thuggo

That sure is making the rounds....

TXshaggy

Lol…that ship sailed in the 997 era.


OBTW, there is no “T” in Mezger.

mjw930

Thanks, corrected.

jmartpr

While the Mezger was great, we have to let it go and move on......all the 991/992 generation GT3/RSs are great cars and deliver the performance. No question about it.
If we think like that then lets go back to air cooled engine because the rest is no good....well, maybe that's stretching it a bit.
4RS vs a Deman 4.5? I briefly considered this option but then you have no warranty and an engine that's modified to the max......the 4RS provides more assurance that engine problem will not be a problem and if they do PAG has you cover for the warranty period.
Also, I'm pretty sure the 4RS can be modified a bit more without having to bore and stroke it....which is the issue I have with the 4.5L being 1-2 mm away from end of life....it needs to last years without having to scrap the block.
The 4RS PDK is also modified with improved ratios. Which would be faster around the track? We will see but I don't think it will be a night and day difference.

JCviggen

On track the RS will be faster because it will sustain its performance way better with the side window intake. You lose tons of power to hot air when its sucking it in through the side scoops.

ExMB

That is true for European track driving and the CS. In the US HPDE track driving requires windows down which could have an effect on the side window air intake since the airflow is being disrupted.

JCviggen

I have little doubt that the effect of windows up or down will be negligible. The difference in intake air temp is massive and there's no reliance on any kind of ram air effect...

Odin

Why are you talking about Mezger engines? Last Porsche equipped with one was back in 2012.

GrantG

I haven't seen any data, but is the air temp really that different a couple feet farther from the track (door height side intake vs. window height side intake)?

jmartpr

According to people with Clubsports, yes......you are taking in hot air from the front brakes, underbody of the car and closer to the track surface.
The new upper intake ducts provide cleaner air with lower temps.

GrantG

What data have these Clubsport owners provided to bolster this claim? Is it simply an opinion or is there more to it?

ExMB

That was proven with the 981 CS update. The old engine benefited from that due to previous power loss because of temperatures.

GrantG

To what degree did it benefit?

In the 991 GT3 world, they choose the lower side intakes for the GT3 RS (instead of the higher rear decklid intakes of the GT3) for better performance.

JCviggen

I stuck two temp probes on my own car. 981 GTS with 3.8 X51 swap. Basically a clubsport. On track the temp starts off equal but then after half a lap or so the reading at the scoop starts to increase. After two laps it was reading 12 degrees C over ambient (the side window reading kept matching the dash temp pretty close)

I don't do Fahrenheit but that's the difference between a mild day and a really warm one. The radiators spill hot air into the wheel well which travels back straight into the scoops. Brakes also of course.

On the street you'll never load the car for long enough that it becomes an issue.

They didn't build that crazy intake contraption for the 718 CS MR for no reason...

Ksdaoski

Oh absolutely none. Porsche just wanted to sell more cars and had to come up with an excuse... 🙄