This weekend I assembled the gearbox but before mounting it on the car I decided to check the clutch disks, I was very surprised when a saw the following :

hummm looks like a tiny crack


two of the holders just fell off


looks like the splines took a beating





So, now I'll be making a sold slightly thicker holder for the clutch plates which will be riveted to the center section .

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Had some free time so I made this for the clutch disks (designed in CAD and laser cut).

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

That is going to be a short lived and very finicky clutch. There is a reason for the air spaces between the clutch pads. Gotta disperse the heat somehow and without the air circulation the only way is by heat transfer through the flywheel.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

I realized that and have made the necessary modifications by adding straight cuts ending in round openings/spaces in order to avoid cracking .

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Here is the modified design .

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Make it light as possible. There has been broblems whith syncros when for example multiplate cluths is been used. added inertia makes gear sifting time longer.

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500whp.net

The car is back on the road, the gearbox and clutch are working perfectly. While the car was in the garage I also installed the old turbo, here are some test performed with an app called perfexpert (supposed to calculate hp at the crank)

t66 turbo


Current turbo


comparison


And an acceleration run

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Installed the new turbo in the car. It's actually the t66 that I tried a while ago but this time with a smaller AR (0.82) on the turbine housing .

Here are the results :






Small video test the turbo going uphill

190E 3.0-24v turbo - YouTube

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Awesome. What was the boost pressure on these runs?

Edit: Saw that it was 1Bar.

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1993 190E 2.6 Sportline

Yes , boost is around 1 bar and the trap speed at the end of the 1/4 mile is ~194km/h(120.5mph).

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Sort of.

The spaces are there ( and the wings so thin ) to produce a Marcel spring. This allows for a greater engagement window so the clutch isn't an on off operation.

Look at the edge of a disc and squeeze it like the flywheel and pressure plate would. This makes the disc look thicker and smoothly compress as it starts to engage.

The major cause for failure on this app is trans to engine misalignment, Spring center discs have a floating center hub to cushion torsional vibration and to take up minor misalignment where this disc is solid.

Look at the sides of the splines, fretting is very heavy for the amount of time on the disc. The base of the splines is rolled over on the outer diameter. This points to a angular misalignment rather than a coaxial misalignment though you might have some of that as well.

This angular misalignment also causes the disc to flex, act like an auto trans flex plate and eventually crack because it is thin and relatively hard. ( The high torque does not help either. )

Updated the comparison graph with the new turbo (t6682 - green lines, same boost level).

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

Joreto,

what was the original AR of your t66 turbo before you changed to 0.82? Thanks

It's time to address the rear end of the car (diff, axles etc.). I'll be converting to a BMW diff and axles, main reason LSD, cheap and easy to find, unlike LSD for a mercedes.

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190E 3.0-24v (M104 980) turbo @ 0.8 bar
1/4 mile: 2.483 / 13.540 / 175.17 km/h (street tires)

It is a Mercedes. It is not supposed to be cheap and easy. But it is a good upgrade. I have a few customers using the BMW differentials in the w123 chassis. You should do what I am doing and painfully research different Mercedes parts until you are blue in the face to come up with expensive parts that are hard to find.