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Rb20 Vs Rb25 Power/weight Now With Maths!

Matvei27

By Matvei27,
in Engines & Forced Induction

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Matvei27 Community Regular

Matvei27

Posted
Posted (edited)

Out of curiosity I decided to calculate the actual performance difference between a R32 GTS-t and R34 GT-T.

One with the RB20DET, and one with a RB25DET NEO.

I decided to share my work if anyone was interested in knowing the actual power/weight ratio of these cars.

I am calculating using the coupe (Type M for the R32) variants, with manual transmission.

For the R32, we are calculating using the zenki which is slightly lighter but not by much

Standard figures are 1280kg @ 215PS for the HCR32,

and 1410kg @ 280ps for the ER34.

Here's the results:

Stock:
R32 GTS-t = 5.95kg/ps
R34 GT-T = 5.03kg/ps

Stage 2 mods:
R32 GTS-t @ 220rwkw = 3.62kg/ps
R34 GT-T @ 250rwkw = 3.55kg/ps

More mods:

R32 GTS-t @ 240rwkw = 3.36kg/ps
R34 GT-T @ 270rwkw = 3.29kg/ps

Tons of mods:

R32 @ 260kw = 3.10

R34 @ 300kw = 2.97

As you can see from the results, the difference is quite significant in stock form, which makes sense because the RB25 has that extra displacement in addition to a bigger turbo. However, once both cars are modified, the difference is quite insignificant until you get past the limits of the RB20.

Edited by Matvei27
Matvei27 Community Regular

Matvei27

Posted
  • Author
Posted

LOL.

seriously?

Dude no.

No.

If it makes you feel better here's how it looks with heavy mods:

R32 @ 260kw = 3.10

R34 @ 300kw = 2.97

The R34 outperforms the R32 in stock and heavily modified forms, but in between they are quite similar at least according to the numbers.

Matvei27 Community Regular

Matvei27

Posted
  • Author
Posted

I'm not making shit up. I'm comparing the data on the two cars. That doesn't mean *real world* performance will be the same, but that's subjective. The only way to objectively compare the two cars is with math, unless you have some better idea.

Ben C34 Grand Master

Ben C34

Posted
Posted

Cmon. You telling me that 270 rwkw is the max safe power of a neo. You're cooked. What are you basing that on?

If what you are saying is true, why aren't rb20 r32s more popular?

Matvei27 Community Regular

Matvei27

Posted
  • Author
Posted (edited)

Cmon. You telling me that 270 rwkw is the max safe power of a neo. You're cooked. What are you basing that on?

If what you are saying is true, why aren't rb20 r32s more popular?

I mean for daily driving. People regularly get 300+kw out of them, but remember the RB25 is slightly less reliable. I included the figures for 260/300 as well for those with more mods.

And as I said above you *will* begin to see a difference at 260/300kw between the two cars. The difference is in stock form and in heavily modified form. Just not in between the two endpoints, apparently.

They're not popular because you have to spend more money to get the same gains that you could get easily from a RB25.

Clearly if you intend to go beyond 260/300kw on either engine you are going to be better off with the RB25.

But if you don't, I'm not sure there's going to be too much of a difference.

Edited by Matvei27

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