cor123

IMSA Releases Sebring BoP
By John Dagys
IMSA has released Balance of Performance adjustments ahead of next month’s Mobil 1 Twelve Hours of Sebring, featuring changes primarily in the production-based GT Le Mans and GT Daytona categories.

The Prototype class remains unchanged from January’s season-opening Rolex 24 at Daytona, except for all cars adopting high-downforce aero packages, which for DPs includes the addition of the rear diffuser.

Additionally, the Dinan-BMW-powered Riley has received a 3 liter reduction in fuel capacity compared to what it ran at Daytona last month.

GTLM sees incremental changes in weight, air restrictor, gurney and fuel capacity for the majority of the competitors.

The Aston Martin Vantage GTE has been given a 15 kg minimum weight increase while the BMW Z4 GTE will be allowed to shed 10 kg compared to its configuration run at Daytona.

Both cars, along with the Rolex 24 class-winning Corvette C7.R will have a 15 mm increase in gurney height, while the Corvette has been given a 0.3 mm reduction in air restrictor, which will translate to a slight loss of power.

Both the Ferrari F458 Italia and Porsche 911 RSR, meanwhile, have fuel capacity adjustments, with the Porsche losing 4 liters and the Ferrari down 1 liter.

In addition to its wright increase, the Aston Martin must revet to its standard downforce package. It was the only GTE car permitted to run its Le Mans aero kit at Daytona.

There are adjustments across the board for all six manufacturers in GTD.

The biggest change comes from the Daytona class-winning Dodge Viper GT3-R, which has a 40 kg weight increase, 200 rpm reduction, 0.5 mm increase in ride height and minor adjustments to the gurney and fuel capacity.

The BMW Z4 GT3 has also gained 40 kg and sees a significant 19 mm reduction in (single) air restrictor, while the Aston Martin V12 Vantage GT3 and Audi R8 LMS both have a 20 kg weight increase.

The Ferrari 458 Italia GT3, meanwhile, gains 35 kg and has a 250 rpm reduction, with a 4 liter reduction in fuel capacity as well.

The Porsche 911 GT America is the car that’s remained relatively unchanged, aside for a 5 mm increase in gurney.

In a first for IMSA, the BoP adjustments were announced nearly a month ahead of the next race, which is scheduled for March 21 at Sebring. Per the regulations, IMSA has until seven days prior to the start of official on-track activity to announce changes.

http://sportscar365.com/imsa/tusc/im...s-sebring-bop/

BWF07

BoP's can't live with them and can't live without them. It is an evil of the series. The problem is sometimes they appear to be politically motivated

hklvette

True. I think the good news here is that there's nothing earth-shattering in this group of adjustments, which suggests that the BoP isn't too slanted towards any chassis.

z060ntrack

Daytona isn't really a road course, and the competition was pretty even. IMSA should have waited until after Sebring which is a great equalizer in and unto itself, to make any BOP's.

raff

IMSA TECHNICAL BULLETIN #15-07

Here's a copy of the BoP in "table from"
http://www.imsa.com/sites/default/fi...s/IMSA-TEC.PDF

JohnAlley

Makes more sense to make the rules much like NASA and have a horsepower to weight ratio classification. Let the builders do what they want so long as you stay in you HP/Wt class.

BWF07

I agree 100%. I am not a fan of the Daytona race as I have always felt that when you spend more lap time on the high banks the the road course, it is pushing it to call it a great sports car race. Of course this in my opinion only. I know there are many out there that don't feel that way.

BWF07

I think deep down we all know that there is a lot of politics involved in the TUDOR series. After all, the GTLM rules state that the max displacement is 5500 liters. So how did an 8 liter engine get in the class last year? also where can you buy a Z4 BMW with a V8 and wishbone front suspension.

I would love to see the weight to HP ratio used, but the only problem there is it would not meet the FIA ACO guidelines for earning an invite to Le Mans.

z060ntrack

BWF07, I've been saying that about the Z4 ever since it's been in the series.

hklvette

I fail to see the problem

Anyway, ditto on the Z4. It would be neat if BMW would offer a V8 powered one from the factory though. Also, the upcoming Ford GT may be a political play as well, since it may be racing before it even enters production.

BWF07

It seems there is as much politics in IMSA as the is in Washington DC. You know as well as I and everyone else, that the GT will be a purpose built race car and they will meet the minimum cars produced to meet the regulations and not lose the homologation. What I find ridiculous in the rules (and this is just one example) is that for a manufacturer to qualify to produce a car for homologation, if they are a large manufacturer, which Ford would be, they only need to produce 1 car a week. That's right one car a week. It will be interesting to see just how mant GT's Ford rolls off the line each week.

blkbrd69

How many more cars can fit on the Pirelli World Challenge grid?

Painrace

Same old IMSA bull ****. They need a guy like John Bishop back running it. BoP is very unfair. How can they ever get it right???

Jim

raff

They already do - the Z4 GT3 - all it takes is $$$$

http://www.bmw-motorsport.com/en/cars/bmw-z4-gt3.html

raff

John did exactly what the BoP is attempting to do ---
attract the largest number of factory-backed teams while keeping the playing field level as competitors exploit the rules.

Painrace

I guess he just let us cheat more!

Jim

raff

Or until Mark, Gordon, etc caught on.

Painrace

LOL !

Jim

PSU_Vette

I could have sworn I read an article earlier in the year from IMSA (may have been Sportscar 265) stating that there would be no BoP changes until AFTER Sebring, due to the fact that Daytona is like no other track on the series. Porsche must've dipped into their funds after seeing the Corvettes and Z4s take the top-4 spots...

cor123

You are right in that the Rolex should not affect the rest of the season's BoP. IMSA had already planned to announce a BoP before Sebring. However, since they added weight to Corvette it makes me feel that the Rolex did count, when it shouldn't.