IMSA: USCR 2018

[Damian Baldi]

Originally Posted by TF110

Look at the Riley head on vs the competition. It's cockpit is wide like the previous dp's. The others are much more slim. That right there has to be a big factor in the poor top speed/high drag.

Yeah, it looks more like a P3 than a P2, I don't know the reason they made it that way.

It's very noticeable the difference on the gap to the rear fenders.

Pictures from www.motorsport.com

[FormulaFox]

Originally Posted by TF110

Look at the Riley head on vs the competition. It's cockpit is wide like the previous dp's. The others are much more slim. That right there has to be a big factor in the poor top speed/high drag.

Not necessarily - if it's shaped right, the drag can be exactly identical as the narrower cockpits. Air is weird like that - size doesn't matter as much as shape when it comes to how much force it takes to move around it(usually - there are some notable exceptions, but most of them are on scales that racecars fall far below), even though it is easier to keep the drag down on a small piece than a large piece.

That said, while the cockpit is wider than the Oreca's, it is not by as big a degree as you'd think. It's far closer in size to the Oreca than the Gen3 DPs, after all.

Nonetheless, this is all why I point to the windshield(well, this and the fact that it's the only standout part that's unchanged on the Mazda) - it's the part that will most likely determine if the wider cockpit is a hindrance or not. The wider cockpit may not guarantee more drag, but any higher-drag shape will have a much greater effect on the wider one than the narrower one - despite all the intricacies of aerodynamics and the greater importance of shape than size, it is indeed FAR easier to keep the drag down with a smaller component than a larger one.

A telling detail is that if you look closely at the first picture posted by Damian Baldi, you can see that the two cars in the back(a Ligier and Ligier-based Nissan) also have slightly wider cockpits - not as wide as the R-M, but visibly wider at both the top and the base(though moreso at the top than the base). The Ligier obviously isn't anywhere near as aerodynamically deficient compared to the Oreca, so it seems unlikely that the cockpit size, in and of itself, is having a massive impact.

[AoB Special Stage]

That wide greenhouse is inevitably going to increase the frontal area though. A loss is a loss, after all. I haven't gotten close enough to the R/M to see for sure, but it looks like no measures were taken to mitigate the adverse effect of the greenhouse either. That may be due to the regulatory boxes, however.

I also wonder about the efficiency of the R/M floor because we all know they don't exactly have vast experience with cars that generate a lot of downforce from the floor.

[Purist]

Well, the Mk. IIIC must have made some notable downforce from the floor to be as fast as it was.

As I've mentioned a couple of times, I talked a little with Marc and Renger during the autograph session at Road America, and the Dutchman said the Riley wasn't as stiff as the Ligier, and so more of the power was soaked up in the chassis and never made it to the road. He mentioned the better downforce and drag with the Ligier, but his main focus was on the Riley's relative lack of structural rigidity.

[chernaudi]

If we're talking about how wide the greenhouses are, then the old Bentley GTPs where insanely wide, but the Bentleys were also a couple of inches shorter than the current cars due to different regs.

But it's pretty clear the the windscreen/greenhouse is probably the least of the problems that the Riley has had until Multimatic took over sole development of the project. The fact that the cars haven't raced since does show how much work they're doing and the fact that the ACO and IMSA are allowing them to re-homolgate the whole car shows the scope of the work that they have to do to get the car competitive, especially in base form.

[FormulaFox]

Originally Posted by Purist

Well, the Mk. IIIC must have made some notable downforce from the floor to be as fast as it was.

As I've mentioned a couple of times, I talked a little with Marc and Renger during the autograph session at Road America, and the Dutchman said the Riley wasn't as stiff as the Ligier, and so more of the power was soaked up in the chassis and never made it to the road. He mentioned the better downforce and drag with the Ligier, but his main focus was on the Riley's relative lack of structural rigidity.

That reeks of inexperience with carbon-fiber chassis designs, IMO.

[JorritVD]

Maybe this is a nice compare of the Riley and Ligier and some others:







With Joest now behind the Mazda programm, and than also the Riley car, I will expect quite some aero changes for at least the Mazda, especially with the fenders. But Riley can kinda copy them for the 'standard' car. Will be interesting how much the compromise of the Mazda styling elements will stay.

About aerowise. You have outer aero, that runs over the car. Especially the Oreca 07 has this. The Ligier, Riley and Dallara have also a lot of inner car air flow. The front end is more 'open'. It could be that the Riley lacks a lot on this part and creates a lot of drag there. A good example of this inner air flow was the Nissan LMP1. At the back of the car, you could see the front
https://thewptformula.files.wordpres...ett_11repl.jpg

It will also be therefore really interesting how the new Acura-Penske-Oreca LMP2 will go. Basicly they put an huge extra front wing on that car. How they solve this extra downforce at the rear to get a balance will be interesting. And will they keep this also for Daytona, as it will increase their drag and lower top speed as well.

[Matt]

I actually quite like the aesthetics of the wider greenhouse.

[AoB Special Stage]

Originally Posted by Matt

I actually quite like the aesthetics of the wider greenhouse.

I do too, but looks don't win championships, now do they?

[Matt]

Originally Posted by AoB Special Stage

I do too, but looks don't win championships, now do they?

Sometimes they do!

[Coach Ep]

The wind tunnel tests for the updated P2s is set for the second half of November and going by this it cannot be long before we see the new - and much improved - Riley-Multimatic (not sure if updated DPi's will be part of that test or have to go later on).

DSC also understands that the package will be out testing this week too, ahead of the wind tunnel test at Wind Shear in November. The deadline given to Dallara to have its full ‘Joker’ packages ready is reportedly the 13th of next month, ahead of the ACO’s wind tunnel test for the three chassis.

http://www.dailysportscar.com/2017/1...-portimao.html

[AoB Special Stage]

Originally Posted by Matt

Sometimes they do!

Only when it has a GM badge though.

[Damian Baldi]

Would be Multimatic able to change something on the tub in these months? I have read that they were working on the suspension and the bell housing. But I think they don't have time to redo the aero of two cars, suspension, and the tub in such short period of time.

[Damian Baldi]

News about upgrades

Riley/Multimatic, which can alter its Mk.30 chassis as well as both aero kits for 2018, has also been hard at work.

The Riley/Multimatic LMP2 Mk.30 is being re-designed in the UK, with Julian Sole, and Larry Holt – who missed the WEC’s trip to Fuji – involved to aid the development. Multimatic is using the Lola wind tunnel in Huntingdon owned by Martin Berrain during the process.

A big part of the effort however, is the Mazda DPi chassis, which is set to be run by Team Joest in 2018. The RT24P in its current for is doing baseline testing for its upgrades; the LMP2 Gibson version of the car will follow on.

Riley/Multimatic has said publically that would like to retain customers for the car. Larry Holt himself told DSC’s editor that the principal issue for the basic package for the 2017-spec LMP2 car was cooling.

http://www.dailysportscar.com/2017/1...-portimao.html

[carbsmith]

Julian Sole has been Lola's chief designer for sports cars since the MG by the way. That includes the Ford GT.

[broadrun96]

We could potentially see Performance Tech bring the remaining ACO chassis to IMSA with them buying a Dallara. Course the cynic in me says they have some kind of deal with Dallara to demo the 'base' chassis in IMSA, or they at least asked to save some money. Performance Tech could be good in a P2 car, they've been the best of the PC guys lately but then their driver did punt/obstruct the Rebellion car at Petit so there's that too.

[Damian Baldi]

Originally Posted by broadrun96

We could potentially see Performance Tech bring the remaining ACO chassis to IMSA with them buying a Dallara. Course the cynic in me says they have some kind of deal with Dallara to demo the 'base' chassis in IMSA, or they at least asked to save some money. Performance Tech could be good in a P2 car, they've been the best of the PC guys lately but then their driver did punt/obstruct the Rebellion car at Petit so there's that too.

Great news. All four chassis's and four DPi one with each one. If the parity displayed at the end of the year continue, 2018 Daytona will be a blast, and the rest of the season, one to remember.

[TF110]

Originally Posted by Matt

I actually quite like the aesthetics of the wider greenhouse.

I feel the direct opposite. For a GT car it would be a nice width. But not for the Riley, especially when these prototypes are 'only' 1900mm wide. Doesn't look proportioned right when the greenhouse is so tall and wide imo. I didn't like how wide the Bentley Speed 8's greenhouse was either, but overall it looked good.

[broadrun96]

For those who already have such things, and don't want to watch on their laptop/tablet/etc, IMSA launched a Roku player channel. I have one so I'll have to check it out tonight and see what's already loaded on there. For those with Chromecast apparently the IMSA channel is castable as well although I have not looked into that at all, but yes I'm that guy and will have to check it out at a later date on the Chromecast at the gf's house. I have to assume something is coming with Xbox soon as well since I think I remember an announcement at Petit about Forza and Xbox with IMSA.

[HORNDAWG]

Originally Posted by Matt

I actually quite like the aesthetics of the wider greenhouse.

So do I, very much.







L.P.

[FormulaFox]

Originally Posted by TF110

I feel the direct opposite. For a GT car it would be a nice width. But not for the Riley, especially when these prototypes are 'only' 1900mm wide. Doesn't look proportioned right when the greenhouse is so tall and wide imo. I didn't like how wide the Bentley Speed 8's greenhouse was either, but overall it looked good.

The Bentley's greenhouse was far wider than the Riley's - much more in line with the greenhouse widths of the old Group C/GTP machinery than today's LMPs.

Which is frankly what I prefer. I don't want them to be GT car wide, but the cockpits should at least LOOK like they can fit two people side-by-side, and these super-narrow cockpits don't give such a look. IMO, the LMP3 cars have a good cockpit size for a prototype.

[HORNDAWG]

Originally Posted by FormulaFox

I don't want them to be GT car wide, but the cockpits should at least LOOK like they can fit two people side-by-side, and these super-narrow cockpits don't give such a look.

Zactly! They are supposed to be Sportscar Prototypes, not roofed single seaters.




L.P.

[TF110]

I just feel they're not GT's, they're prototypes. So imo the two-seater rule is an old-fashioned thing that's kept only for tradition. Which is fine if you're into that type of thing. Regardless of that, I hope the Riley is a better package next year.

[FormulaFox]

Originally Posted by TF110

I just feel they're not GT's, they're prototypes. So imo the two-seater rule is an old-fashioned thing that's kept only for tradition. Which is fine if you're into that type of thing.

I disagree. I feel it's been kept in order to underline the difference between sportscars and single seaters at LEAST as much as mere tradition. Prior to the 1960s that was the only real obvious difference between sportscars and grand prix cars. That difference may not be that important nowadays, but with it becoming a real possibility that the idea of "open wheel" could disappear within our lifetime(never would've been a thing to begin with if anything was known about aerodynamics back when racing first came about) due to how important efficiency is becoming, holding onto such a differentiating detail is all the more important.

That said, having a wider cockpit doens't automatically scream "GT" - the aforementioned Bentley's cockpit was a lot wider than what we've got now, but nobody would compare it to a GT car. And like I said, I don't want GT-style cockpit on the prototypes(thinking along the lines of GT cars for a prototype cockpit is what led to those huge greenhosues on the original DPs, after all), I just want it distinctly two-seater.

And I'll reiterate that I think the LMP3s have got the right size for that.

[Matt]

Originally Posted by FormulaFox

I disagree. I feel it's been kept in order to underline the difference between sportscars and single seaters at LEAST as much as mere tradition. Prior to the 1960s that was the only real obvious difference between sportscars and grand prix cars. That difference may not be that important nowadays, but with it becoming a real possibility that the idea of "open wheel" could disappear within our lifetime(never would've been a thing to begin with if anything was known about aerodynamics back when racing first came about) due to how important efficiency is becoming, holding onto such a differentiating detail is all the more important.

That said, having a wider cockpit doens't automatically scream "GT" - the aforementioned Bentley's cockpit was a lot wider than what we've got now, but nobody would compare it to a GT car. And like I said, I don't want GT-style cockpit on the prototypes(thinking along the lines of GT cars for a prototype cockpit is what led to those huge greenhosues on the original DPs, after all), I just want it distinctly two-seater.

And I'll reiterate that I think the LMP3s have got the right size for that.

The DP cockpits were originally supposed to be much smaller. When Jeff Clinton had his accident they changed that though.