Anyone got a cure for wind noise at 166mph?

[m666 edd]

Whilst going down bruntingthorpe runway I seem to get a fair bit of wind noise through the window at 166mph :laugh:

Here's a couple of vids from the day:

Whole run - http://www.youtube.com/watch?v=OiSzxVpOBOs

Launch & bend - http://www.youtube.com/watch?v=FcQOg3r8xrk

[Hagasan]

Whilst going down bruntingthorpe runway I seem to get a fair bit of wind noise through the window at 166mph :laugh:

Here's a couple of vids from the day:

Whole run - http://www.youtube.com/watch?v=OiSzxVpOBOs

Launch & bend - http://www.youtube.com/watch?v=FcQOg3r8xrk

You must have been ok with the wind noise on that run then? I only saw 165 max ;-)

[m666 edd]

Haha yeah. That was just one of my many runs. The gps was pretty bad at updating. Managed 166 recorded at the beams on at least one of the runs.

[Silver Surfer]

Well done Ed... Certainly did Kevin proud after all the mods he has done to get the car to current state.
I am sure the gearing he has changed to lower ratio allowed the car to accelerate on the straight better.
Did you get into 5th just before you cross the laser timer or well before?

SS

[TheSebringOne]

Slow down may be! :D

Seriously, going at that kind of speed, then probably no?

[SILVER BULLET]

Well done Edd, sounds like you had a fantastic day, I believe regular buttock clenching will help with your high speed wind problem :laugh:.
Hope to see you at a future S. West meet,

Cheers,

Ian

[Papalazarou]

Well done Ed,

makes me want to get up there and have a go. I watched the videos at Pete's earlier; god your exhaust is loud! Sounds pretty good though. I was amazed how quick that GT3 was next to you! Didn't think the performance difference was so great.

Cheers,

James.

[m666 edd]

Silver Surfer:
I was in 5th gear at around 130mph, by the end of the video the revs are at an indicated 8000rpm but it does seem to over read so I believe that was around 7700rpm. The 4.4 final drive definitely helped but the JDM gearing probably didn't. Either way the car is in a high bhp powerband on every change so the difference would be minimal.

James:
Which video had a GT3? They all look the same to me :)
The black porsche only managed 167 when I look closely at the number on the beams, it just got to that speed a lot quicker! Probably all that downforce affecting it's slipperiness. I believe the other porsches were modified.

I didn't do any hard launches with a car beside me, I probably should have!

[Papalazarou]

Edd, it looked like a dark blue 996 GT3. You came past him on the first part then he came past you maybe a couple of hundred yards onto the speed run straight.
Obviously hard to know from a video.

Cheers,

James.

[paulc]

Sorry not had that problem yet!! Hopefully one day.

[NoelWatson]

Silver Surfer:
I was in 5th gear at around 130mph, by the end of the video the revs are at an indicated 8000rpm but it does seem to over read so I believe that was around 7700rpm. The 4.4 final drive definitely helped but the JDM gearing probably didn't. Either way the car is in a high bhp powerband on every change so the difference would be minimal.

James:
Which video had a GT3? They all look the same to me :)
The black porsche only managed 167 when I look closely at the number on the beams, it just got to that speed a lot quicker! Probably all that downforce affecting it's slipperiness. I believe the other porsches were modified.

I didn't do any hard launches with a car beside me, I probably should have!


I would've thought a GT3 would get more than 167 - they were getting mid 170s at the events I have been at.

You now have the NA NSX record! How much power do you have? Our NA2s struggle once beyond 160 and changing into 6th.

[NSXGB]

I would've thought a GT3 would get more than 167 - they were getting mid 170s at the events I have been at.

You now have the NA NSX record! How much power do you have? Our NA2s struggle once beyond 160 and changing into 6th.

http://www.nsxcb.co.uk/showthread.php?7411-Today-s-rolling-road&highlight=rolling

[Nick Graves]

I gave the door/window seals a couple of good doses of Holt's silicone & rubber lubricant. Lots.

It's not completely cured it (the passenger window stops a tad too high & pinches the seal) but it's gone from irritating at 80 to irritating at the sort of speeds you are talking about.

Probably if you could contrive to drown them & then leave the windows down for 24 hours, they'd come back to shape fully. Must try that...

[forumadmin]

Well done Ed... Certainly did Kevin proud after all the mods he has done to get the car to current state.
I am sure the gearing he has changed to lower ratio allowed the car to accelerate on the straight better.
Did you get into 5th just before you cross the laser timer or well before?

SS

I have only just been alerted to this thread and the Vmax. Have to say I am really happy. :) The car has exhaust after the dyno day, might have a bit more power than it did back then. I think the corner could have been a bit quicker though. ;)

[markc]

I can't remember which final drive ratio your car has in it 4.44:1 or 4.55:1? The revs, on the rev counter in the video, look about right for a 4.55 i.e. about to hit the limiter at 166mph.

Either way your car is perfectly geared for VMAX at this event :cool:

Cheers

Mark

[m666 edd]

I can't remember which final drive ratio your car has in it 4.44:1 or 4.55:1? The revs, on the rev counter in the video, look about right for a 4.55 i.e. about to hit the limiter at 166mph.

Either way your car is perfectly geared for VMAX at this event :cool:

Cheers

Mark

I have the OS Giken LSD + 4.4 final drive. As far as I know there is no such thing as 4.44, at least from OS Giken, the 4.44 is a typo on the SoS website. The rev counter shows 8k rpm but that really means about 7700rpm, my car hits the rev limiter at an indicated 8.5k rpm. Also the shift light comes on displaying higher rpm than programmed.

This would mean the gearing could achieve ~175-176mph with the current gears and tyres.

[m666 edd]

I came across this video whilst someone was loading up the previous vids on their virgin media tv:


http://youtu.be/AEbqugjHLdc

I did a few of these at the end of the event which led to me needing a new clutch! More due to a problematic clutch that absolute wear, it still doesn't slip now.

[NSXGB]

Sounds good Ed. When is the next one?

[Lankstarr]

You now have the NA NSX record! How much power do you have? Our NA2s struggle once beyond 160 and changing into 6th.

I thought someone (Leigh perhaps) clocked 185 in his on the autobahn... 185 on the GPS?

L*

[NoelWatson]

I thought someone (Leigh perhaps) clocked 185 in his on the autobahn... 185 on the GPS?

L*

I think a standard 02+ would do around 170 given enough road.

[markc]

I thought someone (Leigh perhaps) clocked 185 in his on the autobahn... 185 on the GPS?

Correct. Bruntingthorpe isn't long enough for NSX's with standard gearing to achieve their true VMax. Both Leigh and Andreas (GreenBeret) have seen GPS verified 180mph+ on the autobahn but both of these cars are far from standard. Noel describes the acceleration, of his close to standard post '02 car, in 6th as "glacial" :)

There is a theory is that, in a pre '02 pop-up, the standard 5spd gearing (geared for 186mph @ 8Krevs) might achieve a higher VMax than the 6spd speed (geared for 202mph @8K revs). The post 02 aero might reverse this but their slightly higher gearing, afforded by the slightly bigger tyres, might negate this aero advantage.

Given that there are very few completely standard NSX's around these days, the VMax title is up for grabs :cool:

Cheers

Mark

[kowalski]

I have seen over 180 mph on a few runs through Germany, the first time I did it the car was almost standard with 15" / 16" wheels and the standard exhaust system. It reached 160 fairly quickly then slowly increased to over 180 (minutes!)

After i changed the wheels to 17"/18" and changed the exhaust system out to the Taitec it would get to 170 quickly then slowly increase to just over the 180 mark. It also has the type R susspension which lowers the car a little so maybe reduces wind resistance.

Whatever mod i have done only improves the time taken to get to the top speed, 184 on gps (187 on the clock) the car seems limited by gearing and aerodynamics (and lenght of road!)

I have had pics of the speeedo, the gps and a video of a 180 run (with 2 people in car and luggage!) on here to prove the numbers.

I am tempted though to change the gearing to the lower jdm and R final drive to make the car more useable and accelerate better, on drives to club meets with lotus olly he always pulls away slightly from bends and roundabouts, I think now im back in the UK I would prefer the Acceleration to the top speed!!

And at 184 the windows dont whistle as much!!

All the best

Leigh

[NoelWatson]

Correct. Bruntingthorpe isn't long enough for NSX's with standard gearing to achieve their true VMax. Both Leigh and Andreas (GreenBeret) have seen GPS verified 180mph+ on the autobahn but both of these cars are far from standard. Noel describes the acceleration, of his close to standard post '02 car, in 6th as "glacial" :)

There is a theory is that, in a pre '02 pop-up, the standard 5spd gearing (geared for 186mph @ 8Krevs) might achieve a higher VMax than the 6spd speed (geared for 202mph @8K revs). The post 02 aero might reverse this but their slightly higher gearing, afforded by the slightly bigger tyres, might negate this aero advantage.

Given that there are very few completely standard NSX's around these days, the VMax title is up for grabs :cool:

Cheers

Mark

I still don't understand why various NSXs have only done 160mph on the Millbrook bowl, which equates to ~165 on the flat.

[markc]

I still don't understand why various NSXs have only done 160mph on the Millbrook bowl, which equates to ~165 on the flat.

Are you sure it's only 5mph (3%) lost to tyre scrub? I've lapped the bowl at about 120mph and even at that speed you need a fair bit of steering to stay in the top lane. I wouldn't be surprised if it's more like 10mph lost to scrub at a true 160mph? Also the aero is effected as the car is rolling and the front wheels aren't pointing dead straight.

Cheers

Mark

[NoelWatson]

Are you sure it's only 5mph (3%) lost to tyre scrub? I've lapped the bowl at about 120mph and even at that speed you need a fair bit of steering to stay in the top lane. I wouldn't be surprised if it's more like 10mph lost to scrub at a true 160mph? Also the aero is effected as the car is rolling and the front wheels aren't pointing dead straight.

Cheers

Mark

1mph per 10mph over 100 is what Autocar always claimed.

http://www.malaysianevo.com/feature/grouptestsfeature/173/the_gathering.html

"-in tyre-scrub of about 1mph for every 10 over 100mph"

No idea how accurate....