Less boot space in GTI vs. other Polo´s..?

[kaanage]

Exactly.

The other thing to consider about the battery weight relative to driver and passengers is that the battery on the TSi is mounted ahead of the front axle and is behind the rear axle in the GTi. The means that the effect of the weight transfer is much more significant than the same amount of weight being shifted from the front seats to the rear seats.

[Smacca]

I'm all for better weight distribution! I was spoilt with my MX-5's perfect 50:50 so any way of getting closer to that is a win, including repositioning the battery at the cost of some boot space.

The other thing to consider ... is that the battery on the TSi is mounted ahead of the front axle and is behind the rear axle in the GTi.

That's a great point Kaanage, I didn't even think of that. The more weight you can move behind the front wheels the better, as a heavy nose always pushes wide. And no one likes understeer.

[pologti18t]

The other point is that the 1.4TSI engine is heavier than the 1.4L petrol or 1.2TSI engines. So moving the battery to the boot offsets the extra weight in engine bay.

[gavs]

I'm all for better weight distribution! I was spoilt with my MX-5's perfect 50:50 so any way of getting closer to that is a win, including repositioning the battery at the cost of some boot space.

I find this interesting how car companies use this as a positive when any race car builder will tell you that 50:50 is a negative......

[kaanage]

The other point is that the 1.4TSI engine is heavier than the 1.4L petrol or 1.2TSI engines. So moving the battery to the boot offsets the extra weight in engine bay.

I thought that everyone would already know this but yes.

I find this interesting how car companies use this as a positive when any race car builder will tell you that 50:50 is a negative......

Depends on what you are trying to achieve. Yes, for a race car, the weight should be biased towards the driven wheels (if not AWD) as traction tends to override mid corner speed for best lap times. But if a car is not excessively powerful (and the MX-5 fits the bill ) then mid corner speed becomes more relevant so a 50:50 weight distribution is better. And on the road, mid corner speed is a lotta fun

[gavs]

Yes, true. But the ultimate balance for any car should be around 40:60 to achieve the optimum balance of 50:50 under brakes, which is where the car generally becomes the most unbalanced, therefore giving more steering control. The optimum car balance will alow for perfect balance as the driver brakes all the way to the apex of a corner, at which point they accelerate, transfering the weight back over the driven wheels. This is of course discounting aerodynamics etc

Obviously in a FWD car, this is a stupid ratio though because it means you have no weight over the driven wheels, hence the optimal FWD balance of 60:40 which gives you weight over the friont for traction, yet you subsequently need better front braking due to the major offset in weight transfer under brakes......

[kaanage]

You often sacrifrice some mid corner speed and even braking stability in order to be able to get on the throttle earlier for fast lap times.

This can put you at a tactical disadvantage when trying to pass or being passed but "extending the straights" has more effect on lap time than anything else and means you can pass down the straight and get enough distance that the cornering entry duel never takes place. This is valid for surprisingly low powered vehicles as well as monsters that have trouble with straightline traction.

[gavs]

True, but if you have to slow down earlier to turn into the corners due to the weight transfer not giving you enough grip through the corner then it kinda makes the ability to get more accelerative traction redundant, don't you think? I'm only speculating though, I'm not an engineer by any stretch, I just like reading an example would be last years F1 race at monza. Button ran the standard bodywork on his car while Hamilton had a different, low drag package. Button's car was faster around the circuit due to being able to hold higher corner speeds and not spin the tyres as much, therefore prolonging their life, especially the options. While the other cars chasing him were much quicker down the straights, it didn't natter because he got better drive out of the corners. Granted, this is aero related, but the aero of an F1 car does dictate it's balance and weight distribution.

[kaanage]

Downforce changes EVERYTHING, especially at a track with lots of fast corners like Monza. The gains on the Parabolica and the Lesmos are carried for a good distance along the front and back straights, negating some of the effects higher top speed while the higher corner speed all around the circuit pulls distance from the cars that have less grip.

The effects of weight distribution is quite different.

Yes, with very long sweeping bends, slightly higher mid corner speed with optimal weight distribution will help but if the drive on to the straight is compromised, this can easily be negated, especially on circuits that have lots of short corners where little time is spent at maximum corner speed and so the ability to drive out as early as possible becomes more important. It's a matter of degree and increasing tractive capacity usually doesn't compromise entry and mid corner speed enough to matter compared to the exit gains. Of course it can be overdone.

[Eaglehawk]

Hi everyone!

My first post here, and I've been watching this thread since joining.

Would VW take the whole balance thing to the extreme and do this?

http://www.eaglehawk.com.au/images/Missing.jpg

Do others have their jack missing too? (Or is it under the space saver?)

Update: RTFM! Yes, it was under the spare...I've attached a picture along with the battery location...

http://www.eaglehawk.com.au/images/PoloGTI/Mystery.jpg