R26.R R26 better lower control arms - chapter 2

Hello guys,

I don't know if I'm happy or upset that my project and comment made so much stir in this small community. Before I could look again, there were 2 extra pages of comments here with people fight. I'm happy everything ended very fast and it seems we are all ok after this. I need to say that, if we get to a point where we flame each other, it will be even worse than just not doing anything.

I will try a small introduction of my own. Unfortunately, I'm not an aero engineer like most here. But I'm a guy with a looot of connections. My main business is engine calibration and engine development which I'm doing for the past years with some patents on the go and all kind of R&D in automotive area. My private business in Romania is a small tuning shop where we build all kind of bespoke racing vehicles. I'm not scared about parts not being available for my car and this is one of the reasons why I choose to buy myself a Megane RS. If I would like a phetora or available parts, I would park a VW GTI on my alley. But I'm not the guy that takes the polished path (and I believe this is what EVERY engineer should do!!!). Also, I have a passion for product development and manufacturing process and this is an exercise for me.

When I'm saying connections, it means I worked in Renault for a couple of good years and all my friends (which all worked for various things in Renault) are now in UK (better jobs here it seems). The whole arm product is conducted by me, but made with a couple of friends on board. The arm itself is designed by my wife (former Airbus A380-800 engineer, Renault part designer and now JLR design engineer). The design itself is corrected by our friend which is a designer (that guy that cares about how the parts looks more then how they perform, just because I want to have a nice part carrying my name). The analysis is made by a team of 3 guys specialised on suspension systems, 2 of them having PhD in suspension testing and simulation (anyone interested in reading some hundred of pages about this subject???) and 2 of them were the people actually designing this shitty part (ask me how do I know our lower arm really flex???). The production is intended to be made in Romania in a shop we own in order to keep prices as low as possible (don't know how important price is, just for 1 or 2 sets, but is everything about exercises). Because we all are trained by Renault at our roots to keep price under-control, we need to push the manufacturing process at its top. This is why we cannot apply the solution that Milos offered.

Because we are OEM engineers and not F1-roots engineers, we are not looking to build the absolute best part possible with money-no-object mentality, rather to tilt the balance a little more towards performance rather than cost.

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I want to thank everybody who offered help here and I will try to use it. So, we want to make some small youtube clips from the simulation it self and post them here, so anyone can come with they're ideas and opinions (we accept only the technical ones) and see if we can improve our product even further.
Also, I will let midnightrunner think what tests he believes are the most important for this part and send him a prototype when they will be ready.

Unfortunately, the thing we lack the most of, is TIME and because we all do it out of passion, curiosity and craziness, we are not fast at all. But something will come through in the end.

Thank you everyone for support!

S.

 

Midnightracer, I tried to answer your message regarding your help, but your mail is full. I will resend the message tomorrow.

Thank you,
S.

 

Ok,

I managed to find some spare time to upload the simulations.
You will see first a displacement test between the original arm and my variant. Keep in mind that the original arm is actually the production CAD and not something made by us, we just used that for the simulation. The material used in the simulation is also correct. Original arm with the correct material characteristics and our arm with our metal characteristics. The forces used are the same and the colour scaling is also the same. And green is good, red is bad.
Our goal was to dissipate the bending energy from a single point to a more broad surface and we consider we touched our goal.





And here is some von Misses stress distribution.





The simulation and testing was more in-depth than this 4 pictures and I hope you are aware of this. But I just wanted to present a couple of images. This way, some of you will understand why you cannot make the OEM arm better by welding some gussets on (someone said this earlier this thread).

To cut any discussion short, we know our simulations are not correct and you all could made them much better and that we are crazy to use such parts on our car which can and will put us in a ditch, but we accept this and we are going to build the first prototypes.
Although, in case you can come up with some clever ideas, please feel free to express them.

Next step is to come up with the best production process to minimise the costs. We overtake the american style idea of CNC them out of a engine block size billet stock for a 10% build efficiency. We want something more efficient and less expensive. Until we finish the first prototypes and we see how much work they involve, we don't have a price yet. So stay tuned.

S.

 

Sorry everybody for being out for so long, but some changes in my life kept me out of this. I still need a week to become completely functional and restart all my daily activities. My car is still crying after this arms.

S.

 

Everything is better
Miss just become Mrs and a dog sharing my name from now on. And also a new car in the shed to accompany all this changes.
When I will find some time, I will also present my new price and joy.

S.

 

Hello,

Finished welding and painting them. Next week I should pressfit the ball-points and hopefully on the car shortly.

I'll keep you guys updated.

S.

Sent from my E6653 using Tapatalk

 

Hello all,

Where it ended...?
I made 2 sets, one for my car and one for a friends car and I’m using them for 3 years now. There was 0 interest for people to actually put some money down. They were interested but not completely sold on this or the need for this part and combined with a lot of ney-sayers “the car goes fast enough, you can’t do it better than Renault...” sort of thing, it didn’t took off.
I realised RS community is not very open to new ideas. Is happy to walk of paved ground and thats about it.

I went further down the line with the mods on my car (suspension wise) but I stopped posting for the same reason.

S.

 

My plan was to move to uniball joints all around on the front and my fear was that the arm will flex a lot once the rubber bushes are gone. Now there is no rubber left almost anywhere in the suspension with some diesel specific springs and shock tuning.
I also changed caster by 2 degrees, getting to where Megane Mk3 is.
I got to that race car feel I was after but still able to daily drive it where needed. And the fact the wheels are still attached to the car for me shows the stiffening does the job. Is very hard to assess the arms in separation.

S.