I don't mean to sound rude etc....but I also think that even if the Megans are a bit rough (for whatever reasons)....if you've had a problem with constantly bending wheels, you may want to consider higher quality wheels. Even with a super stiff suspension a good wheel shouldn't bend just hitting big 'bumps' in the road.....MAYBE....just maybe they'll bend if you hit a massive crater sized pothole.

I agree....Megan's aren't the most comfortable ride out there. And from what I've been hearing....Cross's are great. I just think that if bent wheels are what you're worried about and your wheels are bending on simple bumps..... getting slightly less stiff coilovers might not cure that particular problem.

 

they are stiffer than most, but never had a problem with bending rims. even on the biggest of potholes. Mainly just worried about the strut itself, or mushrooming my towers.. Like rally said a good wheel shouldnt bend. I dont have a link, but there is a video of the schmidt (spelling?) wheels being tested. Really awesome

 

Not sounding rude---I'm just stating a fact in my situation that my previous suspension--FSDs and lowering springs never rattled my teeth or made an impact so loud inside my car that I felt like I was breaking something on the same bumps that I drive every day. But the overall improvements of the Megans mean that I would never go back to non coilovers.

My wife has noticed it and so has another NAM member that lives near me that also bought a set of Megans based on my recommendation. We drive the same roads and experience the same lousy issues. He's on 18's and was on very stiff lowering springs before the Megans and although the overall ride is improved the harsh impacts can't be ignored--when it happens it's bad enough to curse loudly because you don't expect it. I know you guys love your Megans, but if you felt the impacts we are feeling, you wouldn't second guess why the wheels are getting damaged.

And like I said, it's the type of bump that matters. Holes and drop off bumps don't impact my setup like raised bumps do.

When I drove another NAM members JCW with the Cross's around my shop--before I had Megans, we compared the ride, and both concluded that the rides were very similar.

Finally, I'm not trying to convince any of you guys to buy something else--if it works for you great, but it's not working for me, and I have a feeling that my friend wouldn't be on the Megans if he could afford the Crosses.

Maybe I'll shoot some video to document the Megan ride before I switch out on Thursday. lol.

 

I loved mine simply cause they gave me the ride height and camber that I needed....but I know exactly the impacts you're talking about and I had them too. It rattles everything and sounds like "BAM!" Even after 2 years of those bumps...my wheels never bent.

I wasn't trying to say the Megans rock...I know they're a stiff ride and fully agree with you on that. I've been through the rough bumps just like you have. I'm not trying to convince you to not get Cross's..... I'm just saying that the stiff ride may not be the main cause in the bent rims.

I've sold mine and I'm moving to a new smoother suspension...just as you are. I just thought I'd chime in....cause I've run Megans and I've run flik wheels (your custom red+black wheels are fliks right?). Fliks are notorious for bending....

 

You're right about the Fliks. I don't have much experience with other wheels, but I know that after 50,000 miles of driving in the past year, I didn't get the shakes at speed (despite repeated rebalances, the last rebalance the tire shop showed me a flat spot on a rear rim) until I switched to the Megans. They didn't see any flat spots on the front rims when rebalancing, but like I said, the vibration got worse after I hit a new section of concrete last week on my way back from my son's school in Marina Del Rey--so I assumed I bent a rim. Btw, I've also got Powerflex bushings, so that also enhanced the overall shakes, lol.

Any idea if Enkei's (made in Malaysia) are more resistant to bending? I have a set of RS7's now that is awaiting a set or RE-01R's that should be arriving today.

https://www.northamericanmotoring.co...d.php?t=142999

 

Enkeis will be less prone to bending than the Fliks....but they're still what I call 'tuner' wheels which tend to be less strong than other brands.

 

OG, what Projeck7 is telling you is the "holly grail". This is where you should start your search for answers. If you'll be pulling a wheel off, look at available "compression" travel. Just put a jack under the A arm and compress the suspension. Then look at how much travel you have.



On sharp bumps you're compressing the suspension and if there is little left to compress, you'll get that teeth ratling expererience. On holes and drop off, is the opposite (extending) and the C/O recovers much better.

 

Excellent questions and advice. I'll take a look and see.

Richard

 

Nice to see it in writing.

When I set up Megan I do very little preload. Now I understand why I never had the pot hole issue. I just did it because most people really do not want the buckboard ride.

GOOD explanation !

 

 

Sorry, Yes you would have to pull the rubber boot off or try to lift/lower it so you can get a peek at the travel. I did this whole experiment and the answers were...well "shocking"...

 

I think my boots are torn--atleast the rear ones were--so should make it easier I guess, lol.

Once you did the test, were you able to correct it or did it just provide you with more knowledge about what was going on?

 

Another important piece of info:

The amount of preload to get ride height settled at the right place within overall travel varies depending on spring rate and spring length. Therefore it is important to know the specs of your springs.

The Megan dampers have 3.5" of total stroke [which is really not much]. For my car I set it up so that the ride height settles at about the bottom 1/3 of the overall travel [just like stock]. This leaves just a little more than an inch for compression travel, which is decent since we run pretty stiff springs.

 

It gave me more knowledge and understanding of the limits of the suspension/CO.

There is really no way to "correct" it but adjustments can be made to enhance the ride. However, keep in mind that some adjustment will have an effect on other parts of the system such as adding more preload will increase ride height. But that was a compromise I was willing to accept.

I, like Projeck7, ended up changing springs (I'm running with Eibachs 6.75 up front) and it made a world of difference.

But as Projeckt7 stated, pre-load as well as spring rates and lengths will dictate how much travel you can achieve for both bound and rebound.

 

Hey projekt7 you are hired

 

Maybe it's time to give me the keys to the AXC warehouse then

With the Megans, is there a custom spring rate option? If so, perhaps you could specify different front springs (7kg/mm sounds nice ) for future orders. I truly think it's a better option than the 8kg/mm originals in terms of ride height, ride quality, and handling balance.

 

spring travel required/desired is determined by:

Select a desired spring rate

Then take one of your corner weights - one of my front corner weights is 852lbs

Divide the corner weight by the spring rate - lets use 400lb. We get 2.13. This figure is the number of inches a 400lb spring will compress with 852lbs stting on it. so, we've lost 2.13 inches already.

So, when selecting a spring rate, you must find its free length and subtract from this block hieght - spring totally compressed. From free length, subtract 2.13 in the above example and you have the amount of available travel that remains.

for a given length, heavier spring rates have less travel becasue the coils are thicker. Don't let the heavier rate fool you into thinking you can do with less; steady state cornering loads can very easily compress some very heavy springs causing spring bind. Transient respsonse more than likely will not cause a spring to reach block hieght unless it is too soft or too short.

Eibach have a great chart. You can experiment with different rates and lengths to get a feel for what happens to travel. you should set the spring between the perches just tight enough to keep them from unseating at full droop. If you do this, you will have preserved as much spring travel as is possible...they can wiggle just a tiny bit at full droop. no more.

 

For those with the desire to experiment with springs, I've got a few month old set of Megans in excellent condition for a cheap price. Both rear boots are torn--the front ones are fine. I'll be putting this in the Marketplace. I got the Crosses today--dropped the fronts a little lower, and now have gobs of dampening..for most bumps it feels like it's floating over them. For potholes and the same bumps that were teeth shattering are now smoother bumps. And for other road imperfections if feels just like the Megans did. Seems to have given me the best of both worlds. By the way, turns out the vibration wasn't from denting my front wheels from the impacts--so not sure how one of my rear wheels got dented--but the alignment was off on my front left wheel--it's corrected and now the vibration at speed is gone as well.

 

OG, please give us a full write-up once you've had the chance to put them to the test. I would really like to hear (read) a full comparison between the two.

 

Will do!

 

This is a very important statement you've made!! However, I think you're forgetting a critical aspect of the Megan C/O and others. (to be clear, I have underlined and bolded a section of the quote).

In the perfect set up, your analysis would be correct. But in the Megans there is an additional variable that has been introduced and thus changes "available damper" travel. Notice, I've said damper and not spring travel. There is a difference here. The introduction of the damper body into the spring will have an impact on 1) spring compression and/or 2) damper travel.

So, let me see if I can explain this. Let's use the spring you mentioned above Meb and let's use the Megans' spring length of 150mm (6"). Based on your calculations, this spring will compress 2.13". Now let's take the Megans' total damper travel of +-3.5". This means that at full extension, the damper shaft will be 3.5" extended (at maximum) above the top of the damper body.

Now let's do the numbers. First let's assume no weight on the c/o. If we set up the spring w/o preload as you're suggesting, there will be 3.5" of shaft exposed and 2.5" of damper body inside the 6" spring (3.5+2.5=6). I hope this makes sense. So in essence, the lower perch of the spring is 2.5" below the top of the damper body. Second, adding the weight of the car on the c/o will compress the spring 2.13". Now, take this loss of 2.13" from the damper travel of 3.5" = 1.37" of available damper travel (not spring travel). This is critical because we already lost 2.5" of spring travel to the introduction of the damper body inside the spring. To make matters worse, let's take a .5" rubber bump stop on the damper shaft and you've essentially limited your total available damper travel to .87". (just look at the picture I posted above). And this is on a 400lb spring, a lower rate spring will compress even more.

With this set up, you will never hit block rate because you'll run out of damper travel (bottom out) even before the spring fully compresses.

What Projekt7 stated is very important in that preload will determine where in the damper body the shaft will settle thus available travel. So here goes, the less preload....the lower the shaft will settle into the damper body.

Now, IMO, the optimal system, one that would utilize the maximum spring travel, would be one that has very little intrusion of the damper body into the spring area.

All C/Os that have this "intrusion" of the damper body into the spring will have a limiting effect on damper travel. And this intrusion is amplified by not applying preload to the spring.

My goal in setting up my system was to minimize this intrusion by preloading the spring so as to preserve as much damper travel as possible. Ofcourse, there is a limit to how much preload to put on the spring but Megans do not allow for enough/too much preload.

I know this sounds very confusing but I will try to clarify if need be.

 

I have to read your reply a couple more times to understand...I think we may agree. I was simply highlighting spring rate and available spring travel. But you are correct, the damper shaft or position of the stroke from rest is very important. I can tell you that when I used these, my springs were set at the very top of the damper sleeve; I incorporated the shortest spring possible - less weight - but also a length that allowed the damper to utilize its full stroke.

The original bumpstops were a huge problem...I never bothered to check these and at an open event at LRP - open meaning passing anywhere - we all really pushed our cars to the limit. Early that day, after abrupt slides thru most turns at speed, I discovered the bumpstops were too long. yes!

...If I remember, I used a 400lb 8" eibach spring at 2.5" dia - spring travel is about 4 3/4"...I think.

 

Yes! I played with this idea but realized that a longer spring is not necessarily better if there is no preload placed on it.

There is 2" difference from a 6" to an 8" spring. If it's not preloaded, what it's really happening is that the lower spring perch is 2" lower into the damper body as compare to the 6". (does that make sense?). So, the instrusion of the damper body into the spring goes from 2.5" (on a 6" spring) to 4.5" (2.5+2) on an 8" spring. The shaft cannot extend any more than the available length of 3.5".

So, you've gained no additional damper travel.

By preloading, you have limited/controlled where the shaft will settle into the damper body.

We are on the same page, it's just understanding how this additional variable is effecting total spring travel and damper travel.

 

...so I had 2.62" of spring travel left with 852lbs resting on the spring...if the spring perch is nearly as high as it can be, then the piston rod intrude less into the damper body...but this will change with different spring lengths. A shorter spring will allow the pistion to intrude further into the damper body for a given upper perch setting, yes?

I'm sort of lost, but lets assume one thing before moving on. The damper's stroke is 3.5" and the meat of its damping curve is smack in the middle - I never dynoed these so I have no idea what the damping curve looks like, but fine tuning can certainly take advantage of stroke length as it relates to damping curve, which may or may not be smack in the middle...anyway I digress.

 

I think you've got what I'm trying to say. And you're right, I also assume that the meat of the damping curve is in the middle but the Megans have some limits which we can discuss later (i.e. damper body threads not going all the way to the top of the body).