How fast a GT can go?
- Thread starter Patrick965
- Start date
I also think a good set-up also does a lot, good suspension, good tires and pressure in them and good bushings and alignment can make a car feel good, or when something of that list is not good/right, the car can feel unstable/scary when you go fast.
even when its something like good tires but with way to much pressure in them
I can remember 6 years ago when I needed new tires on a S54 M coupe of mine, the tire-man did not leave the pressure out the front wheels after fitting them and then overpressure them so they fit the wheels well, but afterwards they have to unpressure them and then give them the right pressure.
but somewhere it went wrong, I went home, nothing strange when driving max 80<>100km/h
but then a day later I went on the highway and after 160 (and higher)and not such flat road the car seeks up all the lines/holes and felt not that good so I did not get faster (swetty hands of that) I thought WTF went wrong with those new expensive tires...
I checked the rear-wheels, all ok...then the front-wheels...normally I had there 2.2<>2.4 but it had something like 3.4bar
so let about 1 bar out and after that the car felt secure again whatever speed, something as simple as that or alignment or worn-out stuff can make your hands get swetty at high speeds.
even when its something like good tires but with way to much pressure in them
I can remember 6 years ago when I needed new tires on a S54 M coupe of mine, the tire-man did not leave the pressure out the front wheels after fitting them and then overpressure them so they fit the wheels well, but afterwards they have to unpressure them and then give them the right pressure.
but somewhere it went wrong, I went home, nothing strange when driving max 80<>100km/h
but then a day later I went on the highway and after 160 (and higher
)and not such flat road the car seeks up all the lines/holes and felt not that good so I did not get faster (swetty hands of that) I thought WTF went wrong with those new expensive tires...I checked the rear-wheels, all ok...then the front-wheels...normally I had there 2.2<>2.4 but it had something like 3.4bar
so let about 1 bar out and after that the car felt secure again whatever speed, something as simple as that or alignment or worn-out stuff can make your hands get swetty at high speeds.
I agree, that is an area my car can be improved.
RF2 have a revised front end that I am yet to install. I have seen it at work and am very impressed with what I saw.
It is well documented on this forum that I am not a fan of the RF1 geometry.
Happily I have the rear end working reasonably well.
You guys are lucky being so close to autobahns and great tracks.
I'd love to get my car into a genuine flying mile and not a standing few hundred meters... There is precious little opportunity to do real high speed stuff here legally. Even the targa events have limiting chicanes set up to keep the bureaucrats happy.
Tim.
Bureaucrats kill everything, why can't they kill themselves?
RF2 have a revised front end that I am yet to install. I have seen it at work and am very impressed with what I saw.
It is well documented on this forum that I am not a fan of the RF1 geometry.
Happily I have the rear end working reasonably well.
You guys are lucky being so close to autobahns and great tracks.
I'd love to get my car into a genuine flying mile and not a standing few hundred meters... There is precious little opportunity to do real high speed stuff here legally. Even the targa events have limiting chicanes set up to keep the bureaucrats happy.
Tim.
Bureaucrats kill everything, why can't they kill themselves?
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I assume that's the Veilside car a few years ago. 309 by the Jun WRX as well.
Unfortunately we have too many fun police here in Tas to do anything really interesting, legally anyway.
There is a lot of video around of GT-Rs doing 320k plus. Easy to get them to go fast, that's why I have one.
Even with their aerodynamics and extremely untidy undersides they don't seem to have problems... And yet, and yet, my Flying wing GT40 seems better, uncanny...
You should have seen my WRX at speed before I did some aero work - 600+ bhp and lift off at about 250... :shocked::shocked: Those were fun days.
Now please excuse me while I go and enjoy the only legal hobby left in Tas - aging.
Oh the joy of boredom, the quiet fluttering of licence and permit applications, makes it all worthwhile... Now where was I? Oh yes suicide... I'm sure there's a permit here somewhere...
Tim.
Unfortunately we have too many fun police here in Tas to do anything really interesting, legally anyway.
There is a lot of video around of GT-Rs doing 320k plus. Easy to get them to go fast, that's why I have one.
Even with their aerodynamics and extremely untidy undersides they don't seem to have problems... And yet, and yet, my Flying wing GT40 seems better, uncanny...
You should have seen my WRX at speed before I did some aero work - 600+ bhp and lift off at about 250... :shocked::shocked: Those were fun days.
Now please excuse me while I go and enjoy the only legal hobby left in Tas - aging.
Oh the joy of boredom, the quiet fluttering of licence and permit applications, makes it all worthwhile... Now where was I? Oh yes suicide... I'm sure there's a permit here somewhere...
Tim.
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lol @Tim
and also, yes we are happy that on some autobahn in Germany its still aloud to drive fast, here 2 of the guys driving fast in 2008, the car with the video is doing 150, the corvette doing about 320<>330...
http://www.youtube.com/watch?v=8dBTkMdfYg0
after seeing this video some decided not to go with those days anymore, the risks could be to high, and yes you have to stay alert and have to know what you do and how others could react on the road...it can be dangerous ofcorse, but without it, life would be boring...ofcorse safety first, but don't forget to live occasionally.
and also, yes we are happy that on some autobahn in Germany its still aloud to drive fast, here 2 of the guys driving fast in 2008, the car with the video is doing 150, the corvette doing about 320<>330...
http://www.youtube.com/watch?v=8dBTkMdfYg0
after seeing this video some decided not to go with those days anymore, the risks could be to high, and yes you have to stay alert and have to know what you do and how others could react on the road...it can be dangerous ofcorse, but without it, life would be boring...ofcorse safety first, but don't forget to live occasionally.
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Australia has become a nanny country, where the authorities want to protect everyone, so all fun activities are controlled. Many people think your balls will drop off if you go over 110 km/hr.
Trond
Lifetime Supporter
Hi
I have driven my standard "out of the box" SPF MKII with ZF RBT and Roush 427R/530 HP at 305km/h. That is about 190+ miles/hour. The car has not been done anything special with, and runs Michelin Pilot Sport PS2 tires.
This was done on a motorway in Poland, and the car felt stable and ok to drive. I still had power left and I think the car could have been able to reach above 200 miles. At this speed you understand why the car has eyebrows on top of the doors to keep them in place! And there is a symphony of noises (!).
The front felt lighter of course, but not in a critical way. I would think the front canyards would make this quite a bit better.
regards
Trond
I have driven my standard "out of the box" SPF MKII with ZF RBT and Roush 427R/530 HP at 305km/h. That is about 190+ miles/hour. The car has not been done anything special with, and runs Michelin Pilot Sport PS2 tires.
This was done on a motorway in Poland, and the car felt stable and ok to drive. I still had power left and I think the car could have been able to reach above 200 miles. At this speed you understand why the car has eyebrows on top of the doors to keep them in place! And there is a symphony of noises (!).
The front felt lighter of course, but not in a critical way. I would think the front canyards would make this quite a bit better.
regards
Trond
Hi
What you all refer to if you say " it feels lighter". From my experience high speed behaviour of a car can not necessary be felt and the things you "feel" may be something completly different.
Sorry for me it is just taking up some words with no meaning and use them.
For example, does the steering feeling "lighter"?. Probably not, because of the higher geroforces of the wheels at that speed. My 964 RS felt realy more stable(because the steering got heavier with increase of speed) the faster it went, until at one ocassion at around 270 kmh i realised how unstable it realy has been.
For me there is no alternative to the installation of an 4 corner way measuring system to realy find out if your car develops downforce ( or more likely not).
Also a good GPS based data logger can help to define the performance ( g forces corner speeds).
THat said, of course your lap times will give you a good indication to, but usually there are very rarely race tracks where real high speed behaviour ( above 280 kmh) plays a significant role in lap times.
IMHO high speed runs have to be done with high attention on a very well known road
( Don´t want to find out how your cars is doing at a heavy road bump at 300 kmh).
TOM
What you all refer to if you say " it feels lighter". From my experience high speed behaviour of a car can not necessary be felt and the things you "feel" may be something completly different.
Sorry for me it is just taking up some words with no meaning and use them.
For example, does the steering feeling "lighter"?. Probably not, because of the higher geroforces of the wheels at that speed. My 964 RS felt realy more stable(because the steering got heavier with increase of speed) the faster it went, until at one ocassion at around 270 kmh i realised how unstable it realy has been.
For me there is no alternative to the installation of an 4 corner way measuring system to realy find out if your car develops downforce ( or more likely not).
Also a good GPS based data logger can help to define the performance ( g forces corner speeds).
THat said, of course your lap times will give you a good indication to, but usually there are very rarely race tracks where real high speed behaviour ( above 280 kmh) plays a significant role in lap times.
IMHO high speed runs have to be done with high attention on a very well known road
( Don´t want to find out how your cars is doing at a heavy road bump at 300 kmh).
TOM
I'll go along with that.
Please excuse my tetchiness in previous posts, seriously annoyed by bureaucrats and other killjoys ATM. I've cut down this post extensively so as to seem more at peace with the world...
I will say though that I am way more interested in hearing from people with GTs that have tried them out than I am from people comparing experiences in other cars or who just want to talk about what ifs.
Anyway...
Opportunity to do such testing where I am is extremely rare unfortunately.
I can tell you though that my car shows no overt sign of lift at any speed I've driven it as compared to other cars I own, have owned or have driven at high speed.
There are quite a few people who have done much higher speeds in their GTs than I have - I have quite a collection of videos as evidence to that. I have heard of no dramatic general aero problems.
It seems Ross Nichol doesn't frequent this forum anymore... A shame, I'd have liked to have heard what he had to say. Philip island would be pretty quick in his car I reckon. Any lift issue would surely rear it's head there.
I don't think my car produces gobs of downforce, I just don't believe it is the flying wing that some try to portray them as.
Racetrack? Yeah sure a splitter, wing etc would work wonders and make what I believe to be a fairly neutral aero car into a car that produces usable downforce. No surprise if it goes faster.
Re 968: I had a modified 928 that felt pretty good, right up until you took a bend at high speed or the car was unsettled by something... My GT is much much much better than that (and I don't think the 928 was terrible, I've driven a lot scarier).
Tim.
Please excuse my tetchiness in previous posts, seriously annoyed by bureaucrats and other killjoys ATM. I've cut down this post extensively so as to seem more at peace with the world...
I will say though that I am way more interested in hearing from people with GTs that have tried them out than I am from people comparing experiences in other cars or who just want to talk about what ifs.
Anyway...
Opportunity to do such testing where I am is extremely rare unfortunately.
I can tell you though that my car shows no overt sign of lift at any speed I've driven it as compared to other cars I own, have owned or have driven at high speed.
There are quite a few people who have done much higher speeds in their GTs than I have - I have quite a collection of videos as evidence to that. I have heard of no dramatic general aero problems.
It seems Ross Nichol doesn't frequent this forum anymore... A shame, I'd have liked to have heard what he had to say. Philip island would be pretty quick in his car I reckon. Any lift issue would surely rear it's head there.
I don't think my car produces gobs of downforce, I just don't believe it is the flying wing that some try to portray them as.
Racetrack? Yeah sure a splitter, wing etc would work wonders and make what I believe to be a fairly neutral aero car into a car that produces usable downforce. No surprise if it goes faster.
Re 968: I had a modified 928 that felt pretty good, right up until you took a bend at high speed or the car was unsettled by something... My GT is much much much better than that (and I don't think the 928 was terrible, I've driven a lot scarier).
Tim.
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Re Humps, suspension setup etc - YouTube - Longford Revival Festival highlights package filmed by Southern Cross Television‏
This is a Commercial TV package showing the event I did recently at Longford.
You can see the Porsche Carrera GT and to a lesser extent the Shelby Supersnake both getting quite untidy over the humps.
My little RF had no such problems.
And for the Aussies out there, that was the Moffat Mustang and it sounded WICKED!
Tim.
This is a Commercial TV package showing the event I did recently at Longford.
You can see the Porsche Carrera GT and to a lesser extent the Shelby Supersnake both getting quite untidy over the humps.
My little RF had no such problems.
And for the Aussies out there, that was the Moffat Mustang and it sounded WICKED!
Tim.
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Hi Tim
I have done 160 mph in my RF down an airfield runway with standard RF1 suspension and it felt a bit twitchy at that speed, ie the lateral stability didn't seem too good. The car is rigged 1 inch lower at the front and the wheels are 17 inch with 225 tyres on the front and 275s on the rear. I have never known what the correct tyre pressures should be but generally have about 30 psi front and 32 psi rear.
Incidently, my RF was the last one produced (in South Africa) and was an incomplete kit, but chassis, body and suspension were supplied.
Chris
I have done 160 mph in my RF down an airfield runway with standard RF1 suspension and it felt a bit twitchy at that speed, ie the lateral stability didn't seem too good. The car is rigged 1 inch lower at the front and the wheels are 17 inch with 225 tyres on the front and 275s on the rear. I have never known what the correct tyre pressures should be but generally have about 30 psi front and 32 psi rear.
Incidently, my RF was the last one produced (in South Africa) and was an incomplete kit, but chassis, body and suspension were supplied.
Chris
Yeah, my in-car video illustrates some issues in that area that I have been itching to fix. RF2 have a revised suspension/steering package I am going to install when I get organized.
I assume you are not talking aero stability, if so I have not encountered anything worrying. There were some quite strong crosswinds on the second day of the event and they didn't bother me at all.
FYI I have Kuhmo Tarmac 225s and 265s and ran 38 psi warm(ish) f/r on the day.
Tim.
I assume you are not talking aero stability, if so I have not encountered anything worrying. There were some quite strong crosswinds on the second day of the event and they didn't bother me at all.
FYI I have Kuhmo Tarmac 225s and 265s and ran 38 psi warm(ish) f/r on the day.
Tim.
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The aero stability appears to be OK - having the front rigged slightly lower than the rear contributes to this I think. With regard to the lateral instability, I have been told that it might be caused by the King Pin Inclination (KPI) being wrong. Apparently a line drawn through the steering pivot points and extended to the ground should end up under the tyre. On my RF it ends up toward the centre line of the car missing the contact patch of the tyre completely. Perhaps I should talk to Paul about the revised RF2 front suspension.
We (my son and I - he is pretty quick in our Radical) had the car round a track recently and found the handling to be not bad considering the car has not yet had any development at all apart from fitting a rear anti roll bar. The adjustable shocks were set to their hardest mode. The car cornered flat and held on nicely with Michelin Pilot Sport tyres. Any straight line instability wasn't noticed but then everything feels a bit unstable when driving round a race track!
Will keep you informed about anything else that we do to the car. At the moment I am fully occupied in rebuilding the Radical prior to selling it - just too time consuming and expensive to run, but huge fun to drive.
Chris
We (my son and I - he is pretty quick in our Radical) had the car round a track recently and found the handling to be not bad considering the car has not yet had any development at all apart from fitting a rear anti roll bar. The adjustable shocks were set to their hardest mode. The car cornered flat and held on nicely with Michelin Pilot Sport tyres. Any straight line instability wasn't noticed but then everything feels a bit unstable when driving round a race track!
Will keep you informed about anything else that we do to the car. At the moment I am fully occupied in rebuilding the Radical prior to selling it - just too time consuming and expensive to run, but huge fun to drive.
Chris
The scrub radius is what you're talking about and yes it is ridiculous. RF2 have a package to fix this, among other things.
Apologies for the thread drift...
Before you try too hard at the track, I'd suggest you do some analysis of rear bump steer and also rear camber. There's a thread here somewhere with a suggested setup that works well. Some modification is necessary but it's not too difficult.
Front end is much improved by the new RF2 setup, I have seen it in action and am impressed. It has been tested by one of Australia's best known and most successful racing drivers. I have spoken to him privately about the new setup and he is honestly impressed.
Anyway, I hear some improvements are being made to timing and track length for next years speed trial so hopefully I can get the thing into 6th.
Good luck!
Tim
Apologies for the thread drift...
Before you try too hard at the track, I'd suggest you do some analysis of rear bump steer and also rear camber. There's a thread here somewhere with a suggested setup that works well. Some modification is necessary but it's not too difficult.
Front end is much improved by the new RF2 setup, I have seen it in action and am impressed. It has been tested by one of Australia's best known and most successful racing drivers. I have spoken to him privately about the new setup and he is honestly impressed.
Anyway, I hear some improvements are being made to timing and track length for next years speed trial so hopefully I can get the thing into 6th.
Good luck!
Tim
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This Le mans driver talks about 240mp/h :stunned:
Le Mans 1969 onboard Ford GT 40
a round in a GT40 at le mans 1969
YouTube - Le Mans 1969 onboard Ford GT 40‏
Le Mans 1969 onboard Ford GT 40
a round in a GT40 at le mans 1969
YouTube - Le Mans 1969 onboard Ford GT 40‏
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