My 91 Z28 had Monroe shocks and struts on it when I bought it. Shortly after I bought it I replaced the rear shocks because they were leaking with some Lakewood 50/50 drag shocks because I had them laying in the garage left over from the other car. The Lakewoods pretty much feel like any typical parts store shock for these cars. The car handled ok but nothing spectacular.

I lowered the car(about 1 1/2in) by cutting the stock springs. It didn't take long for the Monroe struts to give out once the car was lowered. The car had that floating feeling and would bottom out easily when going over a bump. I ordered a set of Koni Yellow shocks and struts last week from anythingauto.com and installed them yesterday. Got them for $644 with free shipping.

What a huge difference, feels like a completely different car. The tires stay glued to the road over bumps, curves and dips in the road. The handling is much more predictable. I was worried that the ride may be to hard but its not at all. My car isn't a daily driver but I wouldn't hesitate to put these on one. Right now I have them set on the full soft setting, I may try a firmer setting later to see how it feels. The koni's did raise the ride height slightly especially in the rear. I'll see if it settles anymore, if it doesn't I may cut a little more off the rear springs to compensate.

For reference this car also has SFC's, LCA relocation brackets, UMI LCA's, UMI adjustable panhard bar, and 17in(245's front, 275's rear) firestone fire hawk tires.


For those debating if its worth it to upgrade to Koni Shocks and struts...Do it! They are expensive but worth it.

 

They will not settle. The rears monotubes are high pressure gas charged (about 20bar) and the front are twintube gas charged (about 5bar) so they do extend a little more lifinting the chassis just slightly compared to a non-gas hydraulic twintube. That is why the rear lifted slightly more than the front. You will need to just slightly trim the rear coils.

Try the rear on click 1 (0-3 clicks, koni settings are 0,1,2,and 3 in those 4 settings order from soft to firm in rebound ONLY)

Dial the fronts about 3/4-1 turn and you shold have a very decent cornering car. if the car pushes still in the corner, then go to click #2 on the rear

 

Thanks for the info, I'll give those adjustments a try.

 

Every time I read a thread on this forum talking about Koni's I want to buy. I've been rockin' the GR2's for a few years now and am not horribly dis-satisfied by any means, but dang if the Koni reviews aren't always stellar.

 

I ended up cutting a little over 1/2 a coil to get the rear ride height to back to where it was, a little more than I anticipated. The highest point on the front wheel well is at 26.5in and the rear is about 26.75in. Just enough to be noticeably lower than stock but not so low it has ground clearance issues.

I set the rear at click one and the front at 3/4 turn. I drove the car and then tried the front on 1 turn and it seemed to feel best that way. The ride is now more firm for sure, slightly harsh but not horrible and the handling is even better. The car is definitely much more fun to drive now vs when it had the old shocks/struts.

 

No regrets with koni yellows.

 

JamesC

 

I wonder if there has ever been a bad review of them. LOL

How about a neutral review.

I dont pretend to know what they do that makes them so special but whatever it is they do it well.

I have to say bang for the buck they are the best mod I have done for my car. I did completely rebuild my suspension and that included weight jacks with 900lb springs front and 200lb rear but I don't think they did it.... Del-A-Lum, nope, but they for sure are making a firmer smoother front end.

I think it all added up but I give 85% of the credit to the Koni yellows.

I'm still on the softest setting. I also still say they are smoother. Before when I hit bumps it was jarring. Now I glide right over and the car stays planted. I cant even explain it but I let a friend drive my car and he could not believe it. Even he was speechless.

BTW I will for sure spar with Porsches and other "Super Cars" on curvy roads when I can. I bet I will catch a few by surprise now. They are going to hate seeing that GTA badge glued on their bumper.

Just need tires now.

 

Funny you say that becasue I have actually given them some bad reveiw points- 2 different reasons, one being personal

1)they are notorious for having paint dipped ontot he threads of the stud mounts. You need to be careful and run a die (as in tap & die set) over the thread to make sure they do not strip.

2) for my personal choice of my lightweeight 60*V6 build with massive 825lb front springs, the Koni fixed compression valving as a tad too firm. For the V8 cars they are excelent becasuse of the heavier nose weight. I really should have had my revalved 1 point lower becasue sometimes when I hit downhill cornering dips the tires would overload and skip the car sideways rather than absorbing just a bit more travel

 

Excellent. And now wait until you try turning them up to 1/2 turn to 1 full turn. It will be that much difference again from how it was with the old struts.

 

I am going to have to break down and buy these soon. I get so jealous whenever someone posts how happy they are with their new Konis.

 

#1 They may have fixed the problem. Mine had caps on them to protect the threads.

As far as your #2 I bet the LS1 guys would have a problem also. Not the truck engine guys the REAL aluminium block swap guys.

My only complaint is I wish the **** for the front struts snapped on and stayed there. They would have to send 2 but no big deal. I mean with all the storage room in our cars whats one more thing. LOL Also no BOOTS!!

But I will live with that for the upgrade and its not a complaint at all.

 

LS1 over those misused LQ's any damn day.

 

I was thinking about this. Why couldn't you go with a lighter spring and fix this problem.

 

Becasue a lighter weight spring would allow the car to roll left or right at a higher degree of angle when considering the grip I had- as well as front suspension compression height under extreme distance braking zones. A softer spring would eventually aloow the suspension to compress further in 3 seconds time than a higher rate spring under the same braking and grip force. It would increase the pitch and roll angles of the car under dynamic situations.

Lets take two combinations that will for example sake look identical in a 1 second time lapse, but will differ in a 3 second time lapse. Those small bumps and dips,etc will all seem the same but the "set state of the car in a long corner or a long braking zone with over 1 second time frame will start to change.
lets take a compression valve chart like QA1 has (I am very familiar with them since it is what I would revalve when I was in NASCAR)
QA1 valves are 1-12, 12 being most resistance.

you can have a 350 lb spring with 3 compression valve, be equivilant over small bumps as a 250lb spring with a 5 compression vlave on our Supertruck. In corner set, the nose of the 250 spring would dive down from 4 1/8" static ride height (remember we use coilovers so no matter what spring rate I can set the ride height the exact same at 4 1/8" on the LF chassis) it would compress the RF spring 2 5/8" travel in steady state (mid corner set) of the bank turns. The 350 spring #3 valve would travel only 1 7/8" (in most cases- it would vary on temp and track conditions. We would increase grip and have to throw a spring rubber intot he coil in the rare case the bigboys came into town and we ran our race right after they layed down qualifying runs. WHy? they ran synthetic rubber and we ran Hoosier SX race tires which are natural rubber. The two combined will increase track surface grip and cause the car to roll a bit more as a byproduct of a bit more corner speed due to grip. Spring rates have everything to do with supporting the chassis weight in corner roll and overall suspension articulation travel. It is all about different drive feels and wants. Whether a driver wants to run the inside flatter line slower and flatter, or run the outside high line with more speed and more bank turn compression of the chassis. I would also cake other very complicated schanges to go with it all that go with it all to make it work- the main one being how much my crossweight was which each setup. I had less X with the high line and more X with the low line and softer springs- that helps suport the RF wheel travel. The low X would be as high as 56.2, whereas the high spring rate cross would never get over 54.5- mostly at 53.9-54.2 range based on every set of new tires. it gets quite technical, but I think you can see why spring rate changes are not something you do just for kicks. Its what the car needs based on collected data- every car and driver and tire grip, and bushing flex, and so on, and so on, are different. Its why when people ask- What spring rate should I run? we have a general idea as to what range, but can not give individual actual needs.

 

Further more- I would change the compression rate of the left or right front shocks so they they never matched.(In circle track racing nothing ever matches left to right in symmetry becasue we only turn left) but the split in the difference I would change to either tighten of loosen the car going into the corner under initial braking. If the car was tight, I would increase the LF shock compression valving one # so the wwieght transfer would stand on it momentarily a bit more under dynamci motion and thus lessen the x-weight and weight the inside front so it bites and turns- this is ONLY a momentary thing under braking weight transfer force if the car was tight. If it were loose I would go the other way.

More of an answer than you were expecting

If you start to understand just how much I know about vehicle dynamcis, you start to trust and understand why I am fast behind the wheel of anything. I understand what all is going on under the car and know what I need to do to try and trick it to work better under exagerrated mometary forces. I even shift my weight driving something so simple as a go karts- thus the Slick Track God. nickname I was given.
you can watch me at work on a litlle video I did for fun with one of the local 3rd gen groups at a go kart track recently. you need to remeber I am a big ad tall guy 6'4" and 225 lbs. Most of these guys you see me passing are about a buck 50 to a buck 70 range. Figue what would happen if they put a 50 lb bag of cement on their seat adn then tried to race me- they would side as high as me and weight the same. Its all how you wieght the car in corners...or the kart.



ANother footage of another club- this time SC3G at a local slick track. Im the tall guy chomping the cheeseburger- watch me tear them up on the slick track footage..lol- I also beat them all on the dragsters, and their all mostly drag racers.. You can learn alot on go karts by refineing your skills and using proper body weight position.

 

I swapped an aluminum LS2 and Champion alum radiator. It's still heavier than V6 by a bunch - but I took off at least #100 off the front (not including my un-sprung weight savings).

I'm running #850 w/yellows (soft) & #200 w/QA1 (3rd click) coil-overs. Car is firmly planted and not harsh at all. Probably need to swap to a #21 rear sway bar (have stock 36/24) soon, though.