Dave @ COBB

A couple months back, we spent the day at Miller Motorsports Park http://millermotorsportspark.com/3.0/index.php on the West track doing some back to back comparisons of our suspension vs stock. The car we used was my '06 Enthusiast 350Z. It's my daily driver and the company's test bed for Z parts. During this test, it had the Cobb high flow cats, and cat-back. It also has Prodrive 18x9.5 R and 18x8.5 F GC-10G's. The tires are RE-050A Pole Positions (so basically the same stuff as the track edition/grand touring Z's). There were no other mods on the car. The guy we had come drive the car was Matt Guiver http://www.setup-tv.com/crews/teams/team_D/. Between racing and instructing in cars and racing his bike, he has probably close to 1500 hours on this track (that has only been around 2 years). We wanted someone that would be consistent and be able to give us unbiased valuable feedback.

The car went out with our stage 2 suspension package http://www.cobbtuning.com/products/?id=3477 . This consists of Cobb front and rear adjustable anti-sway bars http://www.cobbtuning.com/products/?id=3440 and Cobb sport springs http://www.cobbtuning.com/products/?id=3448 . After a warm-up lap, Matt brought the car in and I set the tire pressure, then he went out for some hot laps. The result: It's fastest lap was a 1:49.2. For reference, National Spec Miatas are running 1:52.2 http://mylaps.com/results/newResults.jsp?id=338004 on this same track.

We took the car into our garage/dyno facility at the track and changed the suspension back to stock. After about 45 minutes, we had the stock springs and anti-sway bars on. No other modifications were done. We checked tire pressure to make sure it was the same as the first session. Then we sat and waited for our turn on track.

About an hour later, we got to head back out on track. This weekend was the Grand-Am race so there was a bunch of teams there still doing testing after the race was over. After a warm-up lap, Matt brought the car in, I made sure tire pressures were the same as session 1 and he went out for hot laps. The result: The car was 1.1 seconds slower than with the Cobb suspension. It ran a 1:50.3.

Now the reason we started with our suspension and later switched to the stock suspension was to help insure that the driver wasn't just getting used to the car in the afternoon. Also, we did the same test to our MazdaSpeed3 the same day. On that car we did the opposite and started with stock and later put the Cobb suspension on. We figured that way we would be maximizing the accuracy of our testing.

Here are Matt's comments:
Stock --- I was astonished with how much body roll the stock 350z exhibited. Sluggish to transition between west 7 and 8. The Nissan did not want to take a set in any turns, moved around excessively, and gave rubbery feedback. Throttle steering had no effect, and the car would get difficult to drive over the red and whites. The Z required a lot of steering to wrestle through the turns. Trailbraking rewards the driver with adequate rotation, but shortly after turn in the front end loses grip and your awesome entry turns into a blundering exit. I often found myself adding copious amounts of counter-steer to keep the car in line. While this normally would have added to the fun factor, the throttle continued to be useless for anything but straights, killing any D1 dreams you may have entertained. Overall it was a lot of work to drive fast and enjoy.

COBB --- I couldn't believe how much easier the 350z equipped with Cobb tuned suspension was to drive. I was amazed at how the Z transitioned quicker, responded faster, and made much better use of its tires. Now the Z responds beautifully to throttle steering, and one finds themselves entering turns a little hot on purpose so you can hang the tail out Hazard county style. If the car isn't checking up on the apex, a little deft footwork brings it right back in line, all the while your hands never move on the steering wheel. The car was a ton of fun from west 1 through 4, easily controlling 80mph slides using only your feet! Even west 7, a challenging off camber triple apex, was a breeze with the new suspension. Again it seems that Cobb got this setup right. Hit a rumble strip hard and the suspension doesn't bat an eye, but the smooth ride exhibited next to zero squat, dive, or body roll. The car attracted a lot of attention with its aggressive stance, and incredible exhaust note.

Here is the video with Matt's commentary: http://forums.cobbtuning.com/videos/350Zsuspension.mov If you have any questions, feel free to PM me or post here.

Laters,
Dave

ADMAN

iTrader: (9)

Nice...

But, I'm a little concerned about the drop. I run non-staggered 17x8.5" ADVAN on the track. This helps balance the car overall and drastically changes the geometry and understeer/oversteer problems. As in, virtually eliminated!!!

<== Body roll is still an issue. However, once the car sits in, it's glued. I'm used to it now.
<== Works for most tracks here on the west coast - like Fontana. Sucks a$$ for others, like Willow.



Comments? Suggestions?? Stock with sways vs. full Stage 2???




P.S. I run staggered 18" for street. Not my concern, though.

Dave @ COBB

Well, the sway bars have 4 points of adjustment on the front and 3 on the rear. So I am sure you could dial in the understeer/oversteer to your liking.

As for tire clearance, unless your offset is pretty far off, I don't see 17x8.5's being an issue. My car has 18x8.5's on the front and I am positive I could fit at least another inch. And the drop is not super aggressive. As for whether or not the springs would be ideal for you... These are designed for stock shocks on the street. They are great for that. They work on the track, obviously, but some uber expensive coilovers with race tires are going to be your best bet for track use if your budget allows. If you run street tires on the track, then I am sure the springs would be ok for you. But you will definitely want to play with sway bar settings.

The main reason we design things for the street and test on the track is because it is easy to quantify an improvement on the track. We of course daily drive our mods on the street and tweak them to get them to where we think they are ideal. But we can only give an opinion. We can't really put a value to the mods. Also, since we have a facility at the track, it makes it easy to go out there for testing.

ADMAN

iTrader: (9)

I have an 03 - looking for testing. Just needs COBB stickers...

DMK

iTrader: (6)

What sway bar settings did you use on the track and why?

ADMAN

iTrader: (9)

Depends on the track...

And, the car...

Dave @ COBB

As he said, it depends on the track. But rather than spend all day tuning the sway bar for optimal results, we wanted more realistic results for street guys that are just going to slap these on and most likely feel an improvement without tuning. So I left it on the same setting I use on the street which is middle hole on the rear and middle/stiff hole (3 of 4) on the front.

ke0ki2k

iTrader: (2)

just out of Curiosity, will the Cobb sways reduce body roll as well as Cuscos? the cobbs are hollow whereas the Cuscos are solid but the stated rates are about the same. exaggeration?

Dave @ COBB

I am not sure how the Cusco's are. But if they claim the same rate, they very well could be. They are probably just slightly smaller O.D. if they are solid. But that also means they are most likely heavier as well.