Is it just an old idea now,big is best? My wheezy 1.8T wouldn't be far behind a 3.2 litre Audi.On paper seems as good if not better than Ford/Vauxhall 2.8 and 3.0 V6's

Can't see the point? Drink more fuel but don't add much to the car/ engine/speed equation.

They add weight, hence why the performance dosent grow proportional to the extra power.

Can't see the point? Drink more fuel but don't add much to the car/ engine/speed equation.

More refined and also a better power delivery (none of the on/off power of a turbo engine) Quite a bit more torque too so pick up is quick and it has good overtaking ability.....

Chris

The power delivery on the boxster is instant, I dont need to wait for 2500rpm for the turbo to kick in, I have full power available from idle. Also doesnt run out of puff till I hit the limiter at 7250rpm, whereas a turbo reaches a limit where it cant put enough air into the engine so your car effectivly becomes a normal 1.8 again. Top speed on the 3.2 Boxster is just under 170MPH, and thats standard. The car can be tweaked to go faster by simply improving the airflow into the engine, and doing some stuff to the exhaust.

edit to answer the fuel economy thing.

Boxster OBC says the car is currently averaging 31 MPG, mixture of town/motorway, so not bad really. Range on around 55 litres is about 330 miles. Around town though it drops to mid 20's.

You cannot whack the power delivery of a V8. Turbos are all very well, but a well set-up V8 is so much smoother than a 4-pot.

V6s are OK, but V8s are so much nicer. My V8 doesn't put out much power on paper, but in reality, it pulls like a train at all speeds, and does so in a lovely, smooth way.

Big engines also tend to be less stressed, so they should last longer.

yeah as said above, my dads S4 which is a 4.2 V8 has power and torque in bucket loads no matter where the revs are, really smooth and pulls all the way.

oh and the sound is fantastic

I have often wondered the same thing. My 1.8T (225) TT is only a shade slower than the 3.2 V6 - and the V6 costs a lot more. I dont really understand why you'd bother with the V6 - unless it really is that much smoother ? Not convinced about the fuel economy argument, 30 mpg vs 25 mpg (IIRC) are the official figures.

and turbos have an expected life of about 100k or so

gimme a biiiig engine anyday :P

or, preferably a biiig engine with one or two turbo's gaffer taped to it

I have often wondered the same thing. My 1.8T (225) TT is only a shade slower than the 3.2 V6 - and the V6 costs a lot more. I dont really understand why you'd bother with the V6 - unless it really is that much smoother ? Not convinced about the fuel economy argument, 30 mpg vs 25 mpg (IIRC) are the official figures.

If you're buying a TT, you wouldn't want to get the V6: you'd want to get the 1.8 with a hairdryer fitted to it :P

1.2 all the way :D

N/A engines are not as tunable as turbo's but are more refined.

I like the sound of the 2.8 v6 24v turbo that's in the updated vectra i bet that goes like a whippet with the smoothness to match and it'll be very tunable. the downside is poor economy.

Isn't the whole idea of turbos is to get the big engine peformance from a small engine whilst retaining small engine economy?

NA engine will generally be faster responding to a turbo due to no wait for turbo to kick in. FLip side is when turbo is not in full use you should get better economy than a performance NA engine.

IMHO.

What turbos 4 cylinders don't have is a great sound....Scooys aside as they have some particular which amkes them sound that way...I can't remember what it is.

Multi-cylinder engines...6 or above...sound great and generally have great wads of low down torque making them easy to drive.

What turbos 4 cylinders don't have is a great sound....Scooys aside as they have some particular which amkes them sound that way...I can't remember what it is.

Different length headers, IIRC...mind you, I think they just sound like they're silencer is knackered.

Multi-cylinder engines...6 or above...sound great and generally have great wads of low down torque making them easy to drive.

3's can sound quite good. IMHO straight-6 sounds the best though!

Rob.

What turbos 4 cylinders don't have is a great sound....Scoobys aside as they have some particular which amkes them sound that way...I can't remember what it is.

It's the flat-four boxer engine with unequal length headers which makes them burble

Didn't one company create an "On Demand" 12-cylinder N/A engine which basically ran on 4 cylinders and then as additional power was needed, used more of the available 12 cylinders.....?

Chris

3's can sound quite good. IMHO straight-6 sounds the best though!

Rob.

Ooops...forgot about the 3s.

I think the sound is something to do with the firing order? 5 cylinder...a la quattro...has a nice sound.

Although I heard a decatted CTR a couple of weeks ago....awesome on full afterburn....racing car scream is how I would describe it....but I bet I can get a bit tiring listening to that all the time.

new big american car does that, the one they drove on the beach on top gear.

it aint the flat 4 which makes he noise chris its the different length headers causing an imblance in the exhaust

if you see a properly tuned imprezza it won't make that noise due to the correct length tuned headers

The sound of the scoobys is due to the boxer engine. The pistons are horizontally opposed. Then some stuff happens and you get that lovely throbbing sound!

Tres technical non?

Didn't one company create an "On Demand" 12-cylinder N/A engine which basically ran on 4 cylinders and then as additional power was needed' date=' used more of the available 12 cylinders.....?

Chris[/quote']

I have heard of that too, didnt it work 4 to 6 to 12? cant remember who made it though

Something similar, didnt Jaguars V12 work in such a way that if there was a problem with a cylinder then one bank of the engine became defunct and it switched into being a straight 6??

Hi

The big engine vs the smaller turbo engine is a matter of taste really. The big engine upsides are ease of use, flexibility and generally instant throttle response. Downside is weight and fuel consumption.

A small turbo engine is lighter, smaller and can achieve similar power outputs to a N/A bigger engine. Downsides are turbo lag, poor relative economy (compared to N/A engies of the same size) and poor low speed / off boost response due to low compression ratios.

Its when you are driving a long way that a big 6, 8 or 12 has the advantage, if cost is not problem. The sound of a straight 4 is always tiring at motorway speed particualrly around 3000 rpm or so. The engine has poor primary balance, so vibration is ever present. The sound and vibration characteristics of a 6, 8, 12 cylinder engine are just much less tiring. I can happily do a 600 mile round trip in the Omega without feeling tired. I have yet to find a 4 pot motor that can manage this. Having said this, the Fabia vRS, with its well surpressed engine noise and tall gearing is the closest a 4 pot has come yet to being a good cruiser that I have driven.

Last, but not least, there is the emotional aspect. A TVR or Lambo sound fantastic, most 4 pots dont. Possibly the most evocative engine sound ever has to be the V12 Rolls Royce Merlin. If that dont make the hairs on the back of your neck stand up, you have something wrong with you.

Chris

The sound of the scoobys is due to the boxer engine. The pistons are horizontally opposed. Then some stuff happens and you get that lovely throbbing sound!

Tres technical non?

sorry but you are wrong.. the pulse sound of a scoob or 911 or any other flat engine is caused by unequal length headers (pipe lenght from exhaust manifold to collector).

You can fit equal lenght headers and the note changes to the equiv v sound... you can also fit unequal length headers to a v and get a "flat" sound. but as unequal lengths rob hp why would you do this.....

. but as unequal lengths rob hp

That's what I heard and apparently Scooby use em because it's now a Scooby characterisitc/trade mark associated.

One things that puzzles me though...do the rally cars use the unequal length headers...I mean they have the burble...but surely they wouldn't want to be robbed of power purely for sound?

The smaller the engine for a given output, the greater the strain it will be under, and (as a general rule) the higher it will have to rev to produce that given figure, further reducing lifespan (and driveability IMHO).

A big engine will also be much faster in the real world, 0-60 on full thrash might be the same, but the bigger engine will be more flexible and torquier.

But it'll drink, and probably have an American at the wheel with a grannymatic gearbox bolted on :thumbdwn:

The power delivery on the boxster is instant' date=' I dont need to wait for 2500rpm for the turbo to kick in, I have full power available from idle. Also doesnt run out of puff till I hit the limiter at 7250rpm, whereas a turbo reaches a limit where it cant put enough air into the engine so your car effectivly becomes a normal 1.8 again. Top speed on the 3.2 Boxster is just under 170MPH, and thats standard. The car can be tweaked to go faster by simply improving the airflow into the engine, and doing some stuff to the exhaust.

edit to answer the fuel economy thing.

Boxster OBC says the car is currently averaging 31 MPG, mixture of town/motorway, so not bad really. Range on around 55 litres is about 330 miles. Around town though it drops to mid 20's.[/quote']

I can't quite agree with the 'normal 1.8' argument. Agreed, for economy and drivability, most modern turbo cars have undersized turbos for full power. Variable vane technology complimented by modern variable valve train/cams means they don't have to be as small as they used to however.

My main gripe with a turbo car is the 'instant' slug of torque that seems to happen around spool-up. You can drive around it but it's rather like lighting box after box of bangers. You have a clue as to when it might go off but it's still a guessing game. Get it wrong one way and you womble out of the corner like a hillman imp, get it wrong the otherway and it could be bye-bye road, hello scenery.

J.

Is it not the case that V6 engines have less torque than 4 cylinder at low revs. Which negates the turbo lag argument. (I'm not an expert, but the msn cars review of the new Vectra VXR said so !)

I agree 4 cylinder engines don't sound as nice. Aftermarket exhaust anyone ?

Oh, and VW will shortly be getting 170 - 200 bhp out of a 1.4 litre engine fitted with a turbocharger and a supercharger - benefit being you get 1.4 litre engine economy when driving "normally".

I can't quite agree with the 'normal 1.8' argument. Agreed' date=' for economy and drivability, most modern turbo cars have undersized turbos for full power. Variable vane technology complimented by modern variable valve train/cams means they don't have to be as small as they used to however.

My main gripe with a turbo car is the 'instant' slug of torque that seems to happen around spool-up. You can drive around it but it's rather like lighting box after box of bangers. You have a clue as to when it might go off but it's still a guessing game. Get it wrong one way and you womble out of the corner like a hillman imp, get it wrong the otherway and it could be bye-bye road, hello scenery.

J.[/quote']

thats the best bit about turbo engines! i love that kick up the **** you get when it winds up, saying that as the americans say 'there aint no substitute for cubes'. listening to the corvettes at le mans when they are wound up is something to behold....

mark