27 replies to this topic

[mariner]

Looking back through some old magazines I was struck by the bhp/litre trends on road cars - I think there is a racing relevance in there.

 

Back in the 1980's the Ford Sierra was the definitive medium family car. The top model was the 2 litre with a SOHC  4 cylinder "Pinto " engine , power output 105 bhp so 52 bhp/litre.

 

Then came the legendary Sierra Cosworth, a pure performance car. Still  . a two litre 4 cylinder but 16 valves and a turbo, 200 bhp so th magic 100bhp/litre. It could do 149mph and became the most stolen car in Britain relative to sales,  such was its speed appeal 

 

Fast forward to 2015 and the Sierra's direct descendant , the Mondeo. The top level is still a 2 litre but now with 16 valves and a turbo. It produces 240 bhp so 120 bhp/litre and 20% up on the Cosworth engine. It also can do 149 mph just like the Cosworth!

 

So 52 bhp/litre to 120 bhp/litre in a volume car. The Mondeo is still well below other , more performance orientated, volume saloons. The Honda civic Type R has  a 2 ltre four 158 bhp/litre. The Peugeot 308 GTI has a 1.6 litre engine so, to compete it has 166 bhp/litre - higher than a Ferrari 430!

 

It amazes me that such high specific outputs can be delivered in engines which must run 100,000 miles with basically only oil and filter changes every 12,000 miles.

 

In  comparision the Gibson etc engines used in LMP2 are limited to 600 bhp from 4 litres and eight cylinders, or 150 bhp/litre , less than a humble Peugeot 308. 

 

I know the Gibson is an NA not turbo unit but   in terms of absolute power per litre or cylinder these turbo road engines are matching race units. Now that is heavily due to the power limits now imposed everywhere in racing via restrictors but it makes you wonder if , eventually, most racing can be done with standard road engines , sealed for equality.

e

Edited by mariner, 01 February 2018 - 22:31.

[kikiturbo2]

merc AMG A45 is 190 hp/litre

the humble pug has forged pistons, trick turbo, and somewhat special block to handle the power... One thing I always admired about peugeot was that every so often they will pull their thumbs out of their a$$e$ and really make a special motor, and not even brag about it... Some other manufacturers just remap what they allready have...

 

As for standard engines in racing... Many years ago, at the point where WRC engines went to special 1.6 litre units, we had a talk with Juha Kankunnen and he basically said that all this 1.6 litre stuff was stupid and stupidly expensive, when you have off the shelf units that will run 300 bhp all day long at 1/20th of the cost..

[ray b]

ls 7 at 600hp add turbos and alcohol 85 pump mix get 1000hp basic cheap power that will live awhile

the the ''caddy'' that won daytona is a ls based motor

 

pony cars have 300hp base v6 now

 

but no little lite rwd cars at all

love to have a bmw2002 with the early m3 spec 4

but prices on unrusted 2002s are nuts as are old m3's

[mariner]

Thank you Kiki for the AMG  engine at 190bhp/litre,. I missed that one.

 

I am not saying these new road engines are better than a full race one but , rather, that with deliberate power limits in most formulae via restrictors only F1 cars are allowed more than 600- 650 bhp and the race engines are up to 4 litres to produce that , so 150bhp/litre, or even if a turbo like the new Mechachrome LMP! engine- 3.3 litre turbo to get 650 bhp, which is 196 bhp/ litre so virtually same as the AMG 190 bhp/litre.

 

Mind you as a contra-argument I dont know if these road units could take 2 - 3 hours of racing at 70% WOT. I would imagine Honda's history and AMG's approach would say " yes" .

 

I know a little bit about the Gibson units for LMP2 , they are all owned by Gibson who lease them to teams with a guaranteed life of , I think , 15,000 miles . So in way they are o road car durability between rebuilds as the road engine approach their specific power. 

 

Again, maybe road and race units are destined to meet up soon?

Edited by mariner, 02 February 2018 - 14:39.

[MatsNorway]

Mariner. This is exactly why no one is watching racing anymore.

 

The cars got tame. Lots of grip and expensive carbon but no power.

 

a fast(relative) car is not always a wild car. Fans want wild cars. NASCAR is and was wild, they have very little cornering performance but a ton of power.

 

Bring back Trans Am and Can Am, Group A and so on. Group A for Rally was awesome if you ask me. The Peugeot 205 GTi beat the Lancia delta integrale on the twisty bits. no turbo, no 4WD, smaller engine etc.

 

 

Touring cars should have close to stock fenders in steel, stripped interior, original block, heads and bottom end. And lets bring ABCD mains from the rallycross track to the racetrack. Making it possible to qualy to A main by winning your qualified group. from C main etc.

 

Le mans Prototypes should be RWD only with fuel flow and no rpm limit++

 

GT racing should allow any drive train config the cars actually come with and turboes too.

 

If you want to race your giant Bentley with turboes you can do that.. But you also have to deal with 1.6 Tonns or more.. you can not strip or cut it down as much as they do today..

 

cage it and race it.

[V8 Fireworks]

Looking back through some old magazines I was struck by the bhp/litre trends on road cars - I think there is a racing relevance in there.

 

Back in the 1980's the Ford Sierra was the definitive medium family car. The top model was the 2 litre with a SOHC  4 cylinder "Pinto " engine , power output 105 bhp so 52 bhp/litre.

 

Then came the legendary Sierra Cosworth, a pure performance car. Still  . a two litre 4 cylinder but 16 valves and a turbo, 200 bhp so th magic 100bhp/litre. It could do 149mph and became the most stolen car in Britain relative to sales,  such was its speed appeal 

 

Turbocharging is cheating.     The 1991 Honda Civic VTi came with 158hp from a 1.6L naturally aspirated, so that's 99 (non-cheaty   ) hp/L, with 1996 Honda  Integra Type R 108 hp/L and 1999 Honda S2000 of course 120/L, eventually surpassed by 2009 Ferrari 458, 124 hp/L.  

 

Engines like the new turbo Civic Type R and similar (Golf R etc) deliberately run small ports to aid spool up and reduce turbo lag.... with turbos the manufacturer can easily toy with and play with the output -- turning variants up and down on output at will -- and toy with drivability like the 488.  See below -- you get a different output depending on what gear you are in, what would Enzo think! 

 

Ferrari 488 variable torque management

 

Modern turbo engines simply haven't been designed to get as much power as possible from the capacity in the way the old FD2 Civic Type R or Mugen RR did, or a Porsche GT3 RS, or a Ferrari 458 or whatever did IMO. 

 

While turbo business (and getting high outputs past increasingly difficult emission regulations) is still clever, the old days of high hp/L naturally aspirated engines coming right out of the factory with nice big ports and high-lift cams (oem 1/2" lift!) is long gone -- such a shame. 

Therefore IMO the "old days" offered purity of driving and engineering IMO, unlike modern trickery (as per 488). 

Edited by V8 Fireworks, 03 February 2018 - 02:32.

[V8 Fireworks]

but no little lite rwd cars at all

love to have a bmw2002 with the early m3 spec 4

but prices on unrusted 2002s are nuts as are old m3's

 

The Toyota 86 is cheap in many countries (apart from EU where it is imported from outside EU so has high tariff), and makes 102.5 hp/L (non-turbo!) while weighing 1250kg (similar to E30 coupe, yet the roof of the 86 won't cave-in in a rollover or anything!).  It should meet your requirements? 

 

If you want a four-door "version" of the Toyota 86, the Toyota Altezza RS 200 is an excellent choice of used car (of course you must live in a countru where imports of used Japanese cars, and specifically this model, are legal... ideally a RHD country but they still drive imported Japanese cars in Canada anyway).  Toyota 3SGE BEAMS engine making 100hp/L from 2.0L non-turbo.  Being a true Toyota, it has arguably superior quality to the Subaru-built 86.

 

The Mazda MX5 and Fiat 124 Spider are even lighter, but may be somewhat more expensive as they only come in higher trims with more equipment.

Edited by V8 Fireworks, 03 February 2018 - 02:31.

[Greg Locock]

The Toyota 86 is a very boring car to drive. It only becomes interesting if you overcook your entry speeds, which as a driver of powerful RWDs since 1985 is just about the worst idea ever invented (fun in a Mini tho). MX5 has it beat in every way, in my opinion.

[mariner]

I rather like the Honda Civic Type R , partly because it combines Honda's traditional rev happy engine design with a strong turbo and partially because it looks so wacky.

'Getting 176 mph out of a $30K saloon with four seats and doors isnt bad either!

 

I've never driven a F86, it looks nice, is  light and has RWD. Being a big Chevy SB fan my real interest would be to measure the engine bay to see if one would fit. Say 1350kg and 505 bhp, hmm.

Edited by mariner, 03 February 2018 - 12:38.

[Greg Locock]

Yeah lack of oomph is my main criticism. It also has rather ungrippy tires. Once a year the boss hires whatever interesting cars he can and we go for a road test (haha) to the beach and have a barbecue. The 86 was rated highly by most of the vehicle dynamics guys because it is nicely balanced, and has good steering feel. On the public roads the lack of sticky tires is no big deal. My main reaction was 'competent but dull'. Mind you I wouldn't have a WRX as a real car, the ride is unbearable. 

[Bob Riebe]

Mariner. This is exactly why no one is watching racing anymore.

 

The cars got tame. Lots of grip and expensive carbon but no power.

 

a fast(relative) car is not always a wild car. Fans want wild cars. NASCAR is and was wild, they have very little cornering performance but a ton of power.

 

 

GT racing should allow any drive train config the cars actually come with and turboes too.

 

 

Wight determined by displacement, that worked extremely well during the golden years. No fuel flow limits, but if you put a blower of a large V-8 you will be racing a multi-ton vehicle.

The blown Porsches dominated because they had little even semi-factory opposition but they found out when blowers were considered as larger displacement the wonderful handling that really helped the 911 went bye-bye as did the high mpg they had..

[Kelpiecross]

I may be a bit old-fashioned but I regard turbo engines to be cheating in a way. You can turbo an engine to make any sort of output if it is strong enough mechanically - even something like a sidevalve engine. To get maximum BHP out of a NA engine takes good design.

[V8 Fireworks]

 

 

The 86 was rated highly by most of the vehicle dynamics guys because it is nicely balanced, and has good steering feel. ... My main reaction was 'competent but dull'.

 

 

I thought you might like the low centre of gravity, allowing it to have low bodyroll despite having relatively soft suspension... guess not.

 

Do you suppose the enthusiastic driver shouldn't be frightened of bodyroll and should embrace it?

 

Personally I hate "floppy" feeling cars, I have the Koni yellows on a car and even on full stiff the car feels too "uncontrolled"/"floppy" (the springs are at the softer end of they can be paired with, maybe too soft?) and doesn't have the steering response I would like...    The other car with OEM Honda suspension seems much better (albeit a little harsher than the Konis), given the choice Japanese style overdamping seems preferrable.    

 

 Mind you I wouldn't have a WRX as a real car, the ride is unbearable. 

 

 

What do you make of the Focus RS?  https://youtu.be/ADzNGKmmX1Q?t=3m27s According to the interwebs, it is "notorious" for having overly stiff shock absorbers.     What were your German colleagues trying to achieve with it's ride? 

Edited by V8 Fireworks, 04 February 2018 - 19:35.

[Bob Riebe]

I may be a bit old-fashioned but I regard turbo engines to be cheating in a way. You can turbo an engine to make any sort of output if it is strong enough mechanically - even something like a sidevalve engine. To get maximum BHP out of a NA engine takes good design.

Bravo     Bravo   !

[MatsNorway]

Wight determined by displacement, that worked extremely well during the golden years. No fuel flow limits, but if you put a blower of a large V-8 you will be racing a multi-ton vehicle.

The blown Porsches dominated because they had little even semi-factory opposition but they found out when blowers were considered as larger displacement the wonderful handling that really helped the 911 went bye-bye as did the high mpg they had..

 

I would not copy Group A too hard if it was entirely up to me. Classes would be:

 

Mini (wheelbase limit and 4 seats minimum) NA engine -typical cars would be org. mini coopers. first gen Golf etc. -

super compacts (4 seats minimum, bigger wheelbase limit) NA engine - Newer golfs, Audi A3, Lancia Delta etc.

Super Touring (any 5 seater car allowed, including 5 seater minis++) - Full size sedans..

Sports car (any 4+ seater car, as in real seats, not mazda Rx-7 rear seats) - Porsche 911, Camaro, AMG models, Nissan GTR

Super car (any car with minimum 2 seats, alu or steel chassie) - Lotus Exige, Audi R8, Gallardo

 

Common for all would be very strict focus on stock chassis. Same engine (block, bottom end, and top) as the car came with, No carbon fiber allowed until supercar/sports car class. Meaning you really get the drawbacks of a big car with a big engine. Such as weight and tire wear

Stock wheel offset (+.-10mm) whould be forced, Fenders can not be more than 5cm bigger than stock. Tiny single element wing for mini class with gradual increase in size as you go up. Lots of rules for placement of wings. Hatchbacks does not get a wing etc. but can run roof spoiler Lancia Delta style.

 

All cars must run manual gearbox, no hybrid tech allowed so New NSX must strip that out.

 

Sorry for derailing the thread. but it is fun dreaming of classes like this.

[mariner]

I may be a bit old-fashioned but I regard turbo engines to be cheating in a way. You can turbo an engine to make any sort of output if it is strong enough mechanically - even something like a sidevalve engine. To get maximum BHP out of a NA engine takes good design.

 

That is a valid viewpoint but then is increasing the bore and stoke of an NA engine also cheating when no legal capacity limit  exists - as in road cars or BoP?

 

Keith Duckworth maintained strongly that the 1.5 litre turbo cars were illegal in F1 vs his 3 litre DFV. His argument was obviously commercially driven but he pointed out that two parts of the Otto cycle , compression and expansion, which had to be done within the limited size of an NA engine ,were partially done externally in the turbo unit and there was no limit on its size or performance. Being Duckworth a good argument.

 

I will play academic for a moment and argue that all this is now irrelevant because my argument that road and race engines are converging is driven by the fundmental fact they are both now fuel flow limited. F1 and LMP, the top racing formulae have fuel flow regs. and the legal CO2/CAFE regs. in EU and USA are another fuel flow formula as a target fuel consumption is required over a specified drive cycle.

 

So capacity doesn't really matter and revs are now bad news in race engines so convergence is inevitable!!??

[7MGTEsup]

I don't see how a turbo is cheating as power = how much air and fuel you can squeeze into the cylinder and burn. A turbo is just a much more efficient way of doing it. Also unless you have a massive displacement an N/A engine can't hope to produce the same levels of torque as a turbo engine. With modern EFI, twin scroll turbos and tuned divided manifolds turbo lag is pretty non existent.

[Bob Riebe]

I don't see how a turbo is cheating as power = how much air and fuel you can squeeze into the cylinder and burn. A turbo is just a much more efficient way of doing it. 

LOL there is nothing efficient about blown engines, period.

Porsche found that out with the fuel mileage on the 930-5.

Add heat, weight, engine strain or as a Porsche mechanic told me once, it is not if your turbo goes out but when.

Edited by Bob Riebe, 05 February 2018 - 20:35.

[gruntguru]

LOL there is nothing efficient about blown engines, period.

This a technical forum with emphasis on F1.

The current F1 power-plant is the most efficient ICE on planet earth, period - and yes it is "blown".

[mariner]

In his great autobiography Tony Rudd, the BRM and Lotus engineer, tells of his apprenticeship with Rolls Royce in the 1930's and his job studying RR Merlin reliability  in WW2. 

 

The Merlin's were not that reliable at first which led to pilot engine handling courses at RR to try to help things. He had a hard time making the pilots realise they must use coarse pitch and high boost to get enough fuel economy to return to base from a long mission. They liked to hear "smooth" engines revving nicely at fine pitch not rumbling away under heavy boost!

 

Inicidentaly the Merlin was a pretty highly stressed engine by 1930's aero standards. It was 27 litres but they got 60bhp/litre out of it by mid war. Might not sound too high but that's at 3,200 rpm or so. Therefore in car terms that is 120bhp/litre at 6,000 rpm.

 

So centrifugally blown engines can be  efficient too. Incidentally Honda's chief engineer in its pre-hybrid days told the FIA that boost will always be cheaper to engineer than revs. 

Edited by mariner, 06 February 2018 - 12:35.

[7MGTEsup]

LOL there is nothing efficient about blown engines, period.

Porsche found that out with the fuel mileage on the 930-5.

Add heat, weight, engine strain or as a Porsche mechanic told me once, it is not if your turbo goes out but when.

 

That's what happens when you run air cooled with a 7:1 compression ratio, we have come a long way in 40 years.

[Bob Riebe]

That's what happens when you run air cooled with a 7:1 compression ratio, we have come a long way in 40 years.

All the same problems are still there.

One of the few time you get more than you pay for.

A blower going out has little to do with the design of the engine.

[7MGTEsup]

All the same problems are still there.

One of the few time you get more than you pay for.

A blower going out has little to do with the design of the engine.

 

From what I understand of the situation they had to run incredibly rich with the air cooled engines as it's a very inefficient way of cooling the engine and also they had a pretty large parasitic loss with the cooling fan. Also low compression doesn't help with your engine efficiency. 

[Nathan]

Are we confusing efficiency and economy?

[Tenmantaylor]

I'm biased (as I drive one) but I'd say the S65 unit in the BMW M3 E92 has to be one of the best ever for purity and bhp/litre at 4L and 414hp. Would the purists consider variable valve timing cheating?

 

https://en.wikipedia.org/wiki/BMW_S65

 

Won engine of the year 5 years straight in it's category, preceded by the 911 Turbo and succeeded by the McLaren 650S engines respectively.

 

The throttle response and sound are quite incredible as is it's breadth of range and tractability. Can pretty much drive it in any gear and never bogs down. The efficiency... not so much.

Edited by Tenmantaylor, 14 March 2018 - 21:29.

[V8 Fireworks]

I'm biased (as I drive one) but I'd say the S65 unit in the BMW M3 E92 has to be one of the best ever for purity and bhp/litre at 4L and 414hp.

 

It's a good engine, apart from the lack of big end bearing clearance and dodgy plastic gears on the ITB mechanism. 

 

How well does the VANOS hold up on the S65?  it's usually a weakness of other BMW engines.

Edited by V8 Fireworks, 15 March 2018 - 23:23.

[omgwtf]

Turbocharging is cheating.     The 1991 Honda Civic VTi came with 158hp from a 1.6L naturally aspirated, so that's 99 (non-cheaty   ) hp/L, with 1996 Honda  Integra Type R 108 hp/L and 1999 Honda S2000 of course 120/L, eventually surpassed by 2009 Ferrari 458, 124 hp/L.  

 

Engines like the new turbo Civic Type R and similar (Golf R etc) deliberately run small ports to aid spool up and reduce turbo lag.... with turbos the manufacturer can easily toy with and play with the output -- turning variants up and down on output at will -- and toy with drivability like the 488.  See below -- you get a different output depending on what gear you are in, what would Enzo think! 

 

Ferrari 488 variable torque management

 

Modern turbo engines simply haven't been designed to get as much power as possible from the capacity in the way the old FD2 Civic Type R or Mugen RR did, or a Porsche GT3 RS, or a Ferrari 458 or whatever did IMO. 

 

While turbo business (and getting high outputs past increasingly difficult emission regulations) is still clever, the old days of high hp/L naturally aspirated engines coming right out of the factory with nice big ports and high-lift cams (oem 1/2" lift!) is long gone -- such a shame. 

Therefore IMO the "old days" offered purity of driving and engineering IMO, unlike modern trickery (as per 488). 

IIRC The BMW engined McLaren F1 & BMW E36 M3 Evo were the first production cars to break 100bhp/litre (NA)

[Tenmantaylor]

It's a good engine, apart from the lack of big end bearing clearance and dodgy plastic gears on the ITB mechanism.

How well does the VANOS hold up on the S65? it's usually a weakness of other BMW engines.

Have heard plenty of rod bearing and throttle actuator issues but none about the vanos in comparison.

Mine is drinking quite a lot of oil (1L per 1500 daily miles) and some have mentioned it's time to get the bearings done as a preventative measure and theirs drank less once replaced. Mine is on BMW insured warranty so am reticent to fork out on the chance they are actually ok and I void the warranty.