50 replies to this topic

[PAD]

Ok, I know at the moment that the Renault powered Benettons are current dragging themselves around the F1 races at the back of the grid, but has Renault seen the future with its 111 degree engine?

What makes me ask this is that I remember several years ago when Renault were introducing their radical new V10 engine, someone from (I think it was Ferrari) said that it had no chance, and that all Renault had done was to show pictures of it, and these never had the exhausts attached. How wrong he was!

[Marco94]

Wide angle engines are certainly the way to go. With a bit of clever thinking, it'll make a much better package.

Marco.

[Dan_G]

If I am not mistaken, arent Renault also experimenting with an electromagnetic valve actuation system as well, as opposed to the pneumatic systems that all they other teams use?

I think Ferrari tried this a couple of years ago, but gave up on it, because the components were too heavy.

Again, if I am not mistaken wasn't it Renault that first introduced the pneumatic valve systems back in the early 90's?

[Ali_G]

Dan: Their are plenty of threads on EM Valve acctuation if you want to have a search.

Essentially though the valves are no slowing down Increased Revs at all.

Renault introduced Aero - Valves which let valves go at 24,000 revs. The reall problem is with Burn TIme. The fuel will not burn any faster.

One advantage with an EM Vale acctuation system is that you can open valves sperately on each cylender as you please. But i can't see any advantage in this.

Niall

[FordFan]

Couldn't you adopt a form of traction control to take advantage of that??

[Ali_G]

Bad idea. Back in 92 for TC they sued to stop a set of cylenders from firing. This approach didn't play well with the engine or gearbox which which caused unreliability.

Imagine the sudden cut of power on the gearbox.

A better way is just having the Computer cut the revs. This is simple to do now as they use Drive By Wire. Back in those days ( I could be wrong) they didn't.

Niall

[kike]

As I have exposed several times, the reason is not combustion time enough for top revs. You can browse Kike´s threads.

[moog101]

Originally posted by Ali_G
Back in 92 for TC they sued to stop a set of cylenders from firing.

Sued? That is a very drastic way to convince cylinders from firing

[Dan_G]

Ali,

I was under the impression that fly-by-wire throttle would be illegal next year. Is that correct?

If so, then it would make rev limiting in regards to TC through electronic means much more difficult. If you could use EM valves actuation to individually select which vavles open and close in any particular cylinder, then you could obviously limit the amount of fuel introduced to the cylinder and thereby limit the power output. Wouldnt this make for a more effective TC than cutting the spark to a bank of cylinders? Wouldnt it also be more fuel efficient, thereby increasing fuel mileage, and thereby allowing the cars to carry less fuel? Also, if fly-by-wire throttle is to be eliminated for next year, then wouldnt this be a very effective substitute for fly-by-wire?

[desmo]

"Fly by wire" throttles are not to be made illegal, in fact the freeing up of powertrain electronics is headed in the other direction. EM valves are probably not going to be seen in the foreseeable future in F1. They are better suited for low-speed engines. The wide-angle banks may reflect an attempt by the designers to move the rpm at which torsional crankshaft harmonics occur as much as lowering C of M or packaging considerations.

[Dan_G]

Thanks, desmo. I was under the impression that electronics were slowly being consolidated to internal engine and geabox control, more so than all out drive train electronics. Guess I heard that wrong. That's a shame. Things keep going this way and it'll be a wonder we need a driver to do anything but steer the car in a few years.

Is it just me or does it seem like the trend is leading us to a day when the driver will only have to put his foot all the way down when he wants to go, and put his foot all the way down on the other pedal when he wants to brake and the black box will control all of the details?

We'll all be able to drive F1 cars.

Instructiosnfor driving f1 car:
1. start car
2. push gas pedal all the way down
3. 80m before turn, push brake pedal all the way down
4. turn car into turn
5. upon reaching apex of turn, repeat step 2 through 5...

Hey, I can do that!!!

[8nebula]

A 111 vee angle might be the way to go once Renault manage to sort out the gremlins. I don't know if anybody else heard during the ITV world feed coverage of the last race but Martin Brundle mentioned that the Benetton unit was 100 horse power down on the engines at the front of the grid. This indicates that they might have a way to go yet because quite frankly 100 hp down is Minardi teritory.

[Ali_G]

They are a hundred horse power down as the vibrations of 18,000 revs coupled with a 111 degree bank angle would shake the engine to bits.

Does anyone know why there is more vibration with a wider angle anyway.

Niall

[Top Fuel F1]

Originally posted by Dan_G
If I am not mistaken, arent Renault also experimenting with an electromagnetic valve actuation system as well, as opposed to the pneumatic systems that all they other teams use?
I think Ferrari tried this a couple of years ago, but gave up on it, because the components were too heavy.

Re: Interview with Mario illian (Current Mercedes/Ilmor F1 V-10)

Ques: With the valve lift increasing and the valve to piston clearances decreasing is there now a case for active valves?

Ans: Mario says "No chance ! ". He points out the enormous power and accuracy that would take. He says they have a dynamic clearance between the piston and valve in the area of 0.2 mm. He goes on to stress that the means to control the valve to maintain this is a great challenge and does not think active valves are a possibility with current technology. In any event the main factor in his mind of discounting the use of active valves is the great amount of energy it would take to open and close 40 valves. He goes on to say "it's not worth considering".

I believe Mario was talking about electromagnetic valves when talking about "Active Valves"

Rgds;

[Top Fuel F1]

Niall:

Originally posted by Greg L
Steve Matchett, during the Speedvision broadcast, attributed some of the Benneton failures to the engine flexing so much under stress that the pistons were seizing in the cylinders (at over 18,000 rpm). This, combined with reports of failures due to exhaust problems, makes me wonder again if it is worth the effort of the wide-angle vee. Also, why would Renault get so much off-season press about a 111 degree vee and nothing is reported about Ferarri's supposed 120 degree vee?

I don't know if a wide angle block typically has more flexing; but apparently the Renault engine does. I would have thought they would have done more testing prior to actual races.

Rgds;

[david_martin]

Originally posted by Ali_G
They are a hundred horse power down as the vibrations of 18,000 revs coupled with a 111 degree bank angle would shake the engine to bits.

Does anyone know why there is more vibration with a wider angle anyway.

Niall

I think you might by drawing a long bow by assuming that there is a direct relationship between included angle and characteristic vibration. It is far more complex than that - crank configuration and firing order will dictate what the predominant order harmonic vibrations are and what their natural frequencies will be. Clearly the crank configuration and firing order will be determined to an extent by the block included angle but for a given block there will be more than one way to "skin the cat" so to speak.

[Top Fuel F1]

Originally posted by david_martin


I think you might by drawing a long bow by assuming that there is a direct relationship between included angle and characteristic vibration. It is far more complex than that - crank configuration and firing order will dictate what the predominant order harmonic vibrations are and what their natural frequencies will be. Clearly the crank configuration and firing order will be determined to an extent by the block included angle but for a given block there will be more than one way to "skin the cat" so to speak.

Seems to make sense to me rather than assuming wide angle has inherently more vibration. If that were true the engineer would avoid using it at all.

Rgds;

[Ali_G]

What makes me laugh is that the wider angle is probabley not lowering the c of g at all. With all the extra material needed to strengten the engine block from flexing it defeats the purpose.

Niall

[TBirdEric]

Not sure if Renault's justification for the 111 degree V is worth the development work, but if any company can perfect a concept, I think Renault is more then qualified.

I expect Fisi will score at least five more points with it this season

Eric

[desmo]

david_martin is exactly right when he warns that the relationship between included bank angle and vibration is not a simple function. The harmonic vibration that F1 engineers lose the most sleep over are torsional vibrations(TVs) in the crank. These can and have "killed" F1 engines. The wide-angle of the Renault engine may be an attempt to address crank TVs. One F1 engineer said on the subject, "The move to weird bank angles is as a result of attempts to nulify TVs and as an offshoot get some form of "Big Bang" traction benefits ~ all this coupled to the aero package of course."

The "Big Bang" aspect deserves further exploration! I am told that the firing order within the banks has been established as 1-2-4-5-3, not coincidentally the same as a humble Audi 5 cylinder sedan! The tricky part is the cross-bank relationship of the FOs. "Big Bang" essentially refers to the cross-bank FO being such that both cylinders that share a crank throw fire on the same crankshaft rotation- the included bank angle defines the degrees of crank angle seperating the firing events. Or perhaps he simply refers to the changing of firing intervals that result from widening the bank angle. Anyone care to speculate how this could provide "traction benefits"? Could the theories that have driven GP motorcycles to adopt this sort of idea- essentially giving a more tire-friendly tractive input- apply to a 10 cylinder engine?

[Top Fuel F1]

desmo:

The only place some answers may be available (if one currently has time to search) may be at www.sae.org .

Rgds;

[delldi]

Is there any pictures of this engine somewhere?

[desmo]

Not where we can see them!

[moog101]

The traction benefits are fairly easy to understand, they stem from the GP500 motorbikes, where V4 engine development far outstripped tyre development. In these bikes it was found that by having the power pulses every 180 deg of the crank (ie: two at once hence 'big bang') it gave the tyre a longer period to regain it's tractive properties - it could deform, slip, bite and reform before it was hit by a slug of power. This prevented the tyre from deforming, slipping, then being hit by more power before it could grip once again. Meaning that some riders had to back off the throttle (which casued highsides) or lowside off anyway!!

As tyres have improved (and Mick Doohan showed everyone how to ride the 90 deg 'screamer' with a conventional firing order) some teams run big bang, and others (with tail happy riders) use screamers.

As I understand all F1 engines fire in a Screamer fashion every (36 deg?) whereas they may well benefit from a firing pattern of 72 deg (I can't believe it hasn't been tried - esp by Honda who started it in GP500)

[IndyIan]

The big bang theory can also proven with dirt bikes. It is a well known fact that 4 stroke bikes are easier to accelerate in low traction conditions than 2 stroke bike given equal hp. This is due to the power pulses of a 4 stroke bike occuring on every second rotation of the crank and the 2 stroke occuring on every rotation of the crank.
Another factor maybe that a 2 stroke bike engine has less rotational mass than an equilvalent hp 4 stroke so the 2 stroke can gain rpms quicker but I don't know.

[Halfwitt]

Originally posted by Ali_G
What makes me laugh is that the wider angle is probabley not lowering the c of g at all. With all the extra material needed to strengten the engine block from flexing it defeats the purpose.

Niall

I am sure that the chassis supplier (Renault) and the engine supplier (Renault) sat down and discussed the pros and cons of this engine. It is likely that the chassis men liked the idea of the lower C of G, and knew about the probable lack of stiffness, and decided to go for it anyway. It isn't working, but it is a completely new concept, and I am sure Renault will get it right eventually.

If the engine is conventional internally, then the power will come. Ferrari and BMW don't struggle with a wider V-angle than Ilmor. If it isn't conventional internally, and Renault are trying something special (I think they probably might be).

As for the lack of chassis stiffness, they know about the problem now, and if they can't fix it this year, they will make sure it is a lot closer next time around.

[Ali_G]

From what I have heard that it is flexing in the engine block which is one of the main problems in the engine. I would have thought that this would be esay to fix.

Niall

[Top Fuel F1]

Originally posted by Ali_G
From what I have heard that it is flexing in the engine block which is one of the main problems in the engine. I would have thought that this would be esay to fix.

Niall

The block is what connects the entire rear (including the forces from the tail wing) of the car to the tub and front end. Only after considering the type of construction (for instance sleeves or not/along with the rest of the design) and also considering the elasticity of the material (for instance what AL alloy and or AL alloy laced with silicon) could you say how easy it is to fix.

Rgds;

[PDA]

Everybody laughed at Renault when they introduced turbochargers to F1. Strike one. Everybody, equally, laughed when Renault introduced the V10 to F1. Stike two. Now they are all laughing at the wide angle V10: strike three?

Do we really know that they are suffering from flexing problems? or is this wild speculation form the Brundles and Matchetts?

Renenber that Ferrari widened the angle to 90 degrees a couple of years ago, and now have probably the best handling car in F1. The new BMW also features a 90 deg. angle. I wouldn;t bet against Renault solving a lot of their unreliability problems, and the Enfield team making big strides with the chassis, before this season is over. They may not get up there with Ferrari/Mc/Williams, but my bet will be for them to get a lot closer than, say, Jaguar.

On the subject of EM valves, I read recently in race Car Engineering that Honda may beat Renault to EM implementation, and that, in the writers opinion, it could be seen on the tracks before the end of this year. the article stated that EM would only be used for valve opening. Pneumatic springs would still be used. Time will tell whther this report has any accuracy.

[desmo]

Two things suggest to me that there is more going on under the Benetton's engine cover than simply a conventional F1 engine with an 111 degree bank angle. First is the dismal performance of the engine thus far. If the only significant innovation of the engine were the bank angle I would expect the results to be much better, the Renault Sport engineers are among the best in the world.

Another signal is the almost unprecedented secrecy of the team in concealing the engine. There are published photos or drawings of every other engine or at least last year's evolution on the grid except the Renault. An exterior shot- especially a publicity shot taken for or by the team who can control what is or isn't revealed- of a conventional F1 engine really tells very little about how it works. Something, be it DI, EM valve actuation or (seems likelier to me) return might be obvious upon viewing the exterior of the engine and the Regie don't wan't to tip their hand yet. I expect that if and when whatever Renault are trying succeeds on the track, we will learn what it is.

[Halfwitt]

Originally posted by desmo
Something, be it DI, EM valve actuation or (seems likelier to me) return ......

I agree. The 'return' part of the profile is the limiting factor in most cases of cams and followers, ands would be the limit of the pneumatic system I would imagine. The system you suggest might allow superfast closing of the valve allowing a longer open duration / height. Whilst this wouldn't be as useful or efficient as full-EM, it does sound to have an advantage.

[Paolo]

On the last issue of Autosprint Mario Theissen of BMW says that he doesn't understand how Renault did find enough space under the cylinders' heads to accomodate the exhausts .
On the other hand, I remember a beautiful article on a recent issue of Race Car engineering where it was explained how clever Renault have been , putting the exhausts in the inside of the Vee ...
I know there are no pics, but anybody has any idea of WHERE are those exhausts located ? Inide or outside the V ?

[Engineguy]

Speaking of that Racecar Engineering article, they claim that it is possible to obtain good valve angles and port shape (and tuck a spark plug in there too) with the intake ports routed between the cams. I haven't had time to do a layout on that to see if I agree. If it is possible though, why stop at 110 degrees? The traditional knock against flat (180deg Vee) engines is the need to raise the entire engine (including heavy crank, rods, main bearing bulkheads, clutch, trannie input, etc.) for exhaust packaging. With the intakes between the cams, and the ehausts on the skyward side of the head, the entire engine mass, bottom end and heads/cams, can sit right on the ground, with only the (very thin, lightweight) exhaust tubing above ankle level. Now we're talkin' a low C of M!

[Marco94]

I have read the RCE article, and have to say that I agree with it's conclusions. As for the exhaust layout of the Benetton, I can only guess that it would be at the bottom. But then maybe Benetton wants us to think so. I never thought it would be a good idea to have your axhausts at the bottom with such a wide angle between the cilinderbanks. For sure we will find out one day.

Marco.

[Marco94]

I have read the RCE article, and have to say that I agree with it's conclusions. As for the exhaust layout of the Benetton, I can only guess that it would be at the bottom. But then maybe Benetton wants us to think so. I never thought it would be a good idea to have your exhausts at the bottom with such a wide angle between the cilinderbanks. For sure we will find out one day.

Marco.

[dearanr]

I don't Belive there is too much wrong with the engine in the Benettons, I think they have toned down the engines power, to have total reliability. Which really the "Renault Engine" hasent foultered yet. all the problems have been electrical onces.

And Fisi after his first run with the new engine raved about the power increce! so i don't belive they are giving all they have! and when' ever they run the B200 with the new 111' engine it's always top 4 on the time sheets.

[marion5drsn]

The thing that most people are missing is how long is the Renault engine? If it is a "Lot" (5.25" or 133.35mm) longer than the regular 72 degree engines then it very likely has five extra crank arms! If this is so then it could very easily have the desirable 72 degree firing pattern. At this point it would also have the piston arriving at the top of the stroke at the same time as one of the cylinders on the opposite bank.This would get rid of the Secondary Shake.
We also have a lot of use of the words ,"Torsional Vibrations" which no one has explained. Do you mean this as being different from the Primary and Secondary Shake and Moments? Or as defined in the Bosch Handbook as Free Forces and Free Moments of the First and Secondary orders. Yours M.L. Anderson

[desmo]

For a great short read on crankshaft torsional vibrations try this:

http://www.sacskyran...om/article2.htm

It obviously talks about Lycoming aero engines but the principle is the same. Gentlemen, start your vector diagrams!

And I really cannot see Renault going to a 10-throw crank but that opens up all kinds of new possibilities as far as balance and FOs.

[marion5drsn]

This article is the same one I read and considered about 5 or 6 years ago when studying the old Hispano-Suiza 180 degree crank V-8. However it is good to read it again. I think several others should read it as it does seem to include the First and Secondary Shake as Torsional. This is one of the problems of vibration as there are just too many ways of describing the same type of vibration. To me the First and Secondary Shake are not Torsional but therein is the problem! M.L. Anderson

[Powersteer]

It amazes me that the 111 vee angle has been the main topic being talked about on Renaults pace. The advancement with most engines in any team comes with more than one modification, such as Ferraris 90 deg engine which didnt improve on the 90 deg itself but came with a whole lot of new parts.


Blame for Renaults pace should be on how the new the engine is until they had to skip winter testing. It also goes to show how new thier approach is with unexpected vibrations, i mean, they could have just gone for the conventional and research on other aspects while purely researching the 111 angle outside competition. Now they have to combat vibrations and torque with power while competing which is confusing and adds unneccesary pressure. Think i read somewhere that they actually had to compromise power to keep the engine reliable.


I just wonder where would the Renault engine be with proven angle and how good is the chassis? They seem little talk about the chassis.

[Melbourne Park]

Just wondering, would the traction control allowance mean a big bang engine is viable?

[Tech_Nut]

Interesting thread.

The engineers at Renault are clever cookies allright. Their track record of innovation (and success) in F1 with the Turbo, V10 and pneumatic valves shows they know the way forward. What is NOT so clever is for them to effectively "waste" a whole season of F1 by doing the engine development so publicly. The performance of the current Benneton is an embarrasment for the team, the drivers and above all, for Renault.

Surely, for an outfit like Renault, with its huge resources, the best option would be to bolt a couple of last season's Mecachromes in the back of the Bennetons (probably good enough right now to promote the cars to the middle of the grid) and to use test mules to develop the new engine in private and well away from the press.

I cannot see what Renault think they are gaining by forcing the whole Benneton team to undergo its current fortnightly humiliation at the hands of the rest of the grid - including Minardi!

T

[Melbourne Park]

Maybe that's Renault bought them: so they could have a live car to play with, otherwise Bennetton wouldn't have used it?

Even if the engine was a BMW, maybe the rest is not up to it yet either. Renault aren't afraid of their reputation hurting anyway; look at what Peugot went through, Renault don't look as bad even now ...

Don't forget BMW also made an F1 engine in 1995, so last year's was a second current generation attempt. Renault are back two years compared to BMW. So maybe they figure the real world pressure is worth it for next year?

I guess Toyota's approach may reveal if it is worthwhile to wait and do it privately ...

[Dan_G]

I would suspect the chassis is not bad at all. Flavio, Jensen, and Giancarlo have said that a significant portion of the performance problem is a result of very bad vibration from the engine. Mike Gascoyne is a good car designer and designed some quality cars at Jordan when they had less than top line engines (although Im sure he had only limited impact on the B201's original design, he will be doing development work).

As an example that the chassis may be going well, is the timing charts from Brazil (a track with a good variety of high and low speed sections)...
Fisichella in qualifying turned in the following sector results...
1st sector (consisting of part of the front straight, the Senna S, and the back straight) - 13th quickest
2nd sector (consisting of the mostly very tight hairpins and a couple quick 3rd and 4th gear corners) - 7th quickest
3rd sector (consisting of the last corner and almost the entire front straight) - 17th quickest
Obviously it is hard to say what kind of downforce settings they were using relative to other teams, but the results would seem to indicate that the chassis is probably not bad, and it is the engine that is causing the poor results.

[Melbourne Park]

I believe that in wet weather engine performance is not significant. There have been wet races and they haven't done so well (although I haven't analysed this).

Also in order to develop a rear suspension, and for that matter a chassis, you need the engine ... maybe not for a middle team, but to win a WDC, you need the full package.

[desmo]

I tend to side with Tech Freak here. The lamentable performance of the Renault engine thus far suggests to me that the concept was not sufficiently tested prior to it being rolled out onto the track, and that whatever testing on the dyno they did that suggested it was was somehow badly flawed. I'm quite sure that Renault would never have brought the engine out for public scrutiny if they had any idea how unready it was for competitive racing. This suggests to me that likely people on the engine development team were being less than frank with His & Co. about the state of development. Whether it was simply optimism on their part or percieved pressure to not be the bearer of bad news is a matter of internal team polotics. Engineers know that an engine that seems fully competitive on the test bench may not work out in the real world. You cannot, for example, reproduce the aerodynamic conditions that affect airbox aero which could mean the difference between pole position and last row on the grid.

[Fudman]

Didn't the last generation of Renault/Mecachrome/Supertec engines use Beryllium in the pistons and or liners? If so T F's idea was a non-starter from Melbourne onwards.

If all the vibration rumors are true wouldn't you rather sort out the bugs this year before going to the full Renault image next year? Also, as can be seen by the debate in this very thread, they can easily make the Benneton chassis at least partially to blame for the sub-par performances thus far.


A slow F1 car does not make for a good corporate image and Next year Renault will only be able blame themselves... mad:

[Top Fuel F1]

Originally posted by Tech_Nut
The engineers at Renault are clever cookies allright. Their track record of innovation (and success) in F1 with the Turbo, V10 and pneumatic valves shows they know the way forward.

They most likely know what the engineering problem is by now. The immediate problem is that they would need to nurse the current hardware along until they can test and phase in the new design (parts).

Rgds;

[Jon Allen]

An (extremely) unreliable F1 car does not make for a good corporate image either, and Renault were the subject of many snickers in 1977. They had the last laugh in 1979 at the French GP with Jabouille's win, and the performance of the Renaults spurred GV to one of the most thrilling drives in F1 history.

Old news, of course, and who knows how they will do in the next few years, but to their credit, Renault does not seem to be afraid of poor initial results, and are willing to give their technical innovations time to mature.

[Top Fuel F1]

Originally posted by Ricardo F1
From what I've read it's definitely detuned by about 100hp in order to stop it self destructing. They now have found the cause of the problem and a new manufacturer for the part has been identified. Gascoyne's comments sounded like this wouldn't be ready for Barcelona but certainly soon and for sure before the end of the season. Don't be surprised to see a Benetton racing for points if not podiums by Suzuka.

This is from the Readers Comments Forum. Interesting and germane to this Thread, if the reading material was accurate about them having had determined the problem.

Rgds;