ALMS Prototype Spec. Adjustments
IMSA’s bulletin released this week not only covered the Aston Martin DBR9 and Konrad Motorsport Saleen S7R (here), it also included adjustments to four of the prototypes – the Lola EX257 / B01/60, the Audi R8, the Courage C65 Mazda and any LMP2 Lolas fitted with 2000cc turbocharged engines (effectively the AER inline four).

Regarding weight changes, the Lola B01/60 has its minimum weight raised to 700 kg (from 675), the Audi R8 to 935 kg (from 900) and the Courage Mazda runs at 750 kg.

However, things are not as simple as that one sentence suggests – and that sentence gives a very misleading impression.

IMSA’s Chief Operating Officer, Tim Mayer, helps clear up any potential confusion.

“All of the cars on the grid went up by 25kg (this year),” explains Tim Mayer (the ACO’s increase to accommodate air conditioning for closed cars in 2007, but applied to all cars). “So we simply followed that logic - if we didn't raise the base weight up (for the older cars) they would gain an advantage. However, the truth of the matter is that the B01/60s normally weigh in at a little bit over 700kg, so in reality it does not affect them.”

So effectively no weight increase for the Autocon and Highcroft Lolas.

But these cars do benefit from a slightly larger restrictor this year.

”The restrictor that we gave them is 1mm larger than the restrictor that they ran last year, so this frees up the engine a little bit. There are a number of technical reasons that we did that, but the best way to sum it up is that they are not operating using the same configuration as when they were run by Dyson. So the additional restrictor is there to bring them back closer to where they were last year.”

So that’s straightforward enough. Autocon’s Michael Lewis adds a little more information.

“The official fuel this year is bit lower octane and the turbos will (could) detonate, so they gave us more restrictor so we could back down into a safer area of curve. IMSA has worked with AER on this problem.”

So all perfectly clear so far – and the net result should be, in effect, no change from last year.

IMSA “will be reviewing their situation,” adds Tim Mayer. “We do not intend to let the band of performance in the class to become too wide.”

Regarding the weight increase (35 kg) for the Audi R8, Mayer explains that “as well as the 25kg that was imposed for all cars, (which would have taken them to 925kg) we wanted to keep the weight increase proportional to the increase for the cars built to the 675 weight class. Thus proportionately the weight added to the Audi is the same as that added to all of the other cars.”

Again, simple enough – and very clear. We’ll only see the Audi R8s race thrice in 2006 anyway.

Almost the final change relates to the cars running the AER 2 litre, turbocharged four cylinder engine. The single restrictor for these engines is increased in size from 43mm to 45 mm.

Tim Mayer again: “We have a reasonable amount of data now from the RS Spyder and from the 2000cc AER powered cars. In reviewing the data, the restrictor change appears necessary to keep the band of performance for the class within our guidelines.”

So Intersport, Miracle and van der Steur Racing (plus Barazi-Epsilon at Sebring) receive a slight performance increase – as they set out to tackle the Porsche RS Spyders.

The restrictor for the Mazda rotary in the B-K Courage has also been increased, but “the particulars of the numbers we chose are too complicated for me to get into here, but our procedure here is consistent with our bulletins that were issued in December,” adds Tim Mayer.

”I think in conclusion, we don't feel that we have disadvantaged any car in any way with this bulletin, we have just provided the teams with ammunition to provide our fans with great and exciting racing.”

All clear? Here's the field about to be unleashed at Sebring almost a year ago. Not long to wait now...

 

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