IMSA DPi Discussion

[canaglia]

Because of lack of time, was easy to find out that a destroked 6.2L was the easiest route.
Anyway making some quick maths, 580hp@7000rpm, means something like 590Nm at that rev. No doubts that torque is still on their side.

[YZFrider]

Interesting article. By destroking it, it brings it within the performance target of the other motors. Shame, basically they are implying the others motors were held back and only now it’s in an even playing field. I suspect with a smaller displacement the new LT will have better fuel consumption in which case the BoP will have to be redone again

[FormulaFox]

Originally Posted by YZFrider

Interesting article. By destroking it, it brings it within the performance target of the other motors. Shame, basically they are implying the others motors were held back and only now it’s in an even playing field.

The performance target was always the Gibson engine. So yes, everything was being held back, even the Cadillac engine(they just didn't hold them back enough initially).

I suspect with a smaller displacement the new LT will have better fuel consumption in which case the BoP will have to be redone again

Thus, the entire point of seizing the engine during the previous test. To help get those adjustments done. Hopefully close to correctly on the first try this time.

[canaglia]

Cadillac teams should not be worried about that.
Last year they had 64L and basically had the same stint lenght of 75-76L fuel tank cars.

[TF110]

Originally Posted by canaglia

Cadillac teams should not be worried about that.
Last year they had 64L and basically had the same stint lenght of 75-76L fuel tank cars.

That was probably aided by the longer gearing too. That on top of the torque they have and the relatively low redline/rev limit.

[canaglia]

Originally Posted by TF110

That was probably aided by the longer gearing too. That on top of the torque they have and the relatively low redline/rev limit.

longer first and second speed means shorter remaning speeds, consumes should not have changed so much. Hearing engine noise in 2017 onboard videos, cadillac's were using sixth speed in long straight like road america, so it wasn't like audi in 2016 whit so long gears that sixth gear has been used only at le mans. Basically if the car upshifted to third at about 180-200km/h, between that speed and about 270-280km/h there were extra short 3rd, 4th and 5th in the middle.

[TF110]

Originally Posted by canaglia

longer first and second speed means shorter remaning speeds, consumes should not have changed so much. Hearing engine noise in 2017 onboard videos, cadillac's were using sixth speed in long straight like road america, so it wasn't like audi in 2016 whit so long gears that sixth gear has been used only at le mans. Basically if the car upshifted to third at about 180-200km/h, between that speed and about 270-280km/h there were extra short 3rd, 4th and 5th in the middle.

Longer gearing will aid in fuel consumption. The Taylor's were saying the gearing was so long that they were close to stalling in some low speed turns And of course they'll use 6th, because iirc, the series (IMSA) dictates at least some of the gear ratios, they'll run too slow with just going 5th.

[canaglia]

https://www.youtube.com/watch?v=P24OSlbRZ3E

onboard with engine sound of #10 cadillac dpi

after slow corner, to me seems that gear shifting was quite usual.... nothing that lets you think about really long ratios at least. For sure taylors were quick shifting in lowest gears.... infact, judging by sound, it seems that the longest ratio was in 3rd or 4th.


ligier lmp2 to compare:
https://www.youtube.com/watch?v=iclJPBv8JK4

[TF110]

Originally Posted by canaglia

https://www.youtube.com/watch?v=P24OSlbRZ3E

onboard with engine sound of #10 cadillac dpi

after slow corner, to me seems that gear shifting was quite usual.... nothing that lets you think about really long ratios at least. For sure taylors were quick shifting in lowest gears.... infact, judging by sound, it seems that the longest ratio was in 3rd or 4th.


ligier lmp2 to compare:
https://www.youtube.com/watch?v=iclJPBv8JK4

I don't know if Road America even uses 1st gear. Detroit I think was when they changed the extra long first gear for the WTR Caddy.

[kvenom]

Solid debut by the Acuras, niggling problems and some rash driving cost them, but its obvious they are going to win races this season.

Caddies gonna Caddy, although they had more troubles this year.

ESM must be shaking their heads, the car was very strong at the end of last season and had the pace in Daytona.

Mazda....Still caught fire, engine still sucks, even Joest caught a case of Speedsource-itis with the #55 losing a wheel. Car was fast, but I don’t think it will ever be reliable enough for the big races. Have race-winning potential for the rest of the season though.

[joeb]

Originally Posted by kvenom

Solid debut by the Acuras, niggling problems and some rash driving cost them, but its obvious they are going to win races this season.

Caddies gonna Caddy, although they had more troubles this year.

ESM must be shaking their heads, the car was very strong at the end of last season and had the pace in Daytona.

Mazda....Still caught fire, engine still sucks, even Joest caught a case of Speedsource-itis with the #55 losing a wheel. Car was fast, but I don’t think it will ever be reliable enough for the big races. Have race-winning potential for the rest of the season though.

I was thinking about the same as you. Mazda might be competitive in the short races, but still problems with the car and engine.

[Damian Baldi]

Originally Posted by kvenom

Solid debut by the Acuras, niggling problems and some rash driving cost them, but its obvious they are going to win races this season.

Caddies gonna Caddy, although they had more troubles this year.

ESM must be shaking their heads, the car was very strong at the end of last season and had the pace in Daytona.

Mazda....Still caught fire, engine still sucks, even Joest caught a case of Speedsource-itis with the #55 losing a wheel. Car was fast, but I don’t think it will ever be reliable enough for the big races. Have race-winning potential for the rest of the season though.

Yeah, I think that way too.

About Mazda, I think it's too late now. Joest should have tell Mazda to change the chassis and even the engine for this year. They should had have end in the same way (out of the race) but with more potential for the future. The chassis was faster this year, but it is still unreliable. Maybe the small 4l could run better in an Oreca or Dallara, but they should develop a v6 or a v8.

[FormulaFox]

Originally Posted by Damian Baldi

Yeah, I think that way too.

About Mazda, I think it's too late now. Joest should have tell Mazda to change the chassis and even the engine for this year. They should had have end in the same way (out of the race) but with more potential for the future. The chassis was faster this year, but it is still unreliable. Maybe the small 4l could run better in an Oreca or Dallara, but they should develop a v6 or a v8.

It's nowhere near too late.

Joest and Multimatic have been working on the chassis revamp for a little over half a year. It's going to take at least a full year to address the massive number of problems the car has.

There's no reason the engine can't be made reliable enough while being powerful enough, but that's not on Joest or Multimatic. They addressed the only detail they could when it came to the engine(cooling). The rest is up to AER and Mazda.

[Damian Baldi]

Yeah, but the rules avoid to change things through the year. So, my point was that it could be better if Jost have told Mazda to review the project. Obviously, it would be too late for this year, but now are are at the same point.

Current car will be good in short races anyway.

[broadrun96]

Originally Posted by Damian Baldi

Yeah, but the rules avoid to change things through the year. So, my point was that it could be better if Jost have told Mazda to review the project. Obviously, it would be too late for this year, but now are are at the same point.

Current car will be good in short races anyway.

How would it be too late for this year? IMSA has multiple times allowed updates to improve the reliability of engine or chassis and allowed Mazda a few last season I believe. It's not like they can't test any changes at any time, they have the time and tech.

[TF110]

Imo, the Riley Mazda won't win anything this year. The car is not reliable, and that's that. The engine needs to be on it's way out. You can't keep going on and on with something that has continually failed for nearly the past decade. It's long time Mazda put up something for a new one or they'll continue to look at the rear of the other dpi's and p2's. The car has improved it's pace, but it's not enough. Otoh, the Penske Oreca Acura will get better and better this season and seeing how it's already on pace I think it will be a title favorite. Sebring should be a very good race.

[kvenom]

Originally Posted by FormulaFox

It's nowhere near too late.


There's no reason the engine can't be made reliable enough while being powerful enough, but that's not on Joest or Multimatic. They addressed the only detail they could when it came to the engine(cooling). The rest is up to AER and Mazda.

Don't really think they've fully solved the cooling issues either considering the #55 caught on fire and the #77 burnt a hole through its bodywork.

[Mike E]

I just don't see how a four cylinder engine producing 300 bhp/litre would be your first choice as a credible endurance engine. That's almost 3 times the specific output of the Caddy, which will run all day and all night without skipping a beat.

[canaglia]

Originally Posted by Mike E

I just don't see how a four cylinder engine producing 300 bhp/litre would be your first choice as a credible endurance engine. That's almost 3 times the specific output of the Caddy, which will run all day and all night without skipping a beat.

Just 3 words: Porsche V4 2L

Even SGT 4I 2L would be great 24H endurance engines with the right tune and updates.

Truth is that AER-mazda is just garbage. Deal with that.

[kvenom]

Originally Posted by canaglia

Just 3 words: Porsche V4 2L

Even SGT 4I 2L would be great 24H endurance engines with the right tune and updates.

Truth is that AER-mazda is just garbage. Deal with that.

Tons of lifting and coasting/hybrid assist with that V4 to be fair though, better example would be those Eagle Toyotas.

[chernaudi]

And in those cases, Toyota and Porsche put tons of money and time into those engines. Mazda either seem to be doing the bare minimum or are putting too much hope into AER.

And you have to remember that Chris Dyson is on AER's board and is a co-owner of the company. Yes, Chris Dyson as in Dyson Racing, as in Rob's son, as in two guys who like to hot rod cars and engines, for better or worse. That's why they never seriously bought into buying Ferrari 333s or Audi R8s even when offered to them.

[hondafan37]

Originally Posted by Damian Baldi

Yeah, I think that way too.

About Mazda, I think it's too late now. Joest should have tell Mazda to change the chassis and even the engine for this year. They should had have end in the same way (out of the race) but with more potential for the future. The chassis was faster this year, but it is still unreliable. Maybe the small 4l could run better in an Oreca or Dallara, but they should develop a v6 or a v8.

Maybe they should ask IMSA to allow them to use the AER V6 of LMP1, which is not very reliable either, but with 100 HP less it should be fine.

[canaglia]

It would be a mess! basically they would need a lot of time to adapt the tub and sub-structures to fit the AER V6 in the car.
Easiest route would be to obtain a permission to badge the gibson V8 as mazda.

[canaglia]

Originally Posted by chernaudi

And in those cases, Toyota and Porsche put tons of money and time into those engines. Mazda either seem to be doing the bare minimum or are putting too much hope into AER.

And you have to remember that Chris Dyson is on AER's board and is a co-owner of the company. Yes, Chris Dyson as in Dyson Racing, as in Rob's son, as in two guys who like to hot rod cars and engines, for better or worse. That's why they never seriously bought into buying Ferrari 333s or Audi R8s even when offered to them.

well.... money effort is one of main factors between a successful program and a shameful one

anyway I just reported that a 4 cylinders engine layout can fit well for endurance racing.

[knighty]

Originally Posted by TF110

Imo, the Riley Mazda won't win anything this year. The car is not reliable, and that's that. The engine needs to be on it's way out. You can't keep going on and on with something that has continually failed for nearly the past decade. It's long time Mazda put up something for a new one or they'll continue to look at the rear of the other dpi's and p2's. The car has improved it's pace, but it's not enough. Otoh, the Penske Oreca Acura will get better and better this season and seeing how it's already on pace I think it will be a title favorite. Sebring should be a very good race.

LOL - I have been saying it for years, the Mazda is too small on capacity, and dare I say not enough cylinders either, and being an I4 way too low on torsional rigidity, hence all the scaffolding around it which originates from the Dyson-Lola days, this is why Porsche went V4, for extra torsional rigidity, also consider the Porsche was hugely assisted by 8MJ KERS systems, its not an apples-to-apples comparison to the Mazda. But really I think the ship has sailed, it looks like Mazda will have to persevere with what they have until the end of 2018.

So far I have not been impressed with Joest, Mazda or AER.......it seems Audi did bring a lot of resource and organisation to their LMP1 operation and it was not all Joest.......the whole Mazda operation screams of under-finding to me, but what other choice did Joest have - none. I hope they sort their issues and turn around their fortunes, but it seems they are just in a tough place at the moment.

AER have the 2.4 V6, 3.6 V8 and 4.0 V8 turbo motors to chose from, to spread say 600hp across 6 or 8 cylinders, with a ton more torsional rigidity will make life a lot easier........But Mazda are on a big sales push to show the US market that a 2.5L I4 can do the job of a V6 or V8 in a big passenger road-car......so watch this space!!! check the links below

http://wardsauto.com/engines/mazda-s...-pulls-big-v-6

https://www.motorauthority.com/news/...r-turbo-engine

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