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The Atom and Quantum GP700 have transverse gearbox layouts as well so I understand the problem. However no LSD is not the solution IMO as you just spin wheels without drive. With both cars I have experimented with rake, anti squat, front and rear roll centers, track settings, shock valving and wheel rates finding good balance with clutch LSD's. I changed the Atom and ran a Kazz LSD but the Quantum runs a Holinger and the ramp angles are soft. Good turn in can be found with wheel alignment settings, mid corner with a balance between front and rear roll centres, rake and ride height.

I also made a bell crank + linkage between the throttle cable and accelerator pedal to create non linear throttle cable movement. Also 4D ignition retard tip in settings with lateral G dependance. This chassis development setup has take 5 years. Handling now is hard to fault with amazing turn in, mid corner balance and corner exit can be slight oversteer or slight understeer depending on the corner speed, traction control and driving style, etc.

Reducing drive grip is not the best solution IMO.
 

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Arouse the DAMPFHAMMER!
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Discussion Starter #802
...I changed the Atom and ran a Kazz LSD but the Quantum runs a Holinger and the ramp angles are soft.
Thank you so much for your experience report jaydee. So both are clutch type LSD. Mmmmhhh...I see your point. I will give it a try.

A late review of the status quo:
Challenge 1: the engine rang violently at full load. I had already turned the ignition back to 2 ° KW v.OT and almost dropped from belief, either that was my DAMPFHAMMER technology on the exhaust side or we are chasing after a wisp.
Issue found, the DAMPFHAMMER intake pulsation is about 130 mbar, making adjustments like guessings. Solved it by an damping of the path to the MAP sensor. The only thing I have to calm now is the fuel pressure regulator. I will disconnect this from the plenum and connect to atmosphere. The fuel injector model will work anyway correctly. What I can't calm without any Resonance Damping, is the plenum side of the injector. With that I will cope next. From the data I saw the cut of oscillation will be at least 50 % in the lambda. We will see if this is enough. Beside that, the 5000 rpm resonance is not the only one, but maybe the toughest.

Challenge 2:
the MAP oscillated at full load with up to 12 mbar and was therefore not easy to catch / coordinate.
Sorry, not 12, it was 120 mbar, I found values up to 130 mbar, which is a 1/10 of the total MAP! But I solved the issue, a reduction to less then a 1/10th is achieved, I saw 1-5 mbar later on.

Challenge 3: at 4000 rpm, the lambda probe began to make lean jumps of 0.4-0.8 s in length...
The lambda value oscillation was caused by a oil pressure limit protection. I lowered the limit, now there is no fuel cut anymore. I didn't expect to have only 3 bar of oil pressure at 4000 rpm. I checked the oil pressures over the engine speed and updated the protetion table. Now it's fine.

Challenge 4:
the parameter "NewVE", which suggests the probably correct degree of delivery due to the measurement, did not work properly and I was unable to clearly analyze the cause of 1st, 2nd and 3rd
I programmed an equation which is more precise.

Challenge 5: Injector # 4 or # 3 seem to be leaking
Changed to RDX, because they have the bigger (= right fitted) O-Rings. I will change the ID's O-Rings.

Challenge 6:
the LL-MAP is getting higher, initially we were at idle (LL) at 26 kPa, now at 36 kPa
We set Helicoils into the TB flange on the plenum side. Now it is sealed again. Issue was one thread was damaged by an to long screw.
 

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Arouse the DAMPFHAMMER!
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Discussion Starter #804
Next week the DAMPFHAMMER will came home. Working progress on the Engine Dyno Room are progressing.

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Insulation is in, I placed the humidity-membran yesterday. So we are ready to close the wall with sterling boards. You see in the last picture the Schenk e2-180, which will be fitting to my K16 Hayabusa killer project, 260 hp minimum up to 11,000 rpm. ROOOOAAAAHRRRRRRR :p!
 

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Arouse the DAMPFHAMMER!
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Discussion Starter #806 (Edited)
Are you building a dyno cell at home?
A friend of mine owns it, I help him to build it up. We want to do some decent race engine development. Around 11/20 we will have finished it and we will be ready to tune with it. Next week after the Lotus arrived, we pull the engine out of the chassis to repair the gearbox and to build up the engine carrier to connect it via shaft to the dynometer.

There is a lot of work to do until that. To build the 86x68 engine I have to collect the parts up. Block assembly is already inquired, around 8 k€ to prototype the crankshaft, rods and pistons. Head will be a development challenge. Then the Drag engine, a...
 

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Re: Update

Not yet Martin. Welder is busy and postponed finalization. I will clarify this with him today.

Intake Manifold:
The DAMPFHAMMER IM looks assembled like following. Now the RDX injectors are a nogo color-wise. Chrom it would be no issue…

View attachment 99955

Brrrrr...blue injectors and this red?! I have to tape them with black foil with heating scratches :D.
Just passing by to see if you have finally dynoed the car with the intake manifold to see what numbers you got.

I recently started working in mine again, but it will be a while.
I am having it 3d printed for fitment and then will do the final version after all tweaks are performed.
 

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Arouse the DAMPFHAMMER!
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Discussion Starter #812 (Edited)
Just passing by to see if you have finally dynoed the car with the intake manifold to see what numbers you got.
Before the gearbox broke at around 5250 rpm the DAMPFHAMMER made 202 ftlb (274 Nm) of torque at flywheel. A bit more as my simulation forcasted.

Unfortunately it broke before we made WOT runs, I was still in the phase of tuning cell by cell on stationary operation. I was asking my dyno operator where we are torque-wise and he told me around 245 Nm at wheel, which relates to about 274 Nm at flywheel. So yet no dyno print. Next week on Monday my car will come back home. We will pull the engine and gearbox, the first will be stored till engine dyno room built is finished and the second will be repaired.

I am having it 3d printed for fitment and then will do the final version after all tweaks are performed.
Great! What kind of printer and material do you use for the clearance testing? What kind of material will the final consists of?
 

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Arouse the DAMPFHAMMER!
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Discussion Starter #813
Yesterday I finished my knock onset calculation model. It is based on a Livengood-Wu-criteria and a RON/MON based Arrhenius-approach, which calculates the self-ignition delay. I've validated it with my DAMPFHAMMER engine dyno measurement operation point: 274 Nm, 124 % VE, 5190 rpm, 23 ° VTC, lambda of 0.88 and a 26,9 °ca BTDC ign. timing. At least the model aligns with the dyno observation. The interesting point was the engine efficiency was there at 34,2 %



which is pretty impressing, as latest TC gasoline engines can't beat it significantly at WOT conditions without help of hybridisation. It's just a NA engine. Typical K20 I see around 30-32 %. The GM based C20XE I4 engine, which was one of the best efficiency engines at it's time and for long after it reached under Lambda 1-conditions 38 % at best point in higher part load and lower engine speeds. I couldn't run 40° VTC as knocking was so massive, so I had to lower VE by retarding the cam phasing (VTC) to 23°. Next time I will test full VTC and lower ign. timing and maybe alcohol to see the full potential of it. The capability of that little engine is amazing.
 
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