What's the technical diffrences between GTP & LMP?

[TIS31]

hey everyone, i'm new to this forum (posted a little on the Indycar side) but first time over here. Went to Lime Rock last year for the ALMS (first time) and LOVED it, and having been trying to follow LMS more closley since. Can someone help me with a tech. question that i'm confused on?
So I know GTP's are closed top and LMP typically are open, but why is the Peugoet (sp?sorry) considered an LMP? a few years ago the Bentley was a GTP. I think i understand the diffrence between LMP1 and LMP2 but i'm just confused about what technical diffrences there are between the two and why couldn't you have two different Prototype fields?

[Jag_Warrior]

Pretty much the same reason they're moving to only one GT class: not enough cars to break it down that much. Notice in LMP2, there are also closed tops and spyders.

When the Bentley was running in GTP, I believe it was required to have slightly narrower tires. I'm not sure if that's still true for closed top cars running in LMP1 or not.

BTW, welcome aboard!

[Bob Riebe]

hey everyone, i'm new to this forum (posted a little on the Indycar side) but first time over here. Went to Lime Rock last year for the ALMS (first time) and LOVED it, and having been trying to follow LMS more closley since. Can someone help me with a tech. question that i'm confused on?
So I know GTP's are closed top and LMP typically are open, but why is the Peugoet (sp?sorry) considered an LMP? a few years ago the Bentley was a GTP. I think i understand the diffrence between LMP1 and LMP2 but i'm just confused about what technical diffrences there are betweens the two and why couldn't you have two different Prototype fields?
The monikers mean little to nothing nowadays.

At one time anything called a prototype had to have certain items relating to street cars, and sports racers--could actually be built on the same chassis, with or without a top, but simply removed the items necessary to qualify for the Prototype classes.
Many true prototypes ran in the Can-Am at times.

When the IMSA/ALMS started-up, after road racing collapsed, some of the cars that the IMSA called "prototypes" were formerly called-SR-sports racer, by the sanction that preceeded it.

A "prototype/sportsracers" could have a top if one chose to put one one.
The current attempts at trying to define cars by whether or not they have a top is because current cars performance is regulated not by how good a team or car is, but by which finger the ACO pulls out of its butt at the moment.
All the names actually represent which spec. class a car runs in although the specs. may change in a heartbeat if the ACO feels like it.

The monikers are supposed to fool the crowd that is all is NOT really same crap different piles, even though it is.
The current economic situation, plus the ACO not able to decide which finger to use, has the ACO scrambling for relevence, as some factories have looked at the rules and said not worth my time or money.

The ACO was going to bring out new EVO rules that would have cars that were different and at least had outward appearence related to street cars but that died on the vine.

If you really want to get confused, check the history of the GT classes.

The ALMS website did have class regs, check there.

[seb_sh]

GTP and LMP had slightly different technical regulations but had equal performance. The current LMP1 and LMP2 regulations allow both open top and closed top cars while GTP is no longer used which is why the Peugeot's are in LMP1.

LMP2 was intended for privateers (lower costs, complexity and performance) but it hasn't really managed to live up to that because even in the class LMP2 evolved from (LMP 675) manufacturers built cars that would be faster than any privateer (the Lola-MG and lately the Porsche are good examples), plus most privateer entries were and are low quality (usually only a few cars make it to the end at Le Mans).

You can read more about these things here: http://en.wikipedia.org/wiki/Le_Mans_Prototype
And about the specific cars here: http://www.mulsannescorner.com/

[V12]

I gather that the "GTP" class basically grew out of the late 90s GT1s when they decided in 1999 to abandon the notion that the Toyota GT-One and co bore any resemblance to road-going supercars. The new for 1999 Mercedes CLR and Audi R8C (forerunner to the Bentley project) were built to these regulations too, and I don't know for sure if the CLR and R8C had to go through any token road homologation process like the GT-One, CLK, 911 GT1, R390 etc. did, but I wouldn't be surprised if they didn't.

I remember saying at the time that if GTP, LMP900 and LMP675 were basically designed to have equal performance, then they'd be better off amalgamating all of them into an "LMP1" category while creating an LMP2 category that unlike 675 (with the low low weight limit) bore no pretentions of competing for overall victory, and make no distinction between open and closed top within these categories for increased variety.

Which is exactly what they did :)

[wedge]

You're right V12

GT1 was a complete joke with its homologation rules because Porsche raced glorified Group C cars in 'GT1' guise but it generated so much manufacturer interest it was certainly a terrific chapter in endurace racing when even the 911 GT1 raced in Brit GTs. Great days those were.....

[V12]

Porsche raced glorified Group C cars in 'GT1' guise

Ah I'd forgotten about the Dauer-Porsche in 1994, I'm guessing that particular loophole was closed for '95, only for the envelope to be slowly pushed outwards through the second half of the 90s by Porsche then Nissan, Mercedes and Toyota?

Having said that, the 911 GT1 may have been a prototype in all but name but at least it "looked" like a road going car, to be honest it wasn't until the GT-One came along that I saw a "GT1" that truly resembled an LMP with a roof (the Dauer car not withstanding).

Then again the BMW M3 V8s that caused all that fuss in the ALMS at the start of this decade looked like nothing more than touring cars to me but were apparently pushing beyond the spirit of the GT (now GT2) regulations of the time beneath the skin, so I guess looks aren't that important.

[wedge]

Ah I'd forgotten about the Dauer-Porsche in 1994, I'm guessing that particular loophole was closed for '95, only for the envelope to be slowly pushed outwards through the second half of the 90s by Porsche then Nissan, Mercedes and Toyota?

Having said that, the 911 GT1 may have been a prototype in all but name but at least it "looked" like a road going car, to be honest it wasn't until the GT-One came along that I saw a "GT1" that truly resembled an LMP with a roof (the Dauer car not withstanding).

Then again the BMW M3 V8s that caused all that fuss in the ALMS at the start of this decade looked like nothing more than touring cars to me but were apparently pushing beyond the spirit of the GT (now GT2) regulations of the time beneath the skin, so I guess looks aren't that important.

Porsche took the biscuit/pushed the envelope because McLaren/Gordon Murray were pursuaded to race the F1 in the BPR series but they only built a short amount of cars which entailed the silly homologation rules to the point I seem to remember you could count the number of homologated road legal spec cars with one hand.

Even though the Toyota GT-1 was the final straw for GT1, by golly that is the best looking looking car I've seen in all my years of watching motorsport!

[seb_sh]

Although the cars were more prototypes than GT the last part of the 90's they were really nice and looked good, very racey, and that period always fascinated me because of the large number of manufacturers involved. The pinnacle was imo the 1999 Le Mans race where only Porsche was missing from an all-star lineup. (in what was also one of the most memorable Le Mans races in recent history, if not the most memorable)

[Bob Riebe]

Although the cars were more prototypes than GT the last part of the 90's they were really nice and looked good, very racey, and that period always fascinated me because of the large number of manufacturers involved. The pinnacle was imo the 1999 Le Mans race where only Porsche was missing from an all-star lineup. (in what was also one of the most memorable Le Mans races in recent history, if not the most memorable)
The GT1 cars were in fact, what "prototypes" had once been and really are by name.
Prototypes for street cars, not sports racers.

The FIA and ACO became too enamored with their god complexes and trying to force auto makers into boxes they would not go into, but had they developed a GT1 mod. prod. class and an GT1 prototype class they could have had a return to the glory years of the sixties, but instead they were too busy trying to force auto companies to do as they were told, instead of letting they do what they did best, build cars that would help them sell more cars, and one by one the car companies told the sanctions bye-bye.

[wedge]

The GT1 cars were in fact, what "prototypes" had once been and really are by name.
Prototypes for street cars, not sports racers.

The FIA and ACO became too enamored with their god complexes and trying to force auto makers into boxes they would not go into, but had they developed a GT1 mod. prod. class and an GT1 prototype class they could have had a return to the glory years of the sixties, but instead they were too busy trying to force auto companies to do as they were told, instead of letting they do what they did best, build cars that would help them sell more cars, and one by one the car companies told the sanctions bye-bye.

Evo magazine said the Mercedes CLK GTR was one of the worst cars they ever tested. They were was built to comply with homologation, uncompromising and ended up in museums and private collectors.

[jimclark]

TIS31 - THESE were the REAL GTPs... ;) :)

http://www.champcarfanatics.com/forums/showthread.php?t=21072

[Bob Riebe]

TIS31 - THESE were the REAL GTPs... ;) :)

http://www.champcarfanatics.com/forums/showthread.php?t=21072
These as in what are we supposed to be looking at?

[jimclark]

These as in what are we supposed to be looking at?


Uuuhhh......yes.
Why do you ask? It's what I posted.

[Bob Riebe]

Uuuhhh......yes.
Why do you ask? It's what I posted.
The only thing that comes up is another forum and a lot of writing.
What am I supposed to look for?

[jimclark]

The pics are there.

[Bob Riebe]

The pics are there.
I think I know of that which you speak, or at least the era.