Jump to content
The mkiv Supra Owners Club

The gixxer_drew suspension thread..


Guest PhuPhu~
 Share

Recommended Posts

Guest PhuPhu~

Disclaimer:

 

Guys it sucks I had to put this in but I just had to. The last thing I want is to get sued over this and I'm just trying to help the community out:

Do not actually ever assemble this suspension and install it because I dont want to be liable for any damages to your car or your person This is a 'for show purposes only' thread. A step by step documentation of how I built my suspension not intended for use on anyone elses car ever ever. LOL. I make no warranty as to the functionality, usability, reliability or anything about the use of this setup. If you use this setup and subsequently crash your car into a tree/have a wheel fall off or anything else I am not responsible because I told you not to ever run this setup

Please read the ENTIRE post, all of it is important.

 

Now that thats over with....

Preface:

Thanks out to Jeff Mueller AKA 'Hiken' on this board for being my beta tester(guinea pig?). Most of the photo credits go to him. There are a lot of hours into this so I hope you guys appreciate it.

Another huge thank you to Jeronimo, ideal98supra for all his work with the street/track version development.

And a final thank you to Brian Lee AKA '95JZA80TT' for listening to my crazy ideas and bouncing them back at me all the time.

Purpose:

I originally began designing this suspension for my Lexus SC (which shares the same suspension as my Supra), I wanted a suspension to suit a Lexus in terms of ride comfort but bring the SC's handling to on par or better than a supra.

After riding in a car equipped with almost every suspension on the market I determined that none of them would fit the bill. I set out originally to build an 'at any cost' setup but ended up discovering that I could build something to achieve my goals in

Please keep in mind that these are street or street/race minded setups, NOT a race setup, things like body roll and a reasonable ride height are a necessity of running a car softly sprung enough to absorb bumps. Soft springs offer more grip on imperfect surfaces, that means the softer version WILL be faster on the street and the stiffer version will be slower on the street. I recommend starting with the softer springs and working your way up. Through the further development of this suspension we discovered the valving bilstein had originally told us the shocks had was capable of supporting much higher spring rates than they originally informed us, additional spring rates have now been tested.

If you are looking to lower your car -2.5" from stock this is definitely not the suspension setup for you, this is for people who don't want to screw up their cars handling and ride comfort in favor of how it looks. A lot of aftermarket suspensions for our cars come over sprung just so that you can lower your car without bottoming out the tires into fenders or worse. 1" is actually a lot to lower your car 2" is compromising your handling seriously unless you have custom control arms/fenders/etc.

I also wanted to utilize components of exceptional quality, Bilstein shocks and hyper-coil springs fit the bill. You may be able to build this cheaper using cheaper springs/sleeves or shocks. I did not research building a cheap suspension as that was NOT my goal. Building a damn good suspension was, and I got lucky that it ended up being cheap. Either that or we just discovered that everything else is overpriced, I'll leave it to you to be the judge.

 

Background:

 

Bilstein shocks are (in my opinion of course) among the best in the world. The top three reasons I selected them are

 

1) They are a gas monotube design with extensive research. They are OE on almost every high end car. Lotus, Mercedes, Porsche you name it, they offer excellent compromises for ride comfort, handling and durability. In my opinion they far exceed anything else in their price range. You CAN do better but you wont do it for less than double to 4x the cost. Take one look at a shock dyno for them and you can tell there's engineering there. The curve is soft in any place you can get away with it as opposed to Tein Flex or most JDM coilovers with a flat linear curve. Flat curves make for cars that are predictable but are not maximizing grip. I dont know much about drifting but I wonder if that is the target audience.

 

2) Rebuildable, a Bilstein rebuild costs roughly $50 and any valving can be integrated. Internally these shocks are identical to the NASCAR ones which means that every valving known to man is available and at a very low price. This setup can be adapted to almost any use from mild street to full blown race car by changing the valving and spring rates.

Bilstein were also the shocks that Toyota selected for the TRD suspension as well as in use for the famous Amuse Supra.

 

3) Price, there is absolutely nothing that touches these shocks for $400 a set. price is the third reason because it was the least important one to me.

OK I lied, there's a 4th reason, they are run on all my favourite and some of the winningest production based cars in history: 787B, Dauer 962, GT ONE. Besides having a different valving these shocks are essentially identical to their race counterparts.

 

How is the ride comfort?

Expect your car will ride as comfortably as it did when stock or better with 500/250 springs and slightly worse with the higher spring rate versions but still better than the JDM coilover conterparts.

 

How is the handling?

Excellent, I'm logging 1.17 lateral Gs on BFG KDW tires on rough streets (Street 500/250 version). For any street car this is a very impressive number, it is near the maximum coefficient of friction for the tires. The goal of any suspension is to maximize the tires even over surface imperfections. I was fortunate to be designing on a car with an awesome setup out of the box. Unfortunately for Toyota, and lucky for me consumer shock absorbers really sucked in the early 90s. On my highly calibrated seat of the pants meter it handles better than any of the off the shelf coil-over setups myself or my friends used.

 

This is some commentary from a user of the street/race version:

"I have tried the car out several times at Sebring which is a very bumpy track and they feel great. With the TRD suspension, I would take Bishop's bend which is a long left hand double apex corner in 4th gear flat out. With your suspension and my spring rates, I can take the same corner in 5th gear flat out. " -ideal98supra note: his spring rates are the ones now specified for the street/track version

And some from a user of the street 500/250 version:

 

I think the softer spring setting is awesome, it still absorbs the uneven surface and ripples and has good contact with the road, non of that bounciness you get with the aftermarket setups with hard springs. It gives a good feedback to the steering wheel and easy to control on uneven/rough parts of the track. ...im very happy with it... it also feels almost like stock on the streets.

I am so hooked, i wanna do some more track days now and get a smaller turbo hehe. -mazman

 

in car video analysis from Mazman's session:

http://www.supraforums.com/forum/sho...&postcount=356

 

What is the height range adjustment?

the adjustment range is roughly 0 to -3" from stock height, this is the maximum POSSIBLE however I advise strongly against using the maximum. It can probably be adjusted lower but -3" is way more than you should ever use anyway. This setup will not work as well if you adjust to more than 1 to 1.5" below stock height. With the street/track version you might be able to get away with more but this is untested. Its a soft spring, street setup, it needs the travel. more than 1.5" is non optimal for a slew of other reasons. I don't believe lowering more than 1.5" is optimal with stock geometry anyway so I did not design for it. If you absolutely must run your car low I suggest you use a different setup.

 

 

Step 1: Gather the parts and tools

 

note: I hope that some of our forum sponsors might be willing to offer these parts up for sale, if they would be so kind we can list them as the sources for the parts

 

The following parts need to be purchased I have also listed where I purchased mine.

 

$379 Toyota Supra Bilstein Shock set (SHOX.COM)

QTY2 part num. AK1242 for Front shocks

QTY2 part num. AK1243 for Rear shocks

QTY 4x Bilstein Coilover Sleeve Kit Bilstein part #193117 these are the 2" sleeves(summit racing) http://store.summitracing.com/partde...5&autoview=sku

Hypercoil Springs

QTY X2 $55 ea Front: 8" x 2.5"ID 500lb/in rate (shock-shop.com)

QTY X2 $55 ea Rear 10" x 2.5"ID 250lb/in Rate (shock-shop.com)

Bump stops

QTY X2 Energy Suspension Bump stops part number 4.6103G (they come in pairs of two so you will have four total bump stops) horsepower freaks carries these as should almost anywhere they are a mustang application

 

http://lukedeals.com/ftm

Link to comment
Share on other sites

Apart from the Bilsteins cited being "exactly the same as their race shocks" or words to that effect it all sounds sensible to me. What are you using for the small ID springs' top mounts? As a matter of curiosity people might like to see what a professional outfit do when turning a road going Audi TT Sport into a safe and reliable race car, I was sent a pdf of the race parts list, if you need to know the total, then yoiu can't afford it, but needless to say the transformation is VERY costly for what still looks very much like a stripped out road car. Note the lengths they go to to effectively lower the car with custom hubs and hub bearings, and all new suspension arms, plus the considerable detail in cooling the thing....

 

 

http://www.chriswilson.tv/auditt.pdf

 

And no, i am not contemplating doing this to the wife's TT ;)

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.