Hey all. Been a while since I've posted. Been stupid busy at work. Anyway, last weekend we did a track test of a set of KW Variant 3 coilovers and Stillen front and rear camber arms on my '06 6MT Sports Package coupe. I wasn't sure what to expect since I've never tested a KW coilover kit before, but I think the results speak for themselves.





We started off by testing the car with the stock suspension around our local test track (Toronto Motorsports Park), where I posted a best lap of 1:28.142. Mods on the car include Stillen intake, headers, high flow cats, exhaust, grounding kit, strut bars and engine damper, Motordyne MREV2 and 5/16th plenum spacer, GTSpec lower tie bars front, middle and rear, Advan RS 18x100 wheels and Goodyear Eagle F1 Asymmetric 265/35-18 tires all around.

Once we were satisfied with our baseline lap time, we threw the G up on jackstands and swapped the Stillen arms and KW coilovers onto it.







We set the dampers to 70% compression and 80% rebound all around and dialed in about 2 degrees of negative camber up front and 1 degree out back, along with 1/16th of toe out up front and zero toe out back. Then it was back onto the track for the comparison test. First session the front end seemed a bit bouncy, so we raised the front compression to full stiff and that really helped the front tires grip without inducing any understeer.





After this small adjustment, I posted a best lap time of 1:25.618, a full 2.5-seconds faster than stock. This is a pretty huge improvement for a coilover system designed primary for street use. Here's some of the data from the G2X we collected along with a track map that summarizes the lateral cornering G-force and average cornering speed improvements compared to stock:









I'm also quite pleased with the ride quality on the street. There is a bit more ride harshness over pronounced seams in the road, but over normal bumps and dips and even potholes the Variant 3's are very civilized. The ride is definitely sportier/firmer feeling than the Sport Package suspension, but not by much. So to gain as much performance on the track without giving up much ride comfort and even gaining a solid and sporty feel on the street, I've gotta say I'm really enjoying my G more than ever.

Here's a before and after pic showing the ride height difference. Looks subtle in the picture, but with the blingy GTF's on the car the lowered stance really gives it a gangster appearance. The high school hotties are going nuts for me now!





Full story will be in the October issue of Modified Mag.

Next up are AP Racing big brakes front and rear, since the OE brakes are really weak. Can only do 1-2 laps at this track before the brake fade is so bad that I have to park the car, and that's with ELF Frelub 650 brake fluid and Hawk HPS pads front and HP+ rear.

 

This is what this place needs..........factual data and good solid information..........fantastic job!!!!!!! Did you notice that you were actually slower in turns 4 & 11 on the fast lap? I think your much lower CG added quite a bit to the final numbers. Car looks 100% better.

 

i just read the track wheel issue a couple weeks ago and now here you go spoiling October...its cool, I like seeing sneak info like this and its reasons like this post I subscribe to your mag!

Do you think you will go with just a 4piston front or the AP 6piston/4piston combo?

Also do you still have plans to go with 275 tires front and rear?

 

just to know, why should he go 275 all around? unless he is all wheel drive i can see how it would be effective, but rwd? just curious as to the train of thought behind that.

 

Yes, I did notice I was a bit slower in Turns 4 and 11. The shape and speed of those corners probably didn't favor the KW's as much as the other ones, plus in looking at the data I can see that as a driver I could have carried more speed in both corners if I just trusted the new setup and let the car rotate naturally. The problem is, with the stock brakes on the car I could only do 1-2 hot laps before brake fade would force me to park the car for 20 minutes. So it was challenging to find the limit with the new setup since I got so few laps in a row to get a feel for it. Once the AP brakes go on, I think we'll see faster and more consistent lap times and better use of the suspension's full capabilities. But as a starting point, I think this test, on average throughout a hot lap, shows that the coilovers are working very well.

Lower center of gravity certainly helps a bit, but lowering a car also alters its suspension geometry in a negative way, so I can't attribute much of the performance gain to the lower CoG. In all likelihood the faster lap times are predominantly a result of the superior damping of the shocks and their independent adjustability (for low speed compression and rebound), along with the slightly higher spring rates compared to stock and the more aggressive alignment settings, allowing me to use more of the tires contact patch. The improved camber control from the poly bushing and front upper spherical bearing on the Stillen arms also helped, I'm sure. It's all about control the wheel rate and utilizing as much of the available grip as possible. The supsension mods definitely help control the wheels better in both bump and rebound, which in turn helps limit weight transfer, all of which contributes to better grip in the turns.

I have a set of 275 BFG R1's on the way, so we'll see how those work compared to the 265's all around. With respect to why I'm using a non-staggered setup on the G, it's because my years of competitive road racing has taught me (the data doesn't lie!) that front grip is KING. Rear grip is obviously very useful in a RWD car, but with the fairly modest power levels of the G (260whp) I don't have any problems putting the power down effectively, but what I did notice in early testing is that the smaller front tires were being completely overwhelmed on corner entry. The G is a big front heavy car, so fitting as much front tire under its nose as possible is going to give it more grip on turn-in and in mid-corner, allowing me to carry more speed into and thru the corner without the horrible understeer that was happening with the staggered setup. Basically what you want to do with any race car where grip and max cornering speeds is your goal, is maximize front grip first and then balance the car's handling from there. Max front grip will give you max cornering speed potential, plain and simple. Now, if I turbo my G and I've got 400whp and tons of torque, then a bigger rear tire might be useful for putting the power down coming out of tight corners, but there is a trade-off with that since you're adding aerodynamic drag with a wider tire and you're also adding rotating mass. Anyway, long story short, with a 3500 lbs car like the G, it needs a lot of front tire. I'm sure the 275's will be faster than the 265's I'm currently testing, but I'll post the results here once they're on the car.

I think we're going to go 6-piston front and 4-piston rear on the AP Racing brake setup. From what I've seen so far, this car desperately needs better brakes! It's by far the weakest link on the car IMO, and unfortunately because in '06 Infiniti changed the front caliper and pad shape, I can't get a track-oriented pad for the OE calipers. The Hawk pads I put on the car are excellent for the street, but they overheat pretty quickly at the track, though admittedly TMP is a track with some very heavy braking zones so this problem is amplified at this particular track. Still, I'm more than happy to add a bit of unsprung weight in exchange for brakes that'll allow me to do more than 1-2 hot laps at a time. With the AP's, I should be able to lap for hours if I want.

 

Great write up.

 

Thanks for clarifying that modified dave, learned something new.

 

awesome write up! should have gotten the 03/04 that came factory with brembo brakes!

 

I was originally looking for an '03-'04 G with the Brembo brakes, but couldn't find one at the right price or in the condition I wanted. I got a smokin' deal on my '06, which has the RevUp motor which is nice, but man do the stock brakes ever suck. Ah well, the AP's I've got coming should be even better than the factory Brembos, so it's all good

 

Thanks for the info Dave, I look forward to remaining installments.

As for:
I know Dave explained it, but I was also referencing his article in the wheel installment issue for this project where he stated he initially wanted 275's. I've also always been a fan of non-staggered setups.

 

Thanks Dave the write up was amazing

 

Here's how the G is looking on the street wheels (19'' Volk GTF's), btw...



Having done a few weeks of street driving on this setup, I've been able to adjust the damper settings for a really pleasant ride quality on the street. I think the ride quality is now superior to the OE setup, by running low speed compression near full soft so that the shocks allow the springs to absorb more of the bump without transferring much noise or motion to the driver. I've left the rebound a little more aggressive though, since this helps stabilize and flatten out the G more quickly whenever it does go over a bump.

I am hearing some squeaking from the poly bushings on the rear Stillen arms now, and the spherical bearings do make the occasional clunking noise at very slow speeds. I may try throwing some marine grease on the poly bushings to see if that quiets them down, but poly bushings are inherently noisy so I may just have to live with it. It's a minor annoyance and is only heard at really slow speeds over things like the curbing at the end of my driveway. Same with the spherical bearing clunks. But at normal driving speeds, the suspension is nice and quiet and feels incredibly solid. So if you can live with the occasional squeak or clunk at low speeds, the upgraded control arms and radius rods do definitely give the suspension a more connected and solid feel overall.

 

Dave, I know I'm bumping a 5 year old thread, but I'm doing a build on my G to have as a track day car and was looking for a knowledgeable review on the KW3's. This is perfect!

However I want to ask, after 5 years of use, how are the KW's holding up?

 

I sold the car a few years ago, but as far as I know the coilovers are still going strong. KW makes a quality product, and the stainless shock bodies mean they stand up very well to all types of environments. As a dual purpose track/street setup, really hard to beat what the V3's offer for the money. If you want to get into a more in-depth conversation about this stuff, shoot me an e-mail at planetdave "at" me "dot" com

 

KW's are known to be very reliable, you aren't likely to have any more trouble than the standard servicing/rebuild depending on how long you own them/how long&hard you drive them. I would honestly guess that unless you drive or track your car a lot, you are more likely to get rid of your car or go track nuts and get a pure track setup before you have issues with your KW's.