Timbo -> re: REVO tune settings

[Timbo]

Actually boost peaks around 2800rpm for the REVO, which is why you feel a big surge of power at that point. It's still holding >12psi at 6000 and pulling willingly, so I am not sure what is meant by the APR V2 "cutting off" power at 5000rpm

[GT3]

so I am not sure what is meant by the APR V2 "cutting off" power at 5000rpm

Yes, I did use the term "cut off power", but more as an expression rather than a precise, technical descriptor. This is how I described it elsewhere today ..."boost begins to drop back from 16psi to 10-11psi between 5100-5600 rpm". So are you really 'not sure' or are you just engaging in a pedantic word play?

[insanekiwi]

...insanekiwi doesn't seem to think so, he's about to blast off into space ha ha ha, nothing will hold him back :ballandchain:

Haha... never really looked at the boost gauge and had it more than 5000rpm in the weekend. Unless it's on a track, I don't think I will be doing it that often. My tuner was driving my car around, I was busy enough to looking at the road...

I think it peaks and holds at 21-22psi at one point, but it does taper off. I am assuming peak / spike is different... it goes up to 23-24psi, then backs down to 22psi, and comes down as rev climbs up.

Come on guys, let's be friends. It always seems to end up being APR this APR that... I guess that's why we hate the chip wars / discussions.

All my fault however, I must admit. Should've just used PM.

[Timbo]

So are you really 'not sure' or are you just engaging in a pedantic word play?

No...there's just been a few posts (not just yours) suggesting there's nothing to be had after 5000rpm; that's not something I have experienced -- my car is still hauling >5000, and I'm happy to use 6000 to redline if I need to, so I was just curious as to what is happening

[Flaps]

Come on guys, let's be friends. It always seems to end up being APR this APR that... I guess that's why we hate the chip wars / discussions.

Don't worry this is a discussion not a chip war.

If it weren't for threads like this, this place word be boring

[Spec83]

Yes, I did use the term "cut off power", but more as an expression rather than a precise, technical descriptor. This is how I described it elsewhere today ..."boost begins to drop back from 16psi to 10-11psi between 5100-5600 rpm".

This boost drop off has nothing to do with the tune... more like the turbo loosing efficency as it drops off the back of it's efficency curve... This is the point at which you are producing more heat (in the form of friction due to exhaust wheel speed) for no power gain and it's time to shift.. The exhaust wheel just cannot efficently flow anymore air due to it's size and design. The only reason you would keep the boot in is to make sure that when you do change you are back in the > 2500rpm range to avoid any lag.

Thats the advantage of big turbos as they run out of efficency after your engine hits the rev limiter, thus making power up untill this point... The only expense is big lag You can't have your cake and eat it too when it comes to turbo's.

Please see the graph and link to a previous thread on intakes that explains this a little better As you increase the airflow (kg/s) to the right, the efficency ratios begin to drop from 70% towards 55% and below.. Acually on a second look, the max power point is in the wrong place and assumes that the turbo holds 1.0bar of boost up until cutout which infact is not correct... The max power should shift vertically down untill it hits an imaginary line at about 150kg/s... This would relate to a boost pressure at max power of about 0.7bar or 10psi.. Which lines up with what GT3 is saying.. It's all physics lol!!!



VW Polo GTI Intake errr... discussion

[Guy_H]

Spec is spot on.

What we need is a retrofit kit for the 997TT VGT turbocharger to go onto the Polo - It would be good to see some of that small / large turbo technology come backwards into the older models.

[Spec83]

Mmmmm Porsche goodness.. goodbye turbo lag

[jasn78]

Spec is spot on.

What we need is a retrofit kit for the 997TT VGT turbocharger to go onto the Polo - It would be good to see some of that small / large turbo technology come backwards into the older models.

now all we need is gt3 or flaps to test it

[GT3]

This boost drop off has nothing to do with the tune... more like the turbo loosing efficency as it drops off the back of it's efficency curve... VW Polo GTI Intake errr... discussion

Hey Spec83, some good technical data there. Although, if we're referencing the Polo GTI intake thread, we should note that there was no distinction made between the K03 or K03S turbo then. So which turbo is shown on your chart this time?