I have a new idea...

[wytbishop]

While working on the suspension last night I was thinking about the value of the active rear suspension. I don’t think it’s really all that useful and makes the suspension in the rear quite a bit less rigid. I want to know what the car would feel like with a totally rigid rear suspension. Instead of Twin Trapezoidal Links, a single Rear Lower Control Arm such as almost every other car on the planet has.

So I drew this up.



Based on the tubing sizes needed and the approximate lengths and stuff I think it would weight about 2.5lbs. It would be significantly stronger...many times stronger and more rigid. I drew it with a mounting tab for the sway bar to bolt directly to the arm rather than using a link.

I have an old picture of a set up that was used years ago by an older member with tubular lateral links and spherical end links everywhere. It was totally rigid. He reported that it worked well but was very noisy. I think that the bushings are not the weak link in the system. It’s the flimsy lateral links and the active suspension that need to be corrected.

I am going to build this and see how it works. Assuming that it was tested and gave an improvement in handling, I’m curious to know if other people would be interested in having something like this.

[Evo_Spec]

sounds very interesting, i'd like to know how the testing goes and maybe a set if all goes well

[onlytrueromeo]

Well considering I just spent money on softer bushings to improve the active rear suspension, along w/ new endlinks, I wouldn't jump on board for a GB...This is interesting though. If you're concerned about rigidity of individual parts, beefing up the thickness of the arms would work, rather than just converting to a solid control arm. You are right - most cars DO use this, but then again, most cars can't handle as well as the mx3. Performance cars usually utilize a double wishbone suspension to achieve the best overall handling and camber gain. This has got me thinking now too though, haha.

Everyone should read this and understand also that most driving is technique.
http://www.tamparacing.com/forums/chass ... uired.html" onclick="window.open(this.href);return false;

[onlytrueromeo]

Oh, and for those of us that want to eventually go AWD design this for me (J/K I'll prob do it myself within the coming years if I don't get sidetracked by my other hobbies)

http://www.corvetteactioncenter.com/for ... nsion.html" onclick="window.open(this.href);return false;

[wytbishop]

Well I'm not really sure what the result would be. I've been thinking about it for a long time. Since I saw this picture...



I think this was babybluemx3, I can't recall for sure. But I remember reading that it worked very well.

Of course I could also design the control arm to retain the active suspension properties. The reason I want to test this is because I don't think that the active steering is worth the loss of rigidity. I think that the car COULD handle better without it.

Anyway. I just wanted to hear what other people think about it.

[onlytrueromeo]

Oh, I definitely think you should try it, not trying to just shoot your idea down. Can't you use the original parts in a mock up, by welding pieces between them? This would certainly be cheaper than machining new parts just to test.

[Nd4SpdSe]

Man if I could find the pics of Luc St-Pierre's car, it was all custom aluminum.

[onlytrueromeo]

Charlie, tell me if I'm crowding your thread but I really like this idea too...

http://forums.probetalk.com/showthread.php?t=1701279872" onclick="window.open(this.href);return false;

[wytbishop]

It's fine. It's the new idea thread. I'm just curious to see if other people are thinking about these things too.

I have been thinking about the back end for a long time because I think it can be improved dramatically. I haven't given the front end much thought because I think it's pretty solid. The PT thread does bring up an excellent point though about routing turbo piping around the transmission mount member. I had thought about revising that member, but not the whole front sub frame.

I don't want to be that guy that dreams up all these crazy things that only like 5 people are willing to buy. I want to come up with parts that will bring benefit to a wide audience. The beauty of the bushings GB is that the vast majority of members are running on 15 or more year old bushings. Anyone with worn out bushings can justify buying them because it's cheaper than stock replacements.

I hope that things like this Rear LCA idea will appeal to enough people to make it worth while. I think with things like this I will build them and see how they work. If people are interested at that point I'll make more. I'm thinking about the rear subframe and front LCA in Chromoly as well. I don't know if anyone but me would want them, but I think it would be fun.

[Mooneggs]

Man if I could find the pics of Luc St-Pierre's car, it was all custom aluminum.

yeah exactly what I was thinking... i can't find any pics or links... they are all gone now

I think his setup is the same as wytbishop's initial drawing?

[wytbishop]

Like this? I saved these pics to my computer a long time ago. This and the other one are the only 2 I have.

[Nd4SpdSe]

I think so, it's been too long, I can't quite remember.

I was just watching his SoloII videos I found searching for his pics
http://video.google.ca/videoplay?docid= ... 5477469107" onclick="window.open(this.href);return false;
http://video.google.ca/videoplay?docid= ... 2689758991" onclick="window.open(this.href);return false;

With that setup, it looks like his car handles amazingly well with no understeer. wytbishop, I understand the concept on your theorized setup, but I think it's counter-intuitive to improving the handling of the car. The Rx-7 itself uses a similar system as the Mx-3, and we all know how well that car, as well as the Mx-3, handles. You have other manufacturers that use similar or more advanced systems, like 4WS, and even Nissans HICAS.

[wytbishop]

I don't know much about the RX7's so I did a little quick reading. I don't know about earlier models but looking at pics and stuff the FD is completely different from the MX-3. Being RWD I don't see how they could be all that similar. I'm going to need some clarification on that point Mike, cuz I just don't see it.

I agree that the MX-3 is a good handling car from the factory. But the more I look at it the more I feel like the "Active" rear suspension is mostly gimmick and the car could be made to handle better without it. I'm not claiming to know anything and I'm definitely not the expert yet, but this really has me switched on. I really want to learn how all this works.

And like I said before I want to spend my time on things that more than just a few people can benefit from. I'm not going to try to put together a GB for $500 worth of stuff that 5 or 6 people will want. I want to deal in volume. I think I coul dmake control arms for <$250 a pair, but I would only do that if it would actually improve the car in a way that everyone would benefit from.

I appreciate everyone's input.

[marcdh]

Charlie, tell me if I'm crowding your thread but I really like this idea too...
http://forums.probetalk.com/showthread.php?t=1701279872" onclick="window.open(this.href);return false;

Awh I was envying that myself a few days ago. That's it! I'm learning to weld

I'm intrigued about this idea too. Here's a bit about TTL useage: TTL and 4WS

These developments include the twin trapezoidal link rear suspension, first employed in the original front-wheel drive Mazda 323 (1980) and the Mazda 626 (1982), and then perfected within the updated Mazda 626; the award winning Dynamic Tracking Suspension System of the second generation Mazda RX-7 (1985); and the elaborate E-link rear suspension of the new Mazda 929 (1987).

While various external forces and loads are exerted to the rear wheels of a vehicle as it combats the elements of the law of motion as defined by Sir Isaac Newton, these new suspension systems convert those forces into "4WS effects" which positively aid in vehicle stability and agility.

[onlytrueromeo]

Yeah, since I now know how to weld, I will be attempting these future projects in the coming years. I just need to wrap up this semester and get me a garage!

The big thing I want to do is a chassis frame brace! It will be awesome and shiny, not to mention useful.