The difference between Legacy RSK B4 and B4?

[Guest]

hi guys, sorry i hope this is not a repost.

if it is, then may somebody direct me to the correct link? :)

but anyway, if it's not a repost, what is the main difference between the RSK B4 and just B4?

i'm guessing it's something to do with the exterior looks, not the engine??

cause both of them has 2.0L twin turbo??

any kind of help is much appreciated!!

cheers guys :)

[Guest]

A B4 is naturally aspirated. A B4 RSK has the twin turbo engine.

People tend to use the terms interchangably but they are actually different.

[DRFVDR]

Yup the B4 is a base spec with from my understanding Bilstein suspension (B=Bilstein 4=Who the fark knows)

Where as the RSK B4 has the same Bilstein Suspension BUT also as the Turboed engine and most likely other goodies (RS=Rallye Sport K = Kompressor )

[pl0x]

mines turbo but no where does it have RSK on it?

[Oesnam]

I'm pretty sure that the RSK means that the car has Bilstein suspension. because you can get trubo'd cars without Bilstein's.

The exterior looks the same as far as i know and i think the 4 stands for 4 cylinders or something haha

[Joker]

K = Kompressor

4 = either 4wd OR 4 pot Boxer - both have been used

[dogmanjunior]

I heard the RSK-B4's are 206kw - is this right? The same as an STi?

Surely this can't be right, my GDA WRX (non STi) is quicker than my mates RSK...? Or are the RSK's just heavy as fuck?

[Koom]

 dogmanjunior said:

Surely this can't be right, my GDA WRX (non STi) is quicker than my mates RSK...?

From the traffic lights.... :

[Joker]

waaay different power delivery yes 206Kw (Flywheel)

[dogmanjunior]

 JoKer said:

waaay different power delivery yes 206Kw (Flywheel)

How / why is the power delivery so different? Just because of twin turbo instead of single? Or is the RSK much heavier too? What is the benefit of using twin over single turbo? Sorry for the n00b questions, this RSK vs WRX business has intrigued me for a while...

[Joker]

Just because of twin turbo instead of single? <<<THIS mainly YES

Gen II and Gen III shape legacies are lighter or equivalent in weight to 03+ STI's if that helps...

[Oesnam]

and also because the RSK's are 1.8 ton haha. very slow off the mark. they just have different power delivery and torque.

twin turbo's peak power at 6400~ revs whereas the singles are around 2500~3400 revs. also the torque in an STi is around 350Nm stock, the B4 being around 250Nm

[subypower]

B4 Stands fort Boxer 4 (Boxer Engine, 4 Cylinder)

B4's are a sedan only model.

Their are 2 types of B4.

1) RSK B4:

2.0l DOHC Twin Turbo, 280hp in Manual, 265hp in Automatic

2) RS B4:

2.0l DOHC Naturally Aspirated, 165hp in both guises.

Hope that helps.

[Guest boostin]

 subypower said:

B4 Stands fort Boxer 4 (Boxer Engine, 4 Cylinder)

B4's are a sedan only model.

Their are 2 types of B4.

1) RSK B4:

2.0l DOHC Twin Turbo, 280hp in Manual, 265hp in Automatic

2) RS B4:

2.0l DOHC Naturally Aspirated, 165hp in both guises.

Hope that helps.

Correct! And you will never see an RS or RSK badge. It does come up in the Subaru system when the chassis number is entered though. Any RS or RSK badge on one of these vehicles was fitted AFTER it left the factory.

[pl0x]

 boostin said:

Correct! And you will never see an RS or RSK badge. It does come up in the Subaru system when the chassis number is entered though. Any RS or RSK badge on one of these vehicles was fitted AFTER it left the factory.

was wondering why you hardly ever see "RSK's" round

[Guest boostin]

 pl0x']

[quote name='boostin said:

Correct! And you will never see an RS or RSK badge. It does come up in the Subaru system when the chassis number is entered though. Any RS or RSK badge on one of these vehicles was fitted AFTER it left the factory.

/quote]

was wondering why you hardly ever see "RSK's" round

Yep, they're all badged simply "B4". Turbo or N/A.

[GravelBen]

 Oesnam said:

and also because the RSK's are 1.8 ton haha. very slow off the mark. they just have different power delivery and torque.

twin turbo's peak power at 6400~ revs whereas the singles are around 2500~3400 revs. also the torque in an STi is around 350Nm stock, the B4 being around 250Nm

You're talking 100% pure bullsh!t.

RSK/GTB has 343 Nm torque and weighs 1.5 ton, about the same as a newage STi. Both produce peak power around 6500, but the twin-turbos make peak torque higher in the revs (5k rpm compared with just under 4k).

The key difference is the twin-turbo setup gives a wider, smoother torque curve (from 2000-7500) whereas the single turbos have a bigger hit of mid-range torque. This makes them feel faster and the closer/lower gear ratios help make them quicker at lower speeds, but don't underestimate the top-end performance of the Legacies.

There is a vid floating around from a clubsub trackday where a standard RSK is dead even with a modified STi-RA above around 100km/h despite the STi having better exit speed.

The '98 GTB also held the world record for fastest production station wagon at 270km/h until the Audi RS6 (I think) pipped it.

[Guest]

thought for an RS/RSK it had a red colour on the bevel of the b4 emblem on the boot

-smurff

[Oesnam]

 GravelBen']

[quote name='Oesnam said:

and also because the RSK's are 1.8 ton haha. very slow off the mark. they just have different power delivery and torque.

twin turbo's peak power at 6400~ revs whereas the singles are around 2500~3400 revs. also the torque in an STi is around 350Nm stock, the B4 being around 250Nm

/quote]

You're talking 100% pure bullsh!t.

RSK/GTB has 343 Nm torque and weighs 1.5 ton, about the same as a newage STi. Both produce peak power around 6500, but the twin-turbos make peak torque higher in the revs (5k rpm compared with just under 4k).

The key difference is the twin-turbo setup gives a wider, smoother torque curve (from 2000-7500) whereas the single turbos have a bigger hit of mid-range torque. This makes them feel faster and the closer/lower gear ratios help make them quicker at lower speeds, but don't underestimate the top-end performance of the Legacies.

There is a vid floating around from a clubsub trackday where a standard RSK is dead even with a modified STi-RA above around 100km/h despite the STi having better exit speed.

The '98 GTB also held the world record for fastest production station wagon at 270km/h until the Audi RS6 (I think) pipped it.

Pretty sure that the legacies weigh a lot more than a standard STi. Have a look at the interior difference to start off. STi's interior is just designed to be light weight whereas the legacies are whales with electric seats etc.

The legacies are somewhat faster than STi's on the motorway but i seriously doubt they weigh 1.5 ton and have 343 Nm torque.

Maybe your gtb is just legit i dunno but mine does not concur.

Not too happy about your opening sentence ay, straight up criticizing rather than trying to give opinions or advice.

[Guest]

Im pretty sure Turbo B4's have red surrounding the B4 and Non Turbos have a grey surrounding?

Turbo Badge

[Ryry]

also on the note of power delivery do the B4's still have the gap from 4000rpm in the turbos where they run no boost? Never been in a B4 but i know from experience of the previous model. A few mates had them.

[GravelBen]

 Oesnam said:

Pretty sure that the legacies weigh a lot more than a standard STi. Have a look at the interior difference to start off. STi's interior is just designed to be light weight whereas the legacies are whales with electric seats etc.

The legacies are somewhat faster than STi's on the motorway but i seriously doubt they weigh 1.5 ton and have 343 Nm torque.

Maybe your gtb is just legit i dunno but mine does not concur.

Not too happy about your opening sentence ay, straight up criticizing rather than trying to give opinions or advice.

Just being honest! When people spout misinformation I'll call them on it, no personal offense intended though.

To be fair there does seem to be significant variation in the performance level of TT Subarus (for whatever reason) and several mechanics have commented on mine being a particularly healthy example - the way it winds out from 100 to 180[arbitrary units] gives me no reason to doubt the claimed output.

GC8 STi's are much lighter (most around the 1250kg mark, some RAs under 1200) but newage cars are pretty heavy in comparison. Subaru quoted the newage WRX at around 1370 from memory and STi at 1485 - the six speed box is much heavier than the 5, along with bigger brakes, more chassis bracing and so on the differences all add up.

Mate put his BG5 Legacy GT on a weighbridge and taking into account the two people and tank of fuel in it the weight was close enough to the factory claimed 1430, though I haven't weighed mine yet.

[GravelBen]

 Ryry said:

also on the note of power delivery do the B4's still have the gap from 4000rpm in the turbos where they run no boost? Never been in a B4 but i know from experience of the previous model. A few mates had them.

Apparently some do but my '02 GTB E-tune has no problem with it - you can find the dead zone and lose boost with a badly timed gearshift on part throttle, but winding through it under enthusiastic acceleration you only notice the bigger kick from the secondary turbo with no drop-off in between.

[Oesnam]

 GravelBen']

[quote name='Oesnam said:

Pretty sure that the legacies weigh a lot more than a standard STi. Have a look at the interior difference to start off. STi's interior is just designed to be light weight whereas the legacies are whales with electric seats etc.

The legacies are somewhat faster than STi's on the motorway but i seriously doubt they weigh 1.5 ton and have 343 Nm torque.

Maybe your gtb is just legit i dunno but mine does not concur.

Not too happy about your opening sentence ay, straight up criticizing rather than trying to give opinions or advice.

/quote]

Just being honest! When people spout misinformation I'll call them on it, no personal offense intended though.

To be fair there does seem to be significant variation in the performance level of TT Subarus (for whatever reason) and several mechanics have commented on mine being a particularly healthy example - the way it winds out from 100 to 180[arbitrary units] gives me no reason to doubt the claimed output.

GC8 STi's are much lighter (most around the 1250kg mark, some RAs under 1200) but newage cars are pretty heavy in comparison. Subaru quoted the newage WRX at around 1370 from memory and STi at 1485 - the six speed box is much heavier than the 5, along with bigger brakes, more chassis bracing and so on the differences all add up.

Mate put his BG5 Legacy GT on a weighbridge and taking into account the two people and tank of fuel in it the weight was close enough to the factory claimed 1430, though I haven't weighed mine yet.

Yeah thats all good man, its just that I don't know you personally or anything. Hopefully one day.

And that boost-lag commonly referred to as VOD (valley of death) is a lot more greater in the non Rev-D models.

Like yours Ben, since its a Rev-D model engine it has way less VOD. Whereas mine is a bit of a gap

[subieboy]

 Oesnam said:

SNIP the B4 being around 250Nm

YAAAR NOOO thee bee wong thaar

The Aus spec B4 was 320Nm torque with 190Kw...

The jap spec was 206KW and 343Nm torque...