Reaching out to those doing their own shock tuning?

[hjdca]

As usual......Im killing myself knowing how good a vehicle can drive if set up properly!

Started with a 2021 JTRD last year and tossed on 1.75 front .75 rear spacers/shock extensions and 37s at 30 miles the day before a 2500 mile overland desert trip.

My vehicle was plagued with the annoying front suspension bottoming out of the box, but the spring spacer combined with the Metalcloak durobumps got me through till my Fox Elite 2.5s and airbumps showed up........At the time of install, I swapped a pair of front Evo 4" JK coils which netted 2" total lift on my truck with a Warn Zeon 10s in the factory steel bumper. I have since installed Airlift rear bags to help when I tow my 19' RV and motorcycle in the bed.

I'm still waiting for the correct spring solution to be brought to market from a manufacturer that I want to buy from. I know I need a much higher front spring rate and 10-20% more 8n the rear would be welcomed.

I'm almost 17,000 miles deep into this and I'm not happy. The front 2.5s out of the box do not have enough compression adjustment and more rebound damping is needed all the way around.

I reached out to Fox and got the standard corporate "We have never had anyone complain" response, but I did get to communicate with the service dept a bit. Of course they wanted me to sent them in........$35 per shock(Which is totally reasonable), but the insured shipping 2 ways would have brought the cost to about $400 and they advised it might take 3 times to get it perfect! Then add in 1-3 week turn around time plus a week each way in shipping? 6 weeks possibly? Doesn't work for me.........

I then asked for them to just sell me the parts and bill me for the tune time.......Long story short, I got a tune and I ordered a master shim kit......of course it was short many of the sizes in the tune!

I finally ended up with 95% of what I needed after 2 months waiting, so I had a go last week and did some driving today. Its much better, but still not great.

I've been researching this for months and watching videos. I'm a serious off road enthusiast, own an undercar repair shop that specializes in truck/Jeep drivetrain and suspension mods, but this is one field I lack experience in.........

Looking for others with the same truck that maybe has played with this a little to compare notes and can save me from pulling these things apart 10 times.....Maybe come up with the perfect solution for us JT guys.

I agree with you --- try heavier duty front Springs. Something like 3.5 inch Clayton front springs - that are known to be heavy duty. Much cheaper than messing with those expensive shocks, and if the spring is too light, the shocks will never fix it.

Sponsored

 

[CrazyCooter]

I agree with you --- try heavier duty front Springs. Something like 3.5 inch Clayton front springs - that are known to be heavy duty. Much cheaper than messing with those expensive shocks, and if the spring is too light, the shocks will never fix it.

Clayton spring are on my list because the front spring rates are more inline with what I think is needed. They are working on a cargo coil for the rear too, but no eta at this point.

 

[Wheelin98TJ]

Wayne at Alltech Motorsports is the man for shock tuning.

 

[Glamisfan]

Here’s a link to my thread on the JL forum https://www.jlwranglerforums.com/forum/threads/ford-raptor-rear-shocks-on-jl.63226/

I‘d be happy to help with valving suggestions. I’m no pro, but have tuned shocks for 7 or 8 vehicles. I’ve done airshocks, coil overs, internal and external bypass. My current project is the link above. 1st gen Ford Raptor rear shocks on the front and rear of my JL. There a 2.5” internal bypass shock. The shock tuning industry is annoyingly secretive!

The .700x.020 shim your looking for is unusual. That would probably be the last shim in the compression valve stack. Compared to the standard .800x.020, the .700 would be a slightly smaller fulcrum for the larger shims to bend over, which will lighten the overall valving a slight amount. It’s a smaller diameter, and the smallest shim in the valve stack is what all the other shim bend over.

 

[CrazyCooter]

Here’s a link to my thread on the JL forum https://www.jlwranglerforums.com/forum/threads/ford-raptor-rear-shocks-on-jl.63226/

I‘d be happy to help with valving suggestions. I’m no pro, but have tuned shocks for 7 or 8 vehicles. I’ve done airshocks, coil overs, internal and external bypass. My current project is the link above. 1st gen Ford Raptor rear shocks on the front and rear of my JL. There a 2.5” internal bypass shock. The shock tuning industry is annoyingly secretive!

The .700x.020 shim your looking for is unusual. That would probably be the last shim in the compression valve stack. Compared to the standard .800x.020, the .700 would be a slightly smaller fulcrum for the larger shims to bend over, which will lighten the overall valving a slight amount. It’s a smaller diameter, and the smallest shim in the valve stack is what all the other shim bend over.

Thank you much for your info!

I have the 0.700's on order, but may not see them for weeks or months.......I put in what I had to see how it came out for now.

Yes, the comp stack that fox sent me called out for (3) 0.700 x 0.020's at the top, but my inventory only allowed me (2) 0.800 x 0.020's and (1) 0.0700 x 0.020 at the very top. I really feel this is why I'm feeling the compression on harder fast hits get increasingly aggressive (Like spine compressing) as I tighten the low speed clicker to minimize body roll and head bobble at low speed.

This morning :
1. I swapped out the very bottom compression 1.800 x 0.008 with a 1.800 x 0.010. which also has a 0.800 x .0.010 flutter above it hoping to add a bit of low speed compression without the need to tighten the clicker more than 2 clicks in.

2. I swapped the very bottom rebound 1.600 x 0.010 with a 1.600 x 0.012 to hopefully add a little more low speed rebound, but I'm a little concerned that it might be not enough low speed and too much overall.......might need to add a flutter to that stack too?

My ultimate goal in the rear is to use no low speed clicks unloaded, 2 clicks with the tent on the bed, 4 clicks with the bike in the bed, 6 clicks towing the RV, and 8 clicks when towing the RV with bike in the bed on the pavement and then deviate as needed off road when the tires are aired down.

If I like this setup for low speed, but it's still too firm on the hard hits, I plan to remove one of the 0.800 x 0.020's from the compression clamp area and test that.

Am I making any sense or am I way off. Been thinking about shock valving and trying to learn about this for probably 5 years, but never had and rebuildable shocks in that time frame that needed work to learn with.

 

[Glamisfan]

Here’s how I like to write my tune and a couple of Dirt Sport articles.

 

[dcmdon]

If I like this setup for low speed, but it's still too firm on the hard hits, I plan to remove one of the 0.800 x 0.020's from the compression clamp area and test that.

Am I making any sense or am I way off. Been thinking about shock valving and trying to learn about this for probably 5 years, but never had and rebuildable shocks in that time frame that needed work to learn with.

I'm new to the jeep world but used to race motocross where damper tuning was a big deal when it came to lap times. So I at least know what I don't know.

You mention that if its set up right for low speed its too stiff in compression at high speed.

Do any shock companies that make dampers for Jeeps make models with adjustable high speed and low speed compression damping? So you could tune each separately?

I've followed this thread with a lot of interest since its not a typical suspension thread here. When I test drove Jeeps I found the Mojave to be the most sorted at speed on the road. Combine that with my wife's desire for leather and all the toys and that's what worked for us. But I also found the Willy's to be oversprung and under damped. Low suspension compliance, but not enough body control over undulating surfaces.

Either way. I'm curious if there are companies that make Jeep shocks with adjustable high and low speed circuits.

 

[Glamisfan]

This is speech to text so bear with me. The smallest shim as far as outside diameter on the compression stack is the clamping shim. When you tighten everything down, the outer edge of that is rigid in the entire valve stack all the way to the largest shim. So that smallest shims outer diameter is what everything bends around. But, at slow speed the largest diameter shims are the only ones flexing. On a medium speed which is not vehicle speed but shock shaft speed, a medium speed hit it’s the middle shims that affected more than anything, and when you land off of jump which is the highest shaft speed that’s when the very smallest shims come in to play. Each shame affects the other of course but that’s a simple way to picture it in your head.The smallest shim on the compression stack, most of the time there’s only one small shim and then the large thick washer after that that’s called the top out plate or rate plate. The top out plates job is to make sure that on a super hard impact the shims don’t flex so much that they crack. It has a little more to it than that but that’s a large part of its job. By adding three of the small shims, you’re letting the overall flex go farther than a shock that only has one of the smallest shims. so I am questioning the use of the .7 Sherman especially three of them that came in your shock tune because I’ve just never seen that before. As far as Flutter on the rebound, I only learned about a year ago that some tutors do that. I tried it one time on my internal bypass shocks and it was not good so I immediately took it out. Most of the time because of the way the springs react, a normal rebound stack is gonna work best. Either a straight .010, .012, .015, or one of those stacks but with thinner shims for the first two larger shims like a .015 stack but with the two largest shims being .012

i’ve only had one vehicle that had reservoir adjusters so I haven’t done a lot of work with them, but I am familiar with the concept and how they work and I do understand what your in goal is and it makes perfect sense.

For anyone else looking at this thread, external bypass shocks are the best thing since sliced bread and at three grand for the fox adjustable reservoirs versus four grand for a set of bypass, if you can afford the extra grand get the external bypass. I’ve only got $1500 into my internal bypass set up and I could not get a set of $4000 shocks by my wife. I did research them though, and it’s extremely hard to find shocks that are the right length for these things. 10 inch external bypass shocks are about the right size but you’re losing out on some available travel as far as what the suspension can handle. 12 inch external bypass shocks are usually too long at the extended length, I think 33 or 35 inches just way too long. There are a couple of companies I think Bill Steen make some but I can never find them when I look for them.

 

[CrazyCooter]

I'm new to the jeep world but used to race motocross where damper tuning was a big deal when it came to lap times. So I at least know what I don't know.

You mention that if its set up right for low speed its too stiff in compression at high speed.

Do any shock companies that make dampers for Jeeps make models with adjustable high speed and low speed compression damping? So you could tune each separately?

I've followed this thread with a lot of interest since its not a typical suspension thread here. When I test drove Jeeps I found the Mojave to be the most sorted at speed on the road. Combine that with my wife's desire for leather and all the toys and that's what worked for us. But I also found the Willy's to be oversprung and under damped. Low suspension compliance, but not enough body control over undulating surfaces.

Either way. I'm curious if there are companies that make Jeep shocks with adjustable high and low speed circuits.

Yes, the shocks I'm using have both high and low speed clickers......The however lack rebound clickers.

The truck is absolutely under sprung especially in the front, so I'm trying to make it tolerable until the correct springs come available.

I'm also not going to pound a truck I have $85K into since I need it to last 10+ years. It needs to be great on the highway under varying conditions and decent off road which works out to be about 5% trail/light rock camping, 30% desert camping, 15% unloaded mixed, 50% on road loaded with either tent, bike, RV, or combination of any of those loads.

 

[CrazyCooter]

This is speech to text so bear with me. The smallest shim as far as outside diameter on the compression stack is the clamping shim. When you tighten everything down, the outer edge of that is rigid in the entire valve stack all the way to the largest shim. So that smallest shims outer diameter is what everything bends around. But, at slow speed the largest diameter shims are the only ones flexing. On a medium speed which is not vehicle speed but shock shaft speed, a medium speed hit it’s the middle shims that affected more than anything, and when you land off of jump which is the highest shaft speed that’s when the very smallest shims come in to play. Each shame affects the other of course but that’s a simple way to picture it in your head.The smallest shim on the compression stack, most of the time there’s only one small shim and then the large thick washer after that that’s called the top out plate or rate plate. The top out plates job is to make sure that on a super hard impact the shims don’t flex so much that they crack. It has a little more to it than that but that’s a large part of its job. By adding three of the small shims, you’re letting the overall flex go farther than a shock that only has one of the smallest shims. so I am questioning the use of the .7 Sherman especially three of them that came in your shock tune because I’ve just never seen that before. As far as Flutter on the rebound, I only learned about a year ago that some tutors do that. I tried it one time on my internal bypass shocks and it was not good so I immediately took it out. Most of the time because of the way the springs react, a normal rebound stack is gonna work best. Either a straight .010, .012, .015, or one of those stacks but with thinner shims for the first two larger shims like a .015 stack but with the two largest shims being .012

i’ve only had one vehicle that had reservoir adjusters so I haven’t done a lot of work with them, but I am familiar with the concept and how they work and I do understand what your in goal is and it makes perfect sense.

For anyone else looking at this thread, external bypass shocks are the best thing since sliced bread and at three grand for the fox adjustable reservoirs versus four grand for a set of bypass, if you can afford the extra grand get the external bypass. I’ve only got $1500 into my internal bypass set up and I could not get a set of $4000 shocks by my wife. I did research them though, and it’s extremely hard to find shocks that are the right length for these things. 10 inch external bypass shocks are about the right size but you’re losing out on some available travel as far as what the suspension can handle. 12 inch external bypass shocks are usually too long at the extended length, I think 33 or 35 inches just way too long. There are a couple of companies I think Bill Steen make some but I can never find them when I look for them.

So, your explanation confirms my thoughts about the 800's vs 700's. I'm not crazy.......

I'm betting a flutter on the rebound might require WAY too much experimentation without a dyno. Funny, the front shocks had a rebound flutter out of the box, but the new tune Fox sent me did not.....This is the only reason I bring this up. Adding a bunch of rebound for the street and idle speeds off road would be nice for head bobble, but have it "pop off" in the faster stuff. I envision a super thin flutter shim for less delay?

I probably should have gone with external bypasses had I known I was going down this road. I was counting on Fox selling a product for the vehicle that worked 80-90% out of the box. The sales guy at fox talked me out of the 3.0 internal bypasses, which I think would have been a nightmare to self tune?

I'm running 11" front and 10" rear with 2"/.75" lift, so with a little more lift and proper bumps/limit straps/double/triple rate coils, could make 12" shocks fit.

 

[CrazyCooter]

So, back together and going to leave it for today until I test with a passenger and some more off road.

Initial feels OK on the road and potholed dirt roads I have near the shop. Had to back off the low speed 2 clicks, so I'm 2 clicks in with the tent on board. I think I will be opening them back up to add some more low speed compression too.

The front air bumps have felt like metal on metal at low speeds, so I put 225psi in them based on the 1/6 corner weight/psi starting rule I see tossed around.

I got this down to 45mins R&R and revalve for the rear pair.

 

[dcmdon]

Yes, the shocks I'm using have both high and low speed clickers......The however lack rebound clickers.

The truck is absolutely under sprung especially in the front, so I'm trying to make it tolerable until the correct springs come available.

I'm also not going to pound a truck I have $85K into since I need it to last 10+ years. It needs to be great on the highway under varying conditions and decent off road which works out to be about 5% trail/light rock camping, 30% desert camping, 15% unloaded mixed, 50% on road loaded with either tent, bike, RV, or combination of any of those loads.

I'm guessing that finding the right spring is doubly difficult because nobody publishes spring free length (so you know what kind of preload you are dealing with ) or spring rates. At least when trying to tune a motorcycle as long as you stayed with one manufacturer you knew that the 440 lb/in spring was going to be 10% stiffer than the 400 lb/in spring.

 

[CrazyCooter]

I'm guessing that finding the right spring is doubly difficult because nobody publishes spring free length (so you know what kind of preload you are dealing with ) or spring rates. At least when trying to tune a motorcycle as long as you stayed with one manufacturer you knew that the 440 lb/in spring was going to be 10% stiffer than the 400 lb/in spring.

Yes, everyone seems to keep their spring numbers pretty secret. As you say, It would be much easier to make an educated decision based on the info if it were available.

I ran into the same thing with Bilstien when selection shocks for my YJ. Off the shelf felt like I needed 3 each at the rear corners. I called them for the valving spec so I could make an educated gues on thier universal valved shocks, but he wouldn't tell me..........He stood behind that they were perfect because a guy who worked there custom valved them for his own YJ back in the day. Took me 2 chnages front and 3 changes rear to get it driveable and then I'm still fine tuning.

Clayton and Synergy seem to be the most honest/open of the vendors. I deal regularly with Metalcloak, but all they can tell me is no you don't want the spring we have, but if you can wait....we have something coming.

As of right now I can say Metalcloak (Tech support confimation), Evo (in the truck now), and Synergy(Super light listed rate) springs are out for sure.

 

[jsalbre]

As picky as you seem to be (not saying that's a bad thing) it sounds to me like you should be ordering custom wound springs. Define the lengths and spring rate yourself.

You may be approaching the point of diminishing returns though, especially with a heavy diesel and the very short travel on the JT front end. The kind of work you're looking to put in (and the related cost) makes a lot more sense when you've got 15+" of travel, not 8".

The odds of you finding a setup that performs well unloaded and equally well when you've got over 1000# of extra weight on the rear axle is pretty unlikely. That's just too large of a difference without running something exotic like magnetorheological shocks. There's a reason that HD trucks ride super stiff when they're unloaded.

 

[CrazyCooter]

As picky as you seem to be (not saying that's a bad thing) it sounds to me like you should be ordering custom wound springs. Define the lengths and spring rate yourself.

You may be approaching the point of diminishing returns though, especially with a heavy diesel and the very short travel on the JT front end. The kind of work you're looking to put in (and the related cost) makes a lot more sense when you've got 15+" of travel, not 8".

The odds of you finding a setup that performs well unloaded and equally well when you've got over 1000# of extra weight on the rear axle is pretty unlikely. That's just too large of a difference without running something exotic like magnetorheological shocks. There's a reason that HD trucks ride super stiff when they're unloaded.

I AM picky.......I know this and got this way by setting vehicles up to my liking. I know how good something can be and can't settle for garbage. I can't go to Taco Bell and eat that junk thinking it's great after I've had the good stuff elsewhere........Cant ever go back......I know its shit. There are people who turn the key and if it starts, the car is the best thing ever accepting it as good enough.....some of them may have already replied to this thread. I have made a living out of helping people get the results from their vehicles based on my research and testing.....There is a market for people willing to pay for it and the rest go to Big O or Les Schwab not knowing any better. Sometimes I wish I could be that guy.....life might be easier!

I would totally get some custom springs wound up if I knew what I needed! I know the Evo springs suck for me, but I don't know the rate. The stock springs sucked, but again don't know the rate. Clayton may be the solution, but if they are not...I could make an educated decision since they advertise the rate. There is a spring builder 150 miles south of me...........

I think this is doable. The truck sucks with these 2.5's out of the box unloaded, so I know that can be improved upon........I proved that already with the changes I have made. The clickers are what will allow some degree of comfort as loads/conditions change. Yes, you are correct that there will not be a perfect solution in one setup, but I'm not asking for that. Just needs to be good on the road (For a Jeep)and decent off road (for an street legal vehicle with payload capability). Plenty of vehicles/setups meet this expectation........I just haven't gotten there yet with the JT. It will never be a trophy truck, rock buggy, or a 3500 dually.

I disagree with you about the short travel being less critical than long travel. It is my opinion that it's MORE critical with less travel since there isn't enough "Fluff zone " to recover from poor damping performance? It needs to be correct or you will be eating bumpstops and bending axles. This is also why I spent the money on air bumps.........Cushion the hits that sneak up on you before it slams and taco's the front axle.

Maybe I should have just gone the coilover route so that I could swap rates at will........ Coilovers are not a trouble free quiet 125K mile solution though. This is how I got to where I'm at now........ I don't have an unlimited budget, but I have a shop full of tools, smarts, years of experience of what I do/don't like, and a reasonable amount of time/$$$ to accomplish this.

Sponsored