Skyline Vs. Silvia

[EliSun]

Hi Guys,

The humble r33 GTS25t. we all know it's got alot going for it:

good looks

good power,

solid engine

etc etc

as far as i know, it seems that most of them can get up to 220rwkw on the standard turbo with all supporting mods.

alot of s15s are capable of up to 237rwkw on the standard turbo with all supporting mods.

this is dyno proven with the usual PFC, full 3", cams etc etc everything upgraded except the turbo.

why? i know the RB25det turbo cant handle boost etc, but what about a similar spec turbo to an S15? would it be able to make the same power?

this is also with the usual PFC, full 3", cams etc etc everything upgraded except the turbo.

an s15 upgrading to a GTRS is capable of up to 260rwkws too..

so tell me why is the RB25det only making 280rwkw at the most with a GTRS?

it's got 25% more displacement etc, why are s15's so close in comparison in terms of power when on paper, we should have a much better performing engine?

thanks

[baron25]

237 is a very specific figure you've got there, I'm always wary when i read dyno reports of 298kw, 252kw - They usualy sound to me like the owner/tuner is chasing some magic target number, and so (not in all cases of course) the engine is probably running a knife edge tune to get every possible last little bit out of it.

The crux of it is, i'd assume that they're totally different engines and that's your inherent difference. Why does an RB25 only have 35 more HP than an RB20, but about 50hp more than an RB30? You're comparing apples and oranges, S15's are much newer cars than R33's and as such i'd expect them to have better engine tech as standard (inc turbo).

[PM-R33]

Well for one if its a jap spec S15 it has a steel wheeled T28 turbo, so it is larger than the stock RB25 turbo, this is why they make more power on a stock turbo.

As far as turbo vs turbo wise goes on different engines. A turbo will max out at a certain power regardless on what displacement engine it's on. You have to think of airflow wise of the turbo, not so much the capacity of the engine.

The larger displacement engine will make more torque from it's displacement and will spool the turbo up quicker due to having more exhaust gas. However once the turbo reaches it's max effeciency the game is over power wise.

[RBwhatever]

Well for one if its a jap spec S15 it has a steel wheeled T28 turbo, so it is larger than the stock RB25 turbo, this is why they make more power on a stock turbo.

As far as turbo vs turbo wise goes on different engines. A turbo will max out at a certain power regardless on what displacement engine it's on. You have to think of airflow wise of the turbo, not so much the capacity of the engine.

The larger displacement engine will make more torque from it's displacement and will spool the turbo up quicker due to having more exhaust gas. However once the turbo reaches it's max effeciency the game is over power wise.

AFAIK the Jap and Aus S15 were both steel wheeled (compressor and exhaust wheels) and the same size. The only diff in them was the aus is bush bearing and the jap is ball bearing....as far as i knew

Overall though the S15 is a better performance package. It'll out perform a 33gtst in every way out of the box, and mod for mod will continue to do so....

[PM-R33]

Sorry, should have worded that better. I just ment the S15 has a steel wheeled T28 compared to the R33 which doesn't hence why the S15 will make more power out of the stock turbo.

Edited May 29, 2009 by PM-R33

[~Hypnotik~]

A S15 cannot get 237rwkw on a stock T28. Just because its been on a dyno and pulled 237rwkw doesn't mean shit. Hell, my S13 pulled 165rwkw with just an exhaust and pod, anyone with a brain would not that is not possible.

But its been on a dyno, it MUST be true!

[PM-R33]

He said it has cams, power FC, full exhaust and god knows how much boost. I would believe it could make in the vecinity of 230.

Either way, it would make more power than a stock turbo'd RB25 could.

[~Hypnotik~]

He said "a lot of S15's" are capable of 237rwkw. Supporting mods or not, its a complete load of shit

[Johnny]

you would have to run a dangerous boost level to kick out that power; over 17psi - my mates s15 pulled 187rwkw with all those supporting mods and i pulled 166rwkw with 11psi + step 1 cams.

regardless, an s15 is alot lighter too and with a good suspension setup + tyres will still eat a similar tuned r33

[iseekool]

I think the RB will have a better power spread (fatter torque curve), firstly they are 6 cylinder engines which mean a cylinder will be fired every 60 degrees as opposed to 90 degrees on a 4 cylinder and capacity does come into play if you are referring to the RB25.

Don't forget there are other factors too like VVT etc...

Max power figures (regardless of the engine) are not the be all end all.

[PM-R33]

Both the S15 and RB25 have VCT.

[Jay_stylz]

not to mention technology advancing in the age difference

[scathing]

The humble r33 GTS25t. we all know it's got alot going for it:

good looks

That's in the eye of the beholder.

alot of s15s are capable of up to 237rwkw on the standard turbo with all supporting mods

Unless one of those "supporting mods" is nitrous or active cooling onto your intercooler core, the dynos pulling that figure must be very downhill. Most S15s I've seen max out the T28 at 200-210rwkW.

an s15 upgrading to a GTRS is capable of up to 260rwkws too..

so tell me why is the RB25det only making 280rwkw at the most with a GTRS?

The GT-RS is rated as a 400hp turbo, if I remember correctly. That's all the air it'll flow, full stop. It doesn't matter how big the engine is - if you can get enough exhaust gas through the impeller to flow 400hp worth of air through the compressor then that's all you're getting. Power is made by mixing air and fuel in a fixed ratio, so if you're only supplying 400hp worth of air then your engine, regardless of displacement, is only going to make 400hp.

it's got 25% more displacement etc, why are s15's so close in comparison in terms of power when on paper, we should have a much better performing engine?

In peak power maybe, but the RB25 will be much fatter in the midrange to hit that 260rwkW. Total area under the dyno graph is what's important to people who want to compete in the real world, not just on paper.

Both the S15 and RB25 have VCT.

But only the S15 has VCT rattle. It'll sound like a diesel, even if it doesn't make torque like one.

[scathing]

P.S. S15 looks heaps better than R33.

[DRD-00F]

aahhhhh I agreed with everything you said but that!

But like you said, it's a judgement call...

[scathing]

The crux of it is, i'd assume that they're totally different engines and that's your inherent difference. Why does an RB25 only have 35 more HP than an RB20, but about 50hp more than an RB30?

It takes about 90hp to dose.

[R33_Dude]

Skyline versus Silvia

Ford versus Holden

WRX versus Evo

Amy Winehouse versus Drugs

Miss R34 versus an informed, intelligent opinion

Ah the eternal arguments....

[GTR-32U]

Skyline versus Silvia

Ford versus Holden

WRX versus Evo

Amy Winehouse versus Drugs

Miss R34 versus an informed, intelligent opinion

Ah the eternal arguments....

lol ..I had a feeling that somehow that thread was gonna resurface in some way or another

[Munkyb0y]

Skyline versus Silvia

Ford versus Holden

WRX versus Evo

Amy Winehouse versus Drugs

Miss R34 versus an informed, intelligent opinion

Ah the eternal arguments....

bahahahhhhahahahahaaa. straight to the post of the year thread for you young man!

[baron25]

It takes about 90hp to dose.

uuhhhh pardon?