[JoelR]

Rather than continuing this: http://www.insightcentral.net/forums/modifications-technical-issues/25935-gaz-rear-shocks-gcs.html thread, I thought it would make sense to start a new one to cover the progress on building a set of aftermarket front struts for the 1st Gen Insight.

Overview:
To my knowledge, there are currently no sources for aftermarket front struts for the Insight. Koni have built at least one set of custom double-adjustable struts and shocks but they are about $400-$500 per corner. GAZ have produced a few sets of REAR shocks that are single-adjustable, appear to be well-built, cost around $120 per corner and as an owner of these myself, I wanted to see what GAZ could do with the front struts. I shipped a pair of old OEM struts to the UK for $95 and have been working through a few issues with Mark at GAZ since they arrived.

Goals:
To improve damping at the front
To match damping rates to different front spring rates
Affordable (Koni solution is about $400 per strut, I'm hoping GAZ can come in well under this price)

Features of the GAZ strut:
Rebound adjustability (e.g. single-adjustable vs. double like the Koni's)
Threaded strut body & adjustable spring perches for coil over springs

Issues So Far:
The 12mm piston rod is too narrow to bore a hole through for GAZ's adjustment screw.
Solution #1: Switch to non-adjustable design. I have no idea what damping rates I'd want so I don't like this option.
Solution #2: Switch the piston rod to 14mm. This will require changing the upper mount from a 12mm bearing to a 14mm bearing. Since I'm planning on installing adjustable camber/caster plates from Ground Control, this solution is acceptable to me. For others seeking a more OEM-like upgrade, we'll need to source a new strut mount or see if the OEM mount can be enlarged.

I'll post more as development proceeds.

Joel

 

[neloner]

Im in for an order for all 4 corners when you get everything figured out. Thanks for putting in the effort!

 

[Blue-Civic-Hybrid]

I'm in!

Joel, you know I am fan of GC, so I'm good with the 14mm bearing and of course throw in the caster/camber plates in for me too!

 

[dkim48]

I had my original top mounts machined to fit my buddy club struts from a rsx. Local machine shop charged $30.

Does ground control currently have the adjustable one in stock/off the shelf? Or is that something custom you are looking at? The reason I'm asking is the rsx top mount has a wider spacing on the 3 stud holes. Wondering what car they got the measurements from...

 

[JoelR]

The Ground Control camber/caster plates would be a custom thing. Once I get the struts back, I'll contact Trevor at GC to confirm compatibility between them and the plate/mount.

Being able to just machine the stock bearings would be a great option for those keeping the stock springs. (And I haven't a clue how good/bad the stock springs are vs. anything else since there's been little activity that I know of in this community to try different springs. Maybe an adjustable damping option will start to change that. )

 

[e*clipse]

Has anyone measured the OE damper?

Also how is the damper held in the strut? Threads, welds, etc?

It doesn't mention replacing the damper in the service manual, and I'm trying to avoid taking mine apart until I have some good solution possibilities.

Thanks a bunch,

E*clipse

 

[JoelR]

E*clipse: The OEM strut housing is welded or is otherwise permanently sealed and is not designed to have its innards changed out/serviced, etc. GAZ are using part if not all of the OEM strut housings, brackets (lower tabs that bolt to the knuckle, steering arms, etc) to construct a new strut that includes an adjustable damping unit at its core. In terms of disassembly and/replacement, you can only swap out the OEM strut as a unit (it doesn't come apart unless you cut it open--which I've done thinking I might try a Koni cartridge conversion).

GAZ have indicated that my struts are "in production" BTW after resolving the issue of the 12mm upper rod (will be M14). I've also learned that the coil-over spring size is 2 1/4" so I'll need to choose a suitable length & rate. Blue-Civic-Hybrid ought to have a recommendation from his Ground Control experimentation.

 

[e*clipse]

Hmmm, that's interesting. The FSM lists the damper as a unique part.

Well, it sounds like a good challenge. Other folks have done this mod for RSX's:

02 RSX-S KONI SHOCKS INSTALL - JDMCITY.COM

I've found a bunch of different Bilstein and Koni dampers with different diameters. Hopefully the Insight has a somewhat standard inner diameter.

Thanks for the info,

E*clipse

 

[JoelR]

I've heard today that my struts are done at GAZ and will be shipped to me with 300in/lb springs to try out. Ground Control ship 425 lb springs w/their kit so these, at more than double the stock rate of 111lb will be more comfortable than GC while still offering a significant increase in firmness. We will see!

 

[neloner]

Exciting!!

 

[Slippery]

Post some pictures when they get to you. I'd like to see them.
These questions may have been answered before but, What are you paying for them? Have you talked to Mark at GAZ about a group buy, especially one where we could save on shipping?

Thanks,
Don

 

[Blue-Civic-Hybrid]

WOW! I can't wait to see them! Please keep us updated Joel!!

 

[JoelR]

The struts arrived today.

My costs:

Donor OEM Struts (free)
Shipping to send donor struts to GAZ in the UK: $95 via USPS
Conversion @ GAZ w/300lb springs & return shipping: $567.55

Total cost for 2 struts: $662.55

In order to mount these to my car, I'm going to get Ground Control camber/caster plates so there will be additional cost there too. If you want to go with OEM upper strut mounts, you'll need to have the bearing machined from 12mm to 14mm & sort out some kind of adapter to go between the 2.5" spring & the OEM mount (I think). GAZ asked me to send my upper mounts but I declined so I'm assuming they have a way to solve this mating issue for you.

 

[Blue-Civic-Hybrid]

Wow those look awesome! Please put them on and let us know how they handle and ride!

 

[MaximumFuelage]

The struts arrived today.

My costs:

Donor OEM Struts (free)
Shipping to send donor struts to GAZ in the UK: $95 via USPS
Conversion @ GAZ w/300lb springs & return shipping: $567.55

Total cost for 2 struts: $662.55

In order to mount these to my car, I'm going to get Ground Control camber/caster plates so there will be additional cost there too. If you want to go with OEM upper strut mounts, you'll need to have the bearing machined from 12mm to 14mm & sort out some kind of adapter to go between the 2.5" spring & the OEM mount (I think). GAZ asked me to send my upper mounts but I declined so I'm assuming they have a way to solve this mating issue for you.

Now that they have made a set, I'm assuming they can repeat the process for less $? What wold they cost for someone to buy a set now that the fitment costs are over.

 

[JoelR]

I wouldn't get your hopes up about a big discount but I'd bet we can save some $ by combining shipping on the cores & the return of the finished parts. We could ask about keeping the OEM spring perches intact to facilitate keeping the stock springs or equivalent-sized springs that work. The Koni custom setup @ $400 per strut uses the stock springs & upper mount. GAZ charge just $218 per strut for their conversion.

I'll ping Mark @ GAZ about the above and see what he says.

Joel

 

[eq1]

....at more than double the stock rate of 111lb will be more comfortable than GC while still offering a significant increase in firmness.

Are you sure the fronts are 111 lbs/in? That doesn't sound right at all. Where did you get that number?

 

[JoelR]

Are you sure the fronts are 111 lbs/in? That doesn't sound right at all. Where did you get that number?

I got this # here: http://www.insightcentral.net/forum...es/10055-rear-spring-rate-2000-insight-2.html

It sounded very low to me but I haven't found another figure in my searching either. I have some extra front springs sitting around and could measure them I suppose.

 

[MaximumFuelage]

They still need cores after they used yours as a template? I was under the impression that they were replacements and not rebuilds of your existing units.

 

[eq1]

Well, that source seems like an honest attempt at the real spring rate, but it seems wrong. The stock rears are nearly 100lbs/in, while the fronts as I recall have a thicker wire (though maybe there's more, bigger coils?, which lower the rate)... Just would be odd considering the weight distribution of the car to have the front spring rate so close to the rear rate.

If you have the chance take some measurements for the fronts and let's put them in an online spring rate calculator.

We just need the number of active coils (ex. 5, 5.5, 6), outside diameter of the coils (ex. 4.5"), and the thickness of the wire (ex. 0.48")... "Active" coils excludes the parts of the spring at the bottom and top that don't get compressed, i.e. usually there's about a half coil at top and bottom that sits flat against the perch and top hat...

Here's a couple online calculators:
Coil Spring Rate Calculations by Wallace Racing
http://www.proshocks.com/calcs/coilsprate.htm

Wasn't anything to load at the second site, not sure if that's temporary or what... Calculations don't beat direct measurement, but it'll give us a good ball park figure... If you have a weight set, drop the heaviest plate you have on one of those springs and measure how much it compresses...