Top RB20 Club... do you have over 260rwkw?

[dangerous_daveo]

But Roy, under boost wouldnt the extra 0.5L make a fair bit of difference, even considering the other factors? Also as you keep saying the RB20 head dont flow too much compaired to the rb25 head etc.

[Roy]

But Roy, under boost wouldnt the extra 0.5L make a fair bit of difference, even considering the other factors?  Also as you keep saying the RB20 head dont flow too much compaired to the rb25 head etc.

Some more thinking, i aint an engine builder, mechanic etc so this is just me thinking out loud, welcome others to point out shortcomings in theory:)

But the internal combustion engine is just a pump. So its all about consuming/passing cfm. A certain amount of cfm allows a certain amount of fuel to be added equating in a certain amount of bang ie power.

Basically you all know this, but as i said just thinking out loud.

So the smaller RB20 needs more revs to pass the same cfm. Ok so where the RB25 flows 25cfm at 3,500rpm, the RB20 may need 4,250rpm. The fact is they should be both able to make the same power, admittedly at different revs.

As for the head thing, the RB25 has larger valves, i think it also has bigger cams, and dont foget it has half a point more compression. So it will always be able to flow more cfm.

That said, if your turbo only supports a certain amount of cfm, so ultimately the turbo will run out of flow, the fact that the RB20 doesnt use the air as effeciently means that to get a similar cfm it may need a bit more boost.

Now obviously if were talking 300rwks then the ability of the RB25 to flow more air probably comes into its own. I dunno, but i suspect at the sort of cfm we are talking about at 250rwkws, well i think the RB20 can still flow that sort of cfm albeit it will need a few more rpms

[R31 POWER]

Thats a good read Roy and it does make me think!

[dangerous_daveo]

Yeah well my after seeing what 1GGTEs can do (toyota 2L inline 6cyl for those that dont know, came turbo and supercharged) I know of people who have made 400rwhp (no correction on the dyno on a 28* day from memory) off these stock internals, just a bit of head work all bolt ons, (quality) and a big mofo turbos. They are a square block, but I dont see why RB20s are THAT much different to the toyota version albit stronger engine, but still, thats lota ponies. (in terms of flow espceically)

Im all for the RB20. Im just up agaist it a bit more having an extra 200kgs or so than most of you lot.

[Roy]

Carryling less weight then the R31, R33, A31 etc also makes the RB20s life a little easier in the R32, its still a pretty heavy car though for a 2L:(

I suppose it comes down to what you want, i dont mind a bit of lag, takes me back to the Sierras/DR30/R31 Grp As:thumbsup:

Plus i love hearing engines scream and pulling big revs, and one of the sweetest things i have heard in a while was a R32 drift car the other day at Calder, the thing was singing, sounded as though it was pulling insane revs, made the SRs sound a bit average:)

Fun to drive, sound trick, cheap, reliable, and can get reasonable power out of them cheaply. Want big power then there are probably cheaper/easier ways to skin a cat.

Did i say how good the R32 drift car sounded:)

[predator]

lol.. rb20 fanboy

[Roy]

But give me a healthy bank account and id want an RB30 that could pull 8,000rpm:whackit:

[V8eta]

Roy, im hoping to see how tough the rb20det std internals are, in march going to be putting a gt3040 on the side of mine and see how it goes

[makaveli]

I hope to join the club very soon as in Jan-Feb I should have a power fc, gtr injectors, dump pipe, and hks gt-rs turbo.

take it easy fellas

and keep up the rb20 talk

[Squizz]

made the SRs sound a bit average:)

When DOESN'T an SR sound average???

If my 26 sounded like any of my previous RB20's I'd be a happy happy man.

[benm]

Just transplant an RB25 Roy, you know you love the response

[Roy]

Just transplant an RB25 Roy, you know you love the response

LOL...that night in your car bummed me out...for a reasonably std car it went great, compared to my laggy ho:(

But looking at your drag times im still 7/10s quicker with a slipping clutch:)

RB20 :kick: RB25

RB20 POWAH...FOREVER!!!:looney: :looney: :looney:

[benm]

or a reasonably std car it went great,

It has even better response now (Ex Cam Gear).

But looking at your drag times im still 7/10s quicker with a slipping clutch:)

I'm waiting delivery on a new set of Splitfire Coils, i'm wanting -atleast- 5/10's out of these suckers if they fix my boost issues

[Roy]

It has even better response now (Ex Cam Gear).

I'm waiting delivery on a new set of Splitfire Coils, i'm wanting -atleast- 5/10's out of these suckers if they fix my boost issues

My cam gears resulted in a loss of power, and worse response:( Bloody RB25 owners you lot are a protected species with all those bolt ons meaning good gains:)

Im waiting for splitfires as well, then i can go back to 1.3-1.4bar and hope the adjusted clutch does the trick...fingers crossed. Your car would still leave mine for dead though on the street:thumbsup:

[benm]

Your car would still leave mine for dead though on the street:thumbsup:

It would up until about 3,000rpm after that yours is like an angry bull on roids!

You're running about 220rwkw right?

[Roy]

It would up until about 3,000rpm after that yours is like an angry bull on roids!

You're running about 220rwkw right?

Yeh around that power level, but typical of when you start modifying cars, im not sure why sometimes the car goes like a cut snake, other times it doesnt rev out near as fast or pull near as hard. Th engine has the miss when i run over 1.0-1.1 bar, so ill fix that and i hope my engine runs more consistantly after that.

When it revs nicely the thing feels way quicker then when i picked it up from the tuner. It just doesnt seem to always want to run like that. Im going to hook a channel of my data logger up to my fuel rail as well, and see if a fluctuating rail pressure has anything to do with it:confused:

Though im scared there is still a problem with my PFC, as it was reading funny ignition values a month or two ago before it got re-tuned. And looking at the position of the crank angle sensor, well im not convinced the timing is where it should be:( perhaps when they tuned it they worked around the problem as they couldnt identify it:confused:

So when i get the new exhaust housing ill send it off for another tune and hopefully they can look at the timing etc as it seems strange to be clocked all the way round like it is...plus id like a 2nd go/opinion on the cam wheels hurting power and response.

Would you expect cam gears to work on an RB20 with HKS 2530, with around 210-220rwkws (bbenny) but not on an RB20 with a TD06 (me) with simialr power:confused:....

Im keen to find out what the turbo goes like with the smaller housing

[R31 POWER]

Bloody RB25 owners you lot are a protected species with all those bolt ons meaning good gains

Hahahahahaha I feel the same and also about how there is tons of crap you R32 and R33 owners can get to just bolt on while us R31 owners need to mod shit and have no body kits and wheels that bolt on

[dangerous_daveo]

So what have most of you guys actually done?

ECU, turbo, extra fuel??? Anything else like custom manifolds to pulse the turbo more, or just stock manifold??? Any other 'crazy' stuff like that?

[R31 POWER]

I've done

- R32 Silver top RB20DET

- HKS GT2535 turbo

- Stainless steel exhaust manifold

- R33 GTR injectors

- Nismo adjustable fuel regulator

- Bosch 040 fuel pump

- Z32 AFM

- Apex'I Duel Funnal pod

- Apex'I Power FC and hand controller

- R32 GTR intercooler and 2.5inch stainless piping

- GReddy Profec B boost controller.On 12psi for now

- GReddy Type S BOV

- Catch can

- Works Auto 3inch dump pipe,3inch mild steel mandral bent zorst with Bazooka muffler

and all it needs is a tune for more boost.Hoping for 300+rwhp

[Sydneykid]

Good power at 4,500rpm would be nice. What sort of power are you making at 4.500,    5000,   5,500rpm,    6,000rpm etc etc  

I have about 135rwkws at 4,500rpm, which is about 30-40rwkws off where i want to be.   At 5,000rpm i have just over 180rwkws...that where i want to be at 4,500rpm. So rather then get the cams im just going to get the smaller (properly sized) exhaust housing for my turbo.

I would have been better off getting a hi-flow or a 2530 tuned normally and make 210-225rwkws with better response. Or perhaps tune the car normally at 13psi to make the same power?!?!?!?!

Hi Roy, this is what mine looks like at 1.25 bar

rwkw-rpm

180 7,750

190 7,500

200 7,250

225 7,000

200 6,500

175 6,000

160 5,500

154 5,250

150 5,000

145 4,750

142 4,500

That's an average of 178 rwkw from 4,750 rpm to 7,750 rpm. How does that compare with yours?

It isn't much more than yours at 4,500 rpm, but the cams help the top end so it doesn't top over badly at 7,250 rpm which is what happens when I have standard RB20 cams in it. There is a bit of turbo selection result here, as well as cams.

I don't want to sound like I am picking on plain bearing turbos, but yours displays the same symptoms I see often. They build boost rapidly at highish rpm for their (small) size and then run out of airflow (because of this smallish size). Looking at it the other way, if you had a larger plain bearing turbo, then the boost build would be even later but you wouldn't loose as much top end. On the other hand the (larger) ball bearing turbo gives slightly better boost build, but it is still large enough to give a much better result at higher airflows (rpm).

Bottom line, it has been my experience that plain bearing turbos have a narrower power band, regardless of size. Time for some cams, toughen up that top end.