pushrod activated suspension idea
 

While measuring the inside of my wheel well to determine how fat of a tire i could fit, i got a bright idea.

If i replaced the shock with a formed bar, and had it connect to a set of shocks that connect between the rear shock towers.

what i discovered, is by doing this, it allows you to fit a 14" wide rear tire, without any fender modification. There are also obviously performance benefits from the loss of sprung weight in the suspension too.

Please guys, let me know if there is a possible market for a bolt in kit for something like this. I am not about to start selling right now obviously, i am just curious, because i think i will be making one for myself.

-Zander

having a hard time picturing it, could u do a crude drawing?

you gonna make a drag car? http://carphotos.cardomain.com/ride_...0029_large.jpg

That sort of suspension- long used in F1 and various supercars- requires an enormous amount of engineering and fabrication experience.
I can't even imagine such a conversion as a "bolt-in kit".

Exactly right.

Yea, that's a good idea but the packaging is tight and I don't think it's worth the effort. Plus I wouldn't want to be driving if the bell cranks failed. Even with finite element analysis to guide the design it's difficult to estimate the loads caused by a big bump.

Here's an example of inboard shocks on a fsae car. Do a google search for 'fsae bell cranks' and 'inboard suspension'

http://www.allenracing.com/Images/fsae4.gif

Only thing about an FSAE car, when that stuff fails, you aren't 1. Spending more money then you need to replace a custom part, or 2. careening into adjacent lanes, or even worse, oncoming lanes!

FEA is key! If you've got the resources to do it, go for it!

I'm going to have to disagree with this.


It could very easily be a "bolt on kit", or more like a "weld on kit"

there would be a little X brace between the two rear shock towers, with a horizontal bar passing between the top of the towers. Placed on top of each shock tower will be a little CNC'd lever, which will connect to the suspension element. The shocks will both connect somewhere in the middle.



here is a build thread, being done in a civic:
http://www.honda-tech.com/showthread.php?t=2040195

http://images.superstreetonline.com/...0rr_shocks.jpg

http://i45.photobucket.com/albums/f8...sion/hatch.gif

Of course you would.

Good luck, post pics of what you come up with.

I would be very cautious about anything you read in SUPER STREET. Those guys think winning is an ice man cold air intake. ;) I hate how the NOZZZZ bottles are mounted high up so they can be seen through the windows.

I dare you to find me picture of front on board suspension.

you shouldn't dare me :)

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I have no doubt you could do it and make it function. It is really not that complicated. The questions is it really worth it... and woudl it be any better.... not really.

On an FC you are going to hit the rear trailing arm before you hit the strut anyway.

the reason why i am doing it is to be able to fit a 345 M/T ET street radial in the stock fenders.

and god damn.. i just went out and looked for myself, and you're right about the rear trailing arm. I guess I would have to make a set of those as well.. or modify the existing one.

hondas have alot of room in the engine bay. rx7s have a lot of engine room but after seeing those pics and how it would have to mount, i think it would be very difficult to get them to fit. with ppl running larger turbos plus the brake master cyl and res. and the clutch res. and ignition coils etc. i dont doubt that the back could be made to work, but the front i really cant see the front happening. if u do get a set going id very much like to see it

Why don't you finish that body kit you were making first? I honestly think this is more trouble than it's worth. As the other guy said, it's gonna hit the rear trailing arm first.

I was going to make that to fit wide rear tires, this is my alternative.
however, i have to finish building my engine first.

i applaud you for your intuitive and innovative ideas. that's the stuff that keeps car guys in the game. maybe this idea won't work, maybe it will. but Chaotic is brave for thinking of trying something not normally used in FC's. Keep trying different things as that is what will make you an expert fabricator and all these naysayers will someday be asking you to build something for them.
i have a friend that i worked with at a performance shop, and he was always creating fast and crazy projects. He started in the same way and now his own shop is busy and packed with work. his shop has cars that are full race cars to sick street cars. He is also my age so he started earlier than me, which makes me motivated in my projects. This all started with him and a welder.

I remember seeing an "area 51" *I think* FD with inboard shocks mounted on the back of the rollbar or cage many years ago.

Cool, but as others have said make up some trailing arms first for rear tire clearance and sell them please.

I can't believe no one makes trailing arms for us that eliminate the triaxial hub as well as give clearance for tire and drop weight...

Once (if) you clear the trailing arms the muffler(s) become a tight fit. I had to use steel u-bolts tightened all the way down instead of donuts on the inside to keep my heavy RB mufflers from swinging into the tire while cornering on 275/40-17 on +40 rim.

thanks for the kind words man (pistones)

and BLUE TII, If this works, i will absolutely be reproducing what i've made, including the trailing arms, and the shock kit.

Just put a Ford 8.8 in it. :)

Not an FC, but from FC3Spro.com:

http://fc3spro.com/TECH/FM2W/canti.jpg

That blue civic with the bike struts in the hatch was the first thing I thought of though.

if it was a straight drag car, then it'd be a no brainer... but this is my daily driver, i want overall performance out of this machine.. without wide enough tires, i'm just wasting the horsepower that i'll make out of my 13bppt when its done. That's why im going this route; its the best of both worlds, without the extra cost or looks of a widebody kit.

im with pistones, theres too little ppl trying new stuff out. i do think it be a super tight fit
but if it could be done, itd be bad ass!!
and besides theres ppl doing things that arent near performance related, that are FAR more dangerous than that!

Chaotic, I say go for it and do it. It can obviously be done, and it can be marketed. Not that your market will be huge but you can maybe get your cost back out of it. I think it will be badass to see the progress you make with it and post some pics.

Adams CAR software could help figure out the motion ratio...

here we go again.....

I'm going to look into this.

don't do it with the intention of making money off of it. do it to to prove it can be done, and make sure it is pretty fool proof. then you can make money on it. have fun and stay creative.

im doing it so i can save money actually! lol
i want to be able to harness my power without buying a $2500 widebody kit.

According to your other thread, your car is going to be a stainless steel tube frame carbon fibre widebody peripheral port turbo daily driver. So why even bother with modifying the stock suspension points?

Since you will be building a tube frame from scratch, you can pick up the suspension anywhere you want. Simply alter the length of the control arms and then you can mount the coilovers more inboard and at an angle. That way they will neatly tuck inside the wheels.

Or, just alter the wheel base. Go with a wider hub-to-hub distance. You'll end up with a wider stance and you'll be able to fit more rubber with room under the car to spare.

As BLUE TII mentioned, Area 51 had a setup like this on his FD. You may find pictures by searching VERY OLD Lounge posts as this was at least 9 years ago. Maybe they were even lost in the hack. Then again, pictures are going to be very little help past the actual layout.

Still an odd idea though because with a tube frame car you can design the suspension to avoid issues like this.

Edit...Also, why would you ever suggest buying a widebody kit? You made it abundantly clear in your other thread that you would make your carbon fibre widebody with a large pottery kiln and by just laying it together.

god damn man that is really unnecessary..:icon_no2:

do you get off from being an asshole to people? like does that get your dick hard?

obviously i am not making the carbon fiber widebody anymore.. it was an idea, just a freaking concept.

but its not necessary for you to rag on me as if im an idiot.. That 13bppt that you make fun of me building really is being built.. It IS going to be my daily driver..

oh man, i never know what to think when reading this kid's threads...too bad TTT and Ted are no longer around.

Let's not let this thread get out of hand.

Trust me, I was not making fun of you. If I was making fun of you, then you'd know it.

In case you have not not noticed, I am never a dick to anyone on these forums or in real life. If you can find any post of mine that is anything past poking simple fun of someone (almost always with a smiley attached) then you win an Internet cookie and I'll give you $100 via Paypal. It is called "gentle ribbing" and is something people do. Perhaps you are a bit oversensitive due to the results of some of your past threads?

I've noticed that you are actually building the engine. That's kind of cool, but not impressive until it runs and makes power (and then holds together). I'm hoping that it works out well for you.

You registered two years ago. Feel free to search back to my posts, beginning in mid 1998 or so, for any in which I have insulted someone or been hostile towards them. I think some of the early posts may have been lost in the hack though.

Grow a thick skin when you make posts like this because you will need it. If I wanted to be a dick, I would have been replying to your other posts.

This setup will cost more than $2500.

You can't have a car that dominates drag, autoX, drift, whatever else there is...tractor pulls or some shit like demolition derbies... and daily driving. You can't have a safe, comfortable daily driver and dominate at whatever type of racing you want to do. If you want to autoX get a shifter cart. If you want to drag, get a solid rear. You don't sound like you know what it takes it win.

why would it cost more than 2500?
i cant see any reasons it would..

at most a total of 200 bucks for all the tubing involved.
the pivot arms would cost about 200 each or so, for me to machine.
all the ball joints and bearings, mabey 200-300 bucks.

then the actual shocks.

so assuming that shocks are less than 1600 dollars, (and it looks like a good set will cost me around 600), its less than 2500.

And i am not trying to make something that dominates everything.. i just dont want to sacrifice street handling, but still want to be able to go fast in a straight line. This is the closest that i can see without loosing what i love about the rx7; the handling.

Chaotic, you might find this site very interesting.

This guy started with an Atom- designed from the git-go with a suspension like you envision- and has spent a ton of time and money to get it to function (and last).

I don't doubt that you can fab up something that holds up the car body.
Making it work as well as the stock suspension will be difficult.
Making it work better than stock will be very difficult.

Assuming you make it past the nuances of the bellcrank design and bearing specs, you then have the fabulously intricate world of shock rebound and dampening rates to deal with, not to mention spring rates.

When I was GP racing- admittedly at the dawn of the on-board data acquision age- without the constant attention of factory Ohlins techs, we could not have dialed in the suspension...the multitude of variables was simply overwhelming.

Being a lifelong machinist/fabricator, I cheer your lofty ambition but fear that you have oversimplified the obstacles- and cost- involved in success.

For instance, a "good set" of shocks for $600?
Unless you have an in with a race team, $600 won't even buy a decent set of standard coilovers, much less the kind of shocks used in a remote setup.

I also notice that your cost estimate includes absolutely no labor.
If you want to discount your time/energy that's fine- in fact, damn near imperative- but do you really think a project of this scope will be done without any outside consultation/fabrication?
Maybe so, and my hat would be doffed in praise should it come to pass.

So I'll remain skeptical but interested.
Again, good luck.

I don't doubt it can be done for $2500. I doubt it can be done right for that price. Clokker said things well in the post above. 4 way coil overs with high and low speed dampening and rebound won't be as cheap as you think. If you like to read you might want to check out some of these books:
http://fsae.com/eve/forums/a/tpc/f/1...883#1956095883

just swap to solid rear axle
http://carview-img02.bmcdn.jp/minkar.../479094/p1.jpg

LOL that looks crazy. I love how it still has the stock rims on the front. So stealth :suspect:.

There was a circuit spec FD running around with a solid rear, ford 8.8 I believe. Car's fast also.

It always seems that people knock your ideas for the usually understated budget assumptions. That should tell you something. Also, don't forget to factor the trial and error multiplier, if you want to build it right.

that site IS very interesting, thanks for it.

do you really think that this will cost more than i think it will?
I am capable of doing all my own work, including machining.. so labor isn't an issure for me.

it looks like these shocks right here should work real well if i can figure out all the right math for the bellcranks.

http://www.denniskirk.com/jsp/tpl/pr...p581896&mmyId=

it says i can tune my own rates and stuff for it.

The expensive part isn't the fabrication, it's the R&D needed to refine the system. If you have 3D CAD software with simulation features, you could do all the theoretical calculations and FEA before manufacturing. This is just one of many challenges you will have to overcome when engineering a new suspension. Have at it!

Grab some books on suspension design and have at it. In order for it to work right you need to get the ENTIRE PACKAGE right. A different bell crank change motion ratio, which will will increase/decrease effective spring rate and possibly suspension travel. Then the spring rates and lengths will need to be determined to match the bell crank motion ratio + suspension ratio. Then the dampers will need to be valved to match the springs, and have sufficient travel to match.

ok, thanks guys, i'll have to get to the reading.

and YaNi, your signature is hilarious :lol: