Discussion
Mave said:
I disagree. What we typically call turbos, are really turbo driven superchargers. Its not the turbine that draws air through a snail shell to compress it, that's the compressor part of the turbine driven suoercharger. The bit that drives it is the turbine. The reason for different types of compressor for different types if supercharger is to make them suitable for the different characteristics of the drive (turbo vs shaft vs belt vs electric)
Doh! Knew it was too early on a sunday to be discussing anything technical. Just as well I'm no a mechanic anymore.I have seen the companies who manafacture these marketing them as 'electric turbos', so suppose tou ciuld get away with it from that point of view
Welshbeef said:
The 335i twin turbo is based off the 272bhp 330i engine direct injection not the 5-8 year older 330i unit.
Heck there was a sweet 258bhp 330i before the 272bhp unit too.
That is not correct. The N54 (twin turbo 35i) is based on the M54 aluminium block, but is closed deck instead. It has direct injection and dual VANOS but does not have Valvetronic. The N52 is the older 30i with magnesium block, port injection, dual VANOS and Valvetronic. The N53 is the replacement 30i with direct injection, dual VANOS but like the N54 does not have Valvetronic. The N55 (single turbo 35i) brought all of the elements together with turbocharging, DI, dual VANOS and Valvetronic.Heck there was a sweet 258bhp 330i before the 272bhp unit too.
Welshbeef said:
The 335i twin turbo is based off the 272bhp 330i engine direct injection not the 5-8 year older 330i unit.
Heck there was a sweet 258bhp 330i before the 272bhp unit too.
The older one (N52B30) one was an absolute peach. Very lightweight magnesium alloy block. Heck there was a sweet 258bhp 330i before the 272bhp unit too.
https://en.wikipedia.org/wiki/BMW_N52#N52B30
BMW felt it was not strong enough to be turbo-charged so they introduced the twin-turbo N54:
https://en.wikipedia.org/wiki/BMW_N54
This was also an incredible engine, but dogged with rattling valve lifters, fuel pump issues and wastegate failures which is why they moved to the 'twinpower' N55:
https://en.wikipedia.org/wiki/BMW_N55
I have had all three. The N52 was the slowest, but the sweetest sounding.
I wanted one of these, but they did not bring it to the UK so had to settle for an A6 BiTDI:
http://www.autoexpress.co.uk/bmw/5-series/18619/bm...
Elysium said:
Since analogous means comparable, similar, or like and equivalent means equal in value, I think we have to conclude that 'twin' turbos must be the same size.
Sequential turbos are not the same size - so they should not be described as twin turbos.
You really don't understand do you? Comparable does not mean they are the same. It means they can be compared as they have similar qualities. That means 2 different size turbos can be classed as twin turbo because you can compare them to each other. When you look for a new phone you compare it with others, that doesn't mean they are exactly the same. Sequential turbos are not the same size - so they should not be described as twin turbos.
You are too stubborn to see that you are wrong.
Edited by Screechmr2 on Sunday 4th December 13:51
Welshbeef said:
The 335i twin turbo is based off the 272bhp 330i engine direct injection not the 5-8 year older 330i unit.
Heck there was a sweet 258bhp 330i before the 272bhp unit too.
Interesting thing is that one would think that the N54 was based off the N52 engine (330i), but the use of magnesium alloy was deemed too weak for turbocharging by BMW, thus the M54 was used instead because of its stronger aluminium block. Heck there was a sweet 258bhp 330i before the 272bhp unit too.
The power jump therefore was 215hp(M54) to 302hp(N54).
If BMW were able to engineer the N52 well enough to add turbochargers the N54 would have therefore been 350-370hp stock!
McVities said:
popeyewhite said:
Warby80 said:
The new Audi Sq7 has a 4 litre v8 with sequential turbos and an electrically driven compressor aswell…
664lb ft at 1000rpm
Tuned M5s (twin turbo) and E63s (biturbo) happily run c.800lbft or more!664lb ft at 1000rpm
Wills2 said:
McVities said:
popeyewhite said:
Warby80 said:
The new Audi Sq7 has a 4 litre v8 with sequential turbos and an electrically driven compressor aswell…
664lb ft at 1000rpm
Tuned M5s (twin turbo) and E63s (biturbo) happily run c.800lbft or more!664lb ft at 1000rpm
Welshbeef said:
I guess you could ask Tesla P90D owners the same question then they destroy you off the line. A Q7 is a family bus so big power little effort to access is a winning combo - who cares what it does or doesn't do on a track as it would never be used as such a vehicle
However torquey a car is, it's rarely a good idea to be driving it at idle-RPM. Even if you were to have peak torque at 600rpm or whatever modern diesels idle at, you're going to have bugger all power compared to a little further up the rev range. I suspect most autos simply wont allow the engine to rev that low under power because the torque convertor/clutches wont be locked up.
Jim AK said:
f1nn said:
It's an attempt to combine the advantages of both supercharging and turbocharging, getting around 170bhp from a 1.4.
I was just muddying the waters!Mate doesn't rate them too highly, thinks the internals are probably a meltdown looking for somewhere to happen.
One development that I'm a bit surprised not to have seen is the use of an exhaust turbine and generator to charge the battery in a hybrid. I'd have thought it a good source of a little (almost) "free" power, with the benefits of not needing an intercooler, or reduced compression ratio, and of potentially excellent throttle response from the electric side of the hybrid system.
Twincharging gas been around for ages. The Nissan Supermarch micra had this setup. I suppose the initial power of the supercharger with no lag gives instantanious power and the turbo takes over to give higher power up the rev range where the blower runs out of guts.
ETA above post got there before me
ETA above post got there before me
Screechmr2 said:
Elysium said:
Since analogous means comparable, similar, or like and equivalent means equal in value, I think we have to conclude that 'twin' turbos must be the same size.
Sequential turbos are not the same size - so they should not be described as twin turbos.
You really don't understand do you? Comparable does not mean they are the same. It means they can be compared as they have similar qualities. That means 2 different size turbos can be classed as twin turbo because you can compare them to each other. When you look for a new phone you compare it with others, that doesn't mean they are exactly the same. Sequential turbos are not the same size - so they should not be described as twin turbos.
You are too stubborn to see that you are wrong.
Wikipedia agrees with me (and I didn't edit it) as do many others. Ultimately both phrases are marketing terms and it can't be proven either way so there is no point in getting fussed about it.
https://en.wikipedia.org/wiki/Twin-turbo
I think twin turbo's are the same size and you don't. It's not a problem!
Edit: they couldn't agree on this in 2010 either:
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Edited by Elysium on Sunday 4th December 17:13
Welshbeef said:
Wills2 said:
McVities said:
popeyewhite said:
Warby80 said:
The new Audi Sq7 has a 4 litre v8 with sequential turbos and an electrically driven compressor aswell…
664lb ft at 1000rpm
Tuned M5s (twin turbo) and E63s (biturbo) happily run c.800lbft or more!664lb ft at 1000rpm
Welshbeef said:
HoHoHo said:
popeyewhite said:
Off the line maybe, but actually modified M5s and E63s run to 100 in 7.5, which is quicker than the Tesla.
Big standard F10 M5's are 7.8 to 100mph 
More importantly it stops on a six pence
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