RE: Fast should mean scary: Tell Me I'm Wrong

[TWPC]

zeppelin101 said:

TWPC said:

This is slightly off topic but why do car companies fit cars with electric power steering?

The excuse given is emissions & economy. We all know that the benefits are infinitesimal & would only benefit an owner who drove the car about 300,000 miles.

Is the real reason that it is more profitable for them?

Just asking.

Powering the hydraulic pump off the engine saps power and engine economy. It's of the order of a few % measured at the engine (not in a vehicle). Given that every car company in the world is chasing fuel economy and emissions and anything that inhibits these appears to be the fault of the Powertrain (experience talking) then manufacturers have to do everything in their ability to make sure that the engine uses the least amount of fuel possible. EPAS just draws some alternator current when required.

It's probably also easier to package. Which from a diesel point of view is probably a good thing since they now have the equivalent of a chemistry lab cleaning up the emissions.

Of course, a lot of these issues could be alleviated through less barn-door styling on bigger cars lower kerb weights and less stupid tyre footprints (rolling resistance) but there we go...

Edited by zeppelin101 on Monday 18th November 09:08

zeppelin101, Thank you for your response.
It sounds very reasonable, interesting, rather depressing and legislation-driven.
Do the powertrain engineers get training in debating and politics? Wish they did so they could hold their own in the briefings/meetings with the finance and marketing departments...

Regarding your comments on the impact of styling, weight & tyre sizes, with which I completely agree, I think the commentary on the BMW i3 is very interesting.
As you no doubt suspect, it seems to suffer very little in terms of grip and stability from its narrow tyres. From Autocar:
"The i3 also has remarkable stability, as a series of driving exercises at Brands Hatch prove. Sharp lane changes and even a stretch of hilly circuit in the pouring rain fail to ruffle the i3, even though it has 155/70 tyres at the front and 175/70s at the rear."
http://www.autocar.co.uk/car-review/bmw/i3/first-drives/bmw-i3-range-extender-first-drive-review

Wide tyres = marketing

[consul]

I Have a 996 GT2 and I could never imagine stepping into these Play Station cars. Not for any price. There like having a girlfriend with Implants, why play with plastic toys when you can have the real thing !
Manuel, Rear wheel drive, No TC and just a sensible right foot

[macky17]

TVR Tuscan S - the perfect solution. Fun even in traffic.

[Kolbenkopp]

iloveboost said:

I may sound like a Buddhist monk but in a good car on an empty road there is a point at which you feel like you are one with the car. Outside you there is noise and chaos but inside you everything flows peacefully and smoothly. That feeling doesn't come from 10% more of a number, or being scared out of your mind.

+1! Ommm .

[adulation] Nice thread this, thanks all for for some surprising insights. [/adulation]

[iloveboost]

havoc said:

Hmmm...Becs runs a MkV Golf GTi - 197bhp 2.0 turbo-petrol. I run an FD2 Civic Type-R - 222bhp 2.0 n/a petrol.

Guess which of us gets better daily mpg and better long-run mpg?!? Yep...the n/a engine with the more power!!!

You may have found the achilles heel of turbo, the temple of VTEC. You should win a prize or something. Seriously though you're comparing different drivers on different journeys. That's like comparing an M5 on a virtual trip to the moon vs a Fiesta driving around Silverstone. I agree with you that a similar size engine will usually get similar mpg but a mountune Fiesta ST now makes as much power as an FD2 civic, and that's going to be quite a but more economical like for like. I'm not saying better to drive, but certainly torquier and as fast in a straight line.

[iloveboost]

TWPC said:

zeppelin101, Thank you for your response.
It sounds very reasonable, interesting, rather depressing and legislation-driven.
Do the powertrain engineers get training in debating and politics? Wish they did so they could hold their own in the briefings/meetings with the finance and marketing departments...

Regarding your comments on the impact of styling, weight & tyre sizes, with which I completely agree, I think the commentary on the BMW i3 is very interesting.
As you no doubt suspect, it seems to suffer very little in terms of grip and stability from its narrow tyres. From Autocar:
"The i3 also has remarkable stability, as a series of driving exercises at Brands Hatch prove. Sharp lane changes and even a stretch of hilly circuit in the pouring rain fail to ruffle the i3, even though it has 155/70 tyres at the front and 175/70s at the rear."
http://www.autocar.co.uk/car-review/bmw/i3/first-drives/bmw-i3-range-extender-first-drive-review

Wide tyres = marketing

Are you trolling? Wide tyres equals marketing st? You need to read more.

[iloveboost]

consul said:

I Have a 996 GT2 and I could never imagine stepping into these Play Station cars. Not for any price. There like having a girlfriend with Implants, why play with plastic toys when you can have the real thing !
Manuel, Rear wheel drive, No TC and just a sensible right foot

Hehe. I share your aversion to fakeness though sometimes done correctly and tastefully fake can be fantastic. Example would be if Dacia reversed engineered the Porsche 996 then sold a modern equivalent for £2.50! I'd be first into a local dealer, then first into a nice hedge! That's not a euphemism! Actually that's not a bad idea considering that I think the Porsche 911 still has less competition than Kim Jong Un.

[iloveboost]

macky17 said:

TVR Tuscan S - the perfect solution. Fun even in traffic.

So you're not bored yet of scaring pensioners with a loud BANG from the pleasure pipes?! Pleasure pipes is my unoffical name for all TVR exhausts from now on.

[Gary C]

iloveboost said:

TWPC said:

zeppelin101, Thank you for your response.
It sounds very reasonable, interesting, rather depressing and legislation-driven.
Do the powertrain engineers get training in debating and politics? Wish they did so they could hold their own in the briefings/meetings with the finance and marketing departments...

Regarding your comments on the impact of styling, weight & tyre sizes, with which I completely agree, I think the commentary on the BMW i3 is very interesting.
As you no doubt suspect, it seems to suffer very little in terms of grip and stability from its narrow tyres. From Autocar:
"The i3 also has remarkable stability, as a series of driving exercises at Brands Hatch prove. Sharp lane changes and even a stretch of hilly circuit in the pouring rain fail to ruffle the i3, even though it has 155/70 tyres at the front and 175/70s at the rear."
http://www.autocar.co.uk/car-review/bmw/i3/first-drives/bmw-i3-range-extender-first-drive-review

Wide tyres = marketing

Are you trolling? Wide tyres equals marketing st? You need to read more.

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

[MC Bodge]

Gary C said:

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

Not quite. They push 'the limit' a bit higher, but make 'the limit' harder to achieve and don't necessarily give an improvement on a road.

[havoc]

iloveboost said:

havoc said:

Hmmm...Becs runs a MkV Golf GTi - 197bhp 2.0 turbo-petrol. I run an FD2 Civic Type-R - 222bhp 2.0 n/a petrol.

Guess which of us gets better daily mpg and better long-run mpg?!? Yep...the n/a engine with the more power!!!

You may have found the achilles heel of turbo, the temple of VTEC. You should win a prize or something. Seriously though you're comparing different drivers on different journeys. That's like comparing an M5 on a virtual trip to the moon vs a Fiesta driving around Silverstone. I agree with you that a similar size engine will usually get similar mpg but a mountune Fiesta ST now makes as much power as an FD2 civic, and that's going to be quite a but more economical like for like. I'm not saying better to drive, but certainly torquier and as fast in a straight line.

Nope - when Becs was on mat'y leave I drove the Golf for a while to stop it sitting there. Same journeys, same driver. Similarly when we do long journeys I do the driving mostly. Can't get above 32-33mpg* in the Golf at a fast M-way cruise (85+ indicated, so ~80 actual), yet the Civic returns ~2 mpg more at the same speeds.

As for a modified car vs factory standard...now who's comparing apples with oranges?!? And I'd have my doubts over the economy there, TBH.



* That said, a friend regularly got 35-36 on a long run in their Octavia vRS - different driver maybe, or maybe the Golf's high-speed aero is crap.

[Gary C]

MC Bodge said:

Gary C said:

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

Not quite. They push 'the limit' a bit higher, but make 'the limit' harder to achieve and don't necessarily give an improvement on a road.

Therefore they can be just due to marketing ste.

And bigger wheels and tyres don't always make 'the limit' higher. While they can increase the steady state grip, it is possible to upset the whole dynamic balance of the chassis settings, but a major manufacture would not do that, would you Porsche

[MC Bodge]

Gary C said:

MC Bodge said:

Gary C said:

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

Not quite. They push 'the limit' a bit higher, but make 'the limit' harder to achieve and don't necessarily give an improvement on a road.

Therefore they can be just due to marketing ste.

And bigger wheels and tyres don't always make 'the limit' higher. While they can increase the steady state grip, it is possible to upset the whole dynamic balance of the chassis settings, but a major manufacture would not do that, would you Porsche

I'm certainly not disagreeing with your last post.

I prefer tyres with some air volume that give some feedback, cushioning and help keep the car stay in contact with the (not necessarily smoooth)road, even though it may not result in the sharpest possible steering and ultimate lateral grip at 10/10ths.

[Kawasicki]

Gary C said:

MC Bodge said:

Gary C said:

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

Not quite. They push 'the limit' a bit higher, but make 'the limit' harder to achieve and don't necessarily give an improvement on a road.

Therefore they can be just due to marketing ste.

And bigger wheels and tyres don't always make 'the limit' higher. While they can increase the steady state grip, it is possible to upset the whole dynamic balance of the chassis settings, but a major manufacture would not do that, would you Porsche

I spent today comparing 35 profile tyres against 50 profile tyres. The steady state grip was about the same, the transient stability was hugely improved with the lower profile tyres. Same pattern, same tread compound, same car, same surface. Lower profile tyre was clearly easier to drive.

[havoc]

Kawasicki said:

I spent today comparing 35 profile tyres against 50 profile tyres. The steady state grip was about the same, the transient stability was hugely improved with the lower profile tyres. Same pattern, same tread compound, same car, same surface. Lower profile tyre was clearly easier to drive.

Did it communicate the transition as well as the higher profile?

[Gary C]

Kawasicki said:

I spent today comparing 35 profile tyres against 50 profile tyres. The steady state grip was about the same, the transient stability was hugely improved with the lower profile tyres. Same pattern, same tread compound, same car, same surface. Lower profile tyre was clearly easier to drive.

Don't disagree, just point out that dictating wheel and tyre size for fashion, does not always work and an over tyred car without the correct setup can be worse.

[zeppelin101]

TWPC said:

zeppelin101, Thank you for your response.
It sounds very reasonable, interesting, rather depressing and legislation-driven.
Do the powertrain engineers get training in debating and politics? Wish they did so they could hold their own in the briefings/meetings with the finance and marketing departments...

God no, most of the engineers I know are dreadful politicians haha

The ones who are politically minded invariably end up managing the engineers doing the "real" work!

In my job, I find I have more difficulty dealing with other engineers from conflicting attributes than I do the likes of finance. All marketing want is more of everything from a powertrain perspective but that can be managed. Other attributes though? Like arguing with a lump of granite at times.

RE: the wide tyres issue - it's fine up to a point in my view but when you're hatchback is rolling around on tyres that wouldn't look out of place of a 400hp+ sportscar then something has gone wrong somewhere. I don't know about anyone else but lower profile wider tyres are all absolutely fine until you get anywhere near the limit (in any sense) and then everything happens VERY quickly? Certainly thought that was the case in my M3 (was on 19s) but I get so much more time and information from my 180SX on 225/45/17s that I wonder why manufacturers who build drivers cars stick 20" wheels on with rubber bands for tyres...

Also on the fuel economy argument that is brewing, it's surprising how much difference a properly run-in engine has over one that has just been "driven". Nothing you can do with a second hand purchase but brand new cars, it's certainly worth the time running them in properly.

Edited by zeppelin101 on Thursday 21st November 13:38

[Digga]

havoc said:

Kawasicki said:

I spent today comparing 35 profile tyres against 50 profile tyres. The steady state grip was about the same, the transient stability was hugely improved with the lower profile tyres. Same pattern, same tread compound, same car, same surface. Lower profile tyre was clearly easier to drive.

Did it communicate the transition as well as the higher profile?

Depends hugely on vehicle size, weight and suspension set-up.

If the car's grip has previously relied on high-speed bumps being dealt with by a 50 profile tyre, then simply buning on 35s may reduce grip in a lot of situations.

[iloveboost]

Gary C said:

He has a point, wide tyres/big rims/low profile just for the sake of looks= marketing ste.

The lotus video shows that perfectly.

I hate doing this I'm going to have to agree with you. That's sorta my point in the other post in a nutshell it's marketing and progress vs driving pleasure and fun. It's a bit complicated. The big downside to less grip and more accessible handling is if it's easier to drive at the limit you may push the limits more frequently and crashes would be more frequent for the average driver because braking distances go up and crash/object avoidance is more difficult.

[JDMDrifter]

consul said:

I Have a 996 GT2 and I could never imagine stepping into these Play Station cars. Not for any price. There like having a girlfriend with Implants, why play with plastic toys when you can have the real thing !
Manuel, Rear wheel drive, No TC and just a sensible right foot

A 911 GT2, Boobs and No TC in a post. This is Pistonheads!