McKinney Motorsports Coilover install

[bryand2]

Hey guys, just thought I would share my thoughts on the McKinney motorsports coilovers which I just installed. The installation was fairly painless and the ride height, at its highest point is pretty low out of the box. There are a few things I am concerned about however. First is that Mack at McKinney, in a previous thread on here assured us here at HBZ that these were not Megan coilovers, when I got them they were in a Megan box, and the coilovers themselves say Megan on them. The second issue that I am concerned about is that according the McKinney, these coilovers are made by them for our cars, or modified for our cars with proper valving for the struts and spring rates for the weight of our cars. Well, the coilovers are really nice and I do enjoy them but the ride is way too bouncy which makes me wonder if these actually are s13 coils and not really tailored for our cars, anyone care to give their input?

[BluDestiny]

I was under the impression that they were megan ( I mean if megan is "modifying them" to fit out cars, then they are megan). I remember seeing a thread with one of them opened. I'm sure the valving is softer than the more basic megans, and the spring rates are a little softer. Doesn't mean they are perfect though. 

[R3VO 3VOM]

I see on their website that for each coilover option (tubes to weld on, full kit, or kit with hats) there is a mention of them using Megan S13 coils.

[johnc]

Its just the crap that Megan is.  Regardless of whether they "made" them for the S30 or not, they are crap shocks.

[RebekahsZ]

What do you mean by "bouncy", the whole point of coil overs is to have stiffer rate springs compared to stock. The only way to have a soft ride is to have soft springs.

[zero]

I think by bouncy he means under or poorly damped. That comes down to the quality of the shock.

[GreenState]

They are Megans, supposedly valved for the S30 chassis.  There was never any question of that.  The website even says, "The McKinney/Megan coil over kit for the 240--260--280 Z cars."

 

When you say "bouncy", what do you mean?  I have them in my car, I know they're not top-shelf, but I wouldn't describe them as bouncy.  A bit harsh on sharper bumps perhaps, but I found that actually went away when I added some more clicks in the stiffer direction. 

[R3VO 3VOM]

They are Megans, supposedly valved for the S30 chassis.  There was never any question of that.  The website even says, "The McKinney/Megan coil over kit for the 240--260--280 Z cars."

 

When you say "bouncy", what do you mean?  I have them in my car, I know they're not top-shelf, but I wouldn't describe them as bouncy.  A bit harsh on sharper bumps perhaps, but I found that actually went away when I added some more clicks in the stiffer direction. 

I never saw anything about the valving, but I may be wrong. What I think is meant by the Mckinney/Megan thing is the collars on the bottom mounting it to the car are from Mckinney and the coils are from Megan.

But either way, arent the S13 and S30 around the same weight? I own both and they feel just as "heavy" when I'm driving. Not saying it's not bouncy or anything, but if they are near the same weight why would they revalve them? I think they mod them to fit their tubes and stuff. But again, I do not know. I have ground control coils and sectioned struts. But interesting issue.

Edited April 4, 2013 by R3VO 3VOM

[Sideways]

What do you mean by "bouncy", the whole point of coil overs is to have stiffer rate springs compared to stock. The only way to have a soft ride is to have soft springs.

 

Maybe im being anal but i thought the "point" of coilovers was to allow for ride-height adjustment, more specific to tne the cross-weight and corner balance of the vehicle.

 

R3v0, the s30 is a fair bit lighter than an s13

 

 

[BluDestiny]

Sideways, my s13 came out at 2700lbs on a truck scale. My friends 280z came out at 2620lbs. My 260z came out at 2540lbs. All these cars had interior and ac and the 280 had a big ass bass in the trunk.

 

On the other hand I've seen a 240z come out at 2300 with interior (no Ac). The 240z is the only s30 that is really lighter. 

[R3VO 3VOM]

Maybe im being anal but i thought the "point" of coilovers was to allow for ride-height adjustment, more specific to tne the cross-weight and corner balance of the vehicle.

 

R3v0, the s30 is a fair bit lighter than an s13

 

 

The point of coilovers (not in the new "Hellaflush" movement) is to provide dampening adjustability and full spring adjustment (preloads, bounce, rebound, etc.). Ride height adjustability is just something that comes with all this. Now however, there are companies that build coilovers for the pure purpose of lowering the ride height of a car.

 

However, coilover spring rates are usually sized for a cars weight. But since these are so close in weight (unstripped S30 and S13) I think the spring rates don't really need to be considered. I think it all comes back to what JohnC said about them and that the bouncyness is because of the quality overall of the base coilovers, in this case Megans.

Edited April 5, 2013 by R3VO 3VOM

[tube80z]

However, coilover spring rates are usually sized for a cars weight. But since these are so close in weight (unstripped S30 and S13) I think the spring rates don't really need to be considered. I think it all comes back to what JohnC said about them and that the bouncyness is because of the quality overall of the base coils, in this case Megans.

 

The one thing to keep in mind besides the weight of the car is the unsprung weight on the corner.  If this is the same between the S30 and S13 then the frequency of the suspension should be the same and the damping should work.  But the difference between wheels and tires is a lot larger than most people would think and this can throw the frequency and the damping way off.  

 

I believe John is referring to the quality of the shocks and the damping curves above rather than the coil springs.  You can have a car that's stiff (2.5 to 3 Hz) that is damped in the 65 to 70 percent critical range that doesn't ride too bad.  Up that number and the ride is likely to become a lot harsher, which could be bouncy.  For a street car where ride is important there are typically setup with what's called flat ride.  This takes into account how bumps are encountered and how the car would feel to occupants.  Generally this is a setup that has the rear slightly stiffer (higher frequency) than the front.  For a race car they are often setup the opposite to help support the chassis and put power down.  And these often feel much rougher when riding in them.

 

There are a lot of kits out there that claim they are "valved" for a certain car.  I'm sure they were but unless you have a setup really close to the car used for development then you may not get very good results.  It really doesn't cost all that much extra to have this done for your car but it does take a lot of work to get all the measurements.  You can find more information in the shocks/springs/suspension sticky.

 

Cary

[h4nsm0l3m4n]

As Cary mentioned there is a bit more to spring rates than just the weight of the car.  Ideally you want to calculate the spring rate on a car based on a variety of factors - unsprung weight, motion ratio, target wheel rate, etc. 

 

The motion ratio of the rear multi-link suspension on a s13 is very different from the Mac-struts on a S30.  I think this alone makes comparing spring rates of different cars relatively meaningless.

 

Regarding the Mckinney kit, I've been running this kit on my car for a while now.  Ride on the street is reasonable (for a car with all heim jointed suspension) and I've had several autox TTODs and usually finish in the top few cars against some stiff competition.  The Megan shocks are far from the best and if youre building a perfect or nationally competitive car are probably not what you want, but they can be made to work well enough.

Edited April 5, 2013 by h4nsm0l3m4n

[GreenState]

Here we go, I'm not imagining things:  http://forums.hybridz.org/topic/100338-new-meganmckinney-coil-over-kits-for-z-cars/

 

From the link:

 

Working with Megan Racing we have developed a new coil over kit for the 70-77 Z cars

 

all CNC machined to insure fit and threads that work with springs and damping to match the Z car these are ""not"" converted 240sx kits...dampaners are a different length and dampaning rate

 

These are spring and hight adj seperate like tandard Megan coil overs.

[R3VO 3VOM]

I guess I stand corrected. I never saw that thread before. But either way, back to what JohnC said, the bounciness is still because of the overall quality, of which Megan is not the top of. Not saying their bad, just saying they are not the best.

[bryand2]

Here we go, I'm not imagining things:  http://forums.hybridz.org/topic/100338-new-meganmckinney-coil-over-kits-for-z-cars/

 

From the link:

 

Working with Megan Racing we have developed a new coil over kit for the 70-77 Z cars

 

all CNC machined to insure fit and threads that work with springs and damping to match the Z car these are ""not"" converted 240sx kits...dampaners are a different length and dampaning rate

 

These are spring and hight adj seperate like tandard Megan coil overs.

Thanks, that is the thread I was referring to

[bryand2]

And yes that it was I meant by a bit bouncy, the valving of the shocks feels like they may have been valved for a heavier car

[240zdan]

its about time megan started toying with producing with s30 specific coilovers, However, I always thought there just wasnt enough demand for them.

 

Either way, s13 coilovers with mckinney adaptors is a bad route to go cost wise!

[Z Fire]

I am in the process of installing the McKinney kit in a 280Z. I noticed that the pillow ball joints are very stiff and that the front springs actually rotate on the spring perch instead of rotating the pillow ball. Is this normal ?

[johnc]

Not normal unless you're checking the rotation with no load on the springs.  Fully loaded should see the pillow ball should take the rotation.