IMSA DPi Discussion

[Akrapovic]

The LMP1 Private Teams category is reserved
exclusively for independent private teams.
A team that is independent of a manufacturer means a team
that does not benefit from any support from a manufacturer
other than for the single supply of engines, services relating
to these engines or commercial support. Any support from a
manufacturer relating to the chassis or to chassis systems is
prohibited. It is understood that traction control is considered
as a chassis system.

http://www.fia.com/file/51748/downlo...token=Ype7CQDQ

Engines are fine. Anything else is not. You'd need to prove that you're getting absolutely no support which might be a bit tricky for those running Caddys. Mazda is certainly no, since there's only one team and it's the works entry.

Even then, do we really want to see watered down DPis at Le Mans? Why not an invitational class where they can properly go for it?

[wdave0]

Originally Posted by Akrapovic

http://www.fia.com/file/51748/downlo...token=Ype7CQDQ

Engines are fine. Anything else is not. You'd need to prove that you're getting absolutely no support which might be a bit tricky for those running Caddys. Mazda is certainly no, since there's only one team and it's the works entry.

Even then, do we really want to see watered down DPis at Le Mans? Why not an invitational class where they can properly go for it?

Why couldn't a privateer team buy outright a Caddy or Mazda DPi (they'd have to be willing to sell) - wouldn't that be eligible?

There has been a long tradition of imsa classes at LeMans - wasn't the Bently GTP?

[Akrapovic]

Originally Posted by wdave0

Why couldn't a privateer team buy outright a Caddy or Mazda DPi (they'd have to be willing to sell) - wouldn't that be eligible?

There has been a long tradition of imsa classes at LeMans - wasn't the Bently GTP?

You could buy a DPi and run it, but as you say, you'd need to make sure you'd get one, and you'd need to prove you're not manufacturer supported.

Bentley was a LMGTP entry, but it wasn't the traditional IMSA Class at the time, as the IMSA class folded in the 90s. But look at 1994, they even had a class called IMSA.

But that's also a good example of the politics involved. The IMSA class hasn't returned since the 90s. Le Mans was really struggling in the 90s, and the ACO allowed Rattel and IMSA to give them a hand with the grid numbers. The ACO do seem to have a rather short memory and forget who bailed them out in the 90s. So are we more likely to see DPis at Le Mans, or more of the ACO regulated cars that are getting turned away from an oversubscribed grid?

[mariantic]

Originally Posted by Akrapovic

You could buy a DPi and run it, but as you say, you'd need to make sure you'd get one, and you'd need to prove you're not manufacturer supported.

So ESM could do it? No Nissan factory support there...

Hey, they just might

Mariantic

[Akrapovic]

ESM (or any future Nissan DPi) would certainly have the easiest job. Caddys possibly too. Mazda has ruled itself out as it doesn't appear it wants to sell the car to customers, making it a proper works effort.

[Mike E]

Originally Posted by Akrapovic

ESM (or any future Nissan DPi) would certainly have the easiest job. Caddys possibly too. Mazda has ruled itself out as it doesn't appear it wants to sell the car to customers, making it a proper works effort.

Doesn't want to sell it yet...
http://sportscar365.com/imsa/iwsc/ma...r-dpi-program/

[Maelochs]

I see no reason why any IMSA team would want to run in P1-L (or P1-P or whatever they call the slow joke of the P1 field this season) because it would be a huge expense for really no reward.

I expect that IMSA is trying to get ACO replace or augment P1-slow with DPi just to sweeten the potential pot for potential DPi teams—if DPi has representation in WEC, it gains tremendously legitimacy and also, longevity

Not that I would expect a lot of IMSA teams to make the crossing and pick up the gauntlet—they’d still be running for second-best. However, if Porsche and Toyota should ever question the enormous cost of P1-H .... there would be a host of teams willing to buy a souped-up P2 chassis and suck up to a factory for DPi status.

I am pretty sure IMSA and ACO are looking several years ahead—and I am sure there are factions in both camps plotting to see their own preferences put into place.

[Starfish Primer]

I thought that Visit Florida took the LMP2 because they wanted to race Le Mans. Racing a Mazda everyday and then switching to a new bodywork and powerplant just for Le Mans seems quite risky to me.

[Matt]

Insinuating teams only own one car?

Easy to have at least two chassis, with one as a Mazda for IMSA, and the rest the normal Riley for ACO competition.

[FormulaFox]

Originally Posted by Matt

Insinuating teams only own one car?

It's pretty common in sportscar racing for a team to only have one car per entry. GA rules for many years even forbade having an extra car for a given entry.

[MoMedic9019]

Originally Posted by FormulaFox

It's pretty common in sportscar racing for a team to only have one car per entry. GA rules for many years even forbade having an extra car for a given entry.

So long as it passes tech, and in a timeframe when tech can be completed, it doesn't matter if you bring 10 cars with you. Is it common to only have one yes, but nothing forbids you from having multiple, or bringing additional rollers to a race.

Three teams I worked for always had spares with them.

[carbsmith]

As it stands you would never take a full season IMSA prototype class chassis to Le Mans because there's an IMSA race between the test day and the race.

[truebeliever]

Originally Posted by Akrapovic

ESM (or any future Nissan DPi) would certainly have the easiest job. Caddys possibly too. Mazda has ruled itself out as it doesn't appear it wants to sell the car to customers, making it a proper works effort.

Rather......"who would want to buy one anyway!" based on Speedsource's efforts to date. I somehow doubt it is gong to be the dark horse of the 2017 field who sweeps all before themselves.

As for taking in to Le Mans, yeah right!

[AoB Special Stage]

The BOOST on the Mazda is insane. Look at those ratios.

[TF110]

Originally Posted by AoB Special Stage

The BOOST on the Mazda is insane. Look at those ratios.

It needs it. The engine is small and a single turbo, the Nissan is twin.

[Damian Baldi]

This is the BoP document with details. I like that IMSA let fuel capacit and weight at standard WEC values.


http://files.constantcontact.com/db5...98d3ece430.pdf

[canaglia]

interesting, nissan gt-r gt3 engine placed in the ESM ligier has no restrictors but less pressure boost than usual (nissan gt-r gt3 has 2x38 or 2x40 with a boost about 2.0 for the whole rpm range).
Anyway, why are still used air restrictors for NA engines when should be enough set a ECU revlimiter when target-power is achieved...

[MoMedic9019]

Originally Posted by Damian Baldi

This is the BoP document with details. I like that IMSA let fuel capacit and weight at standard WEC values.


http://files.constantcontact.com/db5...98d3ece430.pdf

Makes balancing easier at a starting point. For example, if the Mazda ends up being able to go 10 laps longer than a ACO P2, they can take 5 liters out, or add 25kg or whatever. Everyone knows what they get coming in, no questions.

[Damian Baldi]

Originally Posted by canaglia

interesting, nissan gt-r gt3 engine placed in the ESM ligier has no restrictors but less pressure boost than usual (nissan gt-r gt3 has 2x38 or 2x40 with a boost about 2.0 for the whole rpm range).
Anyway, why are still used air restrictors for NA engines when should be enough set a ECU revlimiter when target-power is achieved...

It is because of the air management vs torque. It's not the same using a restrictor on big NA engine, than in a small turbo engine. The small turbo engines suffer of lack of torque while the NA not. That's why it is better to put a limit on the boost pressure, but not restricting the air intake. More air restriction, less RPMs, that's why they prefer to use low RPMs and a flat torque curve.

Bruce Wood from Cosworth explain it here

http://archive.dailysportscar.com/su...cosworthxh.htm

[canaglia]

Originally Posted by Damian Baldi

It is because of the air management vs torque. It's not the same using a restrictor on big NA engine, than in a small turbo engine. The small turbo engines suffer of lack of torque while the NA not. That's why it is better to put a limit on the boost pressure, but not restricting the air intake. More air restriction, less RPMs, that's why they prefer to use low RPMs and a flat torque curve.

Bruce Wood from Cosworth explain it here

http://archive.dailysportscar.com/su...cosworthxh.htm

I know this, but it's a turbo engine matter, I was talking about NA motors.
At example if the GM 6.2 V8 releases an amout of torque that let the engine push 600hp at 7000rpm (at example). Why don't just set an ECU revlimiter that prevent the engine revving higher than that, instead of still using air restrictors?

[MoMedic9019]

Originally Posted by canaglia

I know this, but it's a turbo engine matter, I was talking about NA motors.
At example if the GM 6.2 V8 releases an amout of torque that let the engine push 600hp at 7000rpm (at example). Why don't just set an ECU revlimiter that prevent the engine revving higher than that, instead of still using air restrictors?

Because you can tune around rev-limits... Gear changes are far more expensive than a set of restrictors.

[Damian Baldi]

Originally Posted by canaglia

I know this, but it's a turbo engine matter, I was talking about NA motors.
At example if the GM 6.2 V8 releases an amout of torque that let the engine push 600hp at 7000rpm (at example). Why don't just set an ECU revlimiter that prevent the engine revving higher than that, instead of still using air restrictors?

I think it is because they could get more power at the same RPM because they would have more air for the combustion. I think the IMSA's idea is to be able to change the BoP without the need to alter the mechanic of the engine.

[canaglia]

Originally Posted by Damian Baldi

I think it is because they could get more power at the same RPM because they would have more air for the combustion. I think the IMSA's idea is to be able to change the BoP without the need to alter the mechanic of the engine.

what about some kind of sensor that check in real time the torque released at wheels?
should prevent teams from cheating

[canaglia]

BTW, GM and amg gt3 engines share same displacements and layout...
amg gt3 got 2x36, cadillac dp got 2x31.9.... gt3 power output should be in a 520-540 range. Well, knowing that GM 6.2 is a road derivated engine and not a bespoke one like the new zytek/gibson, how could get close to 600hp with those restrictors?

[Maelochs]

Originally Posted by truebeliever

Rather......"who would want to buy one anyway!" based on Speedsource's efforts to date. I somehow doubt it is gong to be the dark horse of the 2017 field who sweeps all before themselves.

A Sportscar 365 article (V) mentions that Mazda is planning to sell customer cars ... and if the engine proves durable, there is no reason why the BoP'd bodywork would make a difference ... the difference would be that no other DPi manufacturer might Want to sell a car, while Mazda does, explicitly.

As for the past performance of the SpeedSource Mazda ... some might be down to a team which had never run a prototype and hadn't even run a winning car since before the merger (when it won a CTSCC title with an R-8.) Part of it was due, no doubt, to a 2012 chassis racing 2016 chassis, and part down to an engine which never worked (too much heat from the diesel in a chassis which wasn't designed for it, too little time on the new MZR.)

Now Mazda has a single focus--making the MZR last. it was already fast and reasonably reliable, even in a dinosaur chassis, as it proved at Petit---Yeah, the car burned, but it burned while running third, 15 minutes from the finish. it ran fast for 9:45 ... all it lacked was torque out of the corners, and that last 15 minutes. If they had backed of the boost just a little in the last `15 minutes they might have finished on the podium.

In fact, my fuzzy memory seems to say that the Mazda could have had some really good finishes in 2016 sprint races except for some crew bungles.

If the MZR can last (and yes, that is a big "if") then the new Riley-Mazda is a true contender--BoP will make sure the basic package is on par.

Everyone is looking at the Mazda and thinking of Mazda's recent history (and for some, Dyson's previous effort with the same basic motor.) I am wondering if Mazda (which as far as I know didn't do anything much for Dyson (after all, Dyson is AER)) might get serious about making the new motor really run---the company has proved that it is willing to spend at least Some on the program.

If Mazda is willing to do the kind of engine development it had been doing through the past several years (building the diesel, constantly re-engineering it, then rebuilding/re-engineering the gasoline engine) considering there is nothing else to spend on (the chassis is homologated) then why can't a turbo 4-cylinder compete? Why not the Mazda 4-cylinder?

I cannot judge the new Mazda by the past several seasons of Results from Mazda. I have to judge it based on the results, but also the improvements, and the new situation.

I expect the series will continue to be the AXR-WTR show by and large---but I will not dismiss Mazda. They were close several times last year, they have some fast drivers, they have two cars (twice the data.)

Also, for a team (Spirit of Daytona/ Visit Florida) which already owns a Riley (and spares) a Riley-based Mazda makes a certain amount of sense.