ground control... best bang for buck?

[Beedub]

my track buddy asked my opinion on the ground control kit.... ive never spent the time looking at this kit but did yesterday and i have to say im wondering whyso many of us have overlooked this relatively inexpensive kit which looks to be awesome, camber plates, choose our own spring rates, proper z4m kit not an adapted unit....

whats peoples opinions on the ground control track school coilover kit...

a quick search on good shows some quality control issues..... quite afew actually, is this most peoples experience.. i do however agree with my friend that at this price point, it cant be ignored!! i think we all need to be educated on the track school kit and its pro's and cons..... from what chris points out, this kit offers proper track experience but has a few issues, wondering if they've been ironed out over time.

[Kgolf31]

Originally Posted by Beedub

my track buddy asked my opinion on the ground control kit.... ive never spent the time looking at this kit but did yesterday and i have to say im wondering whyso many of us have overlooked this relatively inexpensive kit which looks to be awesome, camber plates, choose our own spring rates, proper z4m kit not an adapted unit....

whats peoples opinions on the ground control track school coilover kit...

a quick search on good shows some quality control issues..... quite afew actually, is this most peoples experience.. i do however agree with my friend that at this price point, it cant be ignored!! i think we all need to be educated on the track school kit and its pro's and cons..... from what chris points out, this kit offers proper track experience but has a few issues, wondering if they've been ironed out over time.

IMO, if you're going to be putting money into something...it should be a kit that offers Dual Adjustable struts. It can be ignored.

As well, a kit that can fit BOTH M and Non-M cars scares me.

My money is going to this kit once I'm done with school:

http://www.tcklineracing.com/webdocs...Details171.cfm

[inTgr8r]

one thing that bothered me with the GC when I had them was the way everything hung loose when the car was on the lift.
They are basically off the shelf components that GC assembles.

The components are good quality though & they did a great job at the track.

[Beedub]

Originally Posted by Kgolf31

IMO, if you're going to be putting money into something...it should be a kit that offers Dual Adjustable struts. It can be ignored.

As well, a kit that can fit BOTH M and Non-M cars scares me.

My money is going to this kit once I'm done with school:

http://www.tcklineracing.com/webdocs...Details171.cfm

The z4m kit is specific according to the website..

[Beedub]

Originally Posted by inTgr8r

one thing that bothered me with the GC when I had them was the way everything hung loose when the car was on the lift.
They are basically off the shelf components that GC assembles.

The components are good quality though & they did a great job at the track.

Again reading the right up it seems everything is made upto gcs specs, hmmmm Interesting to hear everyone's view however...

What do you mean by hangs loose????

[Kgolf31]

Originally Posted by Beedub

The z4m kit is specific according to the website..

Sorry, initially going through it, it directed me to a dfferent kit.

[inTgr8r]

Originally Posted by Beedub

Again reading the right up it seems everything is made upto gcs specs, hmmmm Interesting to hear everyone's view however...

What do you mean by hangs loose????

I'm sure components are made to GC spec such as valving etc but AFAIK they aren't a GC manufactured product.

When the suspension hangs at full travel on the lift the springs hang free & loose.
The springs don't decompress enough to keep any preload.
This may vary with spring selection though.

[Beedub]

Originally Posted by inTgr8r

I'm sure components are made to GC spec such as valving etc but AFAIK they aren't a GC manufactured product.

When the suspension hangs at full travel on the lift the springs hang free & loose.
The springs don't decompress enough to keep any preload.
This may vary with spring selection though.

hmmm will pass this info on...... thanks again, i do note however everyone has basically said this kit is awesome on the track.......

[AUTOX08MC]

My experience: Quality is good, functions exactly as advertised, makes lots of noise

[Beedub]

Originally Posted by AUTOX08MC

My experience: Quality is good, functions exactly as advertised, makes lots of noise

ok now we have an owner piping up.... cornering ability?? ride comfort???
how much noise???

chris noted that he had some quality issues, his was an early kit, do you feel these have been rectified??

and the biggy... chris noted that he couldnt get the brake lines and ABS wires to connect upto the G/C tab/bracket as its mounted to high?? your experience wit this??

how some some pics if possible :-) thanks for your help.... in the UK at least this setup is by far the cheapest and pffers everything you'd need to get a serious handling z4m, i can see the allure, infact i cant lie.... if ihad known about them, i think id have gone this way and saved £1000.

[Beedub]

Originally Posted by AUTOX08MC

My experience: Quality is good, functions exactly as advertised, makes lots of noise

of note he is going spring rates of 500/550... any advice Re this??

[Beedub]

Originally Posted by Kgolf31

Sorry, initially going through it, it directed me to a dfferent kit.

no probs, i can see how you did that as for some reason the website emits the z4m kit sometimes, other times its their??

looking at the tcklines, this kit offers everything that does bar the double adjustability, the GC units are produced in holland by koni and carry their own specific GC product codes.... valvinf and body,s care completely z4m specific, i like that fact this is a proper z4m kit at least....

look like hes going this way.... i for one, am very excited to see how these perform...

[Finnegan]

I've been on the track in a car running this kit with 500/600 (F/R) springs (RunnerX). Car was planted, solid, predictable, and that's on a track with a lot of off-camber turns and serious elevation drops.

Not sure if RunnerX was running the GC camber plates or not (think so), but they were the race camber plates. Plates were noisy coming out of the paddock, but I didn't notice it on track (to be expected IMO when running race camber plates.)

Would the dual adjustable TCKline kit work better? IDK. But there is a big price difference.

Beedub, if you're interested, why don't you give Jay at GC a call? I'm seriously considering these as well, as my stock dampers are a bit tired (compared to Skelekitty's car). Jay is a knowledgeable and easy to work with guy, and quite willing to discuss goals and how to create a set-up to meet those goals. Full disclosure: I know Jay since he's local and I've been on quite a few drives/breakfasts with him.

[dorifto88]

i have these and think they are fine.

suspension does "droop" on a lift, but to rectify this you can
-get longer springs
-use an assist or helper spring for the front
-use gc's weight jacks for the rear

i have no issues with fitment
i have no clunk
car is firm but imo not too much firmer than stock

if you are looking for a plush ride maybe look into kws

[dorifto88]

Originally Posted by Beedub

of note he is going spring rates of 500/550... any advice Re this??

im running 10k/12k which is like 600/670 or something like that. (for me) its not that stiff. lol i could go stiffer

[seank]

Would the dual adjustable TCKline kit work better

I have these on my car. They are noisy and make a slight clunking noise. I called tc kline to get a replacement strut, but they said it is inherent in the Koni DA design and accentuated with the strut to fire wall bar on all Z4 cars. I took off the bar to see, and they were correct.......it is much quieter.

This should be the same with any Koni DA modified strut.

I have run the GC kit SA on my car track e30 m3 for 5 years and it is excellent for the money. I am not sure why anyone is worrying about droop at when on a lift. It makes it easier to change springs and I never had an issue, even running at Thunderhill in the reverse direction (turn 5 in the air).

If I were going to spend the money (I adopted the Tc Kline with the car), I would buy the AST 4200 which is the best shock by far for the money. The best!

[AUTOX08MC]

Originally Posted by Beedub

of note he is going spring rates of 500/550... any advice Re this??

To be be brief, as this discussion could go on endlessly, but in my opinion and the front and rear suspensions are significantly different enough it that requires them to have vastly different spring rates. There is a reason why BMW uses a stock spring rates of Stock Front 160-220(progressive), Stock rear 240-420 (progressive) even though the weight on the front and rear axel is virtually the same. Since I do not track my car I do not know why most of the people on this forum choose to run nearly the same front and rear spring rates but I chose to go with a more autocross oriented setup which tries to get close to matching the front and rear wheel rates. I have a freind that is an expert on autocross suspension set up and this was his suspension suggestion along with a very stiff front bar(GC medium bar set to full stiff). It works quite well. It is tolerable on the street. At low speed the front suspension makes noise over small bumps...and the plates make noise at half lock or more (clunk)...after 25-30mph, or the window open, all is good. No quality issues and Jay is fantastic to work with at Ground Control.

[seank]

I do not know why most of the people on this forum choose to run nearly the same front and rear spring rates

I do not know the answer to this either. I do know that TC Kline were national champions 2 years in a row driving our cars and he said he ran 400 front and rear with no sway bar in rear for their track car (but sometimes ran a small sway bar in rear on some tracks). He does prefer a soft set-up though, which is why he did not run 500 or 600 front and rear.

I will be on the track this Monday (with Finnegan), so I will make my own determination of the 400/400 set-up.

I don't know anything about auto-cross, except that the fastest drivers use a too loose of a set-up for road racing.

[acceleration]

Originally Posted by Beedub

ok now we have an owner piping up.... cornering ability?? ride comfort???
how much noise???

chris noted that he had some quality issues, his was an early kit, do you feel these have been rectified??

and the biggy... chris noted that he couldnt get the brake lines and ABS wires to connect upto the G/C tab/bracket as its mounted to high?? your experience wit this??

how some some pics if possible :-) thanks for your help.... in the UK at least this setup is by far the cheapest and pffers everything you'd need to get a serious handling z4m, i can see the allure, infact i cant lie.... if ihad known about them, i think id have gone this way and saved £1000.

I have a later kit (2011). I brought these issues up to Jay when ordering my kit - I have not experienced any fitment issues with the brake lines.

No noise from the camber plates either.

[F360C]

I have been running a GC kit for over 3 year now and I love it! I am running the single adjustable rears with the double adjustable fronts. I started off with the 525lbs front/650lbs rear and I am now onto the 600lbs front/750lbs rear. I have no complaints about this kit at all. It does everything i ask of it and nothing has broken on it. I am a advanced solo HPDE driver and push this suspension to the limit and back. I do autox's, track days, set it up to drift sometimes and even drive it in NYC. The only gripe I have is the way the camber plates adjust. That is an easy fix though.

[ajw45]

I think you get what you pay for with GC. I had a full GC (single adjustables) kit on my last car which was great until I blew a front shock on it within the first year. When I approached GC they said it wasn't their problem and I should talk to Koni. Koni told me it wasn't their problem and I should talk to GC.

FWIW, for the z4m, I went AST/Vorshag.

[Beedub]

Originally Posted by ajw45

I think you get what you pay for with GC. I had a full GC (single adjustables) kit on my last car which was great until I blew a front shock on it within the first year. When I approached GC they said it wasn't their problem and I should talk to Koni. Koni told me it wasn't their problem and I should talk to GC.

FWIW, for the z4m, I went AST/Vorshag.

well GC answered this question for us... i contacted them via email, called and had no repsonse back, every other vendor got back to us within 1 day, GC??? nothing.... imo this speaks volumns....

In the end, he went with TCKline racing :-)
look forward to comparing to my Clubsports, are the clubsports the only race type setup that makes no noise......;-)????