Clubsport Edition 40 Overboost Question

[Jeffers40]

Hi Guys, I've recently bought a Clubsport Edition 40  awesome wee car so far and really enjoying driving it.

I have a question on the overboost feature though as nothing I've read actually explains how it works in detail. Everything I have read just says it works for 10 seconds then it has a 10 second break before it is available again. You very rarely accelerate for 10 second flat so if you use it for say a 5 second burst, use the brakes, fly round a bend and then plant it again do you have another 5 seconds worth of overboost to use up before it takes a breather or is that your lot till the 10 second break is up. Or does it act like a running total, use 5 seconds of overboost, gain 3 seconds while negotiating the bend and then you have 8 seconds when coming out the other side and so on.

Or am I just thinking about this way too much 

In practice it's quite hard to tell what it is doing with the overboost when going for a spirited drive around the back roads near me as you end up going very fast if you are keeping your foot to the floor for that long 

[wantmygti]

Keep testing and keep us posted! As you say, only those on the track have half a chance of commenting really.

[fredgroves]

I would guess that when you kick down hard (probably through the throttle gate (that notch you feel at the bottom of the pedal travel which is also used to override the speed limiter and maybe get kickdown on DSG boxes) it toggles the "over boost" map on a 10 second timer. (I say "over boost map" but from what I've read, actually the normal map is "under boost" and "over boost" is actually just the normal map for R/Cupra/S3 installations of the same powertrain).

Whether lifting your foot back through the gate on the throttle toggles it back off and resets the 10 second timer? I don't know - it could well do - would be an easy condition for the ECU to test and use.

Interesting to know if anyone has played with this on a rolling road/dyno.

(I'm just interested in knowing technical stuff in case you all hadn't figured it out - engineer's curious mind!)

[scanesare]

From observations, it does not hold a "memory" of the over-boost, so it's not as if lifting your foot before the 10" results in a limited amount of time that you can re-use it. It practically resets itself with every lift, so you can have OB (over-boost) for say 8", lift, and immediately repeat. If you see the boost gauge showing anything over 2bar (that's incl. atmospheric) it's in OB. Standard boost values should be below 2bar, OB is up to 2.2 (it's that extra 0.2bar we are talking about).

However, after extensive testing when I had the Jb4 and logged what boost the ECU wants to make under various scenarios it does seem to have a mind on its own. Sometimes it will come on before you even reach the end of the pedal travel, others you've gone as far as hitting the kick-down switch but it will only make standard boost. Maybe it's load dependent (how much power you ask under which road conditions) but it is definitely not consistent. What is also certain is that it comes on completely un-noticed, you don't a kick forward or anything, it's practically impossible to say if it's on or off without looking at data.

One of the (actually the single) most irritating thing about the car (as stock). Thankfully a remap takes care of that marketing crap and gives you full power at all times 

[scanesare]

Interesting to know if anyone has played with this on a rolling road/dyno.

BMS dyno-ed a CS with OB on and off. The bhp difference with OB off (or at least with their foot well away from the kick-down switch) was less than 10bhp iirc, nothing close to the advertised 25. I can confirm that from my own experience (cross comparing boost and acceleration figures with the "brother" cars) the car drives as a 280-290 one most of the time.

[fredgroves]

Isn't even in the OB map (or the standard) the amount of boost limited depending on gear, revs and maybe speed too?

Its more complex than a straight on or off?

[scanesare]

Isn't even in the OB map (or the standard) the amount of boost limited depending on gear, revs and maybe speed too?

Its more complex than a straight on or off?

Nobody knows exactly how it's coded in the ECU map and which prerequisites it may have to come on and off. Even tuners simply over-write the relevant stock maps they don't alter single values so it's anyone's guess. What has been shown is that the car usually gives you the extra power at most times, even if you're not "going for it" but there are also times that it will make only "standard boost". Thing is the gap between standard and OB when you're pushing it is much smaller than VW claims.

[fredgroves]

A lot of VW hype about "special timed OB" and making it not a FWD Golf-R...

[scanesare]

A lot of VW hype about "special timed OB" and making it not a FWD Golf-R...

 

A ton of marketing crap to ensure the R will not lose its flagship status, which I frankly never understood. The R's appeal is the AWD period which you won't get with any other performance Golf, it's certainly not the sharp looks or focused character.

That been said, a (mechanically identical to Clubsport) 5dr Cupra is slightly faster than a 5dr R once rolling so I can maybe see the need to keep the two Golfs apart, under ALL circumstances.

Or... considering the car makes closer to 290bhp most of the time, at least make sure the "official" figures suggest so 

[Jeffers40]

Cheers for the replies, I certainly haven't really noticed any spikes or drops in power when driving in real life situations so as you say it's all probably just marketing hype. In reality you probably have full power mode when you want to use it in real life driving situations as you can never be fully on it on the road all of the time.

I'm an engineer too so just curious how these things actually work.