RE: Ferrari-developed turbo V8 on the way...

[Charge99]

356Speedster said:

Mr2Mike said:

You may not be bothered, but it's both wrong and confusing when you interchange the names of two quite separate issues. It's especially wrong when you try to pick holes in the arguments of other people using the term correctly. It also encourages the ignorant to pick up on the incorrect usage and propagate it.

Edited by Mr2Mike on Thursday 14th June 19:43

Given this isn't a technical forum and folk generally using the term lag, no I wasn't bothered to correct other posters, but I guess it doesn't wind me up as much as others. Apologies if the casual chat has offended you.

What's the difference between lag and boost threshold from what the driver perceives? Which has more impact on perception of turbo lag? My diesel Mk5 VW Golf for example takes over a second to spool the turbo from low revs, but much less from higher revs, so at higher revs I'm feeling (slight) lag and at lower revs the comedy 1 - 2 seconds where the cars going nowhere is boost threshold - correct?

[otolith]

Yes. Driving round boost threshold is just a matter of being in the right gear. Lag you're stuck with.

[Cyrus1971]

kambites said:

Yes you do and that's why I hate them.

I've never driven a turbocharged car without annoying levels of turbo-lag.

I suggest you try a Porsche 996 Turbo or 997 Turbo, BMW x35i engine in any such equipped models, current BMW M5 or any of a plethora of supercharged cars which always have their forced induction spooled up. BTW I know Superchargers and Turbo's are different. I am just making the point one's not limited to Turbos for boost !

[kambites]

Cyrus1971 said:

kambites said:

Yes you do and that's why I hate them.

I've never driven a turbocharged car without annoying levels of turbo-lag.

I suggest you try a Porsche 996 Turbo or 997 Turbo, BMW x35i engine in any such equipped models, current BMW M5 or any of a plethora of supercharged cars which always have their forced induction spooled up. BTW I know Superchargers and Turbo's are different. I am just making the point one's not limited to Turbos for boost !

Thing is I have driven a 335i and a 996 turbo, and they're laggy!

Superchargers are fine.

[Guvernator]

kambites said:

Thing is I have driven a 335i and a 996 turbo, and they're laggy!

Superchargers are fine.

While turbo lag and boost threshold are not one and the same thing, I would say that they are quite closely related. Correct me if I am wrong but turbo lag is the time it takes for a throttle input (putting your foot down) to be translated into positive power, this obviously involves the time it takes for gases from the exhaust to spin the turbo to a sufficient amount so that it produces positive flow\boost. A turbo engine which has a very low boost threshold means the turbo will be spinning more of the time with enough speed to provide positive pressure\flow. A 335i produces positive boost from as low as 1500rpm so in effect the turbo is almost always "on", a stab of the throttle with anything above 1500rpm produces an almost instant responce i.e. the fact that the boost threshold is so low has a positive effect on turbo lag.

The 997 is even better in this respect with it's variable geometry turbo's. Admittedly it's still not as razor sharp as the best high compression NA's but the gap has closed considerably from even 10 years ago and today's modern turbo engines are a far cry from the push throttle...wait..wait..wait..wham of yesteryear.

[f328nvl]

Nice to see Ferrari are bringing back the ill fitting bonnet; My Ferrari 550 used to open itself at speed too, a really entertaining feature the first time it happens.

[PiB]

And even if the lag isn't that bad the torque can be so immense and not linear to the revs - difficult to portion out with slight adjustments to throttle. Or if the threshold and lag aren't bad your power curve isn't consistent/linear across the rev range. Plus turbos tend to silence the engine. That said boost can be fun on the street