Turbo V Supercharger?

Author
Discussion

funkihamsta

1,261 posts

262 months

Tuesday 7th January 2003
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Oh, that's interesting. But why call it wastegate creep then? I'm sure that weakly sprung wastegates allow some boost to leak away prior to reaching designed peak?

350matt

3,733 posts

278 months

Tuesday 7th January 2003
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What about these new electrically assisted Turbos? where you have a clutched electric motor to keep the turbo up to speed?

Matt

lotusguy

1,798 posts

256 months

Tuesday 7th January 2003
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350matt said: What about these new electrically assisted Turbos? where you have a clutched electric motor to keep the turbo up to speed?

Matt


Matt,

That would certainly seem to solve the problem, assuming you believe it is a problem.

As I previously posted, turbo-lag does not inhibit speed in any way (see my Miata example on a previous posting). My Esprit Turbo has definite turbo-lag, but I can still beat about 98% of the guys on the street. For the other 2%, well I couldn't afford their Vipers or Lambos anyway.

Some have called it bothersome, but personally, I see it as no more an interuption to the driving experience than shifting gears, which one does much more often than experiencing a little turbo-lag, but you don't hear of people calling for automatic transmissions over manual ones. To each his own I guess...Jim '85TE



>> Edited by lotusguy on Tuesday 7th January 21:35

accident

582 posts

255 months

Wednesday 8th January 2003
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i resisted the urge to repost in this thred right up until that last post.i had ignored the saab guy with his fwd as he was batting on a sticky wicket but
mr lotusguy had been posting reasonably well thought out and ok arguments and questions untill.
i quote"My Esprit Turbo has definite turbo-lag, but I can still beat about 98% of the guys on the street. For the other 2%, well I couldn't afford their Vipers or Lambos anyway"
guys on the street? are we talking traffic light grand prix?(hardly an accurate mesure)
and there are so many other cars quicker and faster(in the same price range or less) than a turbo esprit that this statement just looks silly.
turbo lag is the least of your problems in an esprit as it takes so long to get into the next gear even an atmo engine would fall asleep(hate the esprit gear linkage)

lotusguy

1,798 posts

256 months

Wednesday 8th January 2003
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accident said: i resisted the urge "My Esprit Turbo has definite turbo-lag, but I can still beat about 98% of the guys on the street. For the other 2%, well I couldn't afford their Vipers or Lambos anyway"
guys on the street? are we talking traffic light grand prix?(hardly an accurate mesure)
and there are so many other cars quicker and faster(in the same price range or less) than a turbo esprit that this statement just looks silly.
turbo lag is the least of your problems in an esprit as it takes so long to get into the next gear even an atmo engine would fall asleep(hate the esprit gear linkage)



accident,

You are of course referring to the cars offered for sale in Europe. So many of them are not imported here (Sadly). Anyone can state that "there are so many cars...", but what is your source? Car & Driver did a Super Car comparison 2 years ago and the only car faster than the TT Esprit V-8 was a Viper. This comparison was even filmed and shown. Granted, there are faster cars, there will always be. I concede your point, perhaps I can only smoke 95% of the others out there, or, heavens forbid, it may be as low as 93%. In your 'expert' opinion, what would it be? I don't see any mention of the car you drive, either in your post or on your profile ...Hmmmmm???? And, can I help it that you can't shift a car?? All in fun. Happy Motoring.....Jim '85TE

randy

539 posts

275 months

Wednesday 8th January 2003
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This looks like a good thread. Personally Im a big fan of Turbos and I think that Lutusguy has hit the nail on the head with his posts. The fact is that Turbos are more efficient as they run on spent energy as opposed to robbing energy from the crank. I must say, however, my old man has an XKR and the blown motor on that is a little gem and has an awesome ability to pull right through the rev range. I must disagree with Lutusguys comments on normally aspirated motors though:


Realize that forced induction, whether it be turbo or super charging, came about in an effort to make small motors produce the power of larger ones. But there's real truth to the old adage "There ain't no substitute for cubic inches".


If this is the case then why did the 1.4 litre F1 motors beat the atmo ones hands down and why do Turbo motors always win at LeMans. The Judds will never be able to match the turbo engines as they need to make their power through high RPM. This has dire consequences to reliability which has to be a major factor when making comparisons about road car engines. Also, large capacity atmo engines will always have to be compromised from a weight and packaging point of view. Just look at the Group-C Jaguars, they went from a V12 atmo with 800BHP+ to a v6 Turbo with 650BHP. This made them go much faster purely due to less weight and superior packaging.

kevinday

11,555 posts

279 months

Wednesday 8th January 2003
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Racing is a specialised area where weight plays a bigger part. Road cars are different, I am a fan of big unblown engines for road cars, partly because a big V8 or V12 sounds so much better than a 4 pot.

randy

539 posts

275 months

Wednesday 8th January 2003
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Weight is still a very important factor on the road, people forget this. You just have to look at the vast success of the Lotus Elise to see this. Lessons learnt on the track will always play dividends on the road. Admitedly engine tractability and suspension compliance are more of a premium on the road but this, again, plays into the hands of Turbo motors.

funkihamsta

1,261 posts

262 months

Wednesday 8th January 2003
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Not forgetting that a turbo 4 or 5 pot is actually quite the biz for a rapid road car. Weight is one drawback, also the amount of strain put on the longer cranks and associated bearings of v6's and v8's have repercussions for reliability, design restraints a tolerances.

lotusguy

1,798 posts

256 months

Wednesday 8th January 2003
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randy said: This looks like a good thread. Personally Im a big fan of Turbos and I think that Lutusguy has hit the nail on the head with his posts. The fact is that Turbos are more efficient as they run on spent energy as opposed to robbing energy from the crank. I must say, however, my old man has an XKR and the blown motor on that is a little gem and has an awesome ability to pull right through the rev range. I must disagree with Lutusguys comments on normally aspirated motors though:


Realize that forced induction, whether it be turbo or super charging, came about in an effort to make small motors produce the power of larger ones. But there's real truth to the old adage "There ain't no substitute for cubic inches".


If this is the case then why did the 1.4 litre F1 motors beat the atmo ones hands down and why do Turbo motors always win at LeMans. The Judds will never be able to match the turbo engines as they need to make their power through high RPM. This has dire consequences to reliability which has to be a major factor when making comparisons about road car engines. Also, large capacity atmo engines will always have to be compromised from a weight and packaging point of view. Just look at the Group-C Jaguars, they went from a V12 atmo with 800BHP+ to a v6 Turbo with 650BHP. This made them go much faster purely due to less weight and superior packaging.


Randy,

Thank you for your kind words. I think we have a good discussion going here with this thread and several fellow PHer's have written me offline to say that it has been very informative. I too have learned quite a lot.

But, I do have to stand by my original statement. One needs only look at the wave of Turbo offerings which peaked in the 80's to see my point. Back then, materials and computer technologies were insufficient to produce a car w/ a traditional N/A large CID engines that achieved the fuel economy necessary to meet both demands of the buying public and the economy and emissions mandates of several governments, including my own. Engineers saw the weight saving advantages of putting a small displacement engine in a car to achieve economy and lower emissions in normal day-to-day driving, yet posess the ability to emulate the power of a V-8 on demand. Theoretically, the best of both worlds.

But as technology evolved, lighter weight materials in today's cars have reduced curb weights, by in large, a full 1/3. Also, computer technologies allow better engine designs through computational fluid dynamics programs. Multi-valving, variable valve timing, dynamic engine controls and the like have produced larger displacement N/A engines which offer the power advantages of previous Turbocharged models, without the complexity of them. The Honda S-2000 engine's ability to extract 240 ponies from a 4 banger illustrate my point as do the number switches to N/A V-6's in place of forced induction motors. Turbos, save in special applications (where packaging restrictions or specialized markets demand it) are largely a thing of the past.

With respect to Supercharging, I believe this to be more a marketing ploy than anything else. The Jag is certainly a nice car to be sure, but I believe that Jaguars must present the potential buyer with innovation to justify the price increase. There is a real need for Jaguar, Lotus and the like to innovate and Zig while others Zag.

But, as this thread proves, turbo-lag really bothers a lot of people. I think this is more a case of 'Myth becoming Reality' than anything, as Turbo-lag has been labled as 'Bad'. My previous examples prove that it doesn't affect speed as the traditionally turbocharged Miata is 1.1 seconds faster 0-60 mph (5.4 sec.)than a supercharged one (6.5 sec.)and this includes the turbo-lag!

Someone commented that this lag upsets the driving experience, my question is why? Personally, as an ex-Navy Carrier based Fighter Pilot, I love the 'Seat of the Pants' kick I get when the turbo kicks in and since my engine 'lives' just behind my right ear (Lotus Esprit), listening to the turbo spool up just heightens the anticipation. Add to that the fact that turbo-lag really exists only in the lower regions of the Tach. Once the engine is in it's operating range, sufficient EGP (Exhaust Gas Pressure) exists to wake-up the turbo really fast. Another funny thing is that people love the somewhat delayed surge common to Nitro-injected cars, but hate the same effect in turbocharged ones.

To be sure, the Jag, as in most supercharged cars, delivers power more smoothly (though less of it), but not with the same anticipation and excitement. Add to that, the turbo will almost always outperform it. Plus, if 'Giddy-Up' is your thing, the Supercharger seems rather tame by comparison.

Racing is an altogether different discussion, but let me just say that the reasons for forced induction here are completely different. The object here is 'More', not filling-in the gaps between large and small displacement engines. Possibly the most venerable racing engine of the 20th century, the Offenhauser 1.5L 4 cylinder broke onto the racing scene in the 1920's producing 150HP (a huge amount for the time). This engine remained in the forefront of racing, albeit in ever-evolving form, into the 1990's when, in Turbocharged trim, it was producing just over 1,500 Equines - a tenfold increase! Happy Motoring...Jim '85TE

kevinday

11,555 posts

279 months

Wednesday 8th January 2003
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Jim your replies here are very informative, thanks very much.

randy

539 posts

275 months

Wednesday 8th January 2003
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But as technology evolved, lighter weight materials in today's cars have reduced curb weights, by in large, a full 1/3.


It's interesting to see your views on vehicle weight reducing. On your side of the pond I guess that your cars are getting lighter. Over here our cars have seen a dramatic increase in size and weight over the last ten years and this is something that I, personally, really don't like. This is why I'm keen on seeing compact, light-weight engines.

On the Turbo lag front, Ive driven several extremely quick turbo powered cars some with primative ECU control (porsche 962 on early motec) and some with much more up to date equipment (Nissan GTP on Pectel management). The difference is like night and day. The 962 was probably the most evil car on the planet (overly stiff setup didn't help) whereas the Nissan had virtually no detectable lag.

Turbo motors certainly shouldn't be written off for the reason of lag. They add an extra degree of complexity which I agree is a bad thing on any engine but, with modern electronics, lag really isnt a big issue.

lotusguy

1,798 posts

256 months

Wednesday 8th January 2003
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kevinday said: Jim your replies here are very informative, thanks very much.


Kevin,

Thank you for your kind words, but don't encourage me...

I have learned a lot about cars since acquiring my 1st car (a '39 Ford that wouldn't run when I got it) some 30 years ago. There are really three primary reasons for this. They are:

Curiosity: I have always loved things which 'worked', but I could never fully love them unless I understood How and Why they worked. It has never been sufficient for me to just 'Turn the Key and Go'.

Need: I have never posessed sufficient means to explore my passion for cars (I have owned 40 in my lifetime, 5 at present) fully, if I had to depend on and pay others to maintain, repair and upgrade them. I simply Had to learn how to do it myself, and in some cases, it has been a very steep learning curve indeed.

The Gift of Others: I have met an amazing array of knowledgeable, friendly and giving people in this Fraternity we call 'Car Guys', 'PistonHeads' or the like. In almost every case, they were willing to impart the knowledge they posessed to me with no expectation of compensation or return in any way. Some have since passed, but most remain dear friends.

It may seem to some that I chat at length, possibly as an attempt to draw attention to myself or boost my self-importance or prestige. I assure you that such is not at all the case .

Passing this acquired learning on to others is the only way I know of to repay the debt I owe to those from whom I have benefitted so much. In fact, as of this posting, I am leaving to visit a friend who is a 'newbie' to the car scene and show him how to rebuild his Weber Carburettors on his '68 Lotus Elan +2 and to help him install a breakerless ignition...Happy Motoring...Jim '85TE



>> Edited by lotusguy on Wednesday 8th January 16:35

All Terrain

838 posts

256 months

Sunday 12th January 2003
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Novice here, but dont you only get lag in gear one setting off from standstill??

The day I passed my test I had the use of a 1.8t golf gti (new style)
Now have a landrover 300tdi and a Pug 307 110 HDI.

My point is that lag isnt a problem in outright speed cos you drop a cog to bump up revs and change gear only when revs are high enough so when they fall post change they are high enough to keep the turbo spooled up.
For setting off I usually put on a bit of beans and slip the clutch to make it get up to speed that bit quicker.

You dont get lag throughout the gears when giving it some welly.

I know im probably well outa my depth but I thought I'd add my 6th penneth

kevinday

11,555 posts

279 months

Monday 13th January 2003
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All Terrain said: Novice here, but dont you only get lag in gear one setting off from standstill??

The day I passed my test I had the use of a 1.8t golf gti (new style)
Now have a landrover 300tdi and a Pug 307 110 HDI.

My point is that lag isnt a problem in outright speed cos you drop a cog to bump up revs and change gear only when revs are high enough so when they fall post change they are high enough to keep the turbo spooled up.
For setting off I usually put on a bit of beans and slip the clutch to make it get up to speed that bit quicker.

You dont get lag throughout the gears when giving it some welly.

I know im probably well outa my depth but I thought I'd add my 6th penneth



In out and out acceleration terms you are right, but in normal road driving if you are in a queue of traffic and wish to overtake then (on older turbo installations) you will suffer lag because the turbo is not 'spooled up' when cruising. More modern installations have reduced this problem considerably.

kevinday

11,555 posts

279 months

Monday 13th January 2003
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Lotusguy,

Thanks again, I understand your point of view very well. My first real performance car was the 260Z Samuri with a pair of 2" SUs off a Jag. I learnt how to strip, repair and rebuild these practically blindfold, even to the lengths of being able to estimate which needles to try at the rolling road. Developed this further with the 2.8 240Z I had, but am not really mechanically minded (I am an accountant by training).

lotusguy

1,798 posts

256 months

Monday 13th January 2003
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kevinday said: Lotusguy,

Thanks again, I understand your point of view very well. My first real performance car was the 260Z Samuri with a pair of 2" SUs off a Jag. I learnt how to strip, repair and rebuild these practically blindfold, even to the lengths of being able to estimate which needles to try at the rolling road. Developed this further with the 2.8 240Z I had, but am not really mechanically minded (I am an accountant by training).


Kevin,

Very Cool! I too used to collect Datsun Z-Cars! I have owned some 22 of them and still have a '70 240Z (w/20k original miles) and a '77 280-Z. Here in the states, these are vastly underatted cars, but I have always loved them, complete with all their foibles.

I too am trained as an accountant posessing degrees in both Accounting and Finance. I have never worked as one, but it's my source of reference to my experience as an executive manager. Happy Motoring...Jim '85TE

deltaf

1,384 posts

256 months

Monday 13th January 2003
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In actual fact there is an electrically driven turbo device on the market, but i cant remember its bloody name right now.
Apparently it can make about 15% extra power than n/a without the extra problems of manifolds and oil feeds etc of a normal turbo system.
Wonder if itd work ok on my corolla 1.3?
Personally the turbo is my favourite, theres something elegant about an exhaust driven device giving you that kick up the jacksi that does it for me.
Im not really a fan(no pun) of linear power delivery, and the brutal acceleration of a turbo cant really be beaten, i think so anyway.

fatbutt

2,631 posts

263 months

Tuesday 14th January 2003
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Surely this is just an arguement over lag? With a turbo car you get lag (unless you drive constantly at medium to high revs). Normally aspirated and supercharged don't have lag.

You can get a greater rush from turbo'd cars and more efficiency but...

So, its all down to whether you want lag, barely perceptable or not.

Personnally, I like smooth delivery so its either capacity or supercharger - I wouldn't touch a turbo with a bargepole (yes I have driven a fair few on hire, hence my opinion!).

deltaf

1,384 posts

256 months

Tuesday 14th January 2003
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Hmmmmmmm even tho turbos push power outputs to 15bhp per cubic inch as opposed to 10 bhp per cubic inch for a supercharger?
Turbo is the king.
Formula 1 engines on turbos produced more power per cu.in than dragsters on a supercharger.
I dont like the idea that i have to USE power in the form of a belt take off to get SOME power.
So for me at least, itll be turbos.