IHC 3/5 Performance Lowering Kit on 2024 RCSB

[EL5_Zero]

I posted some pictures of my ride height here, I did not want to clutter your thread.
https://www.f150gen14.com/forum/threads/2024-rcsb-build.25689/page-5

I'm glad you finally got your truck dialed in. Hopefully this weekend i can finalize my truck suspension as well.

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[EL5_Zero]

UPDATE: After many miles of R&D, I am happy to announce that my truck finally rides sporty yet smooth, with the capabilities of hauling a heavy load! The front end has rides great, no complaint. The rear end was handful, but fortunately I got it to handle as best as one possibly can with the limited suspension travel.

Over the last 8 months, I tried different setups (shock placement, different shocks, Compression/Rebound settings, psi) all in an effort to have the best suspension with the least amount of compromise. My settings might not be to your liking, but it will give you a good ballpark to start if you have an adjustable IHC 3/5 lowering kit.

The IHC is a good kit, but not a complete kit. When you flip the axle, you greatly reduce the suspension travel (approx. 4" of suspension travel) and increase chances of bottoming out over large dips/potholes. I initially tried increasing the compression on the QA1 shocks from 3 clicks, all the way up to 9 clicks clockwise from full soft to prevent the diff from slamming into the frame. On some road conditions, it did work, but then the truck rode very stiff over road imperfections. I tried different settings, and the rear shocks simply did not control the rear end as it should.

I had a pair of FOX 2.0 laying around in my garage for a stock F-150. I decided to try them on to see if they fit, and fortunately they did without bottoming out. The truck handled the road imperfections way better the QA1's every did. At this point, I was not 100% sure if it was due to the FOX valving, or the shock location. Further tests confirmed that the IHC relocation kit is not needed in a street application. The stock shock location seemed to work best in my application. Further details ahead.

AIRBAGS! This is a MUST DO upgrade if you have a rear axle flip due to the limited suspension travel. I went with Ride Tech air bag kit simply because in my opinion, having the airbag directly over the axle is a better setup as appose to having the airbag pushing on the leaf spring which then pushes on the U-bolts like IHC uses.

Although the Ride Tech air bags did bolt on with the IHC kit, I was not satisfied with the angle of the airbags, or the height of the airbags. The airbag mounting locations were too close causing the airbags to crease and ride poorly with the recommended 15 psi., they needed 25-30 psi to fully inflate the airbags. This however caused the rear end to raise giving it a 1.5" rake and the truck drove horrible once again.

The solution was to cut the top mounts and raising them approx. 2 1/4" allowing the airbag to be in a more natural position. This resulted in a perfect ride stance (1/4" rake front to back) with 0 psi. Once inflated to 15 psi., the rear end raised 1/2" for a total of 3/4" rake front to back. PERFECT!

I later reinstalled the QA1 shocks in the stock F-150 location with the help of 2" shock extenders from amazon. The truck now drives and handles like a dream! Sporty feel, without the harshness. I can load the bed with gear and with a quick air increase and a few clicks of the shocks, the rear end handles the road! I also added amazon bump stops for those unexpected potholes.

If you have any questions, let me know. I'm sure I might have missed something. Here's a picture of how my truck sits with the latest modifications.

 

[JCsTruck]

Did you cut the brackets, weld on an extension, and then re-weld the brackets back to the mounting plate on those air bag mounts? Looks like you did. Awesome job!

 

[EL5_Zero]

Did you cut the brackets, weld on an extension, and then re-weld the brackets back to the mounting plate on those air bag mounts? Looks like you did. Awesome job!

That's exactly what had to be done. I initially moved them up 1" but it was not enough. I removed them once again, added a 1/4" x 3" x 6" extension plate and mocked it up to get the correct airbag angle at ride height.

A few weeks ago, I loaded over 800lbs of welding equipment for a job site. I aired up to 60psi., and increased compression by 3 clicks, the truck handled great! I'm satisfied with the results.

 

[JCsTruck]

That's exactly what had to be done. I initially moved them up 1" but it was not enough. I removed them once again, added a 1/4" x 3" x 6" extension plate and mocked it up to get the correct airbag angle at ride height.

A few weeks ago, I loaded over 800lbs of welding equipment for a job site. I aired up to 60psi., and increased compression by 3 clicks, the truck handled great! I'm satisfied with the results.

Well obviously you can weld. Great job!

 

[OIF_Veteran04]

Can any tell me what the wheel well height front and rear is after the IHC 3/5 lowering kit is installed?

 

[EL5_Zero]

Can any tell me what the wheel well height front and rear is after the IHC 3/5 lowering kit is installed?

My truck measures 32 5/8" Front, and 33 3/4" rear. I adjusted the spring perches to be snug up against the spring. The front can be a little higher if you add compression to the front strut. Also, the rear end is raised approximately 1/2" with the Airbags with 15 psi.

 

[JDStell]

So well done. I’m going to copy some of your mods. Thanks!

 

[JDStell]

Yesterday I spent a good 2 hours and 25 miles of driving making adjustments to the suspension. I'm happy to report that I dialed it perfectly to my likings. My settings may not be to your liking, but I'm sure it is a great starting point to getting your truck dialed in to your preference.

Ride quality Scale: Comfort / Performance / NVH
This is based off of the best and worst driven cars I have owned and driven for over 50K miles.

Comfort:
1 = (80's Foxbody Stock suspension)
10 = ( 2020 Buick Lacrosse )

Performance:
2015 Mustang GT Performance Pack

Stock Ride Quality

Last week I drove the truck a solid 500 miles mainly on the highway commuting to work. My route consists of smooth, bumpy, and 15-year-old asphalt that needed replacement a few years back. The truck had a very smooth, yet floaty feel to it while driving at 75 mph. Whenever I would drive over a dip on the road, the front end would bounce about 3 times before it would settle down while the rear end bounced once. This caused the truck to feel unstable at high speeds. On the street, the front suspension would soak up the bumps nicely, while the rear end was a bit firm. Not bad, but noticeably firmer than the front. Turning at moderate speeds, or slowing down fast, the trucks front end would dance around quite a bit. The stock tires play a bid roll in soaking up the small surface cracks, but also caused the truck to dance around on the highway when hitting big dips.

Comfort: 7
Performance: 3
NVH: 1

IHC 3/5 Performance Ride Quality

Here are the final settings on the truck as it sits right now. Front suspension coilovers where set at 4 clicks Compression, 4 clicks Rebound clockwise. Coilover height was set at 2 5/8" of exposed thread. This is measuring from bottom of lock collar to bottom end of threads where the adjustment knobs are at. Tires are 305/40R22 and they were set at 35 psi cold.
Rear shock setup was 0 Compression, and 1 click Rebound clockwise. Traction bars are set to approximately 1/8" gap between contact pad and leaf spring. At first, I tested it with the pads making contact. It rode firm, but not bad. As soon as I gave it 1/8" gap, the ride became smoother. When I accelerate fast from a complete stop, you can feel the rear end raise from the traction bars doing their job. No more squatting! Rear tires are 305/40R22 and were set at 32 psi cold.

I want to thank the guys at IHC for building an awesome kit, and for answering my questions over the phone. THE TRUCK HANDLES EXACTLY HOW A SPORT TRUCK SHOULD HANDLE!!! The truck no longer dances around at highway speeds, nor does it dip when you slow down fast. This morning when driving thru the "S-style" freeway on ramp, the truck felt 100% planted to the ground! No body roll, no swaying when turning left then quickly right. The small cracks are noticeable compared to stock, but the suspension soaks them up nicely. When driving over the big dip on the highway, the truck bounces once and settles. No drama whatsoever. You will need to remove the rear bump stops to allow the rear suspension to cycle and absorb the bumps. So far, the rear end has not bottomed out. I have a solid 4 inch gap between the axle tube and the frame rail.

Edit*
Comfort: 6
Performance: 6
NHV: 5

All in all, I love the IHC Performance lowering kit. I read many posts where people are not happy with their IHC 3/5 Ride quality drop kit. I believe it comes down to the shocks being used (stock front struts and generic rear shocks). QA1 double adjustable shocks and struts make a HUGE difference in comfort. I will put on miles and report back once I hit 1000 miles. Hopefully by then, the suspension should have settled.

Truck has a fender to tire gap of 3 inches in the front, and 3 1/2" in the rear.

 

[DMTack]

Few questions... first, what wheels are those? they are awesome! second, did you ever look at the Kelltrac rear shocks? They claim the most travel of any shock for the flip kit setup and are double adjustable built by Viking. Just ordered them for my formerly IHC truck.

 

[EL5_Zero]

Few questions... first, what wheels are those? they are awesome! second, did you ever look at the Kelltrac rear shocks? They claim the most travel of any shock for the flip kit setup and are double adjustable built by Viking. Just ordered them for my formerly IHC truck.

Hi! The wheel is Forgestar X12 in 22x10.

I purchased them from here Products (coyotestruckparts.com)

Here is a link for reference on a F150

Red + Blue Ford F150 - Forgestar X12 - Satin Anthracite | Forgestar

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