Rigid collar subframe reinforcement, INTERESTING, any thoughts?
 

First, here's the video -

http://www.youtube.com/watch?v=zWyUD6UXfog&NR=1

According to RHD Japan, Spoon Sports is working on an FD version. RHD Japan does have ones from RE-Amemiya for the FD -

http://www.rhdjapan.com/re-amemiya-r...x-7-fd3s-64819

At $313 for some small pieces of aluminum, that's PRICEY.

Wonder if there's anything substantive to this or if it's just a waste of money?

BTW, I love how the Spoon video shows a Prius. All set for the track day :).

Dale

Looks like FEED makes a set for the rx8
http://www.nengun.com/fujita-enginee...-member-collar

Well here's the thing. The Prius shown in the video has a typical economy car suspension geometry with torsion beam in the rear, MacPherson strut in the front. The FD has a multilink double wishbone design with the power plant frame. I'm not sure how well the possible benefits of these overpriced bushing-looking things will translate to an FD (or Rx-8).

$313 is nuts.

i'll see if i can find something similar and machine it down and try to get some results.

even if it does work, that's still a huge gouging for a product that costs $.10 to produce(i'm sure they buy in bulk from china..) where $312.90 goes to the simple R+D.

these should be selling for more like 85$. its just a frigging collar

its not a bad idea, but it does make 2 assumptions.

1. that the body and subframe are exactly straight. part of the reason the hole is bigger than it "needs" to be is because there are tolerances in the body and subframe

2. the demonstration is interesting as it changes this point, but the subframe "moving around" is really only a problem on track cars with sticky tires. for example, our integra race car was fine on Ra1's but as we've gone to R888's and hankook slicks, we've noticed some really odd things, the upper shock mounts are a plate, like camber plates without the adjustment, and these show wear now, its moving around in the body. it takes sticky tires to make enough force to do that. also the honda body is a floppy noodle compared to the FD.

wait until people start complaining that they can't get the subframe to bolt up with the collars, which is why mount holes are larger than needed. basically the collars force everything to be centered which could technically lead to other issues. i could really only foreseeably see this as an issue if the subframe bolts were not torqued adequately.

with the last possibility sometimes it makes me wonder if they didn't just loosen up the subframe to give a more enhanced visual reaction so that people say "oh shit, i need a set of those!".

i pull subframes down all the time with the elongated holes and i rarely ever see "itching" which tells you that the subframe is in fact moving around. a under car subframe brace should have more effect than these shims/collars would.

which goes back to my point that if anything, this would be a bigger help on a chassis that wasn't designed for a performance application originally.

Right but the car still had to go through an assembly line. The original concept designs for the car were much better than the FD today... but it had to be watered down to make it possible to produce and at the price point they wanted to sell it at.

You know the FD has the 2 long studs in the front on both sides. I can't remember if there was a taper on the upper mounting surface of those long bolts to help center the subframe when torquing the nuts. I'll lower mine tomorrow and see since my engine is out. At any rate I don't see the point of spending that much money when a thin walled stainless steel tube can be inserted around the bolts and rear nuts to center everything just the same on the FD if need be.

Seems like nonsense to me. I've had my subframe out (with R compound tires in use as well), and I didn't see anything indicating movement. The flat areas around the bolt holes plus the torque of the bolt holds it pretty steady I think. For 20 bucks, I would give them a try, but not for 300+.

For 300, I'd replace worn bushings / do other fixes which would help the car more.

yes, you're right. i guess that was my point too, we're running r compound tires on a honda, and we're WAY exceeding what the honda engineers envisioned when they designed it. the body moving around is actually really obvious on the honda.

the FD is not like that at all.

you can picture the prototype was an aluminum tube and a drain plug washer, yes?

Would be interesting to use some method to get real-world evidence if there is movement or what not with a strain gauge or some sort of telltale.

But, this holds true for most of the FD - it would be cool to see where in the chassis needed work and where it's just fine as it is.

Dale

Dale

not exactly, the tube is part of the crush washer. all made of aluminum so that it can compress and even out the uneven mounting surfaces. if the tube isn't part of the washer then the tube could float to the top or bottom of the channel.

My FD definitely had movement in the front subframe as the subframe paint was rubbed off by the bolt heads in all directions around the bolt head.

Then again, the bolts were loose...

I keep an eye on the subframe bolts torque now my theory is the bronze busings in the Tripoint sway bar vibrate everything loose.

Stock class auto-x on Kumho V710.

Also having trouble keeping the front negative camber in alignment- any tricks to keep the eccentrics from turning? Locktight on backside of eccentric?

you could try staking the backside of the cam or inside of the subframe collar.

the miata's do this too, mazda updated the bolt to a finer thread which allows you to double the torque value, or go to like 100lbsft.... the miata people still need to replace the bolts seasonally.

you should look up the miata bolt and nut, and see if the part number crosses to an FD, it might be that the FD had the fine thread from the beginning, and or they updated it somewhere.

it seems like there could/should be some simple way to lock the cam mechanically in place, but IDK...

Thanks for the tip; I will look to see if the stock pieces were superseded.

Wow this is really interesting. Props to that company for this kind of research, this is fantastic.

I'm not sure about the FD in particular, but I do know of some cars that have really bad problems with subframe's moving.
The one I know best is the MKV VW's (2005-2009 GTI, Jetta, Passat, R32)
This is the stock subframe bolt that came on early models, it's a stretch bolt and really sucks!
http://farm3.static.flickr.com/2505/...eb164b9349.jpg
You can see it necks way down and isn't very strong. So what happens is the bolt actually stretches during hard forces and it makes a *clunk* Eventually the bolt gets stretchier and loosens up. It's barely hand tight some times. But you can't just crank it down because it'll twist off.

http://www.034motorsport.com/images/3B_Mk5_DB.jpg
You can see the black stretch bolts at the back.

Simple solution?
http://c1552172.cdn.cloudfiles.racks...30124_x800.jpg
Just a properly sized bolt with 8.8 hardness.

BUT that still doesn't totally fix the problem. I see what they are talking about with the part of the video when the car goes over the bump. The subframe is adding additional spring rate because the two mounting surfaces are not machined perfectly flat.

But really I think I could machine something like this myself for less than $300. It's a really fascinating idea and an interesting solution though. Props to spoon.

well you do see VW and really sucks in the same sentence a lot....

my DD is an 09 jetta, and its SCARY to drive "fast" (3500lbs /120hp), normal speeds are ok, but its no wonder they advertise the new one crashing into a wall. if you go faster than normal its frightening. my other car is a 1958 Triumph, and its suspension SUCKS (no castor, roll centre is in china), but its less scary to drive than the VW

i wonder if this is why it feels so weird?

main point is why did they use a prius as the example for this high performance suspension product?

It's kind of the new generation of car modification. The person who can only afford to own one car and it has to do everything including bring them tax breaks. I was at Autobacs last month and they had a Prius bazaar with all kinds of modifications being sold, even Tein had a booth out there. But yeah I see what you're getting at. This is spoon and it should be a CRZ or Fit, not a Toyota.

Update! These are available through another source besides Re-Amemiya now.

http://rmagic2007.net/parts/products...product_id=546

Same price, but it's interesting.

Hmmm, i have a friend working as a CNC operator with a huge company making pumps and subsea installations... Ill have a chat with him and see if he has something i can use, or maybe he can make me a prototype set. If its promising, we may produce sets.