danTT

I am planning on improving the suspension on my 225QC in the near future and I would like your opinion.

Is it worth just replacing my springs for H&R springs or should I leave the suspension alone unless I am getting coilovers - which is unlikely due to their cost?

Would you suggest an anti roll bar setup as well - I am waiting for Eibach's new offerings. What about bushings on the MKII susp.?

Thanks in advance,

Dan

VAP

And I would presume that would be an even greater enhancement on a MK2 suspension. I think if you choose to go with just H&R sport springs there will be some super deals on them soon as more and more take em off and replace with coilovers (whatta ya say Cliff?). My FWD H&R sport set is available (first 100 bucks +shipping gets em).

Sway bars alone will allow you to corner faster/flatter but with some trade-off in damping quality if not "shocked" and not NEAR the flatness of a better-engineered suspension system. Sway bars are something I'm seriously interested in as well... soon as someone makes them available.

Urethane or Delrin bushings for the TT control arms in either MK1/Mk2 are still a ways out I'm afraid tho I'd be all over a set when they are available. But again, it wont make a Monroe-based factory suspension a stellar performer comparatively speaking (ignorance is truly bliss in that regard).

In order to do this car right... I mean REALLY right handling-wise you have to start with a good foundation. And that brings us full-circle to coilovers. Tho if Bilstein made a shock for this car I would still tout coilovers as my first choice suspension-wise but just the addition of Bilsteins with an H&R sport spring would be a highly endorsed 2nd choice. But then the numbers enter into it and its so close price-wise when you do springs and shocks it becomes almost frivolous to not go the extra yard and do coilovers. Labor on installation is the same either way. And an alignment is imperative on either.

I guess the simplest way I can put it is "If you're gonna be a dog, why be a chihuahua?"

If I had to list how I would go in diminishing order (first choice to last, knowing what I know today)it would be:

1. Bilstein (H&R) coilovers/sway bars/urethane
2. Bilstein "sport setting" shocks/H&R sport springs/urethane
3. H&R sport springs/stock shocks/sway bars/urethane (and swap to Bilsteins soon as cash-flow allowed)

Item number 2 is very likely to cost as much or more than item 1 (coilovers only) and will NEVER perform as well. Thats why the foundation is SO important. Item number 3 will cost almost half as much as item 2 and never perform as well as item 2. And is SO far from item 1 performance-wise as to be absurd.

Save money... make fewer purchases. Do it once instead of twice or three times. Story of my life in pioneering so much stuff is "buy reatil, sell wholesale." Its just not the way to do it. But no one offered us coilovers until recently so I did the next best thing. Had H&R coilovers been available from get-go there's no way I'd be wholesaling a set of H&R's springs today. Or a set of K&W Koni adjustable coilovers for a FWD as well. (Perfect/$725 with less than 500 miles if anyones interested, including shipping).

In closing, it all depends on what you want and expect out of your car. Coilovers are not just for racing/competition use, but also for spirited street use, leisurely drives and great satisfaction knowing (like with the car you chose) you have the best there is...PERIOD. Far better to have that precision/performance at-hand and never need it than to need it once and not have it. But it comes at a price. The best is never cheap... but it remains "the best."

I think I got all my "input" and classified ads in on that subject. (grin)

EighTT

<p><img src="http://home.san.rr.com/winefinds/1.jpg" border="0">

<B>Brad Willis</B>

<FONT COLOR="#FF6600">2001 225q TT Roadster
No Borla
No Garrett
No Stickers</FONT>

<A HREF="http://home.san.rr.com/winefinds">SoCal Audi TT Club</A>

Just Plain Cliff

to make my appointment to remove the H&R sport springs and install the H&R coilovers. I paid $250 for the sport springs, and with less than 3,000 miles on them (right now, less than 2,500 miles on them), will be asking $120 (shipping included), in their original box and packaging (and with their original sticker, I might add, since Todd at AWE gave me the one I have on the car now). And since these are for the quattro, I don't feel badly about piggy-backing on your post, M, with this shameless quasi-advertisement. Actually, I look at it this way--I'm not placing an ad, just providing a service to any interested forum members. And if no one's interested, they will make very attractive red dangling earrings for some elephant. Especially after being polished with Zaino.<p><a href="http://registry.audiworld.com/audi/registry/details.asp?car=3177"><img src="http://members.home.net/cmelick/audipics/sig6.jpg" border="0" alt="Click Image to View Registry Information"></a>

equiTTation

Are these even available for the 225Q at this point? Also: please explain bushings impact. Thanks!

smallTTs

Rubber bushings in suspension pivot points are soft enough to allow slight movement under loads both from cornering (lateral loads), but also from bumps, both large and small (vertical and fore-aft loads mostly).

Up-side of rubber is less noise, less vibration and less harshness (NVH)transmitted to body (car's and yours).

Down side is slower response to inputs. The bushings first squish slightly as load is applied before that load gets to vehicle chassis. Also higher loads from higher g maneuvers change the path the wheels take when they move up/down, again due to compliance or "give" in rubber.

Urethane, or delrin, etc. bushings are harder and therefore stiffer "springs" than the rubber and transfer loads with less deflection. Remember, everything is a spring; rubber, steel, plastic, titanium, etc. Some are just stiffer than others. Less deflection in bushings(and other components like tires) makes car respond quicker to any input such as steering, bumps,running over roadkill, etc.

There's no free lunch. If you want the quicker response from urethane bushings, you must accept the increased NVH they give. However they are only one part of the system. Stiffening up the springs, shocks and tires will point up the rubber bushings shortcomings. Just changing bushings won't do much to a stock suspension.

The NVH effect of urethane can often be approximated by adding about 5 psi to all tires.
Notice especially the impact harshness from potholes, tar strips, tarmac patches, etc. Also, ride in a '97-'99 Corvette. It has fairly stiff bushings, especially in rear. Quite a bit more NVH from suspension than stock TT.

BTW, "impact" was a great choice of words.

VAP

Urethane can be varied in its duronometer hardness (rubberized materials are made in any number of hardnesses measured in "duronometers") a simple Buna N o-ring is usually in the neighborhood of 60-70 duro. A rubber bushing as it comes in this car is VERY similar to that little o-ring in composition (buna N)and hardness... around 70 duro. Rubber also has a terrible memory when deformed past its planned tolerances or over time within its designed use through constant stress exposure to ozone, chemicals, salts, solventsand repetetive stresses.

Urethane on the other hand is an EXTREMELY dynamic and memory retentive compound. If you chucked a piece of rubber in a vice and squeezed the jaws together rubber would deform, split and retain some of that "squished" shape forever once removed from the vice. Do the same thing with a piece of urethane and it will not split or fail catastrophically and after ten minutes will readapt its "cast" shape. It lasts forever, isnt subject to ozone or solvents and always retains its "memory" and its "spring" properties.

And urethane doesnt really have to be harder than rubber in a bushing OR transfer more NVH or harshness to the driver or the car. In fact if the duronometer hardness of existing TT rubber bushings were duplicated in urethane you'd be hard-pressed to "feel" anything. All you WOULD enjoy/benefit from that conversion would be bushings that are capable of lasting a lifetime. So the trick is to get urethane bushings in a duronometer hardness that allows for all the benefits of comforts and diminished compliance in suspension geometry.

I have had great success with 90 Duro hardness urethane in dual-purpose cars. And 110 in all-out race applications.

Conversely Delrin is a solid, machineable plastic. It has NO memory. If its distorted it maintains that shape until distorted again. It is the same as solid or aluminum bushings and isnt even measured in "Duronometer hardness" but rather like steel or aluminum, with Rockwell hardness figures. We tried racing only once with Delrin bushings, destroyed and DNF'd a car in an endurance race and never used it again. That stuff is HARD. But it can be machined, drilled, sanded. Harder urethanes can sometimes be "ground" but never drilled, milled or turned in a lathe. It has to be "cast to size/shape" or die-cut due to resiliency.

Urethane is the way to go if using common sense in hardness. Give me some 90 Duro urethane bushings for my TT in both the control arms and the steering rack and I'm a happy guy.

john s

A Shore durometer measures the deflection of a calibrated spring when a cone point is pressed into the subject material. Different tips have different scales (A,C,D). The numbers are scale divisions without units. A 30 on the "D" scale is similar to a 50 on the "C" scale which is also similar to an 80 on the "A" scale. There is no exact correspondence since the viscoelastic properies do not scale to a static test.<p><a href="http://pictureposter.audiworld.com/"><img src="http://pictureposter.audiworld.com/AudiWorldPics/2000/0.jpg" border="0">
darn satellite signal is off - honest, ask anyone
<b>base link</b></a>

TTinHongKong

<p>180FWD/17" BBS RXII/BS S-02 PP/Pipercross Filter/PIAA/Wetterauer/Remus/GReddy Turbo gauge-A-pillar mount/Forge Motorsport recirculated dump valve/NGK Iridium Spark Plugs/Abt steel flex brake lines/H&R coilovers
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equiTTation

I've looked at the original versus the new modified front control arms side by side, and the ONLY difference I can see is that the bushings on the new part are dramatically larger. They look more robust, but maybe it is just a lot more rubber and thus less responsive.