Maybe I just missed it, but the search isn't helping me so here I am. I was looking for GRM's review and/or testing of the ISC suspension on their project car 350z. All I found was the install. I'm looking at getting ISC for my 328is (E36), and haven't found a ton of other reviews. As with any $1k coilover I'm a little hesitant, so I was looking forward to GRM's thoughts.
Failing that, what do you guys think about ISC vs Feal 441 vs ST XTA vs ? for an autocross/lapping day 328is? Budget is $1500USD. I'm in Canada, so that's more the top end (75c to USD and shipping/duty/15% sales tax on top of the $1500). Would I be better served with konis and springs? The rates on the usual suspect H&Rs don't seem to be high enough to be useful, or do much other than bottom out.
The BMW forums are full of "these $300 ebay coils are the most amazing thing ever", and "$5k or nothing", so I'm hoping you can help find the middle ground.
Edit: And I spelled budget wrong in the title. facepalm
Check out Ksport. http://ksportusa.com/ They had some issues in their early years when they were still learning, but their current stuff seems to be very good. Pierce Motorsports in Torrance, CA has won a bunch of races on them.
For $1kish I'd opt for a set of Fortune 500 series for the 350z or a set of KW v1s if you can find a steep enough discount. If you're willing to spend a little more there's Bilstein B14 or B16 and ST XTA.
Ksports get dumped on quite a bit by various communities for various quality control issues, it seems that the MS3 just eats those things as well as DC's and Racelands.
If you want to go cheaper maybe check Ground Control or another manufacturer makes a set of sleeves for Koni Yellows which would save you a few hundred and pair it with the spring of your choosing if the H&Rs aren't stiff enough.
Edit: you caught me in my ninja edit and I misread the question.
In reply to The0retical:
Yeah, I've looked at the regular ground control sleeves. Adding camber plates makes those expensive, but I probably don't need them.
ST XTA's are KW V2's with a camber plate, so they're a pretty good deal at around $1300.
The ISCs became one f my favorite budget options after putting them on the Z for a couple reasons:
1) The shock body length adjustability is awesome. Incredibly useful feature to retain full travel.
2) The physical quality of the units is really, really good. Excellent, even.
3) James Clay at Bimmerworld is a huge fan, and that's a solid recommendation in my book. The use them on endure cars a lot and report good performance throughout the heat curve.
Of course, the 32-position adjustment is marketing hype, but you got to cut them a little slack. In reality, we found about six zones of rebound adjustment, with the softest three being pretty closely spaced and the firmest three being fairly far apart in response.
I strongly considered ISC for my E36 328i. To be honest, I thought BC Racing, ISC, Fortune Auto, KSport, and Stance to be all similar products (similar designs, parts from China or another Asian country, same warranty time period).
I ended up going with Stance Super Sport coilovers as it had an adjustable camber/caster plate, compared to the camber-only plates from the other brands. I currently run -3.7 of camber and 6.5 caster, with room to get up to -5*; the plates work but I wish they were easier to adjust. They advertise an inverted front strut, so the adjuster is on the bottom of the strut body and you need to buy a 7" extension to be able to adjust the strut on the car. They are 15-way adjustable, but they recommend increments of 2for adjustment (and yes I feel that 7 settings are accurate).
I have about 2000 miles on mine and 3 autocross events. It's been holding up well daily driving through St. Louis too. I don't regret spending $1100 for this kit, as my budget was similar to yours. If I had $1800 to spend, I would have definitely gone with an adjustable Koni setup with better plates though.
In reply to JG Pasterjak:
Thanks for the info. I saw the issue where it was installed, then the axle failure, then never saw the driving impressions. They're probably at the top of my list right now.
In Reply to Minizguy:
Thanks for the input. I forget exactly how much caster I have now, but I've got offset M3 bushings in place, so already quite a bit more than stock. Not sure I'd want more, but some adjustability would be nice. $1800 becomes close to $3k landed here, which is why I'm not going with TC kline or GC or similar.
I'm building an E36 track car with V8 power. I'm getting the ISCs. For the price, their dampers seem to be able to handle a touch higher spring rates than the others at the same price-point. (I'm talking the street/strip version, not the race version; Bimmerworld thinks the dampers aren't up to the task for the race springs.)
I'm assuming they will leave me wanting more, since it's a purpose-built track car and I'm ultimately looking for higher spring rates, more like the higher-end GC stuff or TCK. But I don't have $2500 in the budget for suspension right now, and the stock dampers are shot.
I can't even find a used Bilstein Sport setup for less than $500, and they all look pretty shaggy -- not to mention that revalving prices have gone up to over $100-$150 per damper. I can easily re-sell an ISC setup for $700 if they have only been used for one or two track seasons, so they look like the best interim solution.
Bumping myself, but found a used (8k miles) Ground Control Koni setup for about $100 more than a set of ISC's, and I'm really torn on which to go for.
What would GRM do?
I'd go with the ISCs over the GC+Konis.
If the valve rates on the dampers of the GCs were consistent with my desired spring rates, I would get the GCs. They're a proven product, with good long-term service life. I would be comfortable they will last for many thousands more miles or a few hundred hours more track time. Also down the road I can rebuild the dampers for about $150 each.
But my problem is (1) I don't see decent GC coilovers for that kind of used pricing even though I keep looking and (2) the damper valving is always too low for my ultimate goal. Yes they can be revalved, but that costs something like $600 a set now.
