[MoparMaddness]

Hello all! I am relatively new to the forum but I have a few posts under my belts for my challenger build. Now that i have a power output that I'm content with now. Its pretty pathetic that anytime I put the power down in a straight line for more than 1-2 seconds then car will shake out of control like a earth quake is happening.

Doing so I've researched every single thread about wheel hop since owning the car at the beginning of this year. I believe that I have found what does work, what doesnt work, and what not to do, and what to do.

So my build list is going to be as follows:

Speedlogix billet control arms - PN SX-0004
Speedlogix billet tensioner arms - PN SX-RTA-LXLC
Speedlogix billet adjustable rear sway bar links - PN SX-LXLC-SWR
Whiteline adjustable rear sway bar - PN BCR15Z
Razor's Edge Matrix Brace Subframe Connectors - PN SX-LC-SFC
Hop Not Engine Torque Strut - (Heard this was actually a big deal)

I've heard alot about how pedders bushings are a must. yet when I go on their website all I find is a subframe bushing nothing much else for the rear end. If anyone has a link to the rear end bushing kit I'd like a link if possible.

I love the stock ride height and am not currently interested in lowering the car as I have heard when you lower the car it actually can cause wheel hop to get worse so shocks and springs are not on the build list currently.

I've also taken a look or two at some strut tower braces and I am interested in some but I don't see the need for them immediately compared to the things listed above.

Any comments, information, or research input is always welcome.

This is not going to be a total 1 stop shop build. I am going to eliminate all the possibilities one at a time to see what will truly get rid of wheel hop instead of just tossing a bunch of parts on and not knowing what fixed what.

So bare with me, I am going to be the one who finally breaks everything down bit by bit. So strap in and hold on, we are in for a wild and long ride.

 

[BlackHemi41]

Good luck to you bud. Many Challenger owners have been down this road before, doing any combination of the things you mentioned, with different results. It's been debated and discussed to no end, with no definitive answer as to which part or combination of parts fixes it.

Just to warn you, you might be tearing your hair out over this trying to get it perfect. I've been through it, done the research, spent the money and I have gotten to the point where it's controllable. I could post what I have done but I don't think there is much point. You could do a different combination of fixes and still get results.

Glad you're dedicated to attacking this problem. We're looking forward to hearing/seeing what you find.

 

[MoparMaddness]

Good luck to you bud. Many Challenger owners have been down this road before, doing any combination of the things you mentioned, with different results. It's been debated and discussed to no end, with no definitive answer as to which part or combination of parts fixes it.

Just to warn you, you might be tearing your hair out over this trying to get it perfect. I've been through it, done the research, spent the money and I have gotten to the point where it's controllable. I could post what I have done but I don't think there is much point. You could do a different combination of fixes and still get results.

Glad you're dedicated to attacking this problem. We're looking forward to hearing/seeing what you find.

What all have you done and how bad is your hop now?

 

[BlackHemi41]

Well I had brutal wheel hop at the drag strip, so I figured I'd give the Hop not kit a try. Installed stage 1 and 2. Went to the drag strip again, and it made absolutely no difference. Brutal hop again, this time it was bad enough it damaged the diff (howled all the way home, replaced on warranty after).

Next I tried Pedders cradle bushings. Pain in the ass job, but worth it. They eliminated a lot of the rear end slop, reduced hop noticeably and even improved handling. But the hop was still there. Next I installed Speedlogix tension arms. Once again, noticeable improvement. I went to the drag strip again this past September, aired my tires (BFG comp-2) down to 25 psi, and happy to report, no wheel hop.

I do still sometimes get it on the street though, when it's raining and I step on it quickly to merge or something. It can still be upset in specific scenarios. I will consider more upgrades in the future. Hope this helped anyway.

 

[MoparMaddness]

Well I had brutal wheel hop at the drag strip, so I figured I'd give the Hop not kit a try. Installed stage 1 and 2. Went to the drag strip again, and it made absolutely no difference. Brutal hop again, this time it was bad enough it damaged the diff (howled all the way home, replaced on warranty after).

Next I tried Pedders cradle bushings. Pain in the ass job, but worth it. They eliminated a lot of the rear end slop, reduced hop noticeably and even improved handling. But the hop was still there. Next I installed Speedlogix tension arms. Once again, noticeable improvement. I went to the drag strip again this past September, aired my tires (BFG comp-2) down to 25 psi, and happy to report, no wheel hop.

I do still sometimes get it on the street though, when it's raining and I step on it quickly to merge or something. It can still be upset in specific scenarios. I will consider more upgrades in the future. Hope this helped anyway.

The pedders rear cradle bushings are just the ones for the sub frame connectors right?
LX EP1172 Cradle Bushings

these

 

[BlackHemi41]

Yep, those are the ones. If you decide to install them, hope you have a hoist, air hammer, torch and a lot of patience. Otherwise a good mechanic. They are not fun to do. Great upgrade though.

 

[SRT8U]

Sounds like you have a good list of parts going, we have a customer who is also a member here 3 Peddles, who has done pretty much what you are looking at and he has eliminated his wheel hop, the one item he did that is missing from your list is the whiteline cradle bushings
Whiteline Front & Rear Cradle Bushing Kit 05-14 Challenger, Charger, 300, Magnum

I see you were talking about pedders, I would recommend whiteline as they are virtually the same as pedders were, and for all purposes pedders ins out of business.

 

[YO-EL]

I guess I'll preface this to say, if you're running on 20" tires, whatever you're doing, just forget it..

Run with 17" tires, the wheel hop will be gone..

 

[sick'r bee]

Whitelines for Pedders, and there are also solid/aluminum cradle bushings, all the rubber in our cars is "low bid", replace all with poly/delrin/solid but the major cause of wheel hop in new cars IMO, is the stock tires. Put good sticky tires on rear and you can FEEL the right side "walk" forward (K member flexing the cradle bushings), don't feel alone the Macaros do it also!

 

[MoparMaddness]

Whitelines for Pedders, and there are also solid/aluminum cradle bushings, all the rubber in our cars is "low bid", replace all with poly/delrin/solid but the major cause of wheel hop in new cars IMO, is the stock tires. Put good sticky tires on rear and you can FEEL the right side "walk" forward (K member flexing the cradle bushings), don't feel alone the Macaros do it also!

I run a 20x10 rear rim with a 275/35/20 tire for starts (upgrading to 315 next). I can get rid of wheel hop if I drift sideways but if I launch there is a 50/50 chance that it will hop or burn.

I am going to add the cradle bushings to the build list as well and I'm placing the first order today for the control arms from speedlogix.

 

[YO-EL]

You're running too tall a tire and not enough sidewall to flex, hence the wheel hop..
Look at my rear tires in this launch pic. This is what you need your tires to do...

 

[2015_R/T_74_Duster]

on the old school cars, stiffer rear shocks usually bring wheel hop under control. in extreme cases even the drag shocks are not stiff enough to stop it, in that case they clamp the front half of the springs to stiffen that section.
wheel hop gone.

i'm not sure how that translates to these cars, i'm new here

but i'm guessing adjustable shocks or something may help.

 

[MoparMaddness]

You're running too tall a tire and not enough sidewall to flex, hence the wheel hop..
Look at my rear tires in this launch pic. This is what you need your tires to do...

What size tire are you running?

 

[YO-EL]

What size tire are you running?

Those are 255/50/16

 

[MoparMaddness]

I just placed my order from speedlogix for their rear control arms.

I did some testing for my car today on the street from a dig. I did a 3k rev launch which resulted in wheel hop then burning the tires. After that I did a 4k rev launch which had 1-2 hops before burning the tires again. I did a wet test also with a 2k rev it was just uncontrollable wheel hop.

Hoping to finally get somethings fixed and settled by going through this process.

 

[MoparMaddness]

Ended up going overboard on all the deals! Got my Control arms, tensioner arms, and sway bar endlinks for just over 1k... I'm worried if they put a rear sway bar on or the cradle bushings on sale I'll have to buy those too.

 

[randycat99]

If there is something to "lowering seems to worsen wheel-hop" observation noted earlier, maybe somebody should try the reverse?...1" rise in the rear to put a rake to the car? Maybe there is something to that?

There's 2 possibilities to go with that, though.

-is there an effect of a 1" relative rise (referenced from wherever you were at initially)

-or is it that the car body simply has to reach a threshold (absolute) height for the roll center (from suspension geometry) and mass center (purely based on where center of gravity occurs) to have the desired weight transfer effect on launch?

Yeah, I know the chances that anybody would try that on their car is about nill. I just wanted to put the observation out there.

 

[randycat99]

On an entirely different theme from my earlier post, I bring up rear camber on these cars. I know there are some that hate when I keep doing that, and also feel that if camber is there, then it needs to be there for a reason (by authority of those who engineered the vehicle). However, consider this...

The manufacturer alignment spec for a stock SRT8 cites a significant amount of camber should be there in the rear wheels (2-ish degrees?). Upon loading on launch, even more camber appears (camber gain) as the rear suspension deflects. Now consider the typical practice where a lower tire pressure is employed in the rear to allow more natural tire contact, despite the camber. On its face (no pun intended), all seems well...the tire deforms to better contact the pavement, while in a static state.

However, there is an issue of pressure (and sidewall stiffness effects) not being equal across the entire tire face, even though the entire tire tread face is physically contacting the pavement. So imagine the contant pressure gradient curves against the pavement is like a triangle (instead of a more typical rectangle)...more high pressure blocks at the inside area of the tire (base of the triangle) and less pressure blocks at the outside area of the tire (the tip of the triangle).

Now the car launches with torque attempting to spin the tires. The typical weight transfer occurs, rear suspension deflects, but now more camber is appearing corresponding to deflection. So that pressure triangle will now change shape to a flatter triangle shape. The inside edge of the tire is getting extreme contact at high pressure with the pavement, and the outside of the tire is getting relatively poor pressure with the pavement. Put a different way, increasingly more of that traction force is concentrating on a confined area on the inner side of the tire contact (the base of the triangle will not grow indefinitely, because the tire is inherently a circular shape that sooner or later needs to bend away from the pavement per geometry) with commensurately less force acting on the outer side of the tire contact. The inner side deforms in response to the increasing load until it maxes out. Adhesion collapses, and the entire tire goes from rolling contact to slipping contact. Possibly that adhesion collapse point is when the tire "bounces" upward, as well (a mechanism will naturally seek a lower energy state if one is available, and that is a tire under load that seemingly bounces upward momentarily to become a slipping tire). While the tire is getting air time, everything snaps back (as if to reset), until the tire lands once again. We are back to a tall pressure triangle that favors the inner side of the tread, and getting flatter as loading builds up, until we get another max-out with adhesion collapse...this repeats rapidly giving the familiar wheel hop behavior.

Similarly on wet pavement, the same build-up in load and deformation occurs, except the collapse occurs at a lower threshold, naturally. The snap-back point is still that same wheel hop behavior, occurring rapidly and repeatedly.

The whole idea to this premise is that it isn't really the suspension parts moving around (from flex and soft bushings) that is the source of the effect, rather it is an inevitable build-up in load and distortion in an increasingly focused region of the tire (due to camber gain upon rising load/deflection), until that small area on the tire can no longer support that load. That is the adhesion collapse point and the hop, where it all resets to do it all over again, once the tire "lands". Naturally, each of those cycles is hard on the suspension. The joints loosen up in response to these extreme loading events, making it all that easier for things to move around and move a greater distance than when it was brand new. That's when you throw the stiffer bushings and extra bracing on it to restore/exceed the like-new stiffness that was once there. Maybe it helps a bit, but deep down in the system, it still wants to do it. That's because it is fundamentally happening at that tire/pavement interface with camber gain and nonlinear distortion/loading being the dynamic components to the effect.

 

[2013r/t]

I've never seen anybody running 16 inch wheels like on the corvette. The common diameter with pics all over this site to prove it, is 17 inch using drag radials or slicks. Anything smaller probably wont fit over the brakes. Although most only run those tires at the track and use their 18 or 20 inch regular tires and wheels on the street. Check out the tire and wheel thread and a few others and you'll see what I mean.

 

[YO-EL]

I didn't say to use 16" on the Challenger, I said thats what I use on the Vette..
On my Scat Pack, I'll be using 17" wheels,,