26 replies to this topic

[mariner]

It has staggered height intake stacks inside the sealed plenum chamber.

 

Also, interesting how producing power is no longer a problem on many series due to BoP restrictions. It makes you wonder if ever-improving production power and ever-increasing race  restrictions wil end up with pure sealed road engines in many formulae

 

http://www.enginelab...-1-2-at-daytona

[MatsNorway]

How exacly does BOP work? because from afar it looks like they hand over the win to whoever got the best draw.. and reliable car ++ jadada.

[Prost1997T]

Usually it's through flow restrictors, fuel, ballast and aero adjustments.

[MatsNorway]

But how is it given out? . 1400kg = 4L engine 1200kg = 3L engine etc.?

[BRG]

I thought we had already had instances where the racing version of a car actually had less power than the road car?

[MatsNorway]

Oh for sure. Happens all the time now.. One of the reasons why no one watches racing anymore.

Edited by MatsNorway, 07 February 2017 - 19:35.

[mariner]

For several sports car series BoP is first done analytically then in actual tests pre-season. A lot of data is collected and it's used to ( hopefuly) weed out cheating.

 

 

The restrictors etc are used to equalise the cars. It started in GT3 IIRC as way of letting lots of different cars to race wthout having to be bulit to very strict rules, thus bringing in more makes and hopefuly reducing cost fro waht are , in principle, amateur racers.

 

A big argument at Le Mans last year as the Ford GT's suddenly found lots of extra speed!  Of course you can ballast etc next race to counter but Le Mans isn't any old race

[MatsNorway]

BOP is lame. Make formula that makes the car equal on paper. Fuel flow is one nice way to limit power and let the teams do their best. tire size/weight ratio another one.

[Fat Boy]

BOP is lame. Make formula that makes the car equal on paper. Fuel flow is one nice way to limit power and let the teams do their best. tire size/weight ratio another one.

 

Mats, do you ever have an opinion that is above peanut-gallery level?

 

FFS, you act like everyone involved just fell into this racing thing. Even though you no experience and don't have a clue how/why a certain thing is done you're willing to tell everyone they're wrong and you've got it all figured out.

Edited by Fat Boy, 12 February 2017 - 02:28.

[mariner]

Another US engine biulder article, not worth a new post but it might be of interest. An interesting progression from "hopping up" to a fully digital enterprise doing diesel as well as petrol engines.

 

http://www.streetmus...reaking-records

[Bob Riebe]

For several sports car series BoP is first done analytically then in actual tests pre-season. A lot of data is collected and it's used to ( hopefuly) weed out cheating.

 

 

The restrictors etc are used to equalise the cars. It started in GT3 IIRC as way of letting lots of different cars to race wthout having to be bulit to very strict rules, thus bringing in more makes and hopefuly reducing cost fro waht are , in principle, amateur racers.

 

That would not quite be correct.

At least in the U.S. for years there were fairly simple weight to displacement rules in Sedan/GT racing.

Blowers and multi- valve engines brought in extra equivalency rules but it was still simple weight to displacement.

BoP was supposed to allow lazy makes to compete without having to produce an engine equal to the others

BoP created a huge rule book with increasingly restrictive rules till it has become a farce with money  being the only factor that matters.

Privateers were forced out by homologation rules that catered to  factory entries only.

It used to be modified production, now it is factory races cars some what based on production cars but only those produced by companies the sanctioning body thinks kisses their butt properly.

Saleen and  Lou Gigliotti found out what BoP rules makers thought of the privateers that once were the heart and soul of GT racing.

Edited by Bob Riebe, 12 February 2017 - 17:54.

[GreenMachine]

It has staggered height intake stacks inside the sealed plenum chamber.

Are there performance reasons for the tapered length intakes? Or is it a packaging issue?

I would have thought that the gains from the longer intakes would be offset by the losses from the shorter ones, pointing to it being a packaging choice.

[gruntguru]

I know staggered-length runners have been used for such things as exhaust header primaries on speedway sedans. The idea is to make different cylinders work better at various rpm bands and give a wider spread of torque. (at the expense of peak torque) I always felt that the idea was OK but should also include staggered intake runners and a different profile on each camshaft lobe in order to fully optimise each cylinder.

Edited by gruntguru, 12 February 2017 - 22:50.

[GreenMachine]

Thanks GG.  My reservation was based in the notion that it would be a zero sum game.  This of course assumes that the gains/losses are linear.

 

If you want a broad torque band, why not just optimise the whole engine for that?  These things are all compromises, and I find it difficult to see how tweaking each cylinder in that way will produce a better result.  If it does get a better result, is the difference worth the complication/expense/etc?

[gruntguru]

Tuning an engine for a broad torque band usually involves reducing the peak torque and power rpm. Staggered runner tuning simply takes the top off the torque or power peak and fattens the curve either side.

[Kelpiecross]

Tuning an engine for a broad torque band usually involves reducing the peak torque and power rpm. Staggered runner tuning simply takes the top off the torque or power peak and fattens the curve either side.

Having the runners at an average height of all the staggered runners would surely do much the same thing? Maybe they are actually staggered for packaging reasons - to get the effect of a certain length runner while fitting neatly under a scoop?

[Fat Boy]

Are there performance reasons for the tapered length intakes? Or is it a packaging issue?

I would have thought that the gains from the longer intakes would be offset by the losses from the shorter ones, pointing to it being a packaging choice.

 

 

Thanks GG.  My reservation was based in the notion that it would be a zero sum game.  This of course assumes that the gains/losses are linear.

 

If you want a broad torque band, why not just optimise the whole engine for that?  These things are all compromises, and I find it difficult to see how tweaking each cylinder in that way will produce a better result.  If it does get a better result, is the difference worth the complication/expense/etc?

 

 

Having the runners at an average height of all the staggered runners would surely do much the same thing? Maybe they are actually staggered for packaging reasons - to get the effect of a certain length runner while fitting neatly under a scoop?

 

I gave Mats a hard time, but you two are doing the exact same thing.

 

Why the assumption that the guys that actually produce the engines are somehow missing something? You have no idea what their true goals are. You have no idea what their constraints are. You have no idea what **** they've already tried. You have no idea what the outcome has been to any of their testing. You're completely ignorant to all the information of the people that not only do it for a living, but they do a damned good job of it. Regardless, you've got it all figured out from behind your keyboard. Honestly, are you people f'ing kidding me?

 

Staggered trumpet lengths act in a different matter than when all the trumpets are at an 'average' length. Even if they didn't, you don't know what other bullshit they're dealing with that feeds into solving the overall issue of producing the best race engine they can.

 

When you see something like this, start from the assumption that it's correct and to understand it, you need to know their logic for doing what they've done. You might learn later than they were incorrect, but, more often than not, you'll learn something. The hubris of ******* on the guys that just walked away with the win in the Daytona 24 is pretty outlandish.

[Fat Boy]

That would not quite be correct.

At least in the U.S. for years there were fairly simple weight to displacement rules in Sedan/GT racing.

Blowers and multi- valve engines brought in extra equivalency rules but it was still simple weight to displacement.

BoP was supposed to allow lazy makes to compete without having to produce an engine equal to the others

BoP created a huge rule book with increasingly restrictive rules till it has become a farce with money  being the only factor that matters.

Privateers were forced out by homologation rules that catered to  factory entries only.

It used to be modified production, now it is factory races cars some what based on production cars but only those produced by companies the sanctioning body thinks kisses their butt properly.

Saleen and  Lou Gigliotti found out what BoP rules makers thought of the privateers that once were the heart and soul of GT racing.

 

STOP! You don't even have a clue wtf you're talking about. None of this is BoP. If you're going to spout opinions, at least be semi-informed.

[MatsNorway]

You seem to think i think in black and white. I know it is not easy to make a good racing series. And progress has been made, Fuel flow is a great way allow development and letting the better team win. But Group A was cooler than the WTCC crap we have now with zero road car left. Funny how FIA must have F1 cars road relevant somehow while all other series are tube frame cars.. (WTCC have tubeframe front)

Edited by MatsNorway, 15 February 2017 - 22:37.

[GreenMachine]

I gave Mats a hard time, but you two are doing the exact same thing.
 
Why the assumption that the guys that actually produce the engines are somehow missing something? You have no idea what their true goals are. You have no idea what their constraints are. You have no idea what **** they've already tried. You have no idea what the outcome has been to any of their testing. You're completely ignorant to all the information of the people that not only do it for a living, but they do a damned good job of it. Regardless, you've got it all figured out from behind your keyboard. Honestly, are you people f'ing kidding me?
 
Staggered trumpet lengths act in a different matter than when all the trumpets are at an 'average' length. Even if they didn't, you don't know what other bullshit they're dealing with that feeds into solving the overall issue of producing the best race engine they can.
 
When you see something like this, start from the assumption that it's correct and to understand it, you need to know their logic for doing what they've done. You might learn later than they were incorrect, but, more often than not, you'll learn something.

Feeling better now? Good.

For a start, unlike you, I am not making any assumptions. I asked a couple of questions, aimed at teasing out information/explanation/understanding. I am sorry if that offends you.
 

The hubris of ******* on the guys that just walked away with the win in the Daytona 24 is pretty outlandish.

Whoa! where did that come from? If that was directed at me, I would diagnose an overheated imagination, and prescribe a couple of Bex and a good lie down. 
 

Back OT.
 

Staggered trumpet lengths act in a different matter than when all the trumpets are at an 'average' length.

 

Thanks for this, any pointers on where to look for further information?

[Bob Riebe]

STOP! You don't even have a clue wtf you're talking about. None of this is BoP. If you're going to spout opinions, at least be semi-informed.

BoP started full on in the late nineties and it has become more and more restrictive, period.

It has made road racing irrelevant to the fans who once flocked to road racing.

You now have contrived competition.

 

You can deny this till hell freezes over but all it is, is you denying  the facts.

Maybe the IMSA will adopt the silly NASCAR point system next, no wait, they do not have enough cars in any class than God.

Gee if they want to make it interesting they could start the slowest cars first, x laps and they let the fast boy catch them to win.

No wait, the rich whiny boys would have a snit fit if they had to drive hard to win.

[Fat Boy]

BoP started full on in the late nineties and it has become more and more restrictive, period.

It has made road racing irrelevant to the fans who once flocked to road racing.

You now have contrived competition.

 

You can deny this till hell freezes over but all it is, is you denying  the facts.

Maybe the IMSA will adopt the silly NASCAR point system next, no wait, they do not have enough cars in any class than God.

Gee if they want to make it interesting they could start the slowest cars first, x laps and they let the fast boy catch them to win.

No wait, the rich whiny boys would have a snit fit if they had to drive hard to win.

 

First, you need to educate yourself a little bit, because you don't even know what you're arguing about. You're talking about rules packages, not BoP. If you want to bitch that we don't have old-time racing, then you're talking much more about Pre-WWII Grand Prix cars, USAC cars at Indy and Can-Am v1. These were pretty much no-holds-barred racing. This have been gone for a while and they aren't coming back. Newsflash, often the actual racing wasn't that great. You tend to have one team that has resources the others do not which destroys the competition. It's like playing Monopoly. Sooner or later, 1 person ends up with all the money and wins. When that happens, you have to start a new game.

 

If we look to all sorts of sportscar racing though the 70's, 80's, 90's and 00's, there were all sorts of equivalency formula in place which allowed a turbo 4 to race a V8 to race a V12. For racing to make sense to a manufacturer, they have to look good using a product that's at least reminiscent of the street version. None of this is BoP, it's a rules package and it's a completely different kettle of fish altogether.

 

Balance of Performance (BoP) is a term in use by the ACO/FIA. It's specifically a way where various manufacturers can produce a race car which is then tested by the Stephane Ratel Organization (SRO) and the car, along with all sorts of tuning pieces are homologated for certain forms of racing. The cars are wind-tunnel tested, dyno tested and track tested by the SRO to establish a performance 'window' in which the car is meant to operate. In the case of a GT3 car, the Porsche is kind of the defacto benchmark. They seem to kind of match everything up to that one way or another. Power, weight, aero, fuel capacity, tuning variables, fuel rig flow, etc. are all varied to produce similar levels of overall performance. Having said this, every car will have a tactical advantage. Some cars have acceleration, some straight line speed, some downforce, some low-speed cornering...each car has a signature advantage even though they all will run the same potential lap time (within a damned close margin of error).

 

Do you want to run World Challenge in the US? Cool, buy your favorite GT3 race car and go racing. You decide you want to take that car to the Blancpain sprint series? No problem, same car, same rules, go race. You want to endurance race in Oz or at Spa? No Problem, same car, same rules, go race. They do the same thing basic with LMP2 cars and GT4 cars.

 

SO, WHEN YOU GO ON ABOUT BoP, IN GENERAL, THIS IS WHAT YOU'RE TALKING ABOUT.

 

IMSA uses the BoP framework, but, in their infinite wisdom, changes things up. To keep the US specific manufacturers happy, they've introduced DPi or Daytona Prototype International. It's an LMP2 chassis with manufacturer specific bodywork and engine. They also conduct their own engine/aero testing. At times they've called it Adjustment of Performance (AoP). In my opinion, it's not to the same standard. The performance of the Cadillac at Daytona would tend to reinforce my opinion. Far and away, they were ahead of the competition.

Edited by Fat Boy, 19 February 2017 - 20:56.

[Fat Boy]

And just like that, poof, the righteous indignation vanished....

[Canuck]

Just because you know what you're talking about doesn't mean you're right. There's a reason we're called armchair experts. We're like Tyrian Lannister - we drink, and we know things.

[Fat Boy]

Hey, Canuck, wanna hear a secret?

 

 

 

 

 

 

I just made all that **** up.

[gruntguru]

The prerogative of those who know what they are talking about.

[Canuck]

Made up **** spoken with authority gets people elected. It's a powerful alt-truth.

You're message is still spot on, fabrications aside. We have the easy role of operating in almost complete ignorance of the envelopes that constrain "those that do" versus most of us - "those that talk ****". I am endlessly amused when one of us armchair critics goes to loggerheads with someone that knows. We have at least 1 professional F1 engineer that pops in from time to time, at least two more if not three individuals that make their living racing in various series that I know of. Then there's the amazing storytellers who's knowledge weave amazing tales of industry past, giving us a front seat to the inside of all manner of related activity.

I like this place - it keeps me humble.