The Mustang Forum for Track & Racing Enthusiasts

Taking your Mustang to an open track/HPDE event for the first time? Do you race competitively? This forum is for you! Log in to remove most ads.

  • Welcome to the Ford Mustang forum built for owners of the Mustang GT350, BOSS 302, GT500, and all other S550, S197, SN95, Fox Body and older Mustangs set up for open track days, road racing, and/or autocross. Join our forum, interact with others, share your build, and help us strengthen this community!

Kenny Brown AGS 4.5: Have I Been Living Under A rock Or Is This Brand New?

Dave_W

Cones - not just for ice cream
649
784
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
Found this video where Kenny Brown is explaining his theory on where he wants the front & rear roll centers on an S197. The "we have something coming... that will blow your mind" comment may be about the Mumford link setup.
 

carver

breaker of wrenches
441
587
ontario
I,m curious watching the vid in the first post. After the 2:30 mark it looks like a lot of side to side movement in the rear axle. It actually looks unstable to me. It also looks like the axle is pushing against the left side exhaust pipe. Is that how they work? I'm thinking my pan hard bar has way less side to side movement. IMHO. I am not an expert in suspension it's just something I noticed....
 
5,762
6,899
Exp. Type
W2W Racing
Exp. Level
20+ Years
Pleasanton: 1/2 way between Sonoma and Laguna Seca
The YouTube video is dated March 2021 so I guess that's when he decided to go public with it.
I believe that video is unlisted, only those in possession of the link can view it. We weren't supposed to share it.
Kenny has done a few limited reveals to small groups starting with his speed therapy academy alumni who were able to buy the first 10 production units, then another limited reveal and 10 units went to the speed therapy group with the big public reveal yet to come.
 

Dave_W

Cones - not just for ice cream
649
784
Exp. Type
Autocross
Exp. Level
20+ Years
Connecticut
After the 2:30 mark it looks like a lot of side to side movement in the rear axle. It actually looks unstable to me.
I believe what you're seeing is body roll with the (much) lower roll center of the Mumford link.

With the Panhard & Watts, the RC is about axle height, so when the body rolls around that point, a camera mounted to the body and looking at the diff doesn't see much, if any, lateral movement of the axle, only rotation. But with the RC at ground level, when the body pivots around the RC a camera on the body looking at the diff "sees" the axle moving laterally with the body roll, but it's really the body moving on a different virtual pivot point. It's a frame-of-reference thing.

It does point out that you need to consider the change in body roll-induced lateral movement in relation to the wheels if you're running wide rear wheels/tires and are tight on wheelwell clearance. You might get sidewall rubbing with the Mumford when you didn't with a Panhard or Watts.
 

carver

breaker of wrenches
441
587
ontario
I believe what you're seeing is body roll with the (much) lower roll center of the Mumford link.

With the Panhard & Watts, the RC is about axle height, so when the body rolls around that point, a camera mounted to the body and looking at the diff doesn't see much, if any, lateral movement of the axle, only rotation. But with the RC at ground level, when the body pivots around the RC a camera on the body looking at the diff "sees" the axle moving laterally with the body roll, but it's really the body moving on a different virtual pivot point. It's a frame-of-reference thing.

It does point out that you need to consider the change in body roll-induced lateral movement in relation to the wheels if you're running wide rear wheels/tires and are tight on wheelwell clearance. You might get sidewall rubbing with the Mumford when you didn't with a Panhard or Watts.
I think I get what your saying but the Cortex video ( post# 20) looks rock solid in regards to lateral movement compared to the Mumford Link video but maybe it's just the camera angle and the way I'm interpreting it. :)
 
I think I get what your saying but the Cortex video ( post# 20) looks rock solid in regards to lateral movement compared to the Mumford Link video but maybe it's just the camera angle and the way I'm interpreting it. :)
I think its still what the other DaveW said, the RC is still setup close to axle height on that Cortex video and certainly not on the KB one.

My old tubeframe race car "Mustang" had a front RC at 3.5 and a rear adjustable from 4-8" and typically ran around 6. I could also put the instant center wherever I wanted it and everything had very long links and very little migration of those numbers. And a very low CG and polar moment (crank center about 8" off ground, engine set back 18" from axle center line)

My S197 has none of that. It seems like all the off the shelf panhard/watts for them have the rear RC way too high, but at least the Cortex offers a bit more adjustment (I purchased one, it is on backorder since June) but all that said, I can't figure how a super low rear RC would work without crazy spring rates and blowing forward bite. It seems to get back into all the shiznit I fought back in the Fox Mcstrut days where your front RC is subterranean and moving all over the place and no matter where the rear was, the slope was gigantic and it was wonky at best.

All that said, KB is not a joke and knows more than me, so I am certainly watching all this. A mumford was on my to-do list of the old tube frame car, I just never got around to it before tiring of the car. It offers a lot of advantages and IIRC the RC is crazy stable.

DaveW
 
Kenny actually didn't invent it, the basic concept was in an ancient engineering book he came across decades ago and liked the idea and developed it for the s197.
It’s called a Mumford link.

 

Dark Horse

2012 BOSS 302 LS 541
I installed the K-link this summer. My first impression while the car was on jack stands was that rear axle had a crazy level of articulation compared to the panhard bar. The car does handle differently so there is some learning curve on the new handling characteristics. The car feels much more planted at corner entry all the way through corner exit. At HMP, my home track, I bested my quickest lap time by 4 seconds between two back to back sessions. This was especially impressive considering i was running smaller diameter tires than normal (30/650 vs 30/680) and not having 5th gear due to no synchronizers! I am looking forward to seeing what the car is capable of next year with the larger diameter tires and a healthy transmission.
 
46
40
Exp. Type
Autocross
Exp. Level
3-5 Years
Nashville, TN
I installed the K-link this summer. My first impression while the car was on jack stands was that rear axle had a crazy level of articulation compared to the panhard bar. The car does handle differently so there is some learning curve on the new handling characteristics. The car feels much more planted at corner entry all the way through corner exit. At HMP, my home track, I bested my quickest lap time by 4 seconds between two back to back sessions. This was especially impressive considering i was running smaller diameter tires than normal (30/650 vs 30/680) and not having 5th gear due to no synchronizers! I am looking forward to seeing what the car is capable of next year with the larger diameter tires and a healthy transmission.
Very interested to hear updated feedback on the K-link. It obviously gets the rear roll center much lower than a Watts and a Panhard, but "real world results" are what count in my book. FOUR SECONDS a lap?!? That's, well, almost unbelievable.

Still like it today?

My understanding is that KB was hesitant to "broadcast" this product far and wide because the patent process was still to be finalized. They have a page about it on their website, but it's still "unlisted."

Here's a link with a video showing it in action: https://kennybrown.com/products/k-l...44416&pr_ref_pid=1800189149245&pr_seq=uniform
 
616
605
Exp. Type
Autocross
Exp. Level
10-20 Years
Kansas City, Missouri
I installed the K-link this summer. My first impression while the car was on jack stands was that rear axle had a crazy level of articulation compared to the panhard bar. The car does handle differently so there is some learning curve on the new handling characteristics. The car feels much more planted at corner entry all the way through corner exit. At HMP, my home track, I bested my quickest lap time by 4 seconds between two back to back sessions. This was especially impressive considering i was running smaller diameter tires than normal (30/650 vs 30/680) and not having 5th gear due to no synchronizers! I am looking forward to seeing what the car is capable of next year with the larger diameter tires and a healthy transmission.
What times are you running at Topeka?
 
46
40
Exp. Type
Autocross
Exp. Level
3-5 Years
Nashville, TN
@Dark Horse Holy smokes 4sec per lap! That's incredible. Is your car a dual purpose car? If so, how is it on the street?
I test fit the K-link on my 2012 Mustang GT and did some street driving early in development. That's my car in the videos. Surprisingly, I didn't notice ANY increase in NVH. Very impressive. Because of the lower roll center, KB justifiably specifies higher rear spring rates, but for my street test, I left the spring rates alone. The car naturally felt pretty soft in the rear and understeered at the limit, hence the need for higher rear spring rates. I'm really intersted to hear more detailed feedback from track users. So far, it clearly looks to be a massive (and positive) departure from the status quo in aftermarket rear suspension.
 
46
40
Exp. Type
Autocross
Exp. Level
3-5 Years
Nashville, TN
Im going to pull the trigger on this for my build. Anyone have any more data on lap time improvements with it?
I don't have experience on track yet, but the few people that I've heard use this on their track car, LOVE it. Because the rear roll center is so low, you have to run significantly higher rear spring rates...which makes sense.
 
I don't have experience on track yet, but the few people that I've heard use this on their track car, LOVE it. Because the rear roll center is so low, you have to run significantly higher rear spring rates...which makes sense.
Yup, KB said 650lb and 650lb springs. Im looking at coil overs as I have a unknown setup in the car. I am trying to see if they can get me the coilovers and k-link in time for my Sept race. I would rather do it all at once, I have a opportunity to return to KB part of the rear grip kit I have not installed yet to save a few bucks. I have the KB k-member in the car already.
 
No, still building the car. Its at the body shop, I have been going nights working on it, should be glassing in the brake ducts tonight and getting some primer on the bare metal spots. Its getting close to being sprayed.

I will install the caliper upgrades last so I dont end up twisting the new brake lines. Just a little wiring to go, rear wheel studs, belts, dyno, and KB rear stuff left to do.
o
We have a new track open a couple hours from me, the club booked 2 races, Im trying to make the second one. Compared to our small local track this will be awesome ! I went crazy on aero for this track.

- shows a lap, 36 meters of elevation change.
 
Last edited:
46
40
Exp. Type
Autocross
Exp. Level
3-5 Years
Nashville, TN
No, still building the car. Its at the body shop, I have been going nights working on it, should be glassing in the brake ducts tonight and getting some primer on the bare metal spots. Its getting close to being sprayed.

I will install the caliper upgrades last so I dont end up twisting the new brake lines. Just a little wiring to go, rear wheel studs, belts, dyno, and KB rear stuff left to do.
o
We have a new track open a couple hours from me, the club booked 2 races, Im trying to make the second one. Compared to our small local track this will be awesome ! I went crazy on aero for this track.

- shows a lap, 36 meters of eleveation change.
Sounds like a great build! Please keep us posted on progress.
 

TMO Supporting Vendors

Latest posts

Buy TMO Apparel

Buy TMO Apparel
Top