TKO bump steer correction kit Review

[Aevus]

That's my 2nd review on TKO parts and it's the second time I'm very satisfied.

https://tkomotorsports.com/product/2...orrection-kit/

Our Bump-Steer Correction Kit will correct the unstable and darty feeling experienced at higher speeds and heavy braking zones. Billet aluminum tie rods, 4140 alloy steer pins, and heavy-duty spherical bearing rod ends. Our Bump-Steer Correction Kit is a must for 5th Gen Vipers on track day.

I would say it's a must, period. Gen 3, 4 or 5, track or street. The car felt so smooth the first minutes I drove it, it was a bit unsettling. I was used to fight the steering wheel, with his left-right kicks, especially on bumpy roads or even slightly uneven pavements. Improves a lot the confidence you'll have with the reptile. It feels tamed but not in a bad way, just more predictable. Of course, you still need good sticky tires, alignment, upgraded suspension, etc... but that's a must upgrade to my book. And I'm not being paid by TKO motorsports, just a very happy customer.


A little more on that topic here, combined with a special alignment and TKO's control arm bushings:

https://driveviper.com/forums/thread...Snake-STRAIGHT

[Aevus]

Our Bump-Steer Correction Kit will correct the unstable and darty feeling experienced at higher speeds and heavy braking zones.

Yes. Forgot to mention about the heavy braking. 100% true.

Bottomline, that part is an absolute 10/10 must on all gen 3 & 4 Vipers and probably gen 5 as well, but it raises a question though:

WHY is Dodge engineers didnt equiped the car with that ? Why it's an aftermarket part ?? Was probably very cheap for Dodge to produce, I really don't understand...
The arc difference from the stock tie-rod and the lower control arm must be significant enough to cause problems:

https://suspensionsecrets.co.uk/bump-steer/


....and TKO fixed it with that part, but why Dodge/SRT engineers didnt think of that?

[GTS Dean]

They did. They made the steering rack height-adjustable with shims under the main attachment bolts. Ditto with the rear - adjustable height inner toe links. The question becomes which is easier to set at the factory, vs. what's easiest for a serious enthusiast in his garage or at the track? Bean counters and production line efficiencies are king. Viper suspensions were installed, aligned and bump-steered early on the assembly line with NO bodywork hung yet.

The Gen 5 cars have a cam-adjustable rear toe link bump steer arrangement. Just envision a wishbone ear set turned vertically.

[Lawineer]

Do gen5 really have a bump steer issue? Track I was on was pretty smooth but I didn't notice much under hard braking or accel except for one turn- where the car kinda wanted to turn. I assumed it was something on the track surface causing one side to grip less.

[Aevus]

They did. They made the steering rack height-adjustable with shims under the main attachment bolts. Ditto with the rear - adjustable height inner toe links. The question becomes which is easier to set at the factory, vs. what's easiest for a serious enthusiast in his garage or at the track? Bean counters and production line efficiencies are king. Viper suspensions were installed, aligned and bump-steered early on the assembly line with NO bodywork hung yet.

The Gen 5 cars have a cam-adjustable rear toe link bump steer arrangement. Just envision a wishbone ear set turned vertically.

Few months ago I had my IPSCO steering rack bushings installed, also alignment done and bump-steered adjusted (with the shims)... It was nowhere close to the result I have now.

Can't wait to read TKO's team reply about that, because it looks to me as a bad stock tie-rod design on the gen3 (and maybe gen4) maybe related to geometry...

Took me a year to find the culprit, and it was the f&%& stock tie-rod. I'm happy and pissed at the same time.

[Aevus]

https://www.moparpartsgiant.com/oem-...e_rod_end.html

OEM tie-rod Mopar part number:

2003-2008
5290168AA

and 2009-2010:
5290168AB

Both replaced by the (new and improved?) '' Replaced by: 5290168AC ''

...funny enough, same part that was used for the Compe coupe and the ACR-X



Educated guess here: the ..68AA was the ''defective/bad geometry'' one. Later they replaced it with the ..68AB, then the 68AC (that is maybe on all gen5?)

[TKO MOTORSPORTS TEAM]

Thank you for purchasing the products we mfg Aevus and doing an honest review of our product. GTS Dean your spot on " bean counters" will always pull rank when it comes to the extra little things. Bean counters work on the principal of " good enough".

Bump-steer is weird deal. Most people cant tell the difference until they have a car that has corrected bump-steer; Bump-steer correction is one of those deals you didnt know you needed it until you have it. Bump-steer is also linear, The faster you go the more amplified it becomes. Example: If you car has .030 bump-steer ( wheel goes toe in or toe out .030 through suspension travel) at 90mph you may not feel it very much. But .030 bump-steer at 130mph your car feels almost out of control.

Your standard car has bump-steer designed into it along with other suspension geometry imperfections to keep people from being overly confident in their driving abilities and wrapping their car around a telephone pole.

[RT SERPENT]

Since we're on the topic of suspension, I'll throw this one out for you experts.
2017 ACR-E, lowered to track height (5.5"rear/4" front)
I notice a suspension clunking sound when I crank my wheel hard when making slow turns or backing up and cranking the wheel.
Seems likes a suspension "binding" sound. In the past month or so it's gotten louder and more frequent.

Checked the obvious things like loose bolts in the belly pan, engine cross brace, etc. Doesn't seem to be any play in the wheel bearing, lug nuts tight, ball joints greased.

I'm having the Viper tech at my go-to dealership take another look at it this week. Will check everything from shock mounts, control arms, steering rack, tie-rods,?
Is this a known issue with potential front suspension geometry binding when the car is lowered? Any thoughts would be appreciated.
thanks all

[Aevus]

at 90mph you may not feel it very much. But .030 bump-steer at 130mph your car feels almost out of control.

Your standard car has bump-steer designed into it along with other suspension geometry imperfections to keep people from being overly confident in their driving abilities and wrapping their car around a telephone pole.

Well, it sure felt way more dangerous before than it is now. But, yes, I makes me more confident to go faster, so it might very well be more dangerous, indeed. I would say that I feel the same level of control with 30-40% higher speed. Which is a huge difference.


Edit: on the other hand, keeping the car perfectly straight/controlled under hard braking is priceless. Just for that, I don't mind if it makes ''overly confident'' at higher speed

;-)

[Aevus]

TKO, is your kit an improvement for the gen5 as well? According to your website it is, but do you have any information on the OEM gen3/4 compared to gen5 ?

[TKO MOTORSPORTS TEAM]

TKO, is your kit an improvement for the gen 5 as well? According to your website it is, but do you have any information on the OEM gen3/4 compared to gen5 ?

Only back to back comparison we have is with Gen 5 since our shop test mule is a gen 5. Gen 5 we have alot of track data on all our products. Gen 3/4 we have some track data and always gathering more.

[TKO MOTORSPORTS TEAM]

Since we're on the topic of suspension, I'll throw this one out for you experts.
2017 ACR-E, lowered to track height (5.5"rear/4" front)
I notice a suspension clunking sound when I crank my wheel hard when making slow turns or backing up and cranking the wheel.
Seems likes a suspension "binding" sound. In the past month or so it's gotten louder and more frequent.

Checked the obvious things like loose bolts in the belly pan, engine cross brace, etc. Doesn't seem to be any play in the wheel bearing, lug nuts tight, ball joints greased.

I'm having the Viper tech at my go-to dealership take another look at it this week. Will check everything from shock mounts, control arms, steering rack, tie-rods,?
Is this a known issue with potential front suspension geometry binding when the car is lowered? Any thoughts would be appreciated.
thanks all

I think you have a good plan started having your mechanic check it out first. Throw the car up and grab wheels see if there are any obvious problems. If you just lowered the car check the shock bolts. If you see nothing then its time to go a little deeper. Driver shaft, axles, control arm bushings, rear lower shock mounts, trans mount etc. Most of the time the loud "clunk" you hear inside the drivers compartment is something alot smaller then what it sounds like. Your always welcome to pick our brain directly martin@tkomotorsports.com. Or keep the brain picking on the VOA for others who maybe having same problem

[Aevus]

Only back to back comparison we have is with Gen 5 since our shop test mule is a gen 5. Gen 5 we have alot of track data on all our products. Gen 3/4 we have some track data and always gathering more.

I see. That means it's an upgrade on gen 5 as well. That includes ACR?

So if I understand correctly:
The OEM tie-rods and shims left something to be desired, even with the latest Mopar/SRT parts, TKO designed that kit based on track data using a gen 5 and it's an improvement on both driving feeling and track time? ...and on all Vipers from 2003 to 2017 ?

[Aevus]

Bump-steer correction is one of those deals you didnt know you needed it until you have it.

To be honest, I was starting to believe that this twitchy and somewhat typical 'Viper' behavior was inevitable. After having believed that the cause was the type of tires or too wide tires, the alignment, the suspension, the bushings, the sway bars, I had made myself to the idea that it was in fact a frame flex problem or the configuration (front-engine).... in short: something incorrigible or almost.

But all this time, it was only the tie-rods?? I can't even begin to understand how it's even possible that Dodge / SRT missed the shot on this one.

Anyways.
TKO, get prepared to ship few orders to Canada, I have sent information to the most popular Viper mechanic in the province and some viper owners already want to test drive my car. I'm sure they will be instantly convinced.

[TKO MOTORSPORTS TEAM]

To be honest, I was starting to believe that this twitchy and somewhat typical 'Viper' behavior was inevitable. After having believed that the cause was the type of tires or too wide tires, the alignment, the suspension, the bushings, the sway bars, I had made myself to the idea that it was in fact a frame flex problem or the configuration (front-engine).... in short: something incorrigible or almost.

But all this time, it was only the tie-rods?? I can't even begin to understand how it's even possible that Dodge / SRT missed the shot on this one.

Anyways.
TKO, get prepared to ship few orders to Canada, I have sent information to the most popular Viper mechanic in the province and some viper owners already want to test drive my car. I'm sure they will be instantly convinced.

Thank you Aevus really appreciate you talking up our product. We always encourage and appreciate all our customers to give us feed back. Thank you once again for taking the time. .............And it doesn't always have to be positive. Honest candid feedback good or bad.

[EZ 2B Green]

TKO, does your Bump-steer Correction kit work as intended on an otherwise stock Gen 5 Viper or does it mostly benefit cars that have additional suspension upgrades from TKO? In other words , does it work even if you have no other suspension modifications on both the standard GT/GTS Viper suspensions (set to factory alignment specs) and the ACR variants?
It would be great to hear more about your solution to the problem and how it works.

Also, since the spherical bushings do not appear to be sealed (from dirt etc.), is this kit recommended for track use only?

[Aevus]

TKO, does your Bump-steer Correction kit work as intended on an otherwise stock Gen 5 Viper or does it mostly benefit cars that have additional suspension upgrades from TKO? In other words , does it work even if you have no other suspension modifications on both the standard GT/GTS Viper suspensions (set to factory alignment specs) and the ACR variants?
It would be great to hear more about your solution to the problem and how it works.

Can't say about gen 5 but if that can help: my gen 3 is also equipped with TKO's control arm bushings and sway bar links for lowered suspension (which is BC racing + Swift 12/14kg springs) and ACR's front/rear sway bars... and soon I will have Penske double with 750/950lbs Hyperco springs. Not stock.

But I'm pretty sure that bump-steer correction kit will have an effect on any Viper that is stock. Simply because it's not only about precision or tightness or firmer suspension, it's about keeping the car straight and stable, especially 50mph and up.
With stock bushings, suspension and bars, the car will still feel somewhat soft and mushy but at least with the bump steer perfectly corrected, it will be straight, stable and a whole lot less twitchy in pretty much every road surfaces.

As far as my concerned, TKO is not exactly offering an ''upgrade'' with this part, that's downright Dodge's flawed design that is corrected. Not the same at all. There is a lot of things on the Viper with poor design/conception, but few of them corrected on later generations or with understandable reasons (emissions with the 3.07 gears, costs for the drysump, etc..) but the bump-steer tie-rod thing is unexcusable.

[Aevus]

All Viper owners,
If you passby Montreal, you're welcome to test drive my car, just drop a PM.

So far, it was eyes-opener for 2 of them.

[Aevus]

TKO, do you know if the 2017's that made the 7:01 record on the ring were equiped with a bump-steer kit similar as yours?

Can't help but thinking that sub 7 minutes lap time would have been possible with your kit...


https://youtu.be/nu_LYke16DE?t=173

[Aevus]

Bump-steer explained:

https://www.motortrend.com/how-to/ct...eer-explained/

[TKO MOTORSPORTS TEAM]

TKO, does your Bump-steer Correction kit work as intended on an otherwise stock Gen 5 Viper or does it mostly benefit cars that have additional suspension upgrades from TKO? In other words , does it work even if you have no other suspension modifications on both the standard GT/GTS Viper suspensions (set to factory alignment specs) and the ACR variants?
It would be great to hear more about your solution to the problem and how it works.

Also, since the spherical bushings do not appear to be sealed (from dirt etc.), is this kit recommended for track use only?

Great questions EZ 2B green!. You can install our bump-steer kit on completely bone stock vipers and still get the benefits. If you install our control arm bushing kit and our bump-steer kit you will get the benefits of both. Most everything we design, engineer and mfg works hand and hand. To put all this in perspective and a value we can all understand. lets say you install our bump-steer kit and that drops your lap times ( hypothetically) 1/2 second. Then you install our control arm bushing kit and that drops your lap times another 2/ 10ths. Then you install our rear bump-steer kit ( toe link) and you drop lap times another 3/10ths. Properly designed and engineered performance upgrades are always cumulative and they always vary with effectiveness.
All our parts are designed , engineered, and mfg for extreme track use. As far as exposed spherical bearings . We have cars with spherical bearings going on 20k+ miles. BUT service life is all really dependent on application and use.

As far as how our bump-steer works and what and how our bump-steer corrects. There is the long hair professor explanation that has a boat load geometry formulas and explanations ,SAI numbers, IC etc etc that we can all geek out on and discuss. OR
The down home simple explanation is: You need the steering and the control arms to all rotate off the same IC ( instant center). If they dont you will get changes in toe in and toe out through the suspension travel. Maybe best way to describe bump-steer is: Your were driving 130 mph in straight line over large and small bumps. Of course you have a little pucker factor because its 130mph. Then lets say hypothetically some A--hole is constantly changing your toe setting at the same time your going 130mph now you have a MEGALDON PUCKER FACTOR going and here comes turn 1.

Hope this helped. If you have more questions or something didn't make sense let me know