how would a remapped furby with 180bhp and 300lb/ft of torque perform differently to one with 180bhp but only 250lb/ft of torque??

it wouldn't throw you in the back of your chair as much and in gear would run slower

slower top end and slower 0-60 because in gear acceleration wouldn't be as good

It depends - both those figures will be "peak" values, which don't really indicate a whole lot about when and how to power is delivered over the rest of the rev range...

Rob.

In very general terms, more torque allows the engine to be more flexible, i.e. pull from lower revs. However, as I posted last night, power is derived from torque anyway, so the same engine won't be mappable to produce different amounts of torque from the same power. Here's a link which explains better than I can...

slower 0-60 because in gear acceleration wouldn't be as good

It might be better as you wouldn't be spinning the wheels in the first few gears

Chris

I think this is correct bhp = rpm x torque /5252

I think most PD130 make peak power at 3800ish so 249ftlbs of torque is needed at 3800 to create this power. As I standard furby makes 240ish as standard at about 2500rpm. I would think that upto 2500rpm it would drive the same but after 2500rpm is were we'll see the increase in hp.

Or is that just bull

This would make a pretty much flat torque curve/line.

i was just thinking of keepin mt torque low when gettin it remapped to save my cluch.

i was just thinking of keepin mt torque low when gettin it remapped to save my cluch.

Been thinking about it also

I think this is correct bhp = rpm x torque /5252

I think most PD130 make peak power at 3800ish so 249ftlbs of torque is needed at 3800 to create this power. As I standard furby makes 240ish as standard at about 2500rpm. I would think that upto 2500rpm it would drive the same but after 2500rpm is were we'll see the increase in hp.

Or is that just bull

This would make a pretty much flat torque curve/line.

Yep spot on - see link posted above...

However, as I posted last night, power is derived from torque anyway, so the same engine won't be mappable to produce different amounts of torque from the same power.

But...doesn't the turbo (and the proessure built up by this) increase the amount of torque? Hence mapping an engine to run at a higher boost will increase the torque, and can't you then limit the amount of boost in certain gears over certain areas of the rev range? :rubchin:

Rob.

really when you think about it 300lb/ft of torque would be harder to put down than 250, so surly the less torque would make the car faster of the lights and easier to drive quick?

But...doesn't the turbo (and the proessure built up by this) increase the amount of torque? Hence mapping an engine to run at a higher boost will increase the torque' date=' and can't you then limit the amount of boost in certain gears over certain areas of the rev range? :rubchin:

Rob.[/quote']

Yes, but you affect power AT THE SAME TIME, IN A FIXED RATIO.

Yes, but you affect power AT THE SAME TIME, IN A FIXED RATIO.

Oh, right, yes, I see what you're saying...

Still, if you can make the engine rev higher, then you could achieve 180bhp from 250lb/ft of torque if you had this peak of torque closer to the end of the rev range...?

Rob.

Yep. Diesel engines hit their torque peak low down in the rev range though, so trying to push it higher probably goes against their basic "instincts". Something to do with the massive compression and high rotating mass, I believe.

Yep spot on - see link posted above...

Internets a great place

That really is a very well written article, worth a few minutes of anybody's time.

As I understand. Once a turbo hits its peak boost it then starts to fall off...please correct if wrong. So what ever boost the turbo makes at peak hp couldn't you just limit the turbo to that boost. So making say 1.3 bar of turbo boost across the range will limit the torque lower down.

The turbo will make boost proportional to revs in a closed pipe. But the engine's sucking away the air as fast as the turbo can pump it in (thus dropping the observed pressure), more so at higher revs, plus the engine is the one responsible for driving the turbo anyway - aaaaaaghhhh feedback!!!

Off to trawl tinternet again...

I need to read all this and that man's article when my brain clicks into gear :eyecrazy: sometimes I feel really slow

Bottom line for a numptie like myself: Is it possible to keep the torque down at low rpms yet increasing bhp at the top end?

You see, I find it confusing that, on one hand, people are saying you cannot increase bhp without increasing torque proportionally, and then reading the spec sheet for the PD160 v PD130 seems to suggest otherwise (PD130 = 130 bhp + 229 lb ft, PD160 = 160 bhp + 236 lb ft... PD160 = approx 23% more power yet only 3% more torque)

:confused:

Bottom line for a numptie like myself: Is it possible to keep the torque down at low rpms yet increasing bhp at the top end?

Don't see why not - would just involve having the turbo spool up slower, and run at a higher peak boost, I think...

Rob.

Bottom line for a numptie like myself: Is it possible to keep the torque down at low rpms yet increasing bhp at the top end?

You see' date=' I find it confusing that, on one hand, people are saying you cannot increase bhp without increasing torque proportionally, and then reading the spec sheet for the PD160 v PD130 seems to suggest otherwise (PD130 = 130 bhp + 229 lb ft, PD160 = 160 bhp + 236 lb ft... PD160 = approx 23% more power yet only 3% more torque)

:confused:[/quote']

For the same engine torque is proportional to horsepower. If you modify the engine design - bore / stroke / compression ratio / turbo design etc. etc. etc. then you have a different model with different characteristics. I don't know the difference between those two engines but I bet they aren't just different ECUs (of course I stand to be corrected).

The main difference I know of is a different ECU map and a larger front mounted intercooler and of course better air-ducting. Not sure what other differences there are.

it there not a bigger turbo? Or is that just in the Leon cupra?

it there not a bigger turbo? Or is that just in the Leon cupra?

I believe it's a variation of the same turbo.... a quick search shows the following:

VNT17 ... TDI (130) - GT1749VA

VNT17 ... TDI (160) - GT1749VB

But I couldn't find any specific info about the differences!

Chris