Acura/HPD's future plans

[Joe Taylor]

IES publicly stated that their engine had 490hp last year and the Nissan is reckoned to be around 500, so the HPD is closer, but still not quite there.

[the real Stig]

From AutoSport:

HPD's rivals, Nissan and Judd, urged against hasty changes.
John Judd Jr, whose company has developed a BMW engine for LMP2, said: "We don't think there is anything wrong with the equivalence. Perhaps the HPD is not a good base engine."

[skycafe]

I am not an engine person, perhaps knighty can add to or further clarify, but I would think HPD, Judd, IES, etc. can look at an engine configuration and available rules for modifications and come up with an idea within 5% or less of what the starting point would be in output at the start of development, and also know that they can develop up to about 1-2% of peak within a short period.

It would be difficult to believe that HPD could be too wrong, isn't it? But, on the other hand it does seem that may be the case. Right now there isn't much need for the Level 5 cars to not sandbag, but I can not believe RML or Strakka would have sand bagged too much at Paul Richard.

[AGD]

I'll repost something gwyllion posted a few weeks ago:

Originally Posted by gwyllion

In LMP2 not cost capped the air restrictor size and maximum boost pressure are:

• 3600 cc NA: 2 x 28.9 mm (e.g., Judd/BMW V8)
• 4500 cc NA: 2 x 27.6 mm (e.g., Nissan V8)
• 2800 cc turbo: 2 x 27.6 mm, 1950 mbar boost (e.g., HPD V6)

In GTE the same engine configurations would get the following restrictor and boost:

• 3600 cc NA: 2 x 28.9 mm
• 4500 cc NA: 2 x 28.3 mm
• 2800 cc turbo: 2 x 27.7 mm, 2400 mbar boost

In LMP2 and GTE all engines are supposed to produce similar power levels. However, under the GTE rules the HPD engine would be allowed to run 450 mbar extra boost!

I'm not so sure if these rules make sense. It's not just an HPD problem as there are other engines available for use that are turbocharged (the Roush Ford EcoBoost V6 comes to mind and there may be another turbo Ford from another tuner).

If I remember correctly, HPD committed to the new LMP2 engine rules very early on. Maybe I'm wrong, but I think Nissan (at least the NISMO-Zytek version) and Judd came along later on. Perhaps HPD developed the engine thinking the rules would be different?

Anyway, one can't help but to think that the ACO tried to keep the HPD down for fears that it would kill the category. Maybe they went too far in doing so. I'm not sure if this adjustment will be enough to close the massive gap, but at least it is something.

[the real Stig]

Originally Posted by MulsanneMike

I'm told the HPD engine has about 410 at the wheels, thus about 455 at the flywheel. With a 5% bump that should give them about 470-480 now.

If this is simply a rules issue is there any evidence to suggest that this is so?

Did all the P2 cars pit at the same time? Or did the Acuras go further? If they did not it would suggest they are using the same fuel but not as effectively.

Any count on laps between pits / number of pits?

Not going fast enough does not necessarily indicate the restrictor is too small.

[Victor_RO]

Originally Posted by the real Stig

If this is simply a rules issue is there any evidence to suggest that this is so?

Did all the P2 cars pit at the same time? Or did the Acuras go further? If they did not it would suggest they are using the same fuel but not as effectively.

Any count on laps between pits / number of pits?

Not going fast enough does not necessarily indicate the restrictor is too small.

At Ricard Strakka went somewhat further into the race than the Nissan-powered cars, they were actually able to lead the race on fuel economy for a stint or so.

[MulsanneMike]

Plugging the 1.2 mm diameter increase into the ole spread sheet and the actual area gain is 8.8% (looking at non cost-capped twin restrictors) which puts the HPD motor at 495 hp.

[Le Vieux]

Originally Posted by the real Stig

From AutoSport:

HPD's rivals, Nissan and Judd, urged against hasty changes.
John Judd Jr, whose company has developed a BMW engine for LMP2, said: "We don't think there is anything wrong with the equivalence. Perhaps the HPD is not a good base engine."

As some body once said: "Well, he would say that, wouldn't he?"

[gwyllion]

Originally Posted by MulsanneMike

Plugging the 1.2 mm diameter increase into the ole spread sheet and the actual area gain is 8.8% (looking at non cost-capped twin restrictors) which puts the HPD motor at 495 hp.

There were reports (see here) that with the previous restrictor size, the turbos of HPD engine could only make 0.8 bar boost (instead of the maximum allowed 0.95 bar). Maybe with the increased restrictors, it turns out that the turbo boost is not enough to make competitive power.

Moreover, some has been claimed that the HPD engine only makes 420 bhp (see here), presumably at the flywheel. In that case the 9% restrictor area increase puts it at only 460 bhp!

[MulsanneMike]

Originally Posted by gwyllion

There were reports (see here) that with the previous restrictor size, the turbos of HPD engine could only make 0.8 bar boost (instead of the maximum allowed 0.95 bar). Maybe with the increased restrictors, it turns out that the turbo boost is not enough to make competitive power.

Moreover, some has been claimed that the HPD engine only makes 420 bhp (see here), presumably at the flywheel. In that case the 9% restrictor area increase puts it at only 460 bhp!

I hadn't gone back to calculate a projected hp for the Acura based on their trap speed at Paul Ricard. Doing so, and using 1.71 m^2 and .6 .cd nets...355 hp at the wheels, about 400 hp at the flywheel (I'm calculating for hp absorbed for the top speed)...that's shockingly low. But we know frontal area for all cars is within 5-10% of one another, therefore I can't be too far out there. And I'm assuming they've set the car up to achieve terminal velocity on the front straight. But even if it's gear and not drag limited, I'd have to think the gearing limitation would put it within 5% of top speed. But using 175 mph projected speed (105% of 167 mph), and keeping everything else constant (frontal area and hp), nets a .54 cd which seems a bit on the low side for an open top LMP. Thus...it would appear the 420 claims at the flywheel could possibly be very accurate.

Having said all that, I'm pretty confident of my source which pegs the HPD at 410 at the wheels and thus about 455 at the flywheel.

[cdsvg]

Originally Posted by MulsanneMike

I hadn't gone back to calculate a projected hp for the Acura based on their trap speed at Paul Ricard. Doing so, and using 1.71 m^2 and .6 .cd nets...355 hp at the wheels, about 400 hp at the flywheel (I'm calculating for hp absorbed for the top speed)...that's shockingly low. But we know frontal area for all cars is within 5-10% of one another, therefore I can't be too far out there. And I'm assuming they've set the car up to achieve terminal velocity on the front straight. But even if it's gear and not drag limited, I'd have to think the gearing limitation would put it within 5% of top speed. But using 175 mph projected speed (105% of 167 mph), and keeping everything else constant (frontal area and hp), nets a .54 cd which seems a bit on the low side for an open top LMP. Thus...it would appear the 420 claims at the flywheel could possibly be very accurate.

Having said all that, I'm pretty confident of my source which pegs the HPD at 410 at the wheels and thus about 455 at the flywheel.

Really interesting stuff. Please keep this kind of insight coming!

[MulsanneMike]

Originally Posted by cdsavage

Really interesting stuff. Please keep this kind of insight coming!

I've refined the numbers:

http://www.mulsannescorner.com/RMLARX-01d.PNG

Text:

Speed TV's John Dagys is reported from the ALMS round at Long Beach this weekend that the ACO has allowed a 1.2 mm increase in the inlet restrictor diameter for the HPD LMP2 engine. Going back to the 2011 regulations' restrictor chart for non-cost capped turbo charged LMP2 engines, and we note the inlet size is 27.6 mm if using twin restrictors. Thus the 1.2 mm now makes each of those inlets 28.8 mm, a 8.88% increase in inlet area. Now we have it on good authority that the HPD engine is making about 455 hp. A percentage change in inlet area relates 1:1 to changes in horse power, therefore the HPD motor should be seeing about 495 hp now.

But interestingly enough, when you analyse the Paul Ricard trap speeds for the RML HPD ARX-01d, power output seems suprisingly lower than the informed 455. For this calculation we have to estimate frontal area and drag coefficient with the result being horsepower absorbed for the given speed. At Paul Ricard the RML ARX-01d went through the traps at a 269.1 km/h average for its top 5 fastest speeds. So using 269.1 km/h as the target top speed, estimating frontal area at 1.71 m2, and drag coefficient at .6, gives us a power output of 352 hp at the wheels (or using their high top speed, 270.1 km/h, 358 hp). Assuming a 10% drivetrain loss, that's about 391 hp at the flywheel (398 hp on the high side). These numbers start to cozy up to the rumor that the HPD engine has closer to 420 than 455 hp.

Looking at it another way, we can reason that our frontal area estimate is within the ballpark. Admittedly we are guessing on the drag coefficient. But there's enough body of evidence to suggest that btween .6 and .65 for an open top car in a draggy configuration is reasonable. But one thing we're forgetting, using the ACO provided trap speeds we are assuming RML had set the car up to achieve drag-limited terminal velocity on the front straight. But suppose the speed RML saw at Ricard was gear and not drag limited, we'd have to think the gearing limitation would put our estimate case at least within 5% of the actual drag limited top speed. And by gear limited, we're meaning the car was over geared slightly to allow the ability to draft pass or what have you. So using a 282.5 km/h projected top speed (105% of 269.1 km/h), and keeping everything else constant (frontal area and .cd), the true drag limited top speed needs 407 hp at the wheels to achieve the 105% top speed. This put us at 452 hp at the flywheel. That's within .6% of our informed 455 hp output for the HPD engine.

Of course Homer Simpson famously said, "Oh, people can come up with statistics to prove anything, Kent (Brockman). 14% of people know that."

But we're hearing that the HPD engine won't necessarily be able to take advantage of the increase in inlet area. We understand that it's a case of matching the inlet size to the available boost, and the HPD engine was struggling to utilize full boost as it was.

[Slipknot]

Hi Folks

I have a question and some opinions on this topic.

Question:

This is mostly directed at MulsanneMike. Thanks for you website, it's a gift to his community. I noticed while a Sebring and see it clearly on the image you posted on 4/4/11 on your site of the ARX-01e. That little persimmon wedge at the conner of the headlight housing, what and why? Of course anyone free to answer.

Opinions:

I seem to be willing to give Honda/HPD more than the benefit of doubt as far as the LMP2 V6 Turbo goes.

1. We don't have the Roush engine to compare it to.

2. Honda is on of the largest producers of internal combustion engines in the world. The whole ideal of a V6 turbo racing is hardly a new idea for Honda.

3. I find it more than easy to believe the ACO got a formula to balance engines with different induction and/or fuel types wrong.

Thanks all.

[knighty]

Excellent theories mike, all sounds completley logical to me........one thing about this V6 honda engine that has been bugging me is the integral exhaust manifold which is cast into the cylinder head, whereby the turbo is bolted directly to the head, this is basically done for road car reasons whereby they need to heat up the catalyst and engine as quick as possible in order to reduce emissions, and in that respect it works well as many manufacturers are doing this now.......... but from a race exhaust manifold perspective this really kills the back pressure between the exhaust valve ports and the hot turbine as it really restricts high flow potential, the net result is you need to artificially run more boost, I have sen this happen on a few turbo race engines and it does two things 1) kills power 2) makes the engine run very hot..........I have a feeling HPD are soon going to realise that using this engine route was bad news for LMP2, they are probably better off going the normally aspirated route with an earlier level of this V6 that doesent have the silly single exhaust outlet on each head.........I'm sure someone could post a picture, but I'm in a hotel in sunny Korea at the mo

[gwyllion]

Marshall Pruett toke some pictures of the engine installation in the Level 5 Lola:
http://dlstatic.speedtv.com/imageser...9gzB/1000x.jpg
http://dlstatic.speedtv.com/imageser...n2so/1000x.jpg
The exhaust manifold and turbo are not clearly visible on those pictures.

The mockup engine which was shown at Le Mans last year, indeed had a stock exhaust manifold: http://www.mulsannescorner.com/Honda...P2Engine-1.jpg

[BRG]

If this restrictor break is for all hpd turbos does this mean the cost capped lola are now 495bhp (Mike's figures) + a further 5% as they are cost capped

[gwyllion]

Yes, the HPD engine should produce more power in the open Level 5 Lola.

Originally a cost capped turbo engine had 2 x 28.3 mm restrictors and non cost capped 2 x 27.6 mm.
With the recent rule change the restrictors have been increased to 2 x 29.5 mm and 2 x 28.8 mm respectively.

Using 420 bhp as base line (for the non cost capped engine with the original rules), you get 457 bhp for non cost capped and 480 bhp for cost capped (after rule change).
Using 455 bhp as base line, you get 495 bhp for non cost capped and 520 bhp for cost capped.

[BRG]

Originally Posted by gwyllion

Yes, the HPD engine should produce more power in the open Level 5 Lola.

Originally a cost capped turbo engine had 2 x 28.3 mm restrictors and non cost capped 2 x 27.6 mm.
With the recent rule change the restrictors have been increased to 2 x 29.5 mm and 2 x 28.8 mm respectively.

Using 420 bhp as base line (for the non cost capped engine with the original rules), you get 457 bhp for non cost capped and 480 bhp for cost capped (after rule change).
Using 455 bhp as base line, you get 495 bhp for non cost capped and 520 bhp for cost capped.

Does that now make it the most powerfull cost capped engine.
I've seen guesses that the Nissan engine is about 500bhp is that for cost capped or not

[gwyllion]

Originally Posted by BRG

I've seen guesses that the Nissan engine is about 500bhp is that for cost capped or not

The Oreca 03 chassis falls under the cost cap.

I just reaad the Level 5 report about Long Beach. This part of the report confuses me a lot:

It was announced this week that its two Honda-Powered Lola LMP2 entries would be allowed to use a larger restrictor plate -- and thus have more power -- giving the team confidence it could contend for an overall victory on the challenging streets of Long Beach. However, the changes allowed did not provide the power boost they were anticipating.

Why did they believe that they would be able to challenge for overall victory? LMP2 cars have less power and smaller tyres than LMP1 cars and the Lola coupe has to run with +20 kg of ballast.

[skycafe]

Originally Posted by knighty

Excellent theories mike, all sounds completley logical to me........one thing about this V6 honda engine that has been bugging me is the integral exhaust manifold which is cast into the cylinder head, whereby the turbo is bolted directly to the head, this is basically done for road car reasons whereby they need to heat up the catalyst and engine as quick as possible in order to reduce emissions, and in that respect it works well as many manufacturers are doing this now.......... but from a race exhaust manifold perspective this really kills the back pressure between the exhaust valve ports and the hot turbine as it really restricts high flow potential, the net result is you need to artificially run more boost, I have sen this happen on a few turbo race engines and it does two things 1) kills power 2) makes the engine run very hot..........I have a feeling HPD are soon going to realise that using this engine route was bad news for LMP2, they are probably better off going the normally aspirated route with an earlier level of this V6 that doesent have the silly single exhaust outlet on each head.........I'm sure someone could post a picture, but I'm in a hotel in sunny Korea at the mo

Awesome information! Would they not have known of these limitations/challenges going in? Was it an over-optimistic view to believe they could develop around this, but limitations because of the inability to change configurigurations presents a stumbling block----I still can not believe they were just wrong....but I guess the possibility to be wrong always exists.

robert

[JAG]

Originally Posted by gwyllion

The Oreca 03 chassis falls under the cost cap.

I just reaad the Level 5 report about Long Beach. This part of the report confuses me a lot:
Why did they believe that they would be able to challenge for overall victory? LMP2 cars have less power and smaller tyres than LMP1 cars and the Lola coupe has to run with +20 kg of ballast.

At Ricard the best P2's were two seconds off P1 pole so they could have had an outside chance on a street circuit.

[gwyllion]

In the past LMP2 cars had a chance because of their lower weight. However, now the LMP2 Lola coupe is 20 kg heavier than the Dyson Lola and the Lola Aston Martin.

[JAG]

They'd not be competitive on outright pace but a P2 should be in with a shot of picking up the pieces rather than worrying about LMPC's and GTE's.

[Thumper]

Great insight and assessment Mike - much appreciated. If it helps, I have it on reliable authority that the HPD figure was indeed closer to the 420 figure, while the Nissan was exceeding 500. The restrictor change will narrow that gap, but perhaps by only half.

Making detailed analysis more complex next weekend, however, will be the added issue of RML being permitted to deploy the HPD's lower-downforce aero package, homologated exclusively for Le Mans. Any narrowing of the performance gap will need to take this into account, and it's likely that this may have more of an effect on top speed than the restrictor break. We won't know for certain until the teams head to Spa, and relative comparisons with the Paul Ricard data can be drawn.

[AGD]

Originally Posted by gwyllion

This part of the report confuses me a lot:
Why did they believe that they would be able to challenge for overall victory? LMP2 cars have less power and smaller tyres than LMP1 cars and the Lola coupe has to run with +20 kg of ballast.

Odd, I'm not sure what the thought process was on that one. Perhaps they meant to say overall podium? That seemed to be an achievable goal prior to the weekend, but the first session made even that look questionable. Anyway, if Level 5 wanted to compete for overall wins, they brought the wrong HPD engine. They should have gone for the 3.4L V8 if that was their goal. That would have been the case even if the HPD V6 was up to speed.

John Dagys reported that Marino Franchitti tested the 2nd Level 5 Lola Coupe (the European based one) at Snetterton last week. I wonder if Level 5 has done a lot more testing in the coupe(s) than the cost capped B11/40 since the coupe was quite a bit faster at Long Beach and Tucker decided to choose the coupe as his points scoring entry. It seems to me that the cost-capped car would be the better way to go for Le Mans/ILMC, but maybe not?