RE: Let turbos be turbos: Tell Me I'm Wrong

RE: Let turbos be turbos: Tell Me I'm Wrong

Monday 16th March 2015

Let turbos be turbos: Tell Me I'm Wrong

If we're stuck with turbocharged cars why not make them feel turbocharged?



The humble turbocharger is the saviour of the modern performance car. So why hide it?

PH Explains: what is a turbocharger and how do they work?

Obviously we'd love to keep hold of our fizzy, high-revving four-pots, sonorous straight-sixes and spine tingling Vs, all of them boasting fulsome cubic capacities, sucking through individual throttle bodies and uncorrupted by charisma-sapping forced induction. But a few die-hards aside it ain't going to happen. 'Torque filling' electric assistance is surely going to trickle down from the hybrid supercars. But in the meantime our downsized engines need their turbos to make up the shortfall in performance.

'Turbo' was something to be proud of once
'Turbo' was something to be proud of once
So let's celebrate the fact!

Back when turbocharging first became commonplace it was a badge of honour, literally. BMW even wrote it, ambulance style, on the nose of the2002 Turbo so when glimpsed in the mirror you knew the baby Beemer was on a charge.

Flatter to deceive
It's different these days. Manufacturers are doing their damndest to pretend the turbos aren't there, disguising them behind piped-in engine noise, carefully massaging power and torque curves to mask lag and generally doing everything to convince us 'turbo' is a dirty word.

Don't believe me? Listen to AMG's Tobias Moers in our (shameless plug alert!) latest episode of PHTV, talking about the new 4.0-litre V8 in the C63 and asserting that disguising the forced induction was a key development goal. AMG has managed this better than most and Moers is correct in identifying driveability as the reason for wanting his turbo engines to feel like normally aspirated ones. He's got the luxury of - relatively speaking - more cubic capacity than most to fall back on too.

AMG has mastered switch to turbos
AMG has mastered switch to turbos
But as engines get smaller and turbos get bigger manufacturers are seemingly desperate to use every trick in the book to hoodwink us into thinking the turbos aren't there. Why bother? Let's enjoy them for what they are!

Jump to hyperspace
Back in the turbo's glory days the technology was a lot more crude, meaning there was no choice but to make sudden eruptions of boost a defining characteristic. I'm possibly a product of my age here but in my formative years turbos and Star Wars both figured prominently on my list of cool things. And even the Millennium Falcon had lag. Hell, that pause between Chewie pushing the throttles and the stars going all streaky is, in my head, the same as that one ... two ... WHOOSH sensation you get in an old-school turbocharged car.

I like that tingle of anticipation as the boost builds and then erupts into proper thrill-ride acceleration. To the point where I constantly drive modern cars a gear or two up to deliberately provoke a sense of lag, just for the hell of it.

When men were men and turbos were TURBOS
When men were men and turbos were TURBOS
When it's done well, as it has been in the C63 and GT, the modern technique of managing and playing with boost to balance out the more dramatic peaks in power delivery is effective. Indeed, as AMG's engine man told me with the M177/M178's variable valve timing and boost at his disposal he could make it 'feel' any way you'd like.

But too many modern engines are so fixated on eliminating lag that they forget to manage the power delivery once the engine is on boost. Meaning you get everything up front and steadily diminishing returns beyond. It's almost like reverse lag - back in the day you had nothing, nothing, nothing and then - WHAM - a massive spike of boost. Which, if it happened mid-corner or just as you wanted to back out of the throttle, could cause you significant problems.

M3 does this very easily; not always wanted
M3 does this very easily; not always wanted
Back to front
These days it all happens immediately and then tails off, meaning theM3/M4 syndrome of instant boost that overwhelms the tyres and leaves you dependent on the electronics to mitigate the resulting traction loss. Sure, you can disable the DSC and rely on your god-like reflexes to tame the beast. And it's great for hacks looking to bank the essential fully lit cornering shot for film or photo glory.

But the amount of flashing DSC light you get on a moderate throttle on a dry road is revealing of how hard the electronics are working to manage that power delivery. Indeed, as an experiment on the M3/M4 launch I did an at-pace lap of Portimao with everything fully on and there was so much intervention to stop the wheels spinning up it felt at times like the thing wasn't going to get up the inclines. For all the undoubted cleverness the engineers put into making the engine rev, maintain its boost for optimum throttle response and the rest the cruder, boostier 1 M Coupe's engine is more 'fun' and charismatic.

The all-pervading hot MQB platform cars from the VW group - Golf GTI, Golf R, Leon Cupra, Octavia vRS, Audi S3, et al - don't quite have the same traction problems. But the attempt to mask the forced induction has left a dull, one-dimensional power delivery that gives you everything up front and then leaves the party early. Sure, the rev counter reaches beyond 3,000rpm. But there's little incentive to go there, beyond fake engine noise on the speakers the CIA may want to look at for future 'enhanced interrogation' techniques.

Dan's Subaru makes a virtue of its turbo
Dan's Subaru makes a virtue of its turbo
Maybe I'm just old-fashioned. But one of the things I love about 'my' SubaruWRX STI long-termer is that it feels turbocharged. The peak power and boost are just as short-lived as those MQB cars and you need to be busy with the gear shifts to keep it on the boil. But at least it's higher up in the rev-range, giving you something to work for. And Subaru isn't shy of letting you hear the whine of the turbo spooling up, the rush of the air going through the induction system or the distinctive chuff of the dump valve as you come off the throttle. And I love the fact this varies according to the weather and climactic conditions.

Porsche has seemingly learned this too. The 997 Turbos were epic cars and brutally fast and efficient. The variable vane turbos made for a broader operating range than most too. But even 500hp-plus felt a little soulless. The991 seems to have rediscovered its love for feeling - and sounding - like a Turbo and is so much more entertaining for it.

Turbo McLaren beats atmo Ferrari? Really?
Turbo McLaren beats atmo Ferrari? Really?
See also the McLaren 650S and its relatives. I'm more interested by the hissing and cooing of the induction system than the 'augmented' Intake Sound Generator and much more entertained by it than the binary quiet/LOUD game played by the 458's exhaust system. At civilian speeds it even feels more fun, the boostiness more exciting than the Ferrari's linearity in those sneaky little squirts of acceleration you get to enjoy in everyday driving.

So, manufacturers. Don't be scared. Make our turbos sound and feel turbocharged again. Please!

Punch it, Chewie!

 

 

[Sources: BMW M-Power.com; tonynibbles, via YouTube]

 

 

Author
Discussion

Sampaio

Original Poster:

377 posts

138 months

Sunday 15th March 2015
quotequote all
I drive a naturally-aspirated MX-5 on a daily basis and my father's turbo-diesel Volvo S60 every once in a while. I love driving both cars precisely because of the completely different way the power is delivered.

The Volvo has the famous 5-cylinder diesel engine and it feels properly turbocharged. Certainly not 80's/90's turbocharged but you'd be surprised how strong the sudden boost is for a family saloon. The Mazda has to be pushed to its (rev) limit, but when your at 6k-7k rpm the buzzing feeling is heavenly.

Anyway, just wanted to say I don't think you're wrong in your analysis. Engine character comes from the two extremes: immediate response at high revs or wait-for-boost-and-GO!

Anything in the middle will always feel like a boring compromise.

ging84

8,897 posts

146 months

Sunday 15th March 2015
quotequote all
Modern cars have too much torque and not enough lag
are motoring journalists a different species ?

slipstream 1985

12,220 posts

179 months

Sunday 15th March 2015
quotequote all
I swap between a 1.8turbo vag unit and a bmw straight 6. The straight 6 everytime i get in it gun it for what seems like an age then look at the rev counter and still another 2000revs to go with more power just seems great. Whilst the vag unit pulls instantly from when the boost kicks it fades quickly and if off the boil it has nothing. Its much harder to judge overtakes in the vag unit yet the bmw you can nip out knowing the power will be there.

e8_pack

1,384 posts

181 months

Sunday 15th March 2015
quotequote all
Do manufacturer's not use the improved billet wheel designs for their hotter models? I used to be all for peak power until I saw what a smaller, better designed turbo can do to a more "powerful" car.

anonymous-user

54 months

Sunday 15th March 2015
quotequote all
I can see it from both sides, in a daily driver what you need is quick, easy response to throttle input, in a more focused car you want involvement and fun.

There is no right answer. The market has moved in the direction that the non-enthusiast market and journos have been asking for, torquey fuel efficient engines with minimal lag.

W124

1,532 posts

138 months

Sunday 15th March 2015
quotequote all
Absolutely right on. Still remember the wonder of the 900 Turbo. A friends dad still has one. I used it not too long ago to take some broken bits of wardrobe to the dump. The two of us in hysterics over the power delivery. A savagely fast and enjoyable car on boost. Felt much faster then the figures suggest. That's it I guess. The acceleration of the rate of acceleration. I really regret missing that 900 in the recent carpool. Royalties just a bit late, again. Can see those cars getting very valuable, even as the rest of the market tanks.

MarshPhantom

9,658 posts

137 months

Sunday 15th March 2015
quotequote all
Strange isn't it that petrol turbo engined cars no longer advertise the the fact they are turbo'd yet it's a different matter with diesels.

I think firms like BMW want owners to think it's their engineering genius that makes the cars so powerful, rather than a couple of big old turbos.

I had a couple of Renault 11 turbos, huge fun, and I'd still love a SAAB 900 at some point.

kambites

67,574 posts

221 months

Sunday 15th March 2015
quotequote all
I agree to a point - it'd be nice to have a variety of engine characteristics. However as it gets ever harder to find a car which isn't turbocharged for NDEC reasons, I think the market for an engine that at least feels and sound snaturally aspirated will grow.

Nothing turbocharged that I've driven has come even vaguely close to feeling naturally aspirated, though.

CedricN

820 posts

145 months

Sunday 15th March 2015
quotequote all
Totally spot on, at least for performance cars. I find many of then being way to tractory, masks alot of the performance.

My 924 turbo track car on the other hand, feels way faster than it really is. Power comes on with a bang at 3-3.5k revs and pulls eagerly all the way to the red line, fun as hell with 70s turbo tech smile

sparkey

789 posts

284 months

Sunday 15th March 2015
quotequote all
Old early 80's turbos are great and feel much faster than they really are. I've got a Renault Alpine GTA turbo and never get tired of the "Millienium Falcon" moment. It's rear engined so you really do get the kick in the back feeling. It also makes it more of a challenge to drive which is the point of having that sort of car. Unless you're racing then driving a sports car (even on track days) should be about having fun with the driving experience rather than ultimately covering ground quickly. Modern cars make it too easy to go fast.

S..

FestivAli

1,088 posts

238 months

Sunday 15th March 2015
quotequote all
I wholeheartedly agree. I would also say that badge compensating is something I very much hate. Mercedes-Benz for example, having replaced the 3.5l N/A V6 in the E350 with a 3.0l twin turbo now badges that variant E400. How about E300tt?

djdest

6,542 posts

178 months

Sunday 15th March 2015
quotequote all
I totally agree with this too!
Having owned various cars from the 80's and 90's with on/off switch type boost I LOVE the way they drive.
Holding it in gear just off boost waiting for that over taking opportunity was always huge fun biggrin

Edit:
I don't think I'd enjoy an N/A these days, I find the linear power delivery too boring.
Plus, working around any lag is part of the driving experience and fun, same as manual gearboxes. I'm oldskool smile

Edited by djdest on Sunday 15th March 09:55

robinessex

11,059 posts

181 months

Sunday 15th March 2015
quotequote all
Unfortunately, Turbos aren't really suited to a variable rpm range engine. Turbos were designed and intended to work at an almost fixed engine RPM, boats, airplanes and stationary generators. The out put of a Turbo follows a square law, double the rpm, and you get 4x’s the output. Thus, getting them to 'work' on a road engine is a compromise. You go for the 'all at the top end' set up, large turbo, with sod all below about 3000rpm. Or the ‘boost from 1000rpm’, and you have to dump pressure later. Thus you occasionally end up with the small and large turbo set, getting complicated and expensive. I sometimes wonder if the big lazy engine, with lots of torque isn’t a simpler, cheaper and better way to go. I’ve posted a turbo pressure map, study it, and you see that a turbo has a ‘sweet spot’ in the middle, and venturing away from it, things get worse.


Turkish91

1,087 posts

202 months

Sunday 15th March 2015
quotequote all
I can see the reasons why. As mentioned N/A cars are becoming a thing of the past, yet the manufacturers no doubt want them to feel N/A with quick responses and ease of driving low down. But from an enthusiast perspective, I agree they should pack a punch high up rather than instant torque. My brother in laws Evo 9 has just shy of 420hp and I wouldn't call it laggy by any means but christ does it snap a speed on further up the rev range! Has me chuckling every time, and that's how a boosted car (well performance orientated definitely) should feel!

Herman Toothrot

6,702 posts

198 months

Sunday 15th March 2015
quotequote all
The way I set up my old MX5 with a GT2860RS made for the perfect sports car turbo setup I though. Boost threshold was at ~4000rpm due to the big turbo but because it was a big turbo it had loads of puff meaning power just kept climbing all the way to the 7100rpm red line, torque once on boost was basically linear from 5000rpm to 7000rpm. Like VTEC and VVTI-L enignes I though perfect for a Jeckal and Hyde personality, poodle about changing up below 4000rpm and it was a pussy cat, keep your foot in past 4000rpm and as the Mrs used to say, it felt like being on a plane just before take off.

djdest

6,542 posts

178 months

Sunday 15th March 2015
quotequote all
My old Audi S4 was huge fun, after this graph I changed the RS4 intercoolers for an FMIC and it was as good as 500bhp then.
Coming on boost was always an event, the missus hated it laugh and said it made me drive like a hooligan


Crafty_

13,286 posts

200 months

Sunday 15th March 2015
quotequote all
In the 80s/90s turbos were used to go fast.

Now they are there so an engine can give good power but provide good economy on cruise.

Average joe doesn't want to get caught out by a slug of torque as the turbo starts coming on boost halfway up the rev range, because they'll crash. Now we have more expertise with fuel injection systems the engines can be made smoother, more progressive, no drama, no surprises - perfect for the masses.

This does spill over in to fast stuff too - Golf R is a prime example, its very fast but I found it totally underwhelming. But its a golf, they do underwhelming very well.

s m

23,226 posts

203 months

Sunday 15th March 2015
quotequote all
FestivAli said:
I wholeheartedly agree. I would also say that badge compensating is something I very much hate. Mercedes-Benz for example, having replaced the 3.5l N/A V6 in the E350 with a 3.0l twin turbo now badges that variant E400. How about E300tt?
On a tangent re badges, I've had about 5 or 6 people ( some of whom are reasonably into cars) say to me that they're quite surprised that my Compact BMW is a turbo and "no wonder it shifts so well!" - 325ti

laugh

foreverfalling

527 posts

165 months

Sunday 15th March 2015
quotequote all
He mentions the golf R as having not much after 3000 rpm-

I don't know what car he is driving... Thats when the fun begins!!! And it pulls to the redline.

Crafty_

13,286 posts

200 months

Sunday 15th March 2015
quotequote all
foreverfalling - go drive an astra H VXR. Much slower car but the way it delivers torque is like 'the good old days' as they say. You'll probably hate it, but thats what the author means.