Turbo V Supercharger?
Discussion
kevinday said:
JonGwynne said: Who are you kidding? Harder to find a factory supercharged car that is faster than the slowest factory turbo-charged car?
Tell you what, I'll hop in my XJR and you can have whatever you think is a turbo-charged equivalent and we'll compare notes.
I understood it to mean that if Jaguar produced a turbocharged XKR as well as a supercharged one the turbo car would produce more ultimate power.
Are there any manufacturers who offer both turbo-charged and super-charged models of the same car with the same basic engine?
I can't think of any.
fatbutt said: I think Koenig did a conversion of a Testarossa that had two turbo chargers and two superchargers (turbo for high revs, super for low)!
Just out of curiosity, how were they arranged? Parallel on the induction side? Does this mean lots of one-way valves and stuff to stop the s/c blowing the turbo backwards?
GreenV8S said:
fatbutt said: I think Koenig did a conversion of a Testarossa that had two turbo chargers and two superchargers (turbo for high revs, super for low)!
Just out of curiosity, how were they arranged? Parallel on the induction side? Does this mean lots of one-way valves and stuff to stop the s/c blowing the turbo backwards?
Hi...
Let me just say that, in general, you ask very thoughtful, interesting questions...Happy Motoring...Jim '85TE
JonGwynne, just to add some interest to the debate, and answer your question......
Buick Motor Division
1987 base 3800cc,231cu.in. engine:
150HP@4400RPM
200FT.LBS.@2000RPM
1987 Grand National, 3800cc,231cu.in. engine
245HP@4400RPM
355FT.LBS.@2000RPM
Note: the factory stated that the addition of the turbo package was worth a 122% increase in power-1987
2003 Park Avenue, 3800cc,231cu.in engine "SUPERCHARGED"
240HP@5200RPM
280FT.LBS.@3600RPM
And with just a little tweak of the pop-off valve, enough boost to lift the cylinder heads off the block, not to mention what the power figures do....Alan
Buick Motor Division
1987 base 3800cc,231cu.in. engine:
150HP@4400RPM
200FT.LBS.@2000RPM
1987 Grand National, 3800cc,231cu.in. engine
245HP@4400RPM
355FT.LBS.@2000RPM
Note: the factory stated that the addition of the turbo package was worth a 122% increase in power-1987
2003 Park Avenue, 3800cc,231cu.in engine "SUPERCHARGED"
240HP@5200RPM
280FT.LBS.@3600RPM
And with just a little tweak of the pop-off valve, enough boost to lift the cylinder heads off the block, not to mention what the power figures do....Alan
deltaf...whoa horsey! ....I believe Mr. Gwynne asked: "Are there any manufacturers who offer both turbocharged and supercharged models of the same car, with the same " BASIC " engine ? " I can't think of any.
Well I have not seen any response to this question, not even from you....so I added my version of the answer.
This thread is a " general " discussion on the merits of turbos vs. superchargers, there merits and bad points.
I don't think, IMHO, the Mr. Gwynne was asking for an exact " clone " to base anything on, just a general question about the subject. Now if you are going to "split hairs" or be "anal" about this subject, then there are hundreds of other variables that could be compared so to say....even things up. Cylinder head design/ports, camshafts/valve trains, combustion chambers/shapes and related flame fronts...blah,blah.
This was my "simple" answer, to a very "simple" question. I didn't split hairs to tilt the scale in either direction, turbos or chargers. I tried to let the figures speak for themselves, and to allow everyone to make their own decision on this subject.
Besides, if I was a "hair splitter " my time/information would be more appropriate on a gynecology site..IMHO...Alan
Well I have not seen any response to this question, not even from you....so I added my version of the answer.
This thread is a " general " discussion on the merits of turbos vs. superchargers, there merits and bad points.
I don't think, IMHO, the Mr. Gwynne was asking for an exact " clone " to base anything on, just a general question about the subject. Now if you are going to "split hairs" or be "anal" about this subject, then there are hundreds of other variables that could be compared so to say....even things up. Cylinder head design/ports, camshafts/valve trains, combustion chambers/shapes and related flame fronts...blah,blah.
This was my "simple" answer, to a very "simple" question. I didn't split hairs to tilt the scale in either direction, turbos or chargers. I tried to let the figures speak for themselves, and to allow everyone to make their own decision on this subject.
Besides, if I was a "hair splitter " my time/information would be more appropriate on a gynecology site..IMHO...Alan
mk1 said: Well what a great reply to what i thought maybe a short thread! Thanks so far to the replies - very interesting and informative. Now i pose a question within this thread why did the VAG drop the G-60 supercharger in favour of turbocharging there line up?
Re the G60 supercharger, from memory the guys at AmD, the turners in North of Oxford, said that the spining drum destablized itself because of the bearing problems and was prone to breaking not surprisingly.
It may have been the speed of rotation and trying to make bigger units spinning at higher revs that put them off the cost of developement and therein production. The '60' referred to the drum's width i.e. 60mm to the best of my knowledge.
They found the G40 supercharger far more reliable, I owned, albeit sometime ago, a Polo G40 which they kindly tuned for me to the point where the car struggled to put the power down thro' the front wheels, and then there was teh low down torque, great fun, but you had to hang onto the steering wheel with a vice like grip!!
Have been a fan of SC'c ever since if you look at my current car.
PC
GreenV8S said:
fatbutt said: I think Koenig did a conversion of a Testarossa that had two turbo chargers and two superchargers (turbo for high revs, super for low)!
Just out of curiosity, how were they arranged? Parallel on the induction side? Does this mean lots of one-way valves and stuff to stop the s/c blowing the turbo backwards?
Christ, that was some time ago! It was reviewed in either Fast Lane or Redline in the 80's - can't remember the full technical spec. Sorry.
lotusguy said:
kevinday said:
JonGwynne said: Who are you kidding? Harder to find a factory supercharged car that is faster than the slowest factory turbo-charged car?
Tell you what, I'll hop in my XJR and you can have whatever you think is a turbo-charged equivalent and we'll compare notes.
I understood it to mean that if Jaguar produced a turbocharged XKR as well as a supercharged one the turbo car would produce more ultimate power.
...And be faster, turbo lag and all...Happy Motoring...Jim '85TE
On what do you base this assumption? Faster how? Faster 0-60? Faster 30-70? Higher top speed?
You're right, I don't know as much about automotive engineering as someone like Gordon Murray. In such matters, I'm more or less forced to take the word of someone like him for such matters unless I have specific knowledge that contradicts those claims.
I've owned and driven both turbocharged and supercharged cars (as well as the NA variety obviously) and I find from both personal experience, the experience of friends and the professional opinions of those "in the know" that normal aspiration is the best choice but if forced induction is required, that directly-driven systems like supercharging are less complex mechanically and deliver power more smoothly and predictably.
I think you'll find that the people who favor turbo-charging will give as their reasons that the like the surge of power that comes in when the turbos kick in.
It tends to make the car *feel* faster - which is a subjective measurement. Whether it actually *is* faster is something for someone with a stopwatch to work out.
In the meantime, companies like Jaguar and Mercedes certainly have the budget and technology to choose turbocharging as a means of boosting the power of their high-performance cars. The their choice of superchargers was presumably a deliberate and educated one.
MOTORMAN377 said: JonGwynne, just to add some interest to the debate, and answer your question......
Buick Motor Division
1987 base 3800cc,231cu.in. engine:
150HP@4400RPM
200FT.LBS.@2000RPM
1987 Grand National, 3800cc,231cu.in. engine
245HP@4400RPM
355FT.LBS.@2000RPM
Note: the factory stated that the addition of the turbo package was worth a 122% increase in power-1987
2003 Park Avenue, 3800cc,231cu.in engine "SUPERCHARGED"
240HP@5200RPM
280FT.LBS.@3600RPM
And with just a little tweak of the pop-off valve, enough boost to lift the cylinder heads off the block, not to mention what the power figures do....Alan
Good call and an Interesting comparison. I'm not sure it is "apples and apples" though.
I worked with a guy once who had a 1987 GNX turbo. He raved about it as one of the finest performance cars to come out of Detroit in many years - a stealth rocket and one unlikely to draw unwelcome attention from law enforcement.
Anyway, the engine was, from what he said, heavily modified rather than just buick's plain engine with a turbo slapped on. This car was tuned for performance, first and foremost. They were extremely limited-edition cars as well, if I remember correctly. Only a few hundred were ever made. In fact, I'm not sure they weren't built by a separate division of GM, roughly equivalent to BMW's "Motorsports" division responsible for all the "M" badge cars.
The "Park Avenue" model, because of they market they're targetting, is going to be tuned for low-NVH above all else so they're likely to give up a bit of power in the process.
Well spotted though.
JonGwynne saidI've owned and driven both turbocharged and supercharged cars (as well as the NA variety obviously) and I find from both personal experience, the experience of friends and the professional opinions of those "in the know" that normal aspiration is the best choice but if forced induction is required, that directly-driven systems like supercharging are less complex mechanically and deliver power more smoothly and predictably.
I think you'll find that the people who favor turbo-charging will give as their reasons that the like the surge of power that comes in when the turbos kick in.
It tends to make the car *feel* faster - which is a subjective measurement. Whether it actually *is* faster is something for someone with a stopwatch to work out.
In the meantime, companies like Jaguar and Mercedes certainly have the budget and technology to choose turbocharging as a means of boosting the power of their high-performance cars. The their choice of superchargers was presumably a deliberate and educated one.
Jon,
In one of my previous postings, I used the example of the Miata to show the differences between 'Roots' blowers, Rotary blowers, VATN turbos and standard Turbos. This is because there are kits of each type available and published data for each.
Using the same boost pressures, the stock car went 0-60 in 8.0 sec. Using a 'Roots' type blower the time dropped to 6.5 sec., it dropeed further to 5.9sec. with the roary blower, 5.6 sec. w/ a VATN turbo and 5.4 sec. w/ a standard turbo. Very emprical, very measurable, seemingly indisputable proof that a turbo (complete with lag) is faster than any supercharger. Another example, although not strictly apples to apples is the Buick Grand National and the 'T'Bird S/C. Practically the same displacement and weight, but the Buick will blow the doors off the 'T' Bird. Not as empirical, but a valid comparison.
Why don't Merc and Jag use Turbos? More complex and these cars cater to the 'Gentleman Sportsman' who doesn't normally want the ash to flick off their cigar when the power comes on, so are more pleased with the smoothness of a 'super'. They are not faster, or more powerful or as efficient - not opinion - fact.
I agree with you on normally aspirated engines being the best possible option, not always possible due to packaging, cost etc. Happy Motoring...Jim '85TE
lotusguy said:
JonGwynne saidI've owned and driven both turbocharged and supercharged cars (as well as the NA variety obviously) and I find from both personal experience, the experience of friends and the professional opinions of those "in the know" that normal aspiration is the best choice but if forced induction is required, that directly-driven systems like supercharging are less complex mechanically and deliver power more smoothly and predictably.
I think you'll find that the people who favor turbo-charging will give as their reasons that the like the surge of power that comes in when the turbos kick in.
It tends to make the car *feel* faster - which is a subjective measurement. Whether it actually *is* faster is something for someone with a stopwatch to work out.
In the meantime, companies like Jaguar and Mercedes certainly have the budget and technology to choose turbocharging as a means of boosting the power of their high-performance cars. The their choice of superchargers was presumably a deliberate and educated one.
Jon,
In one of my previous postings, I used the example of the Miata to show the differences between 'Roots' blowers, Rotary blowers, VATN turbos and standard Turbos. This is because there are kits of each type available and published data for each.
Using the same boost pressures, the stock car went 0-60 in 8.0 sec. Using a 'Roots' type blower the time dropped to 6.5 sec., it dropeed further to 5.9sec. with the roary blower, 5.6 sec. w/ a VATN turbo and 5.4 sec. w/ a standard turbo. Very emprical, very measurable, seemingly indisputable proof that a turbo (complete with lag) is faster than any supercharger. Another example, although not strictly apples to apples is the Buick Grand National and the 'T'Bird S/C. Practically the same displacement and weight, but the Buick will blow the doors off the 'T' Bird. Not as empirical, but a valid comparison.
Why don't Merc and Jag use Turbos? More complex and these cars cater to the 'Gentleman Sportsman' who doesn't normally want the ash to flick off their cigar when the power comes on, so are more pleased with the smoothness of a 'super'. They are not faster, or more powerful or as efficient - not opinion - fact.
I agree with you on normally aspirated engines being the best possible option, not always possible due to packaging, cost etc. Happy Motoring...Jim '85TE
Interesting. Do you have any details on the tests? Who did them, who performed the mods, technical details on the devices used, displacement of the donor car engine, etc...
Aren't superchargers, because of how they work, able to deliver higher boost pressure to the engine compared to a turbo without compromising reliability?
In addition, I think you'll find that on small-displacement engines, superchargers may be less effective for various reasons. Perhaps this is why most supercharged cars tend to have larger engines (e.g. Jaguar, Aston Martin, Mercedes) while companies building cars powered by small 4-pots (e.g. Lotus, Subaru, Mitsubishi, etc) tend to stick with turbos.
Put another way, I can't think of any comparison that would more severely tilt the results in favor of turbo-charging than the one you describe.
Also, what do you think about people like Gordon Murray's utter contempt for turbocharging as a way to increase engine power? It isn't as though McLaren lack experience in this field.
On a related note, I looked up the Buick GNX in a reference book I have last night and it claims that McLaren developed the engine and that Buick only built 547 of them.
>> Edited by JonGwynne on Tuesday 21st January 08:58
JonGwynne said:I think you'll find that on small-displacement engines, superchargers may be less effective for various reasons. Perhaps this is why most supercharged cars tend to have larger engines (e.g. Jaguar, Aston Martin, Mercedes) while companies building cars powered by small 4-pots (e.g. Lotus, Subaru, Mitsubishi, etc) tend to stick with turbos.
Not strictly the case Jon. Both Bristol and Bentley opted for turbochargers to get more power out of their big V8s, while VW and I think Lancia used superchargers on small capacity four pots. You also mention Lotus, who of course use twin turbos on their 3.5 litre V8 - which as I recall doesn't seem to suffer from lag.
Personally I don't mind whether a car's normally aspirated, turbocharged or supercharged as long as it's fast.
Interesting. Do you have any details on the tests? Who did them, who performed the mods, technical details on the devices used, displacement of the donor car engine, etc...
Aren't superchargers, because of how they work, able to deliver higher boost pressure to the engine compared to a turbo without compromising reliability?
In addition, I think you'll find that on small-displacement engines, superchargers may be less effective for various reasons. Perhaps this is why most supercharged cars tend to have larger engines (e.g. Jaguar, Aston Martin, Mercedes) while companies building cars powered by small 4-pots (e.g. Lotus, Subaru, Mitsubishi, etc) tend to stick with turbos.
Put another way, I can't think of any comparison that would more severely tilt the results in favor of turbo-charging than the one you describe.
Also, what do you think about people like Gordon Murray's utter contempt for turbocharging as a way to increase engine power? It isn't as though McLaren lack experience in this field.
On a related note, I looked up the Buick GNX in a reference book I have last night and it claims that McLaren developed the engine and that Buick only built 547 of them.
All you really need to do to understand the benefits of turbos over blowers is to read through this thread from the beginning.
The simple fact is that turbos are more efficient as they source their propulsion from wasted energy (exhaust gas) as opposed to blowers, which rob their energy from the crankshaft.
This means that the equivalent blower will never make the power of a turbo.
As you can see from previous posts, turbos are an acquired taste and Gordon Murray obviously is not a fan. I’m sure he has his reasons but you will find plenty of other racecar designers who love turbos.
It’s a matter of taste but there is certainly no doubt about how effective they are at producing power.
JonGwynne said:
In the meantime, companies like Jaguar and Mercedes certainly have the budget and technology to choose turbocharging as a means of boosting the power of their high-performance cars. The their choice of superchargers was presumably a deliberate and educated one.
Jaguar and Mercedes do not make decisions like these based on their engineering capabilites or budgets, these are primarily marketing/economic decisions. If they choose to fit superchargers it is because they view them as less expensive/more profitable and because their marketing people advise them that turbos are 'not quite the thing' for cars in this part of the market
John
JonGwynne said:
lotusguy said:
Jon,
In one of my previous postings, I used the example of the Miata to show the differences between 'Roots' blowers, Rotary blowers, VATN turbos and standard Turbos. This is because there are kits of each type available and published data for each.
Using the same boost pressures, the stock car went 0-60 in 8.0 sec. Using a 'Roots' type blower the time dropped to 6.5 sec., it dropeed further to 5.9sec. with the roary blower, 5.6 sec. w/ a VATN turbo and 5.4 sec. w/ a standard turbo. Very emprical, very measurable, seemingly indisputable proof that a turbo (complete with lag) is faster than any supercharger. Another example, although not strictly apples to apples is the Buick Grand National and the 'T'Bird S/C. Practically the same displacement and weight, but the Buick will blow the doors off the 'T' Bird. Not as empirical, but a valid comparison.
Why don't Merc and Jag use Turbos? More complex and these cars cater to the 'Gentleman Sportsman' who doesn't normally want the ash to flick off their cigar when the power comes on, so are more pleased with the smoothness of a 'super'. They are not faster, or more powerful or as efficient - not opinion - fact.
Interesting. Do you have any details on the tests? Who did them, who performed the mods, technical details on the devices used, displacement of the donor car engine, etc...
The data presented here is the published data from the kit makers themselves - Eaton and Vortec for the blowers and BEGI for the VATN and standard Turbo as reprinted in Vol. 17, Issue 1 (Jan 2001) of Sports Car International. I do not have the maiden name of the persons conducting the test nor their left shoe size, but I consider this data as valid as any out there. It wouldn't surprise me if you didn't, if for no other reason than they didn't invite you to personally observe each test.
Aren't superchargers, because of how they work, able to deliver higher boost pressure to the engine compared to a turbo without compromising reliability?
Absolutely not, no way, no how! Superchargers, especially 'Roots' type blowers suffer from inefficiencies not known to turbo chargers due to the type of compressor (fixed-displacement). They will produce appreciable boost a little earlier, but are left behind by the much more linear power delivery of the centrifugal compressor of the turbo.
In addition, I think you'll find that on small-displacement engines, superchargers may be less effective for various reasons. Perhaps this is why most supercharged cars tend to have larger engines (e.g. Jaguar, Aston Martin, Mercedes) while companies building cars powered by small 4-pots (e.g. Lotus, Subaru, Mitsubishi, etc) tend to stick with turbos.
Again, not true, Rolls Royce and Bentley are turbochatged to name just a couple big cars. AMG also used to turbocharge a couple large displacement Merc engines. Granted, these don't have the 'manners' of a super and are therefore not used as often on luxo marques. Very few performance marques are supercharged though, and please don't present the XKR as a performance example, it would just be silly.
Put another way, I can't think of any comparison that would more severely tilt the results in favor of turbo-charging than the one you describe.
Also, what do you think about people like Gordon Murray's utter contempt for turbocharging as a way to increase engine power? It isn't as though McLaren lack experience in this field.
You keep referring to Gordon Murray and McLaren as if they were the 'Holy Grail' on this topic. May I remind you that McLaren is a chassis builder and has always had another produce their race engines, and, forgive me, but wasn't the F-1 powered by a BMW V-12 if I'm not mistaken?
On a related note, I looked up the Buick GNX in a reference book I have last night and it claims that McLaren developed the engine and that Buick only built 547 of them.
What's your point? Are you inferring that there is some reason, other than a limited production run, that the production was limited to this number?
Happy Motoring... Jim '85TE
>> Edited by JonGwynne on Tuesday 21st January 08:58
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