JUST SAVING SOME NOTES FOR MY FUTURE REFERENCEWith the Ground Control full kit you ca fully rebuild the coilover. If the Koni shocks leak they can be
pulled out and new ones pushed in. ($160 USD each), if the threads on the sleeve get screwed up you can buy a replacement for $15 USD. If you don't like the spring rates a new pair in whatever rate and length you want will be $60 USD.
So many options, tons of travel vs stock STI suspension, cheap rebuilds and should cost about the same as the used Ohlins/Blacks that you want.
The complete kit from Ground Control with Koni shocks minus their camber plates will cost around $1600 USD. Or you can do the complete coils on the front and wrx struts in the rear with koni inserts
and a different set of GC sleeves ($15)
http://www.iwsti.com/forums/gd-suspension-handling-stiffening/85406-ground-control-koni-coilovers-incuding-2005-stis.htmlAn excerpt...
Stage 1: $400
- Get the Ground Control coil-over sleeves and springs
- For the stock dampers, 300/250# springs work great. Mark (@GC) will work with you based on your needs, though.
- Set the springs to stock ride height for best ride quality.
Stage 2: $650
- Install Ground Control camber plates up front
- Since the camber plates add suspension travel, lower the car half an inch. You will still have more bump travel than stock, making Stage 2 a significant improvement.
- Upgrade to off-the-shelf Koni's in the rear in WRX housings
Stage 3: $625
- Get Koni SA's from Ground Countrol
- Get Koni housings from Ground Control
- Lower the car much more thanks to the gobs of new suspension travel
To maintain stock height with an increase in spring rate requires a coilover, no spring available will do this.
With this sytem you get your choice of spring rates and lengths. That means you can run a tall enough spring near the bottom of the perch to limit the chance of coil bind, stay at or near stock height and increase spring rate. Coil bind is fairly common on coilovers and will kill struts.
The best thing would be to call Mark at GC and talk with him abot what you want. There are other guys that answer calls but Mark runs the show.
The best way to ride well and handle is by adding sway bars. The extra stiffness you get by adding a 24mm sway bar is equivalent to an additional 860lbs to your spring rate.
Keep in mind stock is 224 and a performance spring is around 285.
So stick with modest spring rates and run a 24mm front and rear bar and with the extra shock travel you will be off the bumpstops and the euro valving of the konis should keep the ride comfortable.
In my mind the fewer the adjustments on the car the better. Less on your mind that you can tweak(fewer excuses or mind games). The car will pretty much be "all new" for me in Autox with the amount of suspension changes I'm making this winter so eventually I will just learn to drive it again. Once the car is setup, with a decent amount of research and knowledge, then leave it and learn to drive it. At least thats the way I think. I do have the advantage of tweaking my alignment whenever I want. I have a rack and machine at work that I can use whenever I want. 95% of those alignments are just making sure everything is exactly the same as last event.
I don't think there are many of us here who have developed a driving style that can't improve or change. And I think there are fewer who can tune a shock/suspension properly. I have no idea how, I have read how, it seems tedious, seat of the pants is a pretty terrible gauge in my opinion and you would need some data acquisition and track time to set properly.
Here is some information I found with a quick search on Shock Tuning.
Before they even get into shock tuning, take a look at
the precautions. This is geared towards a road course but be honest with yourself and think if you would be able to accomplish
point #2. Specifically stating the handling issue with the car. Especially taking into account factor #4, and #6.
Sure the ultimate suspension is out there, but do we all have the potential to USE IT ? Not on the street, and no one here is driving on a race track full time with endorsement so I doubt it.
I know we are all enthusiasts, we all want to improve out cars, its a passion and a disease at the same time. Driving our
cars isn't paying the bills though...
Quote
Suspension Tuning Tips by Bob Tunnell
Before getting into specifics of suspension tuning, here are some thoughts about suspension tuning drawn from my own experience...
1. When listening to advice, consider the source and the context. Many of the Internet special interest groups are a wonderful source of information. But one of the biggest drawbacks to all the advice you see on SIGs is that the authors are rarely qualified to offer SPECIFIC advice for YOUR car. It's easy to SOUND like an authority... it's rare to actually BE one. When reading their advice, pay particular attention to what make and model of car they own and drive, what modifications have they made that are truly applicable to your car, how experienced they are, what discipline are they tuning for (autocross, road race, street, track, etc.), and how closely their budget resembles yours.
2. Be specific in your analysis. If your car is pushing, pay particular attention to *when* it pushes. Is it on initial turn-in? Is it mid corner? Is it on corner exit? Or is it a combination of all three? For example, if a car pushes in mid corner, but not upon entry or exit, chances are the problem lies with alignment, spring, or bars... not the shocks. So it's critical to properly identify the symptom and isolate the true cause of the problem... the treatment needs to address the root cause.
3. Fix the end of the car that has the problem. If your car isn't turning in properly, don't adjust the rear of the car to try to make the front end work better. Conversely, if the car is extremely tail happy because of low rear grip, decreasing the front grip to compensate may make the car feel balanced, but it will ultimately make you slower. Often in Stock class autocrossing or road racing we're forced into adjusting the "wrong" end of the car because rules limit our ability to adjust properly, but these methods should be considered a last resort.
4. Don't discount driving technique as a big factor. Most drivers don't like to hear this, but it's true. I can't tell you the number of times I've been told by a driver, "My M3 pushes like a pig!" But when I get in the car it seems perfectly balanced to me. I'll ask the driver what his previous car was and invariably it was a Camaro, Mustang, Corvette, or other high horsepower RWD car. M3s were not built to handle the same as pony cars and they cannot be driven quickly with the same technique. Slow sweepers in particular need to be entered slowly, under control, and "carved"... not tail-out Dukes Of Hazard style. And the best part -- changing your driving technique doesn't cost you anything!
5. For the best results stick with one tuner. Professional high performance tuners know more than anyone else about how to make your car fast. We work on making cars faster and handle better day in and day out. We know which products perform best together and which ones don't. By mixing and matching products -- usually in an attempt to get the lowest price -- customers often end up with a car that doesn't respond like any of the advertising claims they've been reading. Put a pot pouri of components on your car and you'll likely end up with a mixed bag of results and wasting your money. Different tuners have their areas of expertise and their advice.... spend a little extra, discuss your needs and budget with a professional tuner, and you'll likely get far more value for your money.
6. "Compromise cars" will not do everything well. I am frequently asked how to set up a car that will be good on the track, but still plenty comfortable to drive on the street. Not everyone can afford to own enough cars to have one for a commuter, one for autocrossing, one for road racing, one for rallying, and another for concourse events. Most of us are forced to live with compromises... one, or maybe two, cars that have to perform a variety of functions. When asking a tuner for advice on how to set up your car, you must first determine in your own mind what compromises you'll be able to live with and be certain to communicate your needs. If winning autocrosses is more important than having a luxurious ride during your 5-minute commute, chances are you'll be happy having your car set up more for performance. But if you drive an hour to work over frost heaves and tar strips, you probably should set up your car more for comfort and leave the WRC Championship for another time. BMWs are amazing cars and can do a lot of things well, but don't expect a tuner to do the impossible.
Also some more good reading here...this car is now owned by a local Autox'er with the SASC club.
The original builder, Dennis Grant won SCCA nationals in the USA, he knows what he is talking about. He
was also a shock engineer at a race team at one point.
He doesn't have a lot of love for adjustable shocks, since on his shock dyno the adjustments do very little or work incorrectly.
http://farnorthracing.com/autocross_secrets6.htmlAnother option. RCE Tarmac Zero. Built by KW to RCE specs. INOX coating, will not rust. Warrantied for life, Ohlins has 1 yr warranty. Myles at RCE is soon flying to Germany to become a certified rebuilder. They are typically seeing 3-4 years between rebuilds on the T Zeros.
The ride hide adjustment of the coilovers is the easiest, results are black and white and measureable, and is only required once or twice if the suspension settles. The damping is the somewhat "black art" part, unless you have some fancy tools, requires much more time and attention to detail, as well as technical knowledge.
I will take ride height adjustment and correct valving over fixed height and adjustable dampers anytime.
Ohlins adjustment seems like a hassle to me. The adjuster is on the bottom of the strut, means laying on your back to adjust.
Tarmac 0 is fixed valving and you just adjust ride height. Spring rates can be 350/300 I believe. 400/340 is their stock rate.
http://www.iwsti.com/forums/gd-suspension-handling-stiffening/161982-attn-rce-could-you-give-comparison-your-t-zeroes-vs-ohlins-rce-springs.htmlAs for comfortable coilovers, correct spring rates, Euro type valving, correct ride height and ample travel will offer good ride.
You can't group all coilovers into one category and say they aren't comfortable. Japanese coilovers are stiff, valved very aggressively and work well on a smooth surface. It is a completely different strategy compared to the Euro builders.
Travel is a big issue with the Stock STI suspension since you are .75" off the bumpstops in the rear with stock springs. The Ohlins gives you 1" longer shock stroke but with a lowering spring you will still be on the bump stops.
The entire suspension has to be able to compensate for varying conditions track to track, varying grip levels etc.
The shocks can be used along with other adjustments to create the handlong you desire.
Here is a lotus forum with a Calgary autox'er verifying his findings. It shows his simple notes on how shock,sway bar or tire pressures can be adjusted to attain the same handling result.
This particular guy and his co driver are very quick...they race the Exige in ASP and went to Lincoln last year for the SCCA finals and the car is competitive enough to win the class. They coned away their chances though.
My point is they know car setup, but notice how many laps he did at race city to verify his notes and research. This is a luxury most of us don't have.
http://www.lotustalk.com/forums/f99/tuning-dual-adjustable-shocks-75126/Since the STI has only 1.75" of bump travel before it hits the bumpstop (at stock ride height) it is effectively more than doubling the
spring rate each time you move more than 1.75" into bump travel.
So mid corner, highway on ramp ,the outside suspension is fighting cornering force and compressing depending on load. Probably more than an inch already. Now add a small bump, the shock compresseses more and runs into the bumpstop, the bumpstop is progressive but gets stiff quickly, now you experience about 600lbs of effective spring rate and bounce upwards on an underdamped shock. The car gets unsettled and bounces up into the air, where there is lots of droop travel to accommodate the bounce. This is not an effective suspension.
A stiffer spring (at stock ride height) will keep the shock off the bumpstop, now hitting that bump mid turn compresses the assembly less (stiffer rate) and you only dealing with the spring rate. 285 lbs lets say.
Realistically though there isn't enough bump travel in the STI struts to make this happen, and by increasing the spring rate on the stock strut you are now underdamped causing extra work and heat and wearing the struts. So you are looking at replacing part or all of the system.
Don't be afraid of spring rates based on what your car has right now. With enough travel and proper valving a slightly firmer
spring rate will probably ride better.
A quality coilover will have proper travel, allowing the suspension to work, controlling the weight of the vehicle while maintaining
contact with the road. Picking the spring rate for your needs and having the ability to adjust valving to match the spring offers the chance at a good ride quality, predictability, consistency and good handling.
The GC setup gives you at least 3" of bump travel. Maybe more, depending on chosen ride height and using the GC camber plates.
Doubling travel is significant. I wish I had an STI and several different suspensions to put all this theory into practice.
No I haven't driven an STI with a good coilover or ohlins. I have driven an 04 STI on stock springs/shocks. An 07 STI on stock shocks with RSR Ti2000 springs, and an 09 STI with stock shocks and Whiteline flatout springs.
This involves learning concepts, theories and common setup, allowing the driver to determine their needs, choose (with the help of others) proper spring rates and lengths for a chosen ride height (also important). And work at adjusting the shock to match the spring once installed.
This is too much work for some people. Different people have different priorities, needs, and wants from their car and probably fewer priorities, needs, and wants when it comes to their spring and shock choice. Its not very glamorous. Its tedious, can be boring and technical reading isn't very fun.
If this isn't for you then move on. Discuss something that does interest you. The potential for something better does interest
some of us.
