The future of Corvette

[Fogelhund]

Was there any significant BoP changes to the Corvettes over last year? I had read elsewhere no, yet they were slower this year. 3:56.210 last year vs. 3:57.051 this year.

[Victor_RO]

Originally Posted by Fogelhund

Was there any significant BoP changes to the Corvettes over last year? I had read elsewhere no, yet they were slower this year. 3:56.210 last year vs. 3:57.051 this year.

Didn't they get a 10kg weight penalty or something? Otherwise, it was probably just a case of missing the setup window completely due to the random (at best) conditions.

[Fogelhund]

Their focus is likely on the C7 at this point as well.

[Simmi]

It was tough to see the Corvettes really not at the races. I'd buy into the 'focus on next year/old car' theories if they weren't slower than 2012. They didn't seem to have an answer.

[Mechanic Z]

My guess is the tires were the issue. Remember, the WEC teams got the new tires at Spa, which gave them about a month's head start on the Vettes, in terms of learning the new rubber. In addition, as Radio Le Mans pointed out, when the Corvettes did get the tires, on test day, they didn't get much development time with them, since it rained about every test session prior to Le Mans.

[JHamilton]

I think the tires might have been an issue but they were very short on top speed. I think the new Porsche and significant developments on the Aston caught them off guard. The Ferraris weren't as quick as I expected either.

[FstrthnU]

http://www.speedhunters.com/2013/06/...iving-le-mans/
Another great article on driving at Le Mans from Speedhunters, with a Tommy Milner interview

[kyoung]

Originally Posted by Fogelhund

Was there any significant BoP changes to the Corvettes over last year? I had read elsewhere no, yet they were slower this year. 3:56.210 last year vs. 3:57.051 this year.

It’s not what they took away from the Corvette, it’s what they gave to the Aston and Porsche. Aston should have been Bopped and everyone else left alone IMHO. I still think Manthey would have won the race, but the Corvette and Ferrari would have been on the same lap or at most one lap down from the Aston and Porky at the end of the race. Which would have made not only a more entertaining race to watch, but a fairly balanced race; again IMHO.

[Chris Draper]

Originally Posted by Fogelhund

Was there any significant BoP changes to the Corvettes over last year? I had read elsewhere no, yet they were slower this year. 3:56.210 last year vs. 3:57.051 this year.

I received a tip on why the Corvette's were down on speed at Le Mans compared to last year.

This person was at the race and talked to the CR drivers and engineers. Apparently this years engine is not making the power where it is required. The Corvettes were slower out of the corners than last year with the same restrictors, a better chassis, better aero and similar tires. GM Engine builders were the problem.

I have confirmed that the only difference in Corvette's LM24 BoP from 2012 vs 2013 was +15kg. No air restrictor changes. This makes us believe that what this person says is at least logical.

Yes the Aston's and the Porsches weights were lower but that is irrelevant when you are just comparing the Corvette's laptime 2012 vs 2013. The Vette's actually ran a 3:55 in qualifying in 2012. The best they could manage all week in 2013 was a 3:57 (late in the race by Garcia).

The tires were not holding them back 10 mph on the top end.

IF IT AINT BROKE DON'T FIX IT!!!!!!

[JHamilton]

Thanks Chris, that makes sense as I heard somewhere (can't remember where) that they identified the problem before the race but couldn't do anything about it. You would think it could be resolved with mapping, but evidently there is a new constraint. Direct injection will help a lot.

[Salamus]

Thank-you Chris! That is a logical reason for Corvette's struggles. A shame that it had to happen right before the biggest race of the year though.

[CyberMotor]

Originally Posted by FstrthnU

http://www.speedhunters.com/2013/06/...iving-le-mans/
Another great article on driving at Le Mans from Speedhunters, with a Tommy Milner interview

Great article. Thanks for the link!

[kyoung]

When Speed Channel interviewed Doug Fehan and was asked about the problem and he said he didn’t know I let out a big WTF. I know that there are variables that can change year to year to consider, but engine power shouldn’t be one of them, that’s just poor preparation. Maybe it’s time for a GM-Katech takeover.

I’m hoping for a couple things in the future, one is that the FIA-ACO will stop telling manufacturers how to build their cars and get rid of the displacement-restrictor rule like they did in P1 and change the BoP to fuel flow. Two, I would really like to see a direct injected LS7 based on the new gen small block in the C7r.

[kyoung]

Doug Fehan on Le Mans, Viper, etc...

http://www.racer.com/video-le-mans-1...rticle/299448/

http://www.racer.com/video-part-2-of...rticle/299629/

http://www.racer.com/video-le-mans-1...rticle/299935/

http://www.racer.com/video-corvettes...rticle/299992/

[dxk1]

Originally Posted by Chris Draper

This person was at the race and talked to the CR drivers and engineers. Apparently this years engine is not making the power where it is required. The Corvettes were slower out of the corners than last year with the same restrictors, a better chassis, better aero and similar tires. GM Engine builders were the problem.

And yet they have won two out of the 3 ALMS races so far this year. How and why is that? Did they have an engine specially made for Le Mans and just blow it?

DK

[Mt. Lynx]

Originally Posted by dxk1

And yet they have won two out of the 3 ALMS races so far this year. How and why is that? Did they have an engine specially made for Le Mans and just blow it?

DK

Logically, top end power would be the problem at LM. GTE cars rarely reach their top speed on other tracks.

[dxk1]

Originally Posted by Mt. Lynx

Logically, top end power would be the problem at LM. GTE cars rarely reach their top speed on other tracks.

Yes, but in post 2109, he also stated that the Corvettes were slower out of the corners. This would seem to imply that the vettes were bad both at the top end and at the low end. Thus, they should not have had the speed to win on either of the tracks they won at in the ALMS so far. Sebring requires both speed (two long straights) and acceleration (many low speed corners), which based on post 2109 they didn't have. It just makes me think that they had a special engine built for Le Mans and the builder blew it.

DK

Edit: Maybe a new engine would be a better description than a special engine.

[Chris Draper]

Interestingly more and more info is leaking out about this. Now I'm hearing that they may have been using Direct Injection secretly and it didn't go as planned. As many of you know this engine was originally designed with DI but per the regs they could not use it since the production C6 didn't have it. But next year they will, since the C7 does have DI.

Who knows if that is true or not. I would think that if it were true they would have been able to remove the DI or have brought some engines that didnt have it.

[ThatGuy]

Perhaps it has something to do with them running E10 instead of E85?

[dxk1]

Originally Posted by ThatGuy

Perhaps it has something to do with them running E10 instead of E85?

I thought about that too, but I thought they worked those issues out a few years back the first time they were faced with that problem. Anyway, it certainly is a good thought.

DK

[zanfo zanfagni]

Yeah me too was thinking about E10, but this year at le mans consumes were more or less the same of 2012 when the car was competitive, so i guess that the power set-up and the power output were virtually the same.
Does somebody know if the C7R will be powered by a new unit or the same current 5.5 V8?

[Chris Draper]

Originally Posted by zanfo zanfagni

Yeah me too was thinking about E10, but this year at le mans consumes were more or less the same of 2012 when the car was competitive, so i guess that the power set-up and the power output were virtually the same.
Does somebody know if the C7R will be powered by a new unit or the same current 5.5 V8?

Same engine, but with Direct Injection.

[JHamilton]

Originally Posted by Chris Draper

Interestingly more and more info is leaking out about this. Now I'm hearing that they may have been using Direct Injection secretly and it didn't go as planned. As many of you know this engine was originally designed with DI but per the regs they could not use it since the production C6 didn't have it. But next year they will, since the C7 does have DI.

Who knows if that is true or not. I would think that if it were true they would have been able to remove the DI or have brought some engines that didnt have it.

Interesting... I don't think you would be able to take it off, certainly not without changing the heads too. It's a lot of work, but this is P&M we're talking about. It wouldn't be too hard to fake though as the injectors are in roughly the same location and I'm sure look similar.

[TRspitfirefan]

Originally Posted by JHamilton

Interesting... I don't think you would be able to take it off, certainly not without changing the heads too. It's a lot of work, but this is P&M we're talking about. It wouldn't be too hard to fake though as the injectors are in roughly the same location and I'm sure look similar.

Direct cylinder injection requires a much higher fuel pressure than manifold port injection, so I bet that most of the fuel supply system is different as well.

[Articus]

Originally Posted by Chris Draper

Interestingly more and more info is leaking out about this. Now I'm hearing that they may have been using Direct Injection secretly and it didn't go as planned. As many of you know this engine was originally designed with DI but per the regs they could not use it since the production C6 didn't have it. But next year they will, since the C7 does have DI.

lol if this is true haha. Are they trying to copy the Porsche team with there engine liners and hoping to get of with a "reprimand." How woudn't the ACO notice this kind of change. In the Data logging equipment.