Nissan is a liar! - Porsche

[DoggieHowser]

Re: Nissan is a liar! - Porsche

Does Porsche submit datalogs?



I recall Sports Auto did 7:50 on their "trial" (aka not serious) run in the wet. Even that is faster than Porsche's allegedly fastest timing on the car How objective can the Porsche testing be?

 

[axl]

Re: Nissan is a liar! - Porsche

Actually might it be possible that the GT-R is indeed faster than the 911TT, as verified independently by the various car mags, but somehow the boost or ECU of the 7:29 record car, was modified?

From one of the comments in autoblog:

"You fanboys think the GTR emits magic fairy dust out of the exhaust. How can a car that has the same flywheel HP, 75lb ft less TQ, weigh 406lbs more, and trap 5mph less on the 1/4 mile, yet has the ability to best it by 25 seconds on the fastest(highspeed) track in world? It doesn't make sense.

I mean, correct me if i'm wrong, but it was beat by the ZR1 by ONLY 3 seconds!?
It has 158 more HP, 174lb ft more tq, weighs 575lbs less, only manage a 3 second gap? It just doesn't make sense. There is no magic involved. Nissan's #'s just don't add up."

Still rooting for the JDM machine though.

 

[DoggieHowser]

Re: Nissan is a liar! - Porsche

From the side by side comparison of the ZR1 vs the GTR videos, the ZR1 was considerably harrier to drive. There was a lot more steering input to counter the oversteer IMHO losing speed AND time, whereas the GTR was a lot more controlled and was able to go more flat out.

 

[DoggieHowser]

Re: Nissan is a liar! - Porsche

Actually, Porsche doesn't doubt the timing, right? Only the configuration of the car, so having datalogs wouldn't exactly quell their doubts either.

Here's an analysis of the data logs from material available during the launch. I got a PDF version of this analysis somewhere.

Nissan GT-R Nurburgring Lap Analysis - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

 

[Shaun]

Re: Nissan is a liar! - Porsche

if data log of the acceleration down any straight is higher than stock car can manage, then the car is not stock. Exit speeds from preceding corner can vary a little, but the gradient of speed curve will be very different.

Same reason people who lie about their car being stock while reaching crazy times that some pretty experienced race drivers disagree can be reached stock, will never share a data log on that very same day because their cars have acceleration that shows modified state and the straights are where they're making all or almost all of their time.

 

[centurion]

Re: Nissan is a liar! - Porsche

from datalogs can see what Gs pulling at slow corner, fast corner, and quantify, then compare with braking Gs ... then can eliminate downforce esp during 40-0 braking loaded, and see what is tyre grip. Can see slip angle ... basically, can really see why the car so fast.

Anyway let the Shaun guy see it lah....

Shaun, here: Nissan GT-R Nurburgring Lap Analysis - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

 

[Darth Vader]

Re: Nissan is a liar! - Porsche

test drive both cars and see which one better,no need to get so technical.its not rocket science and we are not buying it to fly to mars.

 

[Shaun]

Re: Nissan is a liar! - Porsche

Glenn's post doesn't have a control car's traces. Hopefully Porsche will get some...

If other publications have tested stock GTRs and gone quicker than Porsche has, a lot close to Nissan's then Porsche needs to try one of their other drivers or a different stock GTR. I just think they already have, or should have, before making those statements about Nissan. They'd have to be stupid not to.

It's just funny that at the end of all this either Nissan or Porsche will be shown to be idiots. Anyone making bets?

 

[Shaun]

Re: Nissan is a liar! - Porsche

test drive both cars and see which one better,no need to get so technical.its not rocket science and we are not buying it to fly to mars.

People want to be tech, let them be tech. You like test driving, go ahead and test drive. To each his own....

 

[centurion]

Re: Nissan is a liar! - Porsche

just one question: how come the braking G can consistently hit like -1.5G??? That's like high.... my braking spike at about 1.2G but then steady state is 0.7G or something.

And the lateral G, my god, 1.8 G consistently? I'm doing like 0.95g consistently, spiking at 1.1g thereabouts.

These things I don't understand.... somebody explain?

 

[Shaun]

Re: Nissan is a liar! - Porsche

just one question: how come the braking G can consistently hit like -1.5G??? That's like high.... my braking spike at about 1.2G but then steady state is 0.7G or something.

And the lateral G, my god, 1.8 G consistently? I'm doing like 0.95g consistently, spiking at 1.1g thereabouts.

These things I don't understand.... somebody explain?

Elevation changes and/or banking put vertical G on the car, allowing it to pull more lateral G when the vertical Gs are high. There is also noise (look at how fuzzy the G plots are vs the rest) in the accelerometer signal that gives you false peak values. You have to filter them and see what it sustains at to see the car really can hold.

 

[Shaun]

Re: Nissan is a liar! - Porsche

MT, also.. your accels are GPS derived, so a lot less noisy than accelerometer output. 100Hz GPS accels are really good, provided open enough to sky and seeing enough satellites. Hilly tree lined track like Nring.. probably not so good lol

 

[DoggieHowser]

Re: Nissan is a liar! - Porsche

I found my tolerance for g-forces is higher when I am in a harness. More confidence to push harder?

 

[Shaun]

Re: Nissan is a liar! - Porsche

possibly.. if you have to brace your body against the seat by pushing against the dead pedal, etc. then body is all tense and does not sense accelerations well. I used to be amazed what could be felt on a cool down lap at half speed when not bracing in bad stock seats. Bucket seats help a whole lot with allowing relaxation. it seems that really good drivers like to be strapped in real tight (like super tight) even when they have a real good seat already.. they say it makes them part of the car and eliminates lag in feeling what the car is doing

 

[DoggieHowser]

Re: Nissan is a liar! - Porsche

From the vids of the 'Ring run, the only modification I saw on the GT-R was the harness. Seats looked stock.

 

[Shaun]

Re: Nissan is a liar! - Porsche

haha yah talking in general, not that the stock gtr has buckets or a harness

 

[axl]

Re: Nissan is a liar! - Porsche

I found my tolerance for g-forces is higher when I am in a harness. More confidence to push harder?

Same rationale that a D cup babe will feel more comfy when sprinting WOT, if she's wearing a good sports bra.

ADD: As in, the person will be more in touch with the extremities of the (car) body, and how it is reacting against physics.

 

[DoggieHowser]

Re: Nissan is a liar! - Porsche

haha yah talking in general, not that the stock gtr has buckets or a harness

heh.. was actually referring to centurion's post abt how the g-forces were higher than what he experienced on his car. So I postulated that the harness may have helped.

First time I drove the GTR in Sepang, the seat had zero side bolster support. Mandated installing the harness for second outing.

 

[Shaun]

Re: Nissan is a liar! - Porsche

oh i totally missed that connection lol..

while good seat and harness helps with consistency, it won't add 40 - 80% G in any direction!
the main reasons why peak Gs appear so high are as I listed earlier.. very normal to see those characteristics esp at a track like the Nring and in accelerometer signals.

 

[Crufty Dusty]

Re: Nissan is a liar! - Porsche

Since Porsche bought the car in the US my guess is that they pumped California 91 pisstane into it.