DavidM

I met up with a friend with a new (ie. couple months old) C32 AMG Mercedes. It has a 3.2L Supercharged engine producing 260kW (at 6,100rpm) and 450Nm (at 4,400rpm). It weights 1635kg, so it's a reasonably light 4-door sedan with a powerfull engine, big wheels and big brakes. Though, it's an auto as that is all that they come with. Still even with that, this is what the Motor mag managed out of it (so it's a quick car):
- 0-100kph = 5.21sec
- 400m = 13.49sec @166kph
- 1000m = 24.76 @ 218kph
- Winton lap = 1:45.59
- Wakefiel (long) lap = 1:16.72 (ie. about the same time as Integra Type-R, and 0.7sec off the S15 200SX time)

Anyway, he took me for a spin and it goes without saying that the car rides really well and is very refined, comfy and all that. It seems to corner pretty well also for a car like that... and it certainly moves. He took me up to around 170kph or so and the pull from around 90 - 170kph felt pretty intense.

Also, we got my 350Z and did some side-by-side acceleration testing. Where we did it, we could only really run up to about 130kph so it was all reasonably 'low speed' stuff. We did about 8 runs, and this is how things went:

- Test #1: 10 - 130kph rolling start, both in 1st gear:
We did this about 4 times to see what is really happening, but it seems that the C32 AMG has a bit of lag in the computer/system and takes a little while to start moving. What that means is that 1st couple times we run, I'd instantly start pulling away in 1st gear. I'd get 1/2 a car straigh-away and then about 1/4 a car-length before the end of 1st gear. Though, when I need to shift to 2nd gear, I would get a lot of wheel-spin and lose good 1/4 car-length. Then things were pretty even in 2nd gear, but I'd say that the Merc has a slight edge and creeps maybe a foot or two on me before the end of 2nd gear (ie. 100kph). Then I shift to 3rd, keep my 1/4 car-length lead, but the Merc is definatelly a little bit quicker than me and is very slowly creeping up on me. By 130kph we are either right side by side, or the Merc is 1/4 car-length ahead. We did this a few times, and the results followed this pattern. If I could make 1st-to-2nd gear change quick enough, and without too much wheel-spin, then I think I should finish about 1/4 car-length ahead.

- Test #2: 15 - 120kph rolling start, both in 1st gear:
We tried running a couple times from a slightly higher speed, thinking that the Merc would take off a bit better. On one of the runs we really timed it well and took off with minimal loss to the Merc as we punched it. We stayed side by side until about 30kph, and then I pulled about 1/4 car-length of it before the end of 1st gear. Then I had to make the 1st-to-2nd gear-change where I got some wheel-spin again, and lost my 1/4 car-length advatage. Through-out the 2nd gear we stay side by side and even though there is slight movement between us, it is not more than a foot either way. The Merc probably pulls away about a foot, then makes a gear-change and looses a foot. So, I shift into 3rd gear and we are still side-by side. By the time we shut down,, we were doing about 120kph, but we were still very much side by side. There was no more than a foot between us, and I can't even honestly say who was ahead .... it was so close.

- Test #3: 0 - 115kph standing-start (350Z dropping the clutch from 3000rpm):
We figured that we'll try a standing-start run as well. We only did this once, and I dropped the clutch from just under 3000rpm (which resulted in way too much wheelspin in this cold weather), and the Merc was just punched off idle. So as I launch at ~3000rpm, I get way too much wheel-spin and spin the rear wheels all the way through the 1st gear. I had to short-shift it at around 6,000rpm to 2nd gear as the wheels just would not hook up. Still, even with that the Merc did not match my launch and stayed about 1/2 - 3/4 car-length behind through the 1st gear. When I shifted to 2nd gear, the Merc did not really make any ground up on me as this time I actually got some grip and my wheels stopped spining. Through the 2nd gear there was nothing between the 2 cars and the Merc did not really make up any ground. I only shifted to 3rd gear for a second or so, and the Merc made up a foot or two at most on me before we shut down at 110kph otr so. So, at the end I was still goot 3/4 of a car-length ahead.

Was good fun, but I was expecting to get annihilated, in particular from the roll. I figured I could stay ahead from a standing start untill the end or 3rd gear at least, but from the roll, I was expecting the C32 AMG to be always pulling away. Wasn't so as through the 1st gear the 350Z looked to be quicker, through the 2nd gear pretty much even, and in 3rd the Merc would be slightly quciker, but I'm not sure if it would pull a car-length on me before I'd need to shift to 4th .... though, we never went that far. I'm sure that as the speeds would increase, the more advantage the Merc would have, but I could not put that to the test in this instance.

One thing we did not try was to 'load up' the auto-box to launch it better, but my friend wasn't into it so we can only speculate how much that would have helped.

ps. Probably eveyone knows, but my car is stock except for the Hi-tech exhaust and K&N filter. Also, I had more than 3/4 of the tank of fuel.

KY350

Nice report David.

When I read the Motor times, I thought you'd get trounced from both standstill and rolling starts.

Surprised to see that the Z more than held its own in all runs.

A 1500rpm drop in the Benz may have made life more interesting in the standing start runs.

BTW, what rubber do you currently have on the Z?

zuff

that's an unexpected review! It puts a smile on my face though.

mchapman

iTrader: (1)

Good stuff, Keep up the good work David.

scathing

Considering its 0-100 and quarter mile times quoted by Motor, I would have thought that the AMG would have at least kept up.

Still, must have been fun running with the C32. I suppose having an extra gear does make a bit of difference.

Z350Lover

iTrader: (2)

DavidM... thanks for the review! It proves that the zed isnt weak at all compare to those euro sports sedan!!! Always though that the Merc C32 will just have the zed (even with mods) in any gear anytime.. but I think I was wrong! Good one!!!

cheers,

richie

DavidM

Surprised to see that the Z more than held its own in all runs.

Surprised me as well ... I did not think that I'd be ahead at any stage.

A 1500rpm drop in the Benz may have made life more interesting in the standing start runs.

Yep, my thinking exactly. I just looked up some articles on the C32 AMG:
http://www.roadandtrack.com/article....&page_number=1
http://www.roadandtrack.com/reviews/...rcedes_c32.pdf

Here they managed mid 12s for 0-160kph ... which is very impressive. Also they mention that the best acceleration runs were achieved by 'loading up' the Auto with 1500rpm. Would like to see how much difference that would make.

BTW, what rubber do you currently have on the Z?

I still have the OME RE040 tyres that came with the car. My 'other' tyres are 245/40/18" all around, but they are on my spare set of rims and I pull them out for the track.

Considering its 0-100 and quarter mile times quoted by Motor, I would have thought that the AMG would have at least kept up.

I'd say that it 'kept up', and in a way was quicker car ... it just has a hard time with 'getting going' (even from roll, which surprused me the most). Hence I was ahead most of the time ... but it was chasing me down (slowly, but surely). I'll have to see if there is some kind of hidden 'sports mode' button.

Still, must have been fun running with the C32. I suppose having an extra gear does make a bit of difference.

With the speeds we did, the c32 AMG is geared not that differently to the 350Z. It has a 5-speed gear-box so it starts getting 'taller' from 3rd gear onwards ... in a way it just skips our 4th gear. The gearing for the C32 AMG is:
- 1st gear = 61kph
- 2nd gear = 103kph
- 3rd gear = 161kph
- 4th gear = 227kph
- 5th gear = 275kph (though it's speed limited to around 250kph).

So, the 350Z gearbox advantage 'should' come into play over 100kph ... just when the C32 AMG starts pulling away. Still, was a lot of fun ... and I'm still in a bit of a shock from holding the ground so well ... I cartainly was not expecting it.

KY350

I still have the OME RE040 tyres that came with the car.

I would guess that if you had better rubber then the wheelspin between gearchanges would be reduced or eliminated and the Merc would have an even harder time catching up.

With the speeds we did, the c32 AMG is geared not that differently to the 350Z. It has a 5-speed gear-box so it starts getting 'taller' from 3rd gear onwards ... in a way it just skips our 4th gear. The gearing for the C32 AMG is:

The Z is doing about 165 - 170km/h at the top of 4th and the Merc has only just gotten into 4th according to your facts. So I suspect that the Z may pull slightly better than the Merc between 100 - 170km/h.

DavidM

I would guess that if you had better rubber then the wheelspin between gearchanges would be reduced or eliminated and the Merc would have an even harder time catching up.

Yes, when I am on the track with my R-spec rubber on, then I don't get any wheel-spin between gear-changes. Though, the tyres are not the main 'coulprit' as if the the weather/road was warmer, I'd only get a 'chirp' (ie. small wheel-spin) on gear-changes. What I'm getting at the moment is the rear-wheels spinning for good 1 second and the back actually gets a little bit of side movement as it steps out. Current Melbourne weather is doing it's best to keep the grip levels down.

The Z is doing about 165 - 170km/h at the top of 4th and the Merc has only just gotten into 4th according to your facts.

Well, you can hit just over 180kph if you bring the 4th gear in the Zed to red-line. 3rd gear gets you just over 140kph. Still, you're right about the Merc ... it has much taller gearing once you get to those speeds.

So I suspect that the Z may pull slightly better than the Merc between 100 - 170km/h.

That is the odd thing. Bellow 100kph the Merc had nothing on ther Zed. Though, once we got into 3rd, the Merc started to show it's advantage so I would actually expect the acceleration gap to widen as the speeds increase. It seems odd, but laws of physics tell us that, as the speeds increase (and so does the air resistance), the less it's about weight, and more about power. And the Merc does have a very decent power advantage over the Zed.

I might get a chance to do few more runs if I'm lucky ... will try and do something about going to higher speeds.

ps. I'm still a bit bewildered by this .... I don't quiete understand how I am keeping up with a car that mutliple magazines/articles have clocked at low to mid 5s to 100kph, low to mid 12s to 160kph, and mid 13s over 400m. The AMG should, by all means be noticably quicker at any speed. I really need to find an M3 to see how a car with that power and a 'proper' gear-box matches up ;-)

zuff

There are many stock 350z (US spec) doing the 400m in high 13s. Some NA modded ones are getting mid to low 13s.

A good driver is what it takes.

Chuckie

david what do you estimate your 0 - 100 times would be now?

KY350

Perhaps your friend was not getting the most out of the Merc.

As discussed earlier, he should load up the box with 1500rpm when racing from a standstill start. Liek all supercharged Mercs, it will probably deliver about 75-80% of max torque at these rpms, ensuring the car gets off the line a lot more smartly.

Also, do you know whether he just left the box in auto mode to do the gear changing when the gearbox thought it was the best time to do so. If so, he may get better responsiveness from the car by changing the gears manually at redline.

If you can convince your friend for another few runs, try to suggest the above to him beforhand.

I'd be interested to hear of the outcome.

WRT speeds over 120km/h, perhaps this is where the Merc comes into its own. Consider that my stock Z takes almost 14s to hit 160km/h. Now compare that to the Merc which takes approx 12.5s to get to the same speed. I read this to mean that the Merc must be really hauling a** as the speeds get above 120.
I don't expect the Z's advantageous 3rd gear gearing ratio to overcome the Merc's massive power and torque advantage, but it should help to keep you in the race.

KY350

Going by the Motor times for the Merc, David's Z should be cutting and even 5.0 for the 0-100km/h.

LemanZ

DavidM, is your Zed stage 1 mod? what is your 1/4 times?

DavidM

Perhaps your friend was not getting the most out of the Merc. As discussed earlier, he should load up the box with 1500rpm when racing from a standstill start...

Most of the runs we did were from rolling start so the revs should not be an issue. I'm not sure what else he could have done besides flooring it ... I'm still looking to see if there is some 'sports button' or somethign like that, but so far I've found nothing.

Also, we did have at least one run where we seemed to have kept up with me from the word go (ie. test#2), and we were side-by-side all the way to 120kph or so .... he still didn't pull away. So I can't account for the Zed doing so well dou to it's launch advantage.

If you can convince your friend for another few runs, try to suggest the above to him beforhand. I'd be interested to hear of the outcome.

I'll mention it to him again ... and will see if we can get more runs. As I mentioned before, I'd really like to go to higher speeds and see what happens there.

I've just re-read the Motor article from which the times on top of this thread were published. In that article they mentioned that they got those numbers by doing nothing more but leaving it in auto-mode, and tramping the throttle (ie. no 'loading up' of the auto box). On the other hand, the 'Road & Track' article mentioned that they achieved th best numbers by 'loading up' 1500rpm ... I'd certainly want to try it.

Still, keep the ideas/thoughts coming.

WRT speeds over 120km/h, perhaps this is where the Merc comes into its own ... I don't expect the Z's advantageous 3rd gear gearing ratio to overcome the Merc's massive power and torque advantage...

The Merc was definatelly quicker than me over 100kph (ie. once I've shifted to 3rd gear). It was not pulling away (or gaining on me) that much between 100 and 130kph, but it was certainly moving quicker than me. 1/4 - 1/2 car length is about whatadvantage it had in the 100-130kph increment. I'm am sure that would only increase as the speeds climb higher.

I just looked up to see what numbers the Germans got out of the C32 AMG and this is what I found in 'Sports Auto':
C32 AMG:
- 0-100kph = 5.5sec
- 0-200kph = 19.8sec
- Top speed at Nurburgring (ie. longest straight) = 243kph

Same people tested the 350Zand this is what they managed:
350Z:
- 0-100kph = 5.8sec
- 0-200kph = 22.8sec
- Top speed at Nurburgring (ie. longest straight) = 235kph

These tests were not done on the same day ... but they do highlight something. There's not much difference in the 0-100kph times (ie. 0.3sec from ~5.5sec), but from 100-200kph there is a big difference (ie. 2.7sec from ~15sec). That seems to agree with what I've seen so far (even though it was only up to 130kph). Though, interesting to see the top speed on the straight only 8kph appart.

what do you estimate your 0 - 100 times would be now?

I know that my Zed is quicker than stock ... but I'd be only guessing at the 0-100kph time. I know I can pull about 2 car lenghts on a stock Zed before 100kph, but how that transtales to a time, I have no idea. 0-160kph time is easier (and more accurate) to measure, from the timing that I've conducted, I'm sure that I can hit 160kph in very low 13s, compared to stock high 13s - low 14s.

Still, my car is no quicker than DavidC's car, and even Lionking's auto Zed is not that much slower ... from what I remember, I could get about 5 car-lengths on him by 160kph at most.

DavidM, is your Zed stage 1 mod? what is your 1/4 times?

"Stage"? I did not realize my mods warranted 'stages' ;-) I only have the Hi-tech exhaust, K&N filter, R-spec pads and brake fluid ... that is all that is different on my car compared to stock. On the track I have R-spec rubber too.

As far as 400m time goes, I can only speculate as I have never had my car at the 400m strip ... I'm sure I'll take it there once we're coming into spring and the weather is a bit warmer. Still, for the moment I can only guess .... and my guess is that I will pull ~0.3sec quicker time than I would with a stock car. I'm guessing that as from all my pre/post mods testing, I'd say that I'm around 4 car-lengths ahead of where I would have been with the stock Zed by 160kph.

DavidM

You guys might find this interesting. I was thinking about how the 'acceleration vs time' and 'distance vs time' are two different things. So even though the AMG could be accelerating a lot harder, it may not show that much in terms of distance (and same goes for any quicker/slower car relation).

So what I did is pull out the 'best' clocked numbers from the Motor mag for the 350Z (stock of course) and the c32 AMG... they give me the 'speed vs time' (ie. acceleration). From this I worked out how much distance was covered over time for both cars. Then I simulated (mathematically) how the 10-120kph runs should pan out between the C32 AMG and stock 350Z.

Sp, here we have the two cars, right next to each other, starting at 10kph (ie. rolling start), and this is what the numbers say:

- Start side-by-side at 10kph
- When the 350Z reaches 100kph, the C32AMG should be ~1.5 car-lengths ahead.
- When the 350Z reaches 120kph, the C32AMG should be ~3 car-lengths ahead.
- When the 350Z reaches 160kph, the C32AMG should be ~8.5 car-lengths ahead.
- At this stage the C32AMG should be pulling away at the race of 1 car-length per second.

Here it is agian in more detail of you're wondering how I came up with those numbers (starting from 10kph):

When the 350Z reaches 100kph:
- 350Z has been on full throttle for 5.80sec and covered 101.77m.
- If the C32AMG stays on full throttle for 5.80sec as well, then it will cover 108.76m and reach 111kph.
- That means that the C32AMG should be 6.99m ahead (ie. ~1.5 car-lengths), and be pulling away at the rate of 3.05m/sec.

Still keeping it floored, when the 350Z reaches 120kph:
- 350Z has been on full throttle now for 7.74sec and covered 161.38m all up.
- So the C32AMG has also been on full throttle for 7.74sec as well, and therefore covered 174.17m all up, and is traveling at 128kph.
- That means that now the C32AMG should be 12.78m ahead (ie. ~3 car-lengths), and be pulling away at the rate of 2.22m/sec.

Still keeping it floored, when the 350Z reaches 160kph:
- 350Z has been on full throttle now for 13.52sec and covered 387.54m all up.
- So the C32AMG has also been on full throttle for 13.52sec as well, and therefore covered 424.63m all up, and is traveling at 175kph.
- That means that now the C32AMG should be 37.09m ahead (ie. ~8.5 car-lengths), and be pulling away at the rate of 4.16m/sec.

That's interesting as it tells us that if a car is ~1sec quicker to 100kph (and ~2.5sec to 160kph), then it will have only ~1.5 car-lengths on you by 100kph, and ~3 car-lengths by 120kph. The fact that the C32AMG had only 1/2 car-length on me by 120kph (at most) by 120kph, would indicate thatmy car is quicker than stock .... ie. by the 2 or so car-lengths that my pre/post hi-tech exhaust testing showed.

mchapman

iTrader: (1)

I could have just told you your car was quicker than stock

KY350

We all agree that your Z is quicker than stock if that was the point of the above post.

However, by my calculations, some of your figures don't stack up.

You provided the following data for the 350Z:
Initiall velocity = 10km/h = 2.8m/s
Final velocity = 100km/h = 27.8m/s
Time to accelerate from 10km/h to 100km/h = 5.8s

Using the above information, in order to determine the distance covered by the Z, we must first work out the rate of acceleration of the Z (this is theoretial and acceleration is a constant rate and does not take into account a decrease in acceleration during gear changes). To work out acceleration, use this formula:

v = u + at

Where:
v = Final velocity
u = initial velocity
a = rate of acceleration
t = time

Using the info you supplied, then

27.8 = 2.8 + 5.8a
a = 4.3m/s/s

We now use this acceleration rate to determine the distance covered by the Z using the following formula:

s = ut + 1/2att

Where:
s = distance
u = initial velocity
a = rate of acceleration
t = time

So the distance covered by the Z is

s = (2.8 x 5.8) + (1/2 x 4.3 x 5.8 x 5.8)
s = 16.24 + 72.33
s = 86.57m

Therfore, the Z covered 88.57m in the 5.8s it took to accelerate from 10km/h to 100km/h (give ot take a few cm for rounding errors) and not 101.77m that you stated.

Now to calculate the distance that the C32 will be ahead of the Z, I need to know how long it took for the C32 to go from 10 - 100km/h.

David - use the above formulae to work it out yourself and please post the results.

frosty

FARK !

All you blokes need is a virtual Z and yers can mathamatakalize

to yer hart's content !

Save $60k and all the costs!

FROZZLE

KY350

Don't upset me with comments like that Frosty. (j/k)

You should have told me this 15 months ago and I would have saved $65K and lived vicariously through this forum.