Which Has More Potential In The Long Run?

[djr81]

Yes I agree that AWD will have the advantage of the corner exit, but wait, isn't that only 1/3 of the corner? What about braking? What about turning and maintaining that speed?

Yes the exit is only 1/3 of the corner. Just the most important third as it dictates your speed along the straight which is where there is a huge amount of time to be gained/lost. Given a GTR can run a wider tyre, it can brake as well as a GTST, corner as well too.

You can't compare a MR or RR layout, they are very different to the traditional FR. Friction on tyres = coefficient of grip * mass, therefore less load on turning wheels from engine at back = less grip when turning, and especially when accelerating while doing so.

You have assumed the response of the tyre to additional weight is linear. It is not. What you have said there is fundamentally wrong.

Guys, also don't get me wrong. A well advanced AWD will beat a RWD in terms of potential (or anything really) anytime. But in the case of R32s which were made well back in the days, I think it is more potent in the long run without the AWD. To all the guys saying 'this thread is shit' or 'school holidays bro' etc. Why don't you state why this is a stupid theory instead of just cursing? Surely I'm not the only one that's interested.

A well advanced AWD will beat a RWD in terms of potential (or anything really) anytime.

You have summed the whole thing up there. So why say that & then try & back pedal?

[TurboDoseBro]

Yes the exit is only 1/3 of the corner. Just the most important third as it dictates your speed along the straight which is where there is a huge amount of time to be gained/lost. Given a GTR can run a wider tyre, it can brake as well as a GTST, corner as well too.

You have assumed the response of the tyre to additional weight is linear. It is not. What you have said there is fundamentally wrong.

A well advanced AWD will beat a RWD in terms of potential (or anything really) anytime.

You have summed the whole thing up there. So why say that & then try & back pedal?

Sure exit speeds are one of the most important factors in the corner but you will end up with a higher exit speed if you can maximise as much of the corner speed as possible and maintain it to the end (assumng the correct racing lines). GTS-T can also run a wider tyre, all you gotta do it change it...and maybe after a few fender midifications. This is about the long run not just a pure GTS-T with an RB26.

It is linear for that equation. Bare in mind that it doesn't account for the width of a tyre, sidewall flex, temperatures, etc etc. It's a general outlook that more weight = more grip assuming same circumstances.

You haven't read the posts and understood it. "A well advanced AWD will beat a RWD in terms of potential (or anything really) anytime"I'm not back pedalling on anything. I said the R32 GTR AWD system is too primitive (not 'well advanced'). R34 onwards on the other hand, you would want the GTR because of it's independant wheel torque distribution ('well advanced') and it shows, because even though the R34 GTR is a lot heavier than a R32 GTR, they still manage to dominate by quite a lot.

Iplen I also agree with you, except for the rallying comparison. Reason is that in rallying with all the different road surfaces, you will not achieve enough traction, unlike on a race track, therefore an AWD system is infact more beneficial.

[djr81]

Sure exit speeds are one of the most important factors in the corner but you will end up with a higher exit speed if you can maximise as much of the corner speed as possible and maintain it to the end (assumng the correct racing lines). GTS-T can also run a wider tyre, all you gotta do it change it...and maybe after a few fender midifications. This is about the long run not just a pure GTS-T with an RB26.

A 21% difference in lateral grip (Which is absolutely massive) will only produce a 10% difference in cornering speed. There is no way two notionally similar cars ie a GTS-T versus A GT-R will produce anything like that difference in cornering speed. They will, on the other hand, easilly produce a 10% differential in straight line speed based on the GTRs better traction. Given the straights are longer than the corners - well you figure it out.

It is linear for that equation. Bare in mind that it doesn't account for the width of a tyre, sidewall flex, temperatures, etc etc. It's a general outlook that more weight = more grip assuming same circumstances.

The more wieght = less relative grip. If you double the weight of a car you need twice as much grip to corner at the same speed. Unfortunately tyres will not produce twice as much grip with twice as much weight.

You haven't read the posts and understood it. "A well advanced AWD will beat a RWD in terms of potential (or anything really) anytime"I'm not back pedalling on anything. I said the R32 GTR AWD system is too primitive (not 'well advanced'). R34 onwards on the other hand, you would want the GTR because of it's independant wheel torque distribution ('well advanced') and it shows, because even though the R34 GTR is a lot heavier than a R32 GTR, they still manage to dominate by quite a lot.

I have. Most of it is tripe. The R32 & R34 GTR AWD systems are fundamentally the same. They are both sufficiently advanced to more than make up for their weight. Even primitive, 1980's LSD's work, believe it or not.

[NISMO]

GTSt's are great cars, no doubt about it, (i would love to be able to afford one as a track car) but if you're gonna talk modified GTSt, then talk modified GTR!

Otherwise why are you comparing the two and the benefits of one drivetrain over the other.

There's a reason why as far time attack goes GTR's have ALWAYS been chosen over GTSt's for outright honours. I could be wrong, but can't remember too many GTSt's winning time attack comps.

Now if we're gonna talk well sorted modified GTR's, please find me some GTSt's that can do this

Listen to the car through the corner to see just how early you can get on throttle in an awd car.

Or this

[iplen]

The problem with splitting a corner into 3 is that with a 4wd car you can accelerate much sooner than 2/3s through, pretty much get the nose in (lower speed than a RWD) then nail it so your straight is longer, and apex speed could be higher too. Slow in fast out.. FWD is the same, do all the work before the corner, enter pointing toward the exit, then your flat!!

[mad082]

the extra weight of the awd when accelerating down a straight will be more than overcome by the extra traction when coming out of a corner, especially a slow corner, since you can get on the gas earlier as well as use a higher throttle percentage.

[TurboDoseBro]

A 21% difference in lateral grip (Which is absolutely massive) will only produce a 10% difference in cornering speed. There is no way two notionally similar cars ie a GTS-T versus A GT-R will produce anything like that difference in cornering speed. They will, on the other hand, easilly produce a 10% differential in straight line speed based on the GTRs better traction. Given the straights are longer than the corners - well you figure it out.

That's because in a corner all 4 tyres will have different loadings. You never know what differences both cars are capable with aero parts and race tyres fitted on. As Mark said, on high speed corners, the GTS-T will have a big advantage over the GTR, and on low speed corners the GTR will have a big advantage over the GTS-T.

The more wieght = less relative grip. If you double the weight of a car you need twice as much grip to corner at the same speed. Unfortunately tyres will not produce twice as much grip with twice as much weight.

Really? Would an 800kg Cortina corner twice as fast as a 1600kg Commodore? As said before, friction = coefficient of grip x load. The coefficient of grip will always stay constant, it's the load that it differs. So indeed, assuming same conditions, a tyre with with twice the load on it will have twice the grip.

I have. Most of it is tripe. The R32 & R34 GTR AWD systems are fundamentally the same. They are both sufficiently advanced to more than make up for their weight. Even primitive, 1980's LSD's work, believe it or not.

They definitely do make up for their weight, but to an extent. In the long run of modifications, the downforce from the aero parts, the grip from the race tyres, and the well engineered suspension will more than make up for the primitive AWD.

[TurboDoseBro]

GTSt's are great cars, no doubt about it, (i would love to be able to afford one as a track car) but if you're gonna talk modified GTSt, then talk modified GTR!

Otherwise why are you comparing the two and the benefits of one drivetrain over the other.

There's a reason why as far time attack goes GTR's have ALWAYS been chosen over GTSt's for outright honours. I could be wrong, but can't remember too many GTSt's winning time attack comps.

Now if we're gonna talk well sorted modified GTR's, please find me some GTSt's that can do this

Listen to the car through the corner to see just how early you can get on throttle in an awd car.

Time attack R32 GTR video

Or this

Multi talented R32 GTR video

First of all, very convincing views and videos. We certainly are discussing both versions modified in the long run. I definitely see an earlier throttle on AWDs, especially from the videos, however it may be neutral throttle, or slowly easing in the accelerator. The GTS-T would possibly be able to do that too with enough downforce.

Very true on GTRs being selected for TA. If told me to provide a video of a GTS-T winning a TA right now I honestly couldn't do it. However, how do the JGTC cars end up being faster than the TA GTRs? Also there is an S15, yes I know, different car, but still FR traditional layout by Nissan and not one of those mid mounted FR cars too (eg. RX-7, S2000, Ferrari 599) entered in the World Time Attack challenge which does 55s in Tsukuba. Last time I checked, the HKS C230R Evo did it in 55s as well (AWD ofcourse). In the 2010 World Time Attack results, both R34 and R32 GTRs were defeated by the RX-7, although mid mounted FR, still a 2WD.

I have also noticed the R32 GTRs in the videos retained almost stock aero parts.

Here are the results derived from VIC SAU club of where FR has beaten AWD. These are lap records:

Haunted Hills

Modified GTR Anthony Snelling 97 GTR 57.92

Modified RWD Ryan Bell Nissan Sileighty 57.50 (Although not an R32, they have very similar shells, and has beat an R33 GTR)

Winton

Modified GTR Jack Blanas R33 GTR 01:33.46

Modified RWD Adam Newton R32 GTS-T 01:33.264

Bare in mind I have only stated 2 tracks out of the 5 on the site (these were the only 2 where a GTS-T or equivalent has scored a quicker lap time than a GTR). Reference: http://www.sauvic.com.au/lap_records

By the way where is SydneyKid and all the other race GTS-Ts to give some insight?

Edited May 11, 2011 by TyresBro

[NISMO]

The GTS-T would possibly be able to do that too with enough downforce.

However, how do the JGTC cars end up being faster than the TA GTRs? Also there is an S15, yes I know, different car, but still FR traditional layout by Nissan and not one of those mid mounted FR cars too (eg. RX-7, S2000, Ferrari 599) entered in the World Time Attack challenge which does 55s in Tsukuba. Last time I checked, the HKS C230R Evo did it in 55s as well (AWD ofcourse). In the 2010 World Time Attack results, both R34 and R32 GTRs were defeated by the RX-7, although mid mounted FR, still a 2WD.

I have also noticed the R32 GTRs in the videos retained almost stock aero parts.

I honestly think we may be talking too very different things.

Firstly though, i doubt there would be any wing that can generate enough down force to sling shot a car out of a corner like and AWD system can. COuld be worng, but in that first video with the 800hp GTR, i really really doubt that no amount of aero would ever get that same result.

Secondly re JGTC, these after F1, are one of the most developed cars on the planet. We're talking full carbon bodies, suspension set-up which is on par with F1, completely different body which only utilises the factory roof line etc etc. In other words something that 99.999% of people on this planet would never achieve wiht their own cars. The same can be said for the TA cars. Full carbon bodies, completely re-designed etc etc.

If you look at what is achievable for the regular joe, such as those video's i posted, ie not a completely re-designed car, then i stand by the fact that the AWD is the better base. Its been proven time and time again.

I really can't comment on the times you posted for the 2 tracks below, cause i have no idea how far one car is developed v the other.

I'm just saying that take a 32 GTR and 32 GTSt, throw an RB26 in so both have the same powerplant, then do the same mods on both, brakes, aero, tyres etc etc, and almost always the AWD will have an advantage.

[Nee-san]

I honestly think we may be talking too very different things.

Firstly though, i doubt there would be any wing that can generate enough down force to sling shot a car out of a corner like and AWD system can. COuld be worng, but in that first video with the 800hp GTR, i really really doubt that no amount of aero would ever get that same result.

Secondly re JGTC, these after F1, are one of the most developed cars on the planet. We're talking full carbon bodies, suspension set-up which is on par with F1, completely different body which only utilises the factory roof line etc etc. In other words something that 99.999% of people on this planet would never achieve wiht their own cars. The same can be said for the TA cars. Full carbon bodies, completely re-designed etc etc.

If you look at what is achievable for the regular joe, such as those video's i posted, ie not a completely re-designed car, then i stand by the fact that the AWD is the better base. Its been proven time and time again.

I really can't comment on the times you posted for the 2 tracks below, cause i have no idea how far one car is developed v the other.

I'm just saying that take a 32 GTR and 32 GTSt, throw an RB26 in so both have the same powerplant, then do the same mods on both, brakes, aero, tyres etc etc, and almost always the AWD will have an advantage.

JGTC cars whilst highly developed are no where near the level of sports prototypes to name but one series (there are a few) that a much closer to formula 1 in terms of outlay and development.

There have been and will continue to be RWD cars that compete at the highest level against AWD alot of the time coming down to design philosophy or marketing image more then anything, but we are not talking about production based racing then...

Anyway Not going to bore you with TL:DR

The discussion of the traction circle and the tyre loadings through the various stages of a corner is all you need to see really and is something you can mathematically use to contrast data.

Basically, What djr81 said x 10

[djr81]

That's because in a corner all 4 tyres will have different loadings. You never know what differences both cars are capable with aero parts and race tyres fitted on. As Mark said, on high speed corners, the GTS-T will have a big advantage over the GTR, and on low speed corners the GTR will have a big advantage over the GTS-T.

Aero is not magic. Broadly (very broadly) if you can generate, say, 20% of the weight of the car in downforcee you will increase the lateral grip by the same amount (you wont really but for the sake of the argument). A GTR with driver is about 1600kg. So you need 320kg of downforce, biased about 60/40 bias to the front. Near enough to 200kg of front downforce. Have you seen what sort of wings are required for this at the usual 100km/h cornering speeds you get in local circuits? Is doesnt happen.

Really? Would an 800kg Cortina corner twice as fast as a 1600kg Commodore? As said before, friction = coefficient of grip x load. The coefficient of grip will always stay constant, it's the load that it differs. So indeed, assuming same conditions, a tyre with with twice the load on it will have twice the grip.

The coefficient of grip (friction) will NOT stay constant. It is not constant. It falls away as the loads increase.

They definitely do make up for their weight, but to an extent. In the long run of modifications, the downforce from the aero parts, the grip from the race tyres, and the well engineered suspension will more than make up for the primitive AWD.

Well go your hardest. But you will find, as countless others have before you, that you theory is wrong. It is not F1 in the 60's after all.

[TurboDoseBro]

I honestly think we may be talking too very different things.

Firstly though, i doubt there would be any wing that can generate enough down force to sling shot a car out of a corner like and AWD system can. COuld be worng, but in that first video with the 800hp GTR, i really really doubt that no amount of aero would ever get that same result.

Secondly re JGTC, these after F1, are one of the most developed cars on the planet. We're talking full carbon bodies, suspension set-up which is on par with F1, completely different body which only utilises the factory roof line etc etc. In other words something that 99.999% of people on this planet would never achieve wiht their own cars. The same can be said for the TA cars. Full carbon bodies, completely re-designed etc etc.

If you look at what is achievable for the regular joe, such as those video's i posted, ie not a completely re-designed car, then i stand by the fact that the AWD is the better base. Its been proven time and time again.

I really can't comment on the times you posted for the 2 tracks below, cause i have no idea how far one car is developed v the other.

I'm just saying that take a 32 GTR and 32 GTSt, throw an RB26 in so both have the same powerplant, then do the same mods on both, brakes, aero, tyres etc etc, and almost always the AWD will have an advantage.

No amount of aero can slingshot a 2WD out of a corner like an AWD can, but you can have enough to go fast around a track with relatively high power, otherwise F1s would be out of business (~600kg, ~800hp). As you said, our cars will never be as refined as theirs, so lets look at V8 Supercars then? They are getting faster times than the GTRs back in the Bathurst days thanks to grip. If the AWD was so good (speaking specifically for the Skylines, especially earlier models), how could this happen? The V8 cars are larger and heavier. Most importantly FR as on topic. In the reference of Easter Creek Raceway, a touring Commodore VT (V8 supercar) has clocked a much faster lap than a touring Group A R32 GTR. Reference: http://www.eastern-c...lap_records.htm

It's not as simple as same mods on both cars. Each modifications must be specific to each car. For example you would need a bigger/more angled wings on the GTS-T to compensate for the weight and grip disadvantage. Where the GTS-T will need to run wider tyres, the GTR probably doesn't due to it's AWD grip.

JGTC cars whilst highly developed are no where near the level of sports prototypes to name but one series (there are a few) that a much closer to formula 1 in terms of outlay and development.

There have been and will continue to be RWD cars that compete at the highest level against AWD alot of the time coming down to design philosophy or marketing image more then anything, but we are not talking about production based racing then...

Anyway Not going to bore you with TL:DR

The discussion of the traction circle and the tyre loadings through the various stages of a corner is all you need to see really and is something you can mathematically use to contrast data.

Basically, What djr81 said x 10

Philosophy and marketing image? That is what time attack is for (World Time Attack Challenge, which I am most likely going to ), to promote the workshops, teams, and products, and maybe even gain more sponsorship. They wouldn't bother sending out a 'crappy 2WD' when they know AWD is going to win everytime.

Mate, nothing is boring us (at least me anyways). I find all posts very interesting and have at least something to take away by the end of it (apart from the haters). So bring on the TL:DR whatever it is, if you have to.

You mention traction circle, that is definitely something to consider. However, how can you use the front wheels to accelerate in a corner when you are already using them to their full potential turning?

Edited May 12, 2011 by TyresBro

[TurboDoseBro]

Aero is not magic. Broadly (very broadly) if you can generate, say, 20% of the weight of the car in downforcee you will increase the lateral grip by the same amount (you wont really but for the sake of the argument). A GTR with driver is about 1600kg. So you need 320kg of downforce, biased about 60/40 bias to the front. Near enough to 200kg of front downforce. Have you seen what sort of wings are required for this at the usual 100km/h cornering speeds you get in local circuits? Is doesnt happen.

You don't necessarily need the same amount of loadings on each tyre to match the cornering of the GTR. Lets put it this way with a case study. A heavier car will always need to brake at a longer distance from a corner, assuming same cars and road (because of momentum). So therefore every meter you brake later, you are ahead by. True? *true* so because the GTS-T with it's lighter body, and better weight distribution, it is more nimble throughout the corner and can carry more speed throughout the corner, the equation then becomes 'difference in braking distance' + 'distance increased from speed of cornering' = difference in corner exit distance. Also because the GTS-T is lighter it will accelerate quicker. The GTR will have longer braking distance and will not hold as much of the speed through cornering, but the corner exit acceleration will be great. Notice the GTS-T will have better corner exit speed, but the GTR will have better corner exit acceleration from being able to throttle earlier, but start at a lower speed.

The coefficient of grip (friction) will NOT stay constant. It is not constant. It falls away as the loads increase.

It will assuming the track is made of the same material all the way through. If I had to take anything correct from this thread, it would be concerning these statements towards the coefficients of grip and friction. Look at it this way to help you. Get a table with the same material all the way through. Now get a square rubber and run a side along the table. Now do it with less and more downward force. Notice the change in levels of grip? This is the load side of the equation. The coefficient of grip side stays the same because the rubber is always a rubber and the table is always a table so the coefficient of grip between the 2 is constant. Lets just leave that one.

Well go your hardest. But you will find, as countless others have before you, that you theory is wrong. It is not F1 in the 60's after all.

I just want to hear your opinions, experiences, theorys etc etc from you guys. Maybe noone has done it yet because they have the same concepts as you guys or have not taken it to the extreme, thinking that in the Skyline world, nothing goes past a GTR badge. The world's fastest automobiles are 2WD.

Edited May 12, 2011 by TyresBro

[mad082]

ok now you are just clutching at straws. comparing a lap time from 1992 to a lap from 2000 or later is like comparing a model T ford with a ferrari enzo. it's just plain stupid. you have to compare apples with apples. that GTR lap record stood for quite a few years. plus the regulations on the cars has changed over the years (not to mention tyre compounds, etc), so you can't compare the cars. you might as well compare the lap times of a race car on wide slick tyres and road car on 4 space saver tyres, it would be about as relevant. even comparing the r32 GTR to the commodores and sierras it was racing isn't relevant for various reasons (from the cost of the GTR race cars being much more than the others, to pretty ordinary regulations)

realistically you won't really be able to find many real world examples to use to prove your point. you can't even really use the 911 turbo and a GT3 since there is more different than just the drive system. using examples from racing categories where awd cars compete with fwd and rwd cars is also useless since they have rules and regulations to make the racing more equal. only way to know for sure which is better is to build up both cars equal with the only difference being the awd car having the extra weight of the awd system.

i'm not saying that the GTR is the best car every, but if you were building up 2 cars the same, 1 awd, 1 rwd, on most race tracks the awd would be faster, especially in the wet (remembering that a v8 supercar will light up the rears in 5th and 6th gear in the wet). that said, the rwd would be more fun to dick around in as you could just fry the tyres round every corner.

[mad082]

also it is worth pointing out the (theoretically) fastest concept car in the world (fastest race car ever thought up) is AWD. i am refering to the redbull x1/X2010. basically the engineers sat down and designed the dream race car, and suprise suprise, they made it AWD. the reason being that when you are talking about upwards of 1000hp, traction really does become an issue.

[TurboDoseBro]

ok now you are just clutching at straws. comparing a lap time from 1992 to a lap from 2000 or later is like comparing a model T ford with a ferrari enzo. it's just plain stupid. you have to compare apples with apples. that GTR lap record stood for quite a few years. plus the regulations on the cars has changed over the years (not to mention tyre compounds, etc), so you can't compare the cars. you might as well compare the lap times of a race car on wide slick tyres and road car on 4 space saver tyres, it would be about as relevant. even comparing the r32 GTR to the commodores and sierras it was racing isn't relevant for various reasons (from the cost of the GTR race cars being much more than the others, to pretty ordinary regulations)

realistically you won't really be able to find many real world examples to use to prove your point. you can't even really use the 911 turbo and a GT3 since there is more different than just the drive system. using examples from racing categories where awd cars compete with fwd and rwd cars is also useless since they have rules and regulations to make the racing more equal. only way to know for sure which is better is to build up both cars equal with the only difference being the awd car having the extra weight of the awd system.

i'm not saying that the GTR is the best car every, but if you were building up 2 cars the same, 1 awd, 1 rwd, on most race tracks the awd would be faster, especially in the wet (remembering that a v8 supercar will light up the rears in 5th and 6th gear in the wet). that said, the rwd would be more fun to dick around in as you could just fry the tyres round every corner.

Good old Marc with his prehistoric metaphors LOL

If you look into the reference link, the touring Group A R32 GTR lap record in Eastern Creek Raceway was indeed set on 04/09/2010, where as the V8 Supercar record was set on 28/03/1999. Cost should not be a factor in this argument and I don't think it was back then. Back then the Skylines were just too advanced, but still fit in the same class as it was designed to. Sure racing categories have rules and all but last time I checked, TA didn't have that many, or enough to limit the cars potentials. This is where the 2WD RX-7s beat the AWD GTRs. Again going by your rules, this is comparing apples to oranges, so why can't someone make a GTS-T as fast as or similar to the RX-7? Surely it is possible.

Well I mean, we wouldn't want to go to the trouble of building a GTS-T and a GTR just to see which one is faster. Would be damn well interesting though, but most likely not worth it. If I became a millionaire and all I definitely will keep this in mind. Very correct about the wet weather racing. I do believe that in wet weather where traction is very limited, the AWD system would help. However, this video proves something different:

I like to belive that in the rain because of the lower friction, it narrows the traction circle so the limits of the car is shown earlier whether it be oversteer or understeer. It is shown that although the Evo had AWD, it wasn't advantageous in the wet weather (or at least noticable). Also taking a semi-wild guess here but in the rain maybe weight has a bigger advantage than a AWD system also displayed in the video.

Edited May 12, 2011 by TyresBro

[TurboDoseBro]

also it is worth pointing out the (theoretically) fastest concept car in the world (fastest race car ever thought up) is AWD. i am refering to the redbull x1/X2010. basically the engineers sat down and designed the dream race car, and suprise suprise, they made it AWD. the reason being that when you are talking about upwards of 1000hp, traction really does become an issue.

Yes very true. Is that even a real automobile? (As in produced and tested etc)

This although I know you're intentionally doing to prove that in extreme cases AWD is preffered, but is comparing not just apples with oranges, but more accurately apples with beef. I could say hey, guess what, those top fuel dragsters are surprise surprise RWD. But from the not so extreme case, I honestly can't think of a car that is not AWD that can do 0-100km/h in less than 2.2 seconds (off topic).

Edited May 12, 2011 by TyresBro

[zebra]

LOL thread is LOL worthy

Without pointing out every flaw the OP has made.

I'll just say this,

Out of every R32 skyline that has run a real quick time around a track, how many are GTS-t's?

[djr81]

You don't necessarily need the same amount of loadings on each tyre to match the cornering of the GTR. Lets put it this way with a case study. A heavier car will always need to brake at a longer distance from a corner, assuming same cars and road (because of momentum). So therefore every meter you brake later, you are ahead by. True? *true* so because the GTS-T with it's lighter body, and better weight distribution, it is more nimble throughout the corner and can carry more speed throughout the corner, the equation then becomes 'difference in braking distance' + 'distance increased from speed of cornering' = difference in corner exit distance. Also because the GTS-T is lighter it will accelerate quicker. The GTR will have longer braking distance and will not hold as much of the speed through cornering, but the corner exit acceleration will be great. Notice the GTS-T will have better corner exit speed, but the GTR will have better corner exit acceleration from being able to throttle earlier, but start at a lower speed.

Cars today (yes, even GTR’s) are not limited in their braking capacity due to their weight. They are grip limited. The difference between a lighter car under brakes & a heavier one is minimal. In any case it is the least important aspect (time wise) of a corner.

Your assumptions are wrong about a GTST cornering better anyway. Why? Because of the following.

To get anything line acceptable traction with a decent motor a GTST has to run a soft rear spring. To maintain reasonable roll stiffness you then need a stiff front spring and have to make the anti roll bars match. What does this mean? It means the suspension set up makes the car understeer. A GTR does not have to run a soft rear spring for traction – hence can dial out the understeer with a better suspension tune. End result is the GTR is going to corner better.

Once your GTST has struggled its way through the corner it gets to the point of getting the power down. Already hamstrung by a lack of traction you get a double whammy. All that magic aero you are carrying serves to massively increase the aero drag on the car. To the extent that is will accelerate slower than the GTR. Touring car spoilers have horrible lift on drag (L/D) ratios. So the several hundred kgs of downforce you need will come at the cost of a large amount of drag. How much – at any reasonable speed more than the weight of the 4WD system in the GTR.

It will assuming the track is made of the same material all the way through. If I had to take anything correct from this thread, it would be concerning these statements towards the coefficients of grip and friction. Look at it this way to help you. Get a table with the same material all the way through. Now get a square rubber and run a side along the table. Now do it with less and more downward force. Notice the change in levels of grip? This is the load side of the equation. The coefficient of grip side stays the same because the rubber is always a rubber and the table is always a table so the coefficient of grip between the 2 is constant. Lets just leave that one.

Actually no, lets not. For someone who reckons it is “all about the tyres, bro” I would have thought, at the very least, you would have bothered to take the time to understand one of the fundamental properties of a tyre.

This you can take to the bank:

A tyre’s coefficient of friction decreases with increasing vertical load.

At the bottom of the post there is a graph to illustrate it. Note that at 500lb load the friction coefficient is about 1.4. Increase the load to 1000lb and it has fallen away to 1.25 of there abouts. It has, in other words, decreased. As in it is not constant or even linear. The graph comes from Carroll Smiths Tune to Win. I would suggest you read it or any of the other books out there on car suspension – they all make the same point – tyre behaviour is non Newtonian.

Why is this important? A couple of reasons:

1. It shows that there is not a constant relationship between tyre load and lateral grip.

2. It means you can adjust the balance of a car (ie understeer/oversteer) with sway bars & different rate springs.

Perhaps the second of these is not so important for a GTST that has been sprinkled with pixie dust & is therefore the greatest handling, physics defying, most brilliant car ever built. But for the rest of us mortals it is actually useful.

I just want to hear your opinions, experiences, theorys etc etc from you guys. Maybe noone has done it yet because they have the same concepts as you guys or have not taken it to the extreme, thinking that in the Skyline world, nothing goes past a GTR badge. The world's fastest automobiles are 2WD.

You want an example? Nissan once campaigned a thing called a GTSR in group A. It had a front engined RB and rear wheel drive. They replaced it with the GTR. For the highly technical reason that the GTR was faster, everywhere.

Edited May 13, 2011 by djr81

[mad082]

Good old Marc with his prehistoric metaphors LOL

If you look into the reference link, the touring Group A R32 GTR lap record in Eastern Creek Raceway was indeed set on 04/09/2010, where as the V8 Supercar record was set on 28/03/1999. Cost should not be a factor in this argument and I don't think it was back then. Back then the Skylines were just too advanced, but still fit in the same class as it was designed to. Sure racing categories have rules and all but last time I checked, TA didn't have that many, or enough to limit the cars potentials. This is where the 2WD RX-7s beat the AWD GTRs. Again going by your rules, this is comparing apples to oranges, so why can't someone make a GTS-T as fast as or similar to the RX-7? Surely it is possible.

Well I mean, we wouldn't want to go to the trouble of building a GTS-T and a GTR just to see which one is faster. Would be damn well interesting though, but most likely not worth it. If I became a millionaire and all I definitely will keep this in mind. Very correct about the wet weather racing. I do believe that in wet weather where traction is very limited, the AWD system would help. However, this video proves something different:

I like to belive that in the rain because of the lower friction, it narrows the traction circle so the limits of the car is shown earlier whether it be oversteer or understeer. It is shown that although the Evo had AWD, it wasn't advantageous in the wet weather (or at least noticable). Also taking a semi-wild guess here but in the rain maybe weight has a bigger advantage than a AWD system also displayed in the video.

few points to address here.

1: doesn't matter when the group A gtr set the record, as long as it was built to group A regulations as current regulations are totally different.

2: the cost of the GTR very much does play a big part in it's speed. for starters, the purchase price of the GTR was double that of the commodores and sierras it was racing. then take into account the fact that the race cars were built on a much bigger budget that the rest of the cars it was racing. this certainly gave it an advantage. look at single make or twin make races such as the v8 supercars. you won't find many teams on low budgets running at the front of the pack, regardless of how talented the driver is. this is because the more money you have the more developement you can do on engines, etc to get the most power out of them. you do have 1 point right though. the GTR was more advanced than it's competition. this is because nissan designed it to fit at close to the limits of group A regulations as it could and they honestly didn't really care whether the car was a success sales wise or not. on the other hand, holden was building a family car with a few performance enhancements.