IMSA Race 2017 - Rolex Daytona 24

[chernaudi]

And complaining about the tires, aside from their effect on this race, is sort of pointless in the end, since the Continental Daytona/Superspeedway spec tires are now obsolete as of Monday morning.

The newer spec tires that Continental has been working on that should work better with the DPIs should be ready by the time of the Sebring tests. Aren't the GTD cars also supposed to have a new generation tire as well?

[JHamilton]

Originally Posted by knighty

Sorry no, the top-speed figures released by Imsa show the Nissan as the fastest, and the top speed is a result of how fast it acellerates there, which is a factor of torque, not horsepower, with the boost factored in the Nissan engine has the most torque potential in the whole DPi & LMP2 field due to the largest resultant capacity, and I really cannot see the Nissans having their motor pegged back......I watched a lot of the race, and really to me it seemed the Cadillacs had a good well honed package that could set fast sector times in the in-field section, they just turned up with a well developed race car package, and the onus is now on ESM-Nissan, Mazda and the Gibson gang to up their game and get on the same playing field as Cadillac, which is just a polished spec chassis, with a push-rod V8, its hardly a technological marvel, in reality the Gibson, Mazda and Nissan engines are far more advanced than Cadillacs, but they are not yet on the overall pace of the Cadillac package as a whole.......no need for BoP just yet

I agree with your overall point knighty and know you're very knowledgeable, but I'm not sure what your basis for the highlighted portion is. I wouldn't call any of these engines "technological marvels". The MZR-R and the the Gibson V8 platform have been around for around/over a decade. What exactly makes them more advanced in your opinion?

Some seem to have the perception that pushrod engines are old technology even though OHC predates OHV. The Gen IV and V GM small blocks have nothing in common with a Gen I or Gen II small block other than their layout. In the same way, a 2L Porsche flat-6 has nothing in common with a 3.6L, 3.8L, 4L flat-6.

My point is that a pushrod V8 isn't old or outdated technology, but a different answer for how to go fast. As you mentioned, it isn't about comparing peak power numbers but the area under the torque curve. It's hard to argue against the "table top" torque curve a pushrod V8 provides, especially given the small, light, reliable, and efficient package.

...I swear I wasn't trying to get preachy, but I did anyway. Get between me and my V8 "motors" and it just spills out of me.

[JHamilton]

Originally Posted by chernaudi

And complaining about the tires, aside from their effect on this race, is sort of pointless in the end, since the Continental Daytona/Superspeedway spec tires are now obsolete as of Monday morning.

The newer spec tires that Continental has been working on that should work better with the DPIs should be ready by the time of the Sebring tests. Aren't the GTD cars also supposed to have a new generation tire as well?

I know you just squashed the argument, and this may have been posted, but I felt like the lack of an intermediate tire really showed up last weekend. My instant reaction was too much heat in the full wets on the banking was causing the failures.

Luckily, as you mentioned, we'll never know. Here's hoping that Hoosier... I mean Continental has "fixed the glitch".

[chernaudi]

As far as I know, only the WEC/LM have the intermediate tire option. Continental won't stump for it, and IMSA haven't had the option for years overall. I'm not sure about the ELMS, but I can see them not having it due to cost cutting and/or Dunlop not wanting to do it for a regional series that races only a few times a year and is mainly a pro-am series.

[Mike Hedlund]

Originally Posted by chernaudi

As far as I know, only the WEC/LM have the intermediate tire option. Continental won't stump for it, and IMSA haven't had the option for years overall. I'm not sure about the ELMS, but I can see them not having it due to cost cutting and/or Dunlop not wanting to do it for a regional series that races only a few times a year and is mainly a pro-am series.

In the ELMS GTE we had 2 options for slicks, intermediates and full wets.

-mike

[Akrapovic]

Originally Posted by Mike Hedlund

In the ELMS GTE we had 2 options for slicks, intermediates and full wets.

-mike

When you say inters, that's the traditional inter isn't it? With soft rubber and a tread pattern? Not the 'slickermediate' with no tread pattern? Do you know if that's available to anyone in ELMS?

[knighty]

Originally Posted by JHamilton

I agree with your overall point knighty and know you're very knowledgeable, but I'm not sure what your basis for the highlighted portion is. I wouldn't call any of these engines "technological marvels". The MZR-R and the the Gibson V8 platform have been around for around/over a decade. What exactly makes them more advanced in your opinion?

Some seem to have the perception that pushrod engines are old technology even though OHC predates OHV. The Gen IV and V GM small blocks have nothing in common with a Gen I or Gen II small block other than their layout. In the same way, a 2L Porsche flat-6 has nothing in common with a 3.6L, 3.8L, 4L flat-6.

My point is that a pushrod V8 isn't old or outdated technology, but a different answer for how to go fast. As you mentioned, it isn't about comparing peak power numbers but the area under the torque curve. It's hard to argue against the "table top" torque curve a pushrod V8 provides, especially given the small, light, reliable, and efficient package.

...I swear I wasn't trying to get preachy, but I did anyway. Get between me and my V8 "motors" and it just spills out of me.

Hey, your preaching to the choir here! I am a big fan of push-rod engines, they are very light, compact and have a very low centre of gravity compared to over-head cam engines, it pains me that nobody ever put the Katech 7 litre motor into an LMP1 chassis, I feel that Cadillacs efforts have finally shown what a good push-rod engine can do in an LMP type chassis, and believe me I am quite happy about it.

I race with my 11 year old son 5 days of every month, in cadet karts for the past 5 years, we use a Honda GX160 8hp engine, its a push-rod engine, and I just love the simplicity of it, its the most popular form of UK karting, I build, dyno and maintain my own engines, and we are regular podium visitors.

The Gibson engine is nothing special in my opinion, its just a spec race engine built to a budget......but the Mazda motor is quite special, it features a combination of both port fuel injection + side mounted homogeneous direct injection which gives it a good combination of low and high rpm performance, plus good fuel economy, but in my opinion the Mazda capacity is too small, it needs to be in the region of 2.5-3 Litres, and Mazda will hence struggle to hold a candle to Cadillacs big capacity motor due to a substantial torque deficit of 20-30%......same for Gibson, they will have a substantial torque deficit to the Cadillacs due to a lack of capacity......if IMSA they ever apply BoP, I think they will need to impose an rpm limit to the Cadillac, which will effectively reduce the air consumed by the motor to a comparable amount to the Gibson and Mazda, it would be minimal cost and quick to implement, as fuel or air restrictors cost a fortune to implement.

[Matt]

Doesn't matter how much tech is in the Mazda engine, if it blows up spectacularly every race.

BTW, the Gibson engine sounds INCREDIBLE in person. Very loud.

In the beginning of the race when the Dallaralacs were running 1-2-3, we were up in the stands near T1, you'd hear the 4th place Gibson engine over all three 6.2l V8's.

[Akrapovic]

Originally Posted by Matt

Doesn't matter how much tech is in the Mazda engine, if it blows up spectacularly every race.

BTW, the Gibson engine sounds INCREDIBLE in person. Very loud.

In the beginning of the race when the Dallaralacs were running 1-2-3, we were up in the stands near T1, you'd hear the 4th place Gibson engine over all three 6.2l V8's.

I'd actually be disappointed if Mazda finished a race. It's almost charming when it catches fire.

[Matt]

I was standing near the pit wall opening when it drove by alight.

That was a proper fire.

[fieldodreams79]

Originally Posted by Akrapovic

I'd actually be disappointed if Mazda finished a race. It's almost charming when it catches fire.

They've become the new Dyson; prop bets on how long until she blows.

But no one will ever top Dyson at one race, think it was the 12 hours one year, where the first step in multiple 16 Dyson pit stops was to put out the turbo fire before refueling.

[Damian Baldi]

Doesn't have Mazda a v6 to develop with the current technology used in the 4 in line ?

[Matt]

Originally Posted by fieldodreams79

They've become the new Dyson; prop bets on how long until she blows.

But no one will ever top Dyson at one race, think it was the 12 hours one year, where the first step in multiple 16 Dyson pit stops was to put out the turbo fire before refueling.

It's always at the same time in every race, just proportionate to the length of the race.

[knighty]

Originally Posted by Matt

I was standing near the pit wall opening when it drove by alight.

That was a proper fire.

as you may have detected, I am also no fan of the 2.0L Mazda I4 turbo engine.....I am bemused that Mazda actually continued with it this year, they should have used the 2.4 AER V6 and evolved that into something with bigger capacity like 3 litres for more torque and lower revs for better reliability and fuel consumption.....yes the V6 also has a bad reliability record in the WEC, but it would have been a better basis that the high revving small capacity I4.......it always has the life expectancy of a mayfly.

[nasportscar]

data analysis http://nasportscar.com/2017-weathert...ysis-rolex-24/

[Matt]

I'm unrealistic and think they should run a rotary, so.

[MoMedic9019]

Originally Posted by Matt

I'm unrealistic and think they should run a rotary, so.

I support this idea. Skyactiv has been a bit of a failure for Mazda.

[fieldodreams79]

Originally Posted by Matt

I'm unrealistic and think they should run a rotary, so.

One of the endearing things about the Grand Am series was the rotary powered RX-7s. They sounded terrific and shot flames out the exhaust. Unburnt fuel flames, just to clarify.

[knighty]

Originally Posted by nasportscar

data analysis http://nasportscar.com/2017-weathert...ysis-rolex-24/

very interesting.....

https://i0.wp.com/nasportscar.com/wp-content/uploads/2017/02/P.jpg

In all the deceleration zones, which is about 8 or 9 of the total 12 sectors, the Cadillac had anywhere from 0.1 to 0.3 secs advantage over the fastest gibson engine......I'm sticking to my guns, the Cadillac has a torque advantage......will be interesting to see if or how they apply BOP......but I still think its early days and everyone needs to catch up a bit first to level the playing field.

[Mike Hedlund]

Originally Posted by Akrapovic

When you say inters, that's the traditional inter isn't it? With soft rubber and a tread pattern? Not the 'slickermediate' with no tread pattern? Do you know if that's available to anyone in ELMS?

Yes, correct. Confidential Michelin tires are the only "slickermediate" option with an ultra soft compound on a slick tire. Confidential Michelin tires aren't allowed in ELMS. Only the customer Michelin tires on P3 and whatever compounds Dunlop provides for GTE/P2 (which is sort of up in the air and I personally think why the GTE Aston in ELMS was so good... always thought they were running the Dunlop WEC tire but I dunno, maybe not. :-)).

-mike

[chernaudi]

Well, it does seem that all the GTLM teams opted for the Michelin customer spec rain tires while running confidential/individual team spec slicks. Though I do think that this was a decision made by Michelin as it seems that the felt that the customer rain tires may've been a bit more durable for Daytona.

I also didn't know that Michelin made the slick intermediates for GT cars, I thought that only LMP1 and LMP2 teams had them available

[Akrapovic]

Originally Posted by chernaudi

Well, it does seem that all the GTLM teams opted for the Michelin customer spec rain tires while running confidential/individual team spec slicks. Though I do think that this was a decision made by Michelin as it seems that the felt that the customer rain tires may've been a bit more durable for Daytona.

I also didn't know that Michelin made the slick intermediates for GT cars, I thought that only LMP1 and LMP2 teams had them available

They started with LMP1, then LMP2 and now the GTE cars. But yeah at one point it was LMP1 only.

[Maelochs]

LOL, Michelin has a slick tire that works in the rain, and Conti doesn't have a rain tire which works in the rain.

[TF110]

Originally Posted by MoMedic9019

I support this idea. Skyactiv has been a bit of a failure for Mazda.

The diesel skyactiv was (in racing), but I don't think the 'new' engine has much to do with Mazda anyway. I don't know what is going on with AER, but Kolles was quick to get out and picked up the Nismo V6. I think that says something.

[seanyb505]

Originally Posted by chernaudi

Well, it does seem that all the GTLM teams opted for the Michelin customer spec rain tires while running confidential/individual team spec slicks. Though I do think that this was a decision made by Michelin as it seems that the felt that the customer rain tires may've been a bit more durable for Daytona.

I also didn't know that Michelin made the slick intermediates for GT cars, I thought that only LMP1 and LMP2 teams had them available

It wasn't driven by the teams or "the unique nature of daytona." The customer rain is just good enough to use on gtlm cars. I think it'll be the case for the rest of the season as well.