View Full Version : BMW Z4 GT3 - Wrong car?

05-08-2015, 16:06
Compare this:




Is it the Z4 GTLM in the game? Or why does the Z4 lack so much power in relation to SLS and Bentley?

The fuel tank is also from the GTLM.

05-08-2015, 16:37
I'd assume it's the GT3 variant of the car in the game. If it was GTLM it'd probably be the fastest out of all the GTs. As it stands, it's about where it should be in terms of performance. Not the fastest but does well around the corners.

If there's one GT3 car that's just too-damn-fast in my experience it's the Audi. That thing is absolutely lights out.

05-08-2015, 16:44
The Z4 GTLM was build to race in the USA, it replaces the M3 GT. It is based on the Z4 GT3 car. The Z4 GT3 usually is restricted a bit so it doesn't get to 535 PS in the GT3 serieses. From the two I'd suspect that the GT3 car would be faster, it has more downforce and about the same power.

PS: The Z4 GT3 "lacks" so much power because it has a smaller engine than the SLS or Bentley, on the other hand, it is such a well balanced and quick car, it would be overpowered with more ps.

Jussi Viljami Karjalainen
05-08-2015, 16:48
Our car is the previous generation GT3 car, back from when they still ran the BMW M3 GT and before they ditched that and started work on the modern platform that became the current Z4 GTLM and GT3 cars. It's a different car altogether. Here's an archived copy of the page for the old car: https://web.archive.org/web/20120415001255/http://www.bmw-motorsport.com/en/cars/bmw-z4-gt3.html

You can also see the notification "depending on air restrictor regulations" after the engine power. The cars in GT3 racing are balanced with each other by using ballast weight adjustments, air restrictors etc. The cars are also very different from each other in terms of how they're built, how efficient the aerodynamics are and so on. So some cars can be quite light and lower power with very efficient aerodynamics, whereas others can be heavier with more power and inefficient aerodynamics, but they try to adjust the Balance of Performance (BoP) with weights and restrictors so that all cars are roughly the same speed across a lap. Unlike in GTE, there isn't a very strict ruleset that the cars need to match, the manufacturers are essentially quite free to build whatever they want, then SRO (who owns the GT3 classification, like ACO owns GTE) tries to balance it out with the rest of the field.

So, the reason why the Z4 GT3 has less power than some of the other cars is because it needs less. It's well over a 100 kg lighter than the SLS for example, and the aero kit on it is very efficient (the real car is known for not being a monster on the straights, but being blistering in the corners). If you pumped up the power to match the SLS GT3, it'd easily be the fastest car in the class. =)

The original Z4 GT3 page says that the engine produces around 515 bhp, in-game at low altitude it's putting out around 490 bhp the last time I checked, so it's restricted a bit from what it could do, but not massively.

As for why the fuel tank is 105 instead of 115 liters... Not sure. Could be that when deciding on that the homologation documents they used had different figures from what BMW claims. The tank size can also change from year to year and series to series in some cases.
If there's one GT3 car that's just too-damn-fast in my experience it's the Audi. That thing is absolutely lights out.The Audi is indeed a nice car for being quick in, but I don't think it's necessarily the quickest when pushed to the limit. I took a look at the top times for each car on 15 popular tracks (filtering out times that were obvious cheats) and the car that had the lowest average time was actually the Ruf RGT-8 GT3, followed by the Audi and the 12C. Ignoring the M3 GT (which should be getting an update in the future, or has it already, not 100% sure) and the Ginetta (which I think is capable of super duper quick times, but does require significant setup work and a different driving style from the others) the average times of the rest of the GT3 cars were well within 1 second, so overall they seem really well balanced, even surprisingly so considering how different they can be from each other.

06-08-2015, 10:40

06-08-2015, 12:22
Cool feedback Jussi - was an interesting read - thanks :)

19-10-2015, 09:31
I dig up this thread.

My question is, if there will be some rebalancing in the future for all of the GT3 cars?

There's is no doubt that the z4 is not a GT3 spec, as is the Porsche.

N0body Of The Goat
19-10-2015, 16:05
I've written it before and I'll write it again, I would love to have the GT3/GTE class re-balanced so that the "force default setups" online option gives a good battle at most tracks.

Perhaps SMS would appreciate a few respected setup gurus to suggest their default setup re-balancing changes?