The Reality of Speed

[[PIMPIN]]

Note that this thread is to explore the top speed potential of a GTR and if possible to separate fact from fiction based on first hand experience or knowledge (basically not something we read online or heard from your friend's cousin who heard it from his best friend's college mate's uncle etc).

It goes without saying that all of us take pride in our rides and there are some who even use the car in legal competitive environments while some would be reluctant to even drive their pride and joy in the rain. I don't quite fall in either category cause I was born with this heavy foot and rebellious streak which means I tend to drive my cars hard, very hard.

The thing that excites me the most: Wangan style runs. I'm a fan of speed (not the drug!) and over the years I've read about GTR owners supposedly reaching unbelievably high speeds on other Skyline forums such as in Australia and the UK.

From what I gather, the R32s and R33s stock gearbox will not allow you to see 300km/h. True or false? Note the word stock.

As for the R34GTRs, what is the actual top speed of the car? We all know the speedometers can read up to 320km/h but that does not mean it should end there right? Hugh Keir, a GTR owner who needs no introduction had uploaded a Excel file calculating the theoretical top speed of the GTR based on the stock Getrag ratios, differential ratios , weight, tire size, aspect ratio, diameter, etc and it shows a top speed of 241.0 mph @ 9000 rpm.

That's an unbelievable speed but I find little reason to doubt Hugh Keir.

Anyways, to get to the point - what's the highest speed you've experienced and given enough power, empty road and higher rev limit do you think 210-215 mph is possible?

 

[Edward Chew]

Perhaps do the experiment in GT4. Just raise the HP without touching the gear ratio.

A stock GTR in GT4 topped out at 276km/h. Forgot at what rpm but still got lots to go as it was still early on 6th gear at 276km/h.

 

[gobiz]

Top speed is basically power and aerodynamics.

241mph seems optimistic, what's the power in that calculation?

Surprisingly I haven't seen/heard about that many Japanese high powered cars running high speeds on the autobahn which is the natural place for top speed runs. On the other hand, conti cars seem well-suited to the autobahn.

Check out this car, 202mph on GPS.
http://www.youtube.com/watch?v=rPBl_g1GMAY

 

[[PIMPIN]]

Top speed is basically power and aerodynamics.

241mph seems optimistic, what's the power in that calculation?

Surprisingly I haven't seen/heard about that many Japanese high powered cars running high speeds on the autobahn which is the natural place for top speed runs. On the other hand, conti cars seem well-suited to the autobahn.

Check out this car, 202mph on GPS.
http://www.youtube.com/watch?v=rPBl_g1GMAY

Top speed runs by Japanese cars are common on the Wangan expressway. I agree 241mph is extremely optimistic but bear in mind that is at 9000rpm in 6th which is higher than what most GTRs are able to achieve unless they have had major work. Those are pretty high revs in anyone's book.

As for the power in the calculation, its very modest from memory but I think to reach high speeds what's also important is the cars aerodynamics in which the GTR is at a disadvantage if you were to compare to Supras or NSXs. Also, maybe tweaking the angle of the spoiler, experimenting with different tire pressures and the like would add to the many different variables that contribute to obscene speeds.

Having said that, it seems to me that the general consensus is that one would need 600hp to reach 200mph cause other GTR owners with less power tend to hit 180mph or so.

 

[farique]

now that you mentioned rear spoiler. Running spoiler-less will help with top speed. But ofcourse, stability at that insane speed is greatly reduced compared to having one at the back. Personally thinking, GTRs adjustable spoiler is meant for grip driving and not for high speed attack.

If anyone cares, the COD of R32, R33 and R34 gets better each of the gen. I can't remember the exact numbers tho. Damn it. I should've noted it down. It was on a website.. totally forgotten the site's name..

 

[[PIMPIN]]

now that you mentioned rear spoiler. Running spoiler-less will help with top speed. But ofcourse, stability at that insane speed is greatly reduced compared to having one at the back. Personally thinking, GTRs adjustable spoiler is meant for grip driving and not for high speed attack.

If anyone cares, the COD of R32, R33 and R34 gets better each of the gen. I can't remember the exact numbers tho. Damn it. I should've noted it down. It was on a website.. totally forgotten the site's name..

Correct.

R32 - 0.40
R33 - 0.35
R35 - 0.27

Only the R34 figures remain elusive. Apparently the lowest is 0.36 with the rear wing at 0 degrees and so it changes as you adjust. That's from what I gather having searched.

 

[gobiz]

CoD is not everything... frontal area is also important.
Lift to drag ratio also.

Did Hugh Keir base the calculations on his own car?
If I remember correctly, he's running a OSG RB30.... the power will be anything but modest

 

[cosmicgate]

241 mph?????????????????????????????????????????!!!


!!!!!!

i also want a stock GTR that run that fast!

i trade everything, even my virgin butt.

Bump: 241 mph?????????????????????????????????????????!!!


!!!!!!

i also want a stock GTR that run that fast!

i trade everything, even my virgin butt.

 

[[PIMPIN]]

CoD is not everything... frontal area is also important.
Lift to drag ratio also.

Did Hugh Keir base the calculations on his own car?
If I remember correctly, he's running a OSG RB30.... the power will be anything but modest

No, the horsepower is not part of the formula. I've emailed you the exact file he uploaded.

I'm still trying to make sense of it.

 

[gobiz]

No, the horsepower is not part of the formula. I've emailed you the exact file he uploaded.

I'm still trying to make sense of it.

Whaattt?? Hp not part of the formula??? Very strange since hp is integral!

That doesn't make sense at all as it's just simple physics..... need power to overcome drag at high speeds.

Now weight or mass is NOT part of the formula.

Bump: Thanks Pimpin, just had a quick look... the programme includes bhp and torque.

If the aerodynamics and gearing are sorted, I'm confident an R34 with OS Giken RB30 can reach 241mph at 9000rpm...

For stock R34, I'm confident it cannot reach 180mph.

 

[Edward Chew]

I recall this video of this guy doing his top speed.
http://www.youtube.com/watch?v=Hf2f0gNXarQ

He did 320km/h, 9000rpm at 5th gear. Rev dropped back at 7800rpm at 6th gear.

No clue of the specs and he shifted close to 10,000rpm.

Ignore the resistance, assuming the engine has the ability to overcome all the gears to peak rpm, but does the stock Getrag ratios really long enough for 241mph?

I'm learning too. :-)

 

[NISMO S-TUNE]

I'll be peeing in my pants for doing that in Malaysia "super highway"....:stupid: :stupid: :stupid:

 

[Edward Chew]

There's a guy posted his video in youtube of his attempt going high speed at Plus Highway. "R34 at plus highway" I think.

Yeah. Scary. It was a 2 lanes...

 

[[PIMPIN]]

Whaattt?? Hp not part of the formula??? Very strange since hp is integral!

That doesn't make sense at all as it's just simple physics..... need power to overcome drag at high speeds.

Now weight or mass is NOT part of the formula.

Bump: Thanks Pimpin, just had a quick look... the programme includes bhp and torque.

If the aerodynamics and gearing are sorted, I'm confident an R34 with OS Giken RB30 can reach 241mph at 9000rpm...

For stock R34, I'm confident it cannot reach 180mph.

Sorry what I meant was that the huge horsepower that we all know he has was not used as part of the formula to calculate the 241 mph. Note the bhp used.

Also, what's a stock R34?

When you say stock, do you mean stock power? Naturally its not going to get there.

There's a guy posted his video in youtube of his attempt going high speed at Plus Highway. "R34 at plus highway" I think.

Yeah. Scary. It was a 2 lanes...

Seen that video ages ago, love the song LOL. That wouldn't happen to be you right?

That car took ages to get up to speed and he only hit 280 barely touched 300? I don't know cause I lost interest halfway. Very short attention span.

I've been in one R33 that genuinely registered over 300km/h...

Stock gearbox?

Bump: Btw, how do you tell speed when past the 320km/h mark? Would the reading on the PFC Hand Controller continue displaying?

 

[omaroDDin]

i'm confused ar.
how do we get good speeds considering that it won't burn a hole in our pockets?

 

[eyong]

i'm confused ar.
how do we get good speeds considering that it won't burn a hole in our pockets?

Take a "speed" hit instead .... :hmmmm:









Just kidding

 

[[PIMPIN]]

i'm confused ar.
how do we get good speeds considering that it won't burn a hole in our pockets?

LOL what does that mean? Still sleepy issit when typing?

 

[joethurr]

Edward Chew: can anyone identify what language they speak in that video?...sounds foreign to me... I might be wrong :)

 

[semperfi]

Edward Chew: can anyone identify what language they speak in that video?...sounds foreign to me... I might be wrong :)

The website's from philippines but they sounded like Thai at the beginning. It ain't clear as the sound quality is pretty bad. Could be either tagalog or Thai. I could be wrong. :hmmmm:
Fortunately, the RB sounded way better!!!

 

[farique]

I recall this video of this guy doing his top speed.
http://www.youtube.com/watch?v=Hf2f0gNXarQ

He did 320km/h, 9000rpm at 5th gear. Rev dropped back at 7800rpm at 6th gear.

No clue of the specs and he shifted close to 10,000rpm.

Ignore the resistance, assuming the engine has the ability to overcome all the gears to peak rpm, but does the stock Getrag ratios really long enough for 241mph?

I'm learning too. :-)

at 0:45s~0.46s the 5th gear rev bounced back. Why is that?


check this video, Kismo's R34.

http://www.youtube.com/watch?v=l0P1rycfADo

http://www.youtube.com/watch?v=InVDzpC_J3Q

Both are the same run except the 2nd video included the actual car's picture and 3rd person camera view from outside. What's best is that it was running on stock bottom RB26. Not sure if there's any stroker kit tho.

190mph. Not sure if there is a 'restriction' to that.

I noticed that Kismo's shifting is more conservative, avoiding the redline region.