Koni STR.T LT Shocks

[mracer]

I think this may be my first post here.  I purchased my 2015 GMC Sierra All Terrain new on 12/31/2015 and it currently has 75,000 miles on it.  The stock Rancho shocks weren’t great new and have since degraded to the point I needed an upgrade.  Been looking at options for a long time trying to figure out what I really need, not just want.  I drive 98% on the road.  A half mile of gravel road at my lake house is the most off-roading I ever do.  I wanted something that would be good for the type of driving I do.  I’ve used bilsteins in the past (4600 and 5100) on different vehicles.  When I had them on my GMC Yukon I felt they were a little stiff.  Anyway after searching for months I ran across these new shocks from Koni.  Tire rack had a smoking deal on them so I decided to take a chance.  I’ve had the rears installed about 2 weeks and the fronts installed a week ago today.  Just got back from a trip to the lake and, after putting about 500 miles on them, I have to say I am very pleased.  They ride great, especially compared to the Ranchos.  Really eliminates the hard impacts that I was experiencing with the ranchos.  I feel that the suspension is actually able to work now.  I have had a motofab 1” level on it since right after I purchased the truck, and I left that on there with the new shocks.  Thought I would share this info as I’m sure there are others, like me, that don’t do much off reading and need a good shock for the road.  

Edited June 18, 2020 by mracer

[TrillWill]

Thanks for letting us know. Theres always going to be someone who will search and find your post. Do you have a link to the shocks you bought? I want to purchase the same ones you have

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[TrillWill]

I think this may be my first post here.  I purchased my 2015 GMC Sierra All Terrain new on 12/31/2015 and it currently has 75,000 miles on it.  The stock Rancho shocks weren’t great new and have since degraded to the point I needed an upgrade.  Been looking at options for a long time trying to figure out what I really need, not just want.  I drive 98% on the road.  A half mile of gravel road at my lake house is the most off-roading I ever do.  I wanted something that would be good for the type of driving I do.  I’ve used bilsteins in the past (4600 and 5100) on different vehicles.  When I had them on my GMC Yukon I felt they were a little stiff.  Anyway after searching for months I ran across these new shocks from Koni.  Tire rack had a smoking deal on them so I decided to take a chance.  I’ve had the rears installed about 2 weeks and the fronts installed a week ago today.  Just got back from a trip to the lake and, after putting about 500 miles on them, I have to say I am very pleased.  They ride great, especially compared to the Ranchos.  Really eliminates the hard impacts that I was experiencing with the ranchos.  I feel that the suspension is actually able to work now.  I have had a motofab 1” level on it since right after I purchased the truck, and I left that on there with the new shocks.  Thought I would share this info as I’m sure there are others, like me, that don’t do much off reading and need a good shock for the road.  

Thanks for letting us know. Theres always going to be someone who will search and find your post. Do you have a link to the shocks you bought? I want to purchase the same ones you have

Sent from my SM-N975U using Tapatalk

[mracer]

11 minutes ago, TrillWill said:

Thanks for letting us know. Theres always going to be someone who will search and find your post. Do you have a link to the shocks you bought? I want to purchase the same ones you have

Sent from my SM-N975U using Tapatalk
 

https://www.tirerack.com/suspension/suspension.jsp?make=Koni&model=STR.T+LT+Series&group=STR.T+LT+Series&partNum=8850-1037&autoMake=GMC&autoModel=Sierra+1500+4wd&autoYear=2015&autoModClar=Crew+Cab

[lucas287]

35 minutes ago, mracer said:

https://www.tirerack.com/suspension/suspension.jsp?make=Koni&model=STR.T+LT+Series&group=STR.T+LT+Series&partNum=8850-1037&autoMake=GMC&autoModel=Sierra+1500+4wd&autoYear=2015&autoModClar=Crew+Cab

Thanks for taking the time to make this post! I, too, agree that Bilsteins can be a bit harsh. Controlled = yes, but they don't do the best job of filtering out small bumps. No doubt, these are not monotubes, but Koni makes some of the best twin tubes out there. 

[lucas287]

On 6/18/2020 at 5:28 PM, mracer said:

I think this may be my first post here.  I purchased my 2015 GMC Sierra All Terrain new on 12/31/2015 and it currently has 75,000 miles on it.  The stock Rancho shocks weren’t great new and have since degraded to the point I needed an upgrade.  Been looking at options for a long time trying to figure out what I really need, not just want.  I drive 98% on the road.  A half mile of gravel road at my lake house is the most off-roading I ever do.  I wanted something that would be good for the type of driving I do.  I’ve used bilsteins in the past (4600 and 5100) on different vehicles.  When I had them on my GMC Yukon I felt they were a little stiff.  Anyway after searching for months I ran across these new shocks from Koni.  Tire rack had a smoking deal on them so I decided to take a chance.  I’ve had the rears installed about 2 weeks and the fronts installed a week ago today.  Just got back from a trip to the lake and, after putting about 500 miles on them, I have to say I am very pleased.  They ride great, especially compared to the Ranchos.  Really eliminates the hard impacts that I was experiencing with the ranchos.  I feel that the suspension is actually able to work now.  I have had a motofab 1” level on it since right after I purchased the truck, and I left that on there with the new shocks.  Thought I would share this info as I’m sure there are others, like me, that don’t do much off reading and need a good shock for the road.  

Still enjoying these bad boys? Silly question, but does the color bother you? Have any pics you could post?

[lucas287]

Okay y'all. Despite not hearing back from @mracer  I went ahead and bought the Koni STR.T LT shocks for my truck. All four corners. I hope to get some free time today to put the fronts on, but did the rears last week since they only took about 5 minutes. I've driven a couple hundred miles since then. 

 

ALSO PLEASE NOTE: My truck has 76,000 miles on it. But I already had Bilstein 5100s on the rear. Fronts are the stock factory units. 

 

There are hardly ANY reviews out there on this new line of Koni's. In fact, they've never played in the truck space because it's dominated by a handful of competitors. Koni has a generally good reputation in motorsports though. Lots and lots of great experience out there and that was a big guiding factor. 

 

Also, these statements from Koni carried a lot of weight:

 

"One of the key reasons why we chose twin tubes for the LT STR.T is that they generally have better ride quality on imperfect road surfaces when compared to mono-tubes which can tend to provide a more harsh ride quality over impacts, kind of like reading the road surface in braille and transmitting it to the cabin. That is a bit of an umbrella statement because it is still very dependent on the actual piston valving technology inside the shocks regardless of monotubes vs. twin tube and gas pressure but all else being equal, higher gas pressures do kick back more of the road feel.”

 

“Pickup trucks are particularly challenging because they are over sprung especially in the rear for usually 95% of standard usage when they are unloaded but they need a lot more control for the limited time when the bed is loaded or they have trailering tongue weight on them. They have a basically 2 dimensional frame with the cab and bed as two separate parts which make them easier to flex in the middle than a one piece body car or van. A good twin tube can help isolate that and that is the goal of LT STR.T. It is never going to ride like Grandpa’s Cadillac but it will take some of the edge off.”

 

Observations:

 

*Build quality isn't as nice as Bilstein. 

*The orange color isn't THAT offensive. Though a zinc coated 5100 piston mounted downward is a much better look. 

*Before installing I did the ole trusty "push" test. They compressed very easily. In the past I would've been concerned about that. Now that I understand shock damping (a little) I realize that test means next to nothing. 

 - the Bilsteins by comparison are much harder to compress. 

 

Ride Quality:

 

Dramatically different. It feels like I did something much more substantial than just a shock swap. It feels like I put a set of Deavers on. (have them on my NBS Silverado) With the Bilsteins I was a little disappointed. They were just too stiff. In my mind, I didn't attribute it to the Bilsteins themselves. I thought it was the spring rate! But I removed the Bilsteins the morning my Koni's were supposed to arrive. Later in the day I climbed into the bed to gather up some ratchet straps forgetting that I removed the shocks. What I noticed is how easily the rear end bounces up and down. It took hardly any weight to cause it sag. I could push on the tailgate and get quite a bit of motion with little effort. With the Bilsteins it was almost rock solid. Rear end felt really stiff. I realize some people like that. Some people tow or haul a lot or just like a stiff truck for bragging rights. I don't do any of that on a regular basis and would much prefer a softer riding truck to capability. 

 

Do the Koni's feel TOO soft? Nope. Not one bit. What they do is the let the rear suspension move! I actually have suspension travel now. There's a section of IH-10 I travel regularly that's under construction and it's like whoops in the desert. It's handles these beautifully! Chopped up roads and broken pavement are also much improved. I'm rolling on 275/55R20 Michelin Defenders so I still have quite a bit of road feel. But all the little bumps and breaks in the road feel much better. 

 

I haven't even done the front yet! I'll report back once I do. But I imagine that I'll be even more impressed. 

 

 

 

 

Edited July 13, 2020 by lucas287

[lucas287]

Installed the fronts yesterday. What a bi***. Primarily because I tried using a rented spring compressor. Horrible idea. These springs have a CRAZY high spring rate. Makes sense though because the shock has such little travel. I gave up after the assembly came apart and shot across my garage lol took it to a local shop and paid $30 and they were done in 20 minutes. Aside from that debacle, super easy install. 

 

*Old shocks looked like crap. 

*Old shocks still functioned fine according to the trusty "push" test. The piston moved smoothly in and out with no qualms. It seems they weren't "shot" just the valving sucked. 

*Koni's assembled just fine, reusing the top mounts, jounce bumpstop things, dust covers, etc.. 

 

I've only driven about 30 miles and don't want to make any hasty comments, but here's what I can say so far,...

 

*Rebound damping is spot on. IMO, this is where OE K2 shocks suck. This is evident when you drive over a speed bump at any speed >5 mph and the front wheels drop down so fast and clunk in the process. It's like there was zero rebound damping. Pot holes, expansion joints, constructions zones all sucked. 

 - But now, that edge/harshness is not there at all. 

 

*Compression damping seems a bit stiffer at lower velocities, as in less than 20 MPH. Not a big deal mostly because that's super slow. But gravel roads might actually be a bit rougher. 

 - on the blacktop and >30 MPH - it's fine and don't have complaints as of yet. 

 

*the biggest, unexpected change is a reduction in shift shock. Those of you that have seen how these trucks are tuned during shifts will understand. The timing goes way retarded during a shift, literally as much as -20 degrees timing. That causes weight transfer to the front tires in that split second during the shift. (that's how Mazda tunes handling BTW - it's called G-vectoring and it's all about timing advance to enhance weight transfer) Anyways, you notice that less. Odd, right?? It just feels more serene altogether. I've noticed myself going over the speed limit in town quite often because of how smooth it is. 

 

I'll give an update after a 400 mile road trip this weekend!

[truckguy82]

^you basically just explained what 5100’s feel like

 

i dunno if they truly are good or if you just got rid of the garbage oem shock

[lucas287]

18 minutes ago, truckguy82 said:

^you basically just explained what 5100’s feel like

 

i dunno if they truly are good or if you just got rid of the garbage oem shock

You missed the part where I had 5100s on the rear. They were far too stiff for my liking. Can imagine that's how the fronts would've been too. 

[mracer]

Apologies lucas287 for not responding to your previous request.  Things have been crazy the last few weeks.  I’m glad to hear that your liking them so far.  I’ve now put about 1000 miles on mine and I still really like them and don’t have any regrets on my choice.  Especially considering the amazing deal Tire Rack had on them when I bought them.  I don’t mind the orange color at all.  When I first installed them I still had my 20” factory All Terrain wheels with 275/60/20 tires.  Last week I switched to Raceline 17x9 wheels with a P285/70/17 tire size.  Between the shocks and the new wheels and tires, I love driving my truck again.  Picture of the rear shocks for those interested in what they look like.

[MisterC]

I've had the Koni's on my truck for about 2 weeks now. Not a dramatic change from the Rancho's ,  but a definite improvement. The rear suspension actually works! There was no flexibility before. The front struts were a bit less of an improvement. But the harshness of small irregularities in the pavement is greatly reduced. Going down the road is much more relaxed. My driving is mostly county roads, and some highway.   I do have the Z-71 suspension. I wonder what these Koni's would be like with the standard springs.     I was just in time to take advantage of the sale price at Tire Rack. At that price, these should standard equipment  on our trucks. Gotta love the orange!