ALMS LMP2 vs GT2
10-07-2010, 03:56 PM
#1
Racer
Thread Starter
ALMS LMP2 vs GT2
How is it that ALMS LMP2 cars are so much faster than GT2 and GTC cars.
I was just reading an article that, among other informative things, LMP2 is limited to 450hp. Although higher in horsepower than a GT3 RSR the LMP2 cars sure seem to do lap times much better than the horsepower delta would indicate. Putting aside the handling characteristics are obviously better, in a straight line the LMP2 cars seem exceedingly fast. What say you?
I was just reading an article that, among other informative things, LMP2 is limited to 450hp. Although higher in horsepower than a GT3 RSR the LMP2 cars sure seem to do lap times much better than the horsepower delta would indicate. Putting aside the handling characteristics are obviously better, in a straight line the LMP2 cars seem exceedingly fast. What say you?
10-07-2010, 04:08 PM
#2
Rennlist Member
How is it that ALMS LMP2 cars are so much faster than GT2 and GTC cars.
I was just reading an article that, among other informative things, LMP2 is limited to 450hp. Although higher in horsepower than a GT3 RSR the LMP2 cars sure seem to do lap times much better than the horsepower delta would indicate. Putting aside the handling characteristics are obviously better, in a straight line the LMP2 cars seem exceedingly fast. What say you?
I was just reading an article that, among other informative things, LMP2 is limited to 450hp. Although higher in horsepower than a GT3 RSR the LMP2 cars sure seem to do lap times much better than the horsepower delta would indicate. Putting aside the handling characteristics are obviously better, in a straight line the LMP2 cars seem exceedingly fast. What say you?
The P2 cars are (near) idealized carbon-fiber open race cars, the GT3 RSR is a barn door with a steel unibody. I suspect you could turbocharge the living daylights out of an RSR and it still wouldn't touch an RS Spyder.
pete
10-07-2010, 04:09 PM
#3
Burning Brakes
Join Date: Jan 2010
Location: erin, Ontario, Canada
Posts: 1,240
Likes: 0
Received 0 Likes
on
0 Posts
difference in power to weight ratios+downforce+center of gravity comparisons=faster lap times
I'm sure I missed a hundred things, but this is a good start.
I'm sure I missed a hundred things, but this is a good start.
10-07-2010, 04:19 PM
#4
Rennlist Member
Join Date: Feb 2006
Location: Wishing I Was At The Track
Posts: 13,519
Received 1,729 Likes
on
916 Posts
You're looking at approx. 800kg weight for LMP2 and 1125-1325kg for GT2 depending on make. That's a big power-to-weight advantage for LMP2. LMP2 are running carbon brakes (Muscle Milk RS Spyder below) were as GT2 run steel (Risi 430 GT2 entry). Combine the above with significantly higher downforce generated by LMP2 cars and it equals much faster speeds/times.
10-07-2010, 11:35 PM
#5
Rennlist Member
Join Date: Mar 2010
Location: Houston, TX
Posts: 369
Likes: 0
Received 0 Likes
on
0 Posts
3 things differentiate....downforce, power to weight and superior braking ( a combination of large carbon discs and the aforementioned power to weight) ...in that order. The GT2 cars actually make excellent mechanical grip. This is best evidenced by low speed corner exit (see turn 7 at Petit/Road Atlanta). The LMP2 cars make excellent aerodynamic grip (see turn 1 at Petit/RA).
Obviously the LMP2 cars are also full carbon fiber tubs vs production chassis offshoots in GT2. BTW, the GTC cars (essentially cup) are about as fast as the GT2 cars in the high speed straights due to the narrow body configuration and resultant reduced aerodynamic drag, however they have less mechanical and aero grip...and have their lunch eaten at the first turn. A similar phenomenon as LMP2 vs GT2 despite reasonably close power to weight in GTC vs. GT2.
Obviously the LMP2 cars are also full carbon fiber tubs vs production chassis offshoots in GT2. BTW, the GTC cars (essentially cup) are about as fast as the GT2 cars in the high speed straights due to the narrow body configuration and resultant reduced aerodynamic drag, however they have less mechanical and aero grip...and have their lunch eaten at the first turn. A similar phenomenon as LMP2 vs GT2 despite reasonably close power to weight in GTC vs. GT2.
10-08-2010, 04:42 AM
#7
Platinum Dealership
Rennlist
Site Sponsor
Rennlist
Site Sponsor
hahaha am I the only one who thinks that this isn't a serious question?
no- really. you're serious? okay.
LMP2 is not making 450hp btw. LMP-C or LMP-challenge (oreca built spec cars with chevy v8) makes 430.
LMP2 is more like 525-550hp. so- at about 60-65% of the weight of a 480hp GT2 car, and less drag, they're WAY faster accelerating...
the bigger and fastest LMP1 diesels make over 1000lb/ft of torque, but "only" about 650hp- but with that much torque, and long gearing, they don't need bling HP...
last- lap times are very subjective in regards to the makeup of the course- the discrepancy at somewhere like Road Atlanta can be made into a HUGE time gap because of the extra downforce entering turn 6, followed by acceleration allowed from lower weight exiting turn 7, as well as carrying much more speed up through turn 1 (downforce), which in the prototypes is nearly flat (a terrifying thought to anyone who's ever taken a gt3 or similar up that hill)- just those two sections could account for 5 seconds of extra speed on a lap.
no- really. you're serious? okay.
LMP2 is not making 450hp btw. LMP-C or LMP-challenge (oreca built spec cars with chevy v8) makes 430.
LMP2 is more like 525-550hp. so- at about 60-65% of the weight of a 480hp GT2 car, and less drag, they're WAY faster accelerating...
the bigger and fastest LMP1 diesels make over 1000lb/ft of torque, but "only" about 650hp- but with that much torque, and long gearing, they don't need bling HP...
last- lap times are very subjective in regards to the makeup of the course- the discrepancy at somewhere like Road Atlanta can be made into a HUGE time gap because of the extra downforce entering turn 6, followed by acceleration allowed from lower weight exiting turn 7, as well as carrying much more speed up through turn 1 (downforce), which in the prototypes is nearly flat (a terrifying thought to anyone who's ever taken a gt3 or similar up that hill)- just those two sections could account for 5 seconds of extra speed on a lap.
Trending Topics
10-08-2010, 06:41 PM
#8
Racer
Thread Starter
Thanks guys, great info.
Yes CJ, it was a serious question and thanks for your response, sarcastic as it was. Who better to get good information from but those who know? I admire your knowledge on the subject as well as others that contribute. Love learning from you guys and in doing so I feel stupid for not knowing the LMP cars are so amazingly light.
The subject sparked my interest due to an article about Roush Yates Ford developing a 450 hp turbo 3.2 motor for LMP2 2011 season.
Yes CJ, it was a serious question and thanks for your response, sarcastic as it was. Who better to get good information from but those who know? I admire your knowledge on the subject as well as others that contribute. Love learning from you guys and in doing so I feel stupid for not knowing the LMP cars are so amazingly light.
The subject sparked my interest due to an article about Roush Yates Ford developing a 450 hp turbo 3.2 motor for LMP2 2011 season.
10-08-2010, 07:54 PM
#9
Platinum Dealership
Rennlist
Site Sponsor
Rennlist
Site Sponsor
tim no biggie- I got to sit in the Dyson RS spyder and had a million questions myself- although most of them were about the traction control and fuel pump settings. I guess in this day and age I just google everything or look it up before I ask. LMP cars are AWESOME. and when you see them in person they make way more sense.
GT2 ALMS cars are like trucks compared to the prototypes (especially the peugot which to me is the sexiest thing on 4 wheels)
GT2 ALMS cars are like trucks compared to the prototypes (especially the peugot which to me is the sexiest thing on 4 wheels)
10-09-2010, 12:49 AM
#11
Rennlist Member
Join Date: Mar 2010
Location: Houston, TX
Posts: 369
Likes: 0
Received 0 Likes
on
0 Posts
The LMPC car is now making closer to 450 HP as they allowed us to change the air restrictor to ease battling with the GT cars on certain circuits. That said, the LMPC cars are still somewhat overweight for what they are...which is partially the result of the heavy chevy derived engine. We approach 2,500 pounds....which is way too much IMO. The car can handle right around 3GS at speeds generating material downforce (over 110 mph). If the car was slightly lighter, made a littlle more downforce and had a better Michelin compound it would be 3.5 g + capable....and essentially become an LMP2 car. I hear this is already in the works as Oreca is heading in this direction in Europe.
Incidentally it does have a ton of torque and can be a handful, particularly on cold tires, as it has no traction control.
Incidentally it does have a ton of torque and can be a handful, particularly on cold tires, as it has no traction control.
10-10-2010, 12:14 AM
#12
Platinum Dealership
Rennlist
Site Sponsor
Rennlist
Site Sponsor
polesitter- how do you guys feel about the reliability and value of the platform- compared to open wheel or GT2 stuff it's supposed to be way cheaper yeah? they look like a lot of fun but you're right that corvette v8 is a lump of excess weight
10-11-2010, 01:21 AM
#13
Rennlist Member
Join Date: Mar 2010
Location: Houston, TX
Posts: 369
Likes: 0
Received 0 Likes
on
0 Posts
The reliability has improved, but the car wasn't originally designed with true endurance racing in mind....particularly on rougher US circuits like Sebring. The drivetrain is pretty rugged and we have not seen any engine problems of note. Parts availability is less than stellar but that should improve with an expanding fleet and a new distribution agreement with Haas.
As far as the value proposition vs GT2, it is less expensive as intended. Not having to develop a car saves a considerable amount of money. A full season campaign will cost between 1.0mm and 1.5mm depending on the usual variables. Some GT2 teams are spending over twice that per car. A Daytona Prototype effort will cost about $2mm....and they are an inferior chassis with typically better engines. We may see some migration to a more economical LMP2 class over the next few years with tighter control over the chassis package and more liberty on engine manufacturers....or so I hear from the European guys.
As far as the value proposition vs GT2, it is less expensive as intended. Not having to develop a car saves a considerable amount of money. A full season campaign will cost between 1.0mm and 1.5mm depending on the usual variables. Some GT2 teams are spending over twice that per car. A Daytona Prototype effort will cost about $2mm....and they are an inferior chassis with typically better engines. We may see some migration to a more economical LMP2 class over the next few years with tighter control over the chassis package and more liberty on engine manufacturers....or so I hear from the European guys.
10-11-2010, 03:16 AM
#14
Platinum Dealership
Rennlist
Site Sponsor
Rennlist
Site Sponsor
well not that 1 or 1.5 is cheap but yeah compared to an RSR at 2-4million for each flying lizard car that's not bad...sebring is a torture chamber for any car (but a really fun track), I can't imagine turn 17 in something with real downforce fighting all those bumps...
