USCC (leave your axe outside)

[joeb]

Originally Posted by carbon_titanium

strange they are using the HPD powered one. Maybe have been built only 3 ligier so far so the only one available for oak was that.

I was wondering how many of the new chassis they have available. Obviously at least the three that ran at Le Mans, G-Drive is switching to the Ligier for Cota as well, so 2 chassis will be in Texas. Does TDS have the only other chassis then, or has Oak retained one as well? If Krohn is able to buy one, will it be a new build or one of the 3 known chassis?

[Danathar]

Originally Posted by TF110

Oak to switch to the Ligier with hpd power from Austin, according to autosport.

Honestly, it will be VERY interesting to see how it does vs the DP cars on the straights.

[carbon_titanium]

Originally Posted by joeb

I was wondering how many of the new chassis they have available. Obviously at least the three that ran at Le Mans, G-Drive is switching to the Ligier for Cota as well, so 2 chassis will be in Texas. Does TDS have the only other chassis then, or has Oak retained one as well? If Krohn is able to buy one, will it be a new build or one of the 3 known chassis?

I think that is just as we suppose... one nissan chassis is TDS, the other one is involved in WEC. Oak had no choice to use the HPD ligier, anyway they had 3 months to change the engine...

[MoMedic9019]

Originally Posted by Danathar

Honestly, it will be VERY interesting to see how it does vs the DP cars on the straights.

About as well as the HPD chassis from ESM. Hopefully OAK will be able to get a setup nailed quickly and actually have a shot..

[CyberMotor]

How much extra room for horsepower is left in the HPD, if they were allowed to exploit it?

[Danathar]

Originally Posted by MoMedic9019

About as well as the HPD chassis from ESM. Hopefully OAK will be able to get a setup nailed quickly and actually have a shot..

Aero should be a bit better than the old HPD chassis. Might result in better straight line speed once it gets up and running.

[Purist]

Someone posted Le Mans trap speeds a little while back, and there was no appreciable difference between the Ligiers and the open-top cars.

[Danathar]

Originally Posted by Purist

Someone posted Le Mans trap speeds a little while back, and there was no appreciable difference between the Ligiers and the open-top cars.

That's interesting considering that there is less drag on an open top car vs closed.

[Christian Mogami]

Originally Posted by CyberMotor

How much extra room for horsepower is left in the HPD, if they were allowed to exploit it?

No room.

In a short sprint race(90 min) they could get more but not in a Endurance race(6hrs or more).

The HR28tt is design limited because of it's production based Heads and Block.

Heads=SOHC
Block=98mm bore centers(small bearings that can't handle more boost)

[Purist]

Don't know what to tell you, Danathar, as I would normally expect a bit more top-end from a coupe as opposed to a spyder. From what I recall of the table, the fastest P2 on top-end was one of the Zyteks, I think.

[Ginaro Zukovsky]

Originally Posted by Purist

Don't know what to tell you, Danathar, as I would normally expect a bit more top-end from a coupe as opposed to a spyder. From what I recall of the table, the fastest P2 on top-end was one of the Zyteks, I think.

http://fiawec.alkamelsystems.com/Res...Speed_Race.PDF
http://elms.alkamelsystems.com/Resul...Speed_Race.PDF
etc

[joeb]

Originally Posted by Danathar

That's interesting considering that there is less drag on an open top car vs closed.

Originally Posted by Purist

Don't know what to tell you, Danathar, as I would normally expect a bit more top-end from a coupe as opposed to a spyder. From what I recall of the table, the fastest P2 on top-end was one of the Zyteks, I think.

There is a list of qualifying trap speeds and sector times here:
http://nasportscar.com/bens-analysis...ns-qualifying/

Maybe the Ligier has some more potential speed in the setup that has yet to be found vs the other P2's which have years and years of data.

[Purist]

I mis-remembered, apparently. So, it was the Oreca-Judd that went a couple miles per hour quicker than the rest.

I will say that, apart from the Lotus T128 LMP2, none of these new-spec P2 coupes look especially slippery compared to earlier, enclosed LMPs.

[carbon_titanium]

Originally Posted by Purist

I mis-remembered, apparently. So, it was the Oreca-Judd that went a couple miles per hour quicker than the rest.

I will say that, apart from the Lotus T128 LMP2, none of these new-spec P2 coupes look especially slippery compared to earlier, enclosed LMPs.

Juding by the top speeds and shamefull laptimes, I guess that T128 simply had not any downforce... I guess that the extra downforce produced by the new lmp2 coupè is counter balanced by the extra drag.

[carbsmith]

Closed top LMPs have never had inherently less drag. They have a lower Cd but higher frontal area because of the minimum size of the roof. They can be a little more efficient because of smoother air flow around the cockpit area but that's also a tradeoff against the amount of exposure the rear wing gets and a higher center of mass.

The reasons people are building closed top cars these days are 1) they're mandatory in P1, 2) they quite likely may become mandatory in P2, 3) they look cool, and 4) they're perceived safer by many customers besides the governing body. They were probably more optimal for diesels and hybrids anyways because those cars had to be bulky regardless.

[Deleted]

Originally Posted by carbsmith

The reasons people are building closed top cars these days are 1) they're mandatory in P1, 2) they quite likely may become mandatory in P2, 3) they look cool, and 4) they're perceived safer by many customers besides the governing body. They were probably more optimal for diesels and hybrids anyways because those cars had to be bulky regardless.

5) Pitstop rules have been adjusted so that there is no time advantage in running open top anymore

Also coupes WILL become mandatory in P2 with the new rules, already confirmed.

[Purist]

I'd imagine hitting the blunt front of those roll-over structures on the open cars stirs up the air quite a bit. So, I'm not sure that a coupe is particularly worse for getting undisturbed airflow to the rear wing.

[TF110]

Theres reason Audi went coupe on the R18, Toyota went coupe on the TS030, Peugeot on the 908 etc. Iirc, the big benefits of the open cars was no need for air-con and driver change.

[Jack Spratt]

Originally Posted by carbsmith

Closed top LMPs have never had inherently less drag. They have a lower Cd but higher frontal area because of the minimum size of the roof. They can be a little more efficient because of smoother air flow around the cockpit area but that's also a tradeoff against the amount of exposure the rear wing gets and a higher center of mass.

The reasons people are building closed top cars these days are 1) they're mandatory in P1, 2) they quite likely may become mandatory in P2, 3) they look cool, and 4) they're perceived safer by many customers besides the governing body. They were probably more optimal for diesels and hybrids anyways because those cars had to be bulky regardless.

Excellent post, most unusual these days and very refreshing.

As has already been pointed out, a coupe will be mandatory in the near future. The part in bold would actually have been the major driving force to go to a coupe had that not been the case. There are several drivers in TUSC alone that would be participants in P2 now had coupes been readily available, (the once temporarily semi defunct Lola not withstanding).

Originally Posted by CyberMotor

How much extra room for horsepower is left in the HPD, if they were allowed to exploit it?

The same engine in 3.5 liter form (DP) makes considerably more horsepower.

[CyberMotor]

Originally Posted by Jack Spratt

The same engine in 3.5 liter form (DP) makes considerably more horsepower.

In cubic inches and metric volumes, what are the differences in sizes? I don't think the engine sizes are equal.

[Jack Spratt]

Originally Posted by CyberMotor

In cubic inches and metric volumes, what are the differences in sizes? I don't think the engine sizes are equal.

2.8 for the P2 vs 3.5 for the DP. Same base engine though, (originally a 3.5), it has the mechanical potential to be able to apply more power to it but physics rears it's ugly head with the smaller displacement.

[Coach Ep]

New rules for drivers on (not) existing their cars after an incident:
http://www.racer.com/imsa/item/10760...driver-conduct

Not sure how to interpret this part:

the Driver should take the following steps as a Full Course Yellow is declared:

Somehow I read this as: "No more hope to have anything done under local yellows".

[Deleted]

Something was done under local yellows before?

[joeb]

Well, Riley has now thrown their hat in the ring with Coyote for building 2017 protos. Interesting quote from Mr Riley says that they are building the car but it is up to Elkins (he didn't mention anybody else by name for some reason?) to decide what the rules will be regarding manufacturer specific body kits.

I feel like a broken record, but if there was little interest in body kits for DP's why do they think it will be different with 2017 Protos? Fans are fine looking at lmp style bodywork, doesn't need manufacturer cues....although the Aston Lola's did look pretty good.

[Deleted]

Well even the ACO mentioned those NA-specific/LM-illegal bodyworks so I'd say they are coming... and since GM appears to be bothering (to consider) to upgrade the current "C6 Corvette" DP bodyworks to "C7 Corvettes" for next year, I'd say they are one of the forces driving for it. And it's not like Grand-Am and people involved in it ever really listened to what fans wanted...

Anyway interesting bit about the P3

Riley said he would like to see LMP3 find a home in North American racing, preferably in a development series such as IMSA Prototype Lites, before being considered for the TUDOR Championship as a replacement to Prototype Challenge in 2017.

Not sure how many Lites team would like to invest in such product but that would be a good first stepping stone.