leak. So I put in auc sensor no more codes. Had dye put into a/c. No leaks. Filled it up and it works great.
Not sure whats going on. Lol

[BMWWorld]

Some progress

[WDE82]

Put in the 135 master cylinder. It's not that bad of a job. ISTA D bleeding did not act as anticipated like INPA did with you E46. INPA ran the reservoir from max to min on each wheel by cycling each wheel's circuit. The E82 DSC just gives a few pulses and tells you to press the pedal. Before that you're supposed to pressure bleed it. So...dang. Gonna bleed the old fashioned way tomorrow. Shoulda bought a motive power bleeder (lost my last one).

[dtla1]

Originally Posted by WDE82

Put in the 135 master cylinder. It's not that bad of a job. ISTA D bleeding did not act as anticipated like INPA did with you E46. INPA ran the reservoir from max to min on each wheel by cycling each wheel's circuit. The E82 DSC just gives a few pulses and tells you to press the pedal. Before that you're supposed to pressure bleed it. So...dang. Gonna bleed the old fashioned way tomorrow. Shoulda bought a motive power bleeder (lost my last one).

I've always read that there was an automated bleeding procedure like you mentioned you had for the E46. I've never tried it before but might be useful to try a bit more searching around the forums including e90post to double check?

[Afam28]

Finally was able to perform some maintenance...
Cars been on jack stands for 3 weeks...
Work is starting to ramp up heavily for me...
Anyway:
Power steering drain/refill
Oil change
New filters
Brake pads front/rear

Nice long drive...
No leaks!

[WDE82]

Originally Posted by dtla1

I've always read that there was an automated bleeding procedure like you mentioned you had for the E46. I've never tried it before but might be useful to try a bit more searching around the forums including e90post to double check?

Nah that's all there is. You're supposed to have it hooked up to a pressure and fluid source so when you open that blows valve and activate the pump, it works the air out of the DSC unit. Then you pretty much just let it flow like normal.

[bmw1racer]

Changed out all the coils (Delphi) and plugs (NGK) to (hopefully) correct my intermittent and random engine stumbling.

So far, so good.

[Gray_Panther]

Took my parent's E88 out for fun drive, with the top down of course!

[..Rush..]

Your parents have great taste in cars

Originally Posted by Gray_Panther

Took my parent's E88 out for fun drive, with the top down of course!

[Gray_Panther]

Originally Posted by ..Rush..

Your parents have great taste in cars

Thanks! I have to get it from somewhere

[Gray_Panther]

Oops I did it again.

[b1aze]

Bought AliExpress headers. For $350 shipped with all the hardware, I’m willing to gamble.

https://m.aliexpress.com/item/400087...3dd86075mX0A6J

[Ric in RVA]

Originally Posted by b1aze

Bought AliExpress headers. For $350 shipped with all the hardware, I’m willing to gamble.

https://m.aliexpress.com/item/400087...3dd86075mX0A6J

Please do a thread once they arrive and let us know!!!

[krhodes1]

Originally Posted by Gray_Panther

Took my parent's E88 out for fun drive, with the top down of course!

Is the GTI yours? My '17 Sport, also in white, says HI!

And if it's a 3dr (can't quite tell), I'm jealous!