[MOD] 42056 - Ultimately playable Porsche 911 GT3 RS

[Didumos69]

Didumos69, isn't the original Porsche has positive rake angle?

I look at the original pictures (as mine is already heavily modded, mostly with your suggestions) and it has positive rake angle too.

So rear ground clearance HAS to be more than front ground clearance so that the Porsche nose is pointing downwards (as the floor of 42056 is perfectly flat).

Currently I tweak the rear suspension about half stud from the stock version as I put 2 heavy >< battery boxes at the back. My front clearance is 1 stud, back clearance 1.5 stud.

I took a testdrive tonight and it was clear there is currently not enough downforce, so I think you're right, the lack of rake angle must be the reason .

(I'm thinking of doing somehing like this video as my presentation for the rebrick contest...)

Back to the drawing table...

Edited July 13, 2016 by Didumos69

[stevenhalim]

I took a testdrive tonight and it was clear there is currently not enough downforce, so I think you're right, the lack of rake angle must be the reason .

(I'm thinking of doing somehing like this video as my presentation for the rebrick contest...) Back to the drawing table...

Good presentation video, clearly showing the manual play-ability of your modifications so far :).

PS: I know you have invested lots of time modifying this set, so just apply the stickers... I don't think you will disassemble it anytime soon.

Yeah positive rake should help. This one (yours) looks flat (and that rear wing is too aggressive at that angle.):

This one has positive rake. My PF mod doesn't look like this as mine currently back heavy (2 PF battery boxes + 2 XL there ><), but I have modified the rear suspension so that the back still about half stud higher than front.

And regarding your other question about gears that only have half-stud axle to support them popping out from its place if I do 2*L through the gearbox...

I haven't do any other bracing around those gears, but I guess even after I brace that, another weak point(s) will appear under heavy torque.

Another weak point that I have spotted is the CV joint at rear axle.

This CV joint

will pop out from

at rear axle under heavy torque (of 2 * hard coupled L motors, without white clutch gear)

Currently I replace those with universal joint

which appears to be stronger

That same CV joint does not pop out from this though, and I need the second CV joint for some play when rear suspension is compressed/not compressed:

as this part helps protect the connection

So my setup is 2 hard coupled L on 2 BB (it is crawling with just 1L and frequently stall if just 1 BB -> 2 L motors) --> differential --> U joint (the CV joint here breaks under heavy torque) -> CV joint (so far fine) -> wheel

After few nights of running on dummy race track using chairs and dining table (using 9398 PF controller style -- hence my 2 * L setup), this U joint part hasn't break yet so I am currently at this solution.

[Didumos69]

@stevenhalim, thanks for your feedback and clarifying the breaking issues. The CV-joint is indeed quite weak and there is al lot of difference between individual instances. Some sit tight and some drop out even when shaking.

I will certainly apply the stickers and I also have a better dash gear indicator in mind for the video. You are right about the rake angle and I will certainly fix that soon.

Edited July 14, 2016 by Didumos69

[brunojj1]

Another weak point that I have spotted is the CV joint at rear axle.

This CV joint

will pop out from

at rear axle under heavy torque (of 2 * hard coupled L motors, without white clutch gear)

Currently I replace those with universal joint

which appears to be stronger

I made the same experience with CV joints / U-joints under heavier torque such as 2 x XL or 2 x XL + 2 L motors combined at the drivetrain. The female part of the CV joint uses to wear out quickly under heavy load because it´s out of softer plastic which feels almost like rubber. The U-joints are surprisingly strong and don´t crack as fast as the older ones did. Also at smaller scale there was the problem that axles shifted out of the differential when suspension´s arms are not in horizontal position or is decompressed too much. At 1/8 scale you can eliminate this issue because of the much more realistic suspension´s pivot points far away from the center.

@stevenhalim, thanks for your feedback and clarifying the breaking issues.

...

Hats off for your endless efforts! Are you being paid by TLC for your almost 24h work? If not - they should grant you 10 sets for free at least..

[Didumos69]

Hats off for your endless efforts! Are you being paid by TLC for your almost 24h work? If not - they should grant you 10 sets for free at least..

Thanks! No, I'm not being paid by TLG. It's actually the other way around, I paid them 300 euros . The point is that I have a deadline. End of next week I will be off for vacation for three weeks and I want to enter the rebrick contest with this. I'm affraid I will be completely reset and have forgotten all about the Porsche after my vacation...

@stevenhalim, is this better or is it too much? The clearance difference between front and back is approximately 0.8 studs. I used the stock geometry and only lowered the point where the shock is mounted to the chassis by half a stud.

Edited July 14, 2016 by Didumos69

[phattyg]

Maybe because of the 361 extra parts - and counting - that I added,

Would love to know the list of those parts for the ultimately playable version before you head off on vacation

[stevenhalim]

I made the same experience with CV joints / U-joints under heavier torque such as 2 x XL or 2 x XL + 2 L motors combined at the drivetrain. The female part of the CV joint uses to wear out quickly under heavy load because it´s out of softer plastic which feels almost like rubber. The U-joints are surprisingly strong and don´t crack as fast as the older ones did. Also at smaller scale there was the problem that axles shifted out of the differential when suspension´s arms are not in horizontal position or is decompressed too much. At 1/8 scale you can eliminate this issue because of the much more realistic suspension´s pivot points far away from the center.

Noted brunojj1. I will keep that U-joints solution for rear axle then.

Hats off for your endless efforts! Are you being paid by TLC for your almost 24h work? If not - they should grant you 10 sets for free at least..

Agree, I hope you win one prize of the Porsche contest.

Many people will want to apply your list of modifications to their 42056.

The positive rake angle at latest photo is good enough :).

[Didumos69]

Your efforts are very much appreciated! I have had my Porsche sitting and waiting for this to be completed so I can build it. Are you still going to making BI / erratum sheet for all the changes to make it even easier to apply them?

I just posted a new topic with a link to errata and a parts list for all 'miison-critical' MODs. Hope you have your Porsche still sitting and waiting

Edited July 15, 2016 by Didumos69

[ddeklerk]

I just posted a new topic with a link to errata and a parts list for all 'miison-critical' MODs. Hope you have your Porsche still sitting and waiting

Just a heads up, your link is not working. You are missing a colon.

[Didumos69]

Just a heads up, your link is not working. You are missing a colon.

Thanks. Fixed it.

I actually want to tweak the front suspension, but my son is playing with it for over an hour already

Edited July 15, 2016 by Didumos69

[Didumos69]

Would love to know the list of those parts for the ultimately playable version before you head off on vacation

I will post the LDD-file and parts list before I will head off for vacation.

I'm still not completely satisfied about the front suspension. It can carry the weight, it's actually fully expanded despite the weight, but even then the front ground clearance is less than a stud. The suspension simply doesn't expand far enough.

So I will try this tonight. If it's equally strong it will give half a stud extra clearance.

[lcvisser]

Hats off for your endless efforts! Are you being paid by TLC for your almost 24h work? If not - they should grant you 10 sets for free at least..

I think Didumos69 needs a badge. Or at least a subtitle. "Porsche Perfectionist", or something like that

[Didumos69]

I think Didumos69 needs a badge. Or at least a subtitle. "Porsche Perfectionist", or something like that

That would be too much, but thanks!

This is what I did:

And ithe front clearance is perfect now:

This is how it was:

Edited July 15, 2016 by Didumos69

[Didumos69]

Here's an update of my most recent modifications to the front and rear axles to get the ground clearance and rake angle right..

For the rear axles my MOD boils down to simply replacing the parts that mount the shocks to the chassis. This brings the rear half a stud up and helps compensate for the extra weight that comes with the extra parts that I used:

For the front axles I'm very satisfied with my last changes (see previous post). This setup still includes Ackermann steering and a slider for the gear rack. It also secures the suspension arms much better and adds a second (push rod) shock on each side. The LXF-file with the front axles can be downloaded here.

Edited July 18, 2016 by Didumos69

[stevenhalim]

For the rear axles my MOD boils down to simply replacing the parts that mount the shocks to the chassis. This brings the rear half a stud up and helps compensate for the extra weight that comes with the extra parts that I used:

Ah this is what I basically did too with the rear axle.

I will copy your second shock at front axle (that push rod idea) :).

[Didumos69]

Ah this is what I basically did too with the rear axle.

I will copy your second shock at front axle (that push rod idea) :).

My setup makes use of the full length of the suspension arms to eliminate bump steer. You could also add the push rod idea to the stock build, which would make the suspension even more hard, see this post.

[Didumos69]

And finally, before I finish up this project, here's an important mod to box 2 to better secure the top side of the panel in front of the rear HoG gears:

Before:

After:

[Didumos69]

Time to deliver. Here's the video of my ultimately playable version for the Rebrick competition:

And here's the LXF-file showing the differences in terms of groups: In each group there is a subgroup representing the old structure and the new structure. Both new structures and old structures are embedded in a version of the chassis. By clicking on a group or subgroup you select all parts in that group. That way you can inspect the differences.

Enjoy!

P.S. Sorry, didn't have time for stickers

Edited July 18, 2016 by Didumos69

[Didumos69]

And extra parts list for the ultimate version:

EDIT: Just updated the list.

Edited July 18, 2016 by Didumos69

[phattyg]

You're the best, Didumos. We are really grateful for this! Enjoy the vacation, well earned!

[Didumos69]

You're the best, Didumos. We are really grateful for this! Enjoy the vacation, well earned!

Thanks! It's a good feeling to have finished this before going on vacation .

I updated the list, apparently there were two gears missing...

I entered the rebrick contest with this description:

The looks of the Porsche 911 are timeless. It's what's inside that evolves continuously. The same is true for the 42056 Porsche 911 GT3 RS set. Hence this ultimately playable version.

Response from Rebrick contest:

Unfortunately we’ve had to remove your entry into the Build the Porsche of Your Dreams Contest, as it is not an original model you created yourself. Only unique models designed and built by participants are edible in the contest.

If possible, you can still build a unique model and submit it into the contest before August 1st. If you feel there has been a mistake or have further questions, please contact us at ReBrick@lego.com.

Sorry for the trouble,

Edited July 18, 2016 by Didumos69

[phattyg]

Well that response is just a giant middle finger...

And to not even mention the improvements made on their suboptimal product is not fair

[Didumos69]

Well that response is just a giant middle finger...

And to not even mention the improvements made on their suboptimal product is not fair

I don't bother too much. Apparently it's a contest based on 'what something looks like', not on 'how something functions'. Has little to do with Technic in my opinion.

[suffocation]

[...] Only unique models designed and built by participants are edible in the contest. [...]

I'm glad I'm not on the judging panel - I've never been too keen on ABS sandwiches.

[stevenhalim]

Wew, sorry to hear that your excellent entry is not allowed :(.

Your work for these set 42056 improvements is clearly beneficial for this community judging from the high number of views in this and the mods/improvements thread.

I personally thank you for that.

And enjoy your holiday.