Rb26/30 Build, Yet Another One... ;)

[Simonster]

Oil air sep- none handy it's just like any other, however lots of baffling and steel wool. Smaller than most i've seen, however the pathway through the baffling is pretty intricate.

Mushrooms- yes, not my first pick, was the only thing that fit easily while i found a standard airbox- want it to look as factory as possible. The location of the CDI meant the existing Z32's and Apexi pods would not fit.

Fitted the STD box on the weekend only to find it snares on the main y pipe just after the join- more minor mods to make it fit.

Wasn't a great deal taken off the crank, i wasn't keen on taking much off. Good point though.

Hoping to find another 50-80hp yet. The cam timing was pretty aggressive on the inlet side, i think most of it will be found here. Very lumpy idle for only using 260x9.1's Man its fun to drive though

Got it set up for 10psi in 1st gear 14 in 2nd and 19 in 3rd+ Lights all 4 in 2nd which is pretty nice just.

Bit surprised by the fuel economy( or lack of it). Be interested to hear what others with 3litres get? Mines hovering around 6.8km/L or for other types almost 15L/100km.

I must say i'm a little disappointed with it, was hoping it would be nearer to 10km/L. And yes, this is without lots of "playing" just normal drive to/from work at normal speeds boring, but i've done it three times now and it's 6.8 6.8 and 7.2km/L.

Edited May 4, 2011 by Simonster

[Harey]

Congrats to get it up and running!

That fuel consumption sounds ok to me for driving in medium to heavy traffic in the suburbs. Do you know what the afrs are like at cruise?

Your cams will use more fuel then standard cams.

Even a pre 2004ish normal commodore or falcon 6 will get more than 10L/100km in peak hour driving to work and back. My dads 2005 monaro V8 gets over 20L/100km.

Have you done any measurements in lighter traffic or on the highway etc? How about when you give it a hard time? If its good in some conditions but not in others it could be the tune is too rich for different conditions. But doesnt sound excessive to me.

[r33_racer]

Time for more power Simon! :D

[Simonster]

Congrats to get it up and running!

That fuel consumption sounds ok to me for driving in medium to heavy traffic in the suburbs. Do you know what the afrs are like at cruise?

spot on 14.7

Your cams will use more fuel then standard cams.

Even a pre 2004ish normal commodore or falcon 6 will get more than 10L/100km in peak hour driving to work and back. My dads 2005 monaro V8 gets over 20L/100km.

Have you done any measurements in lighter traffic or on the highway etc? How about when you give it a hard time? If its good in some conditions but not in others it could be the tune is too rich for different conditions. But doesnt sound excessive to me.

That is pretty much highway driving, with a very small amount of "traffic" but it's pretty constant with 3 stops. That was why i was of the opinion it wasn't that great.

My tuner spent quite some time on light load fueling as he know's i do a bit of highway driving.

[Simonster]

Time for more power Simon! :D

Yes Michael, i was pretty surprised it stopped where it did. That said, i'm pretty sure it's mainly the cam timing, very aggressive idle sounds like its got 290's with massive lift in there - i love it shakes like a really lumpy V8

Trying to organise some more dyno time...

[rockabilly]

simon, mines pretty bad on fuel have to admit. the rb26 i had before with 25/30,s beat the 30 hands down, also on track the 26 is much more fuel effecient for not much less power.

[Marko R1]

simon, mines pretty bad on fuel have to admit. the rb26 i had before with 25/30,s beat the 30 hands down, also on track the 26 is much more fuel effecient for not much less power.

Hey bernie, in what regard was the 26 better than the 30, response, trackable power?

I agree the fuel efficiency of my old 30 was terrible in comparison to my 26...I'm happy that I went back

[Simonster]

simon, mines pretty bad on fuel have to admit. the rb26 i had before with 25/30,s beat the 30 hands down, also on track the 26 is much more fuel effecient for not much less power.

Ah, ok, that's interesting. The 26 with powerFC was getting around 10km/L in the GTR, so the 3 litre is definitely worse than that.

I'm about to start a 26 build for my Sil80 so it'll be interesting to see what that gets- but won't see much street driving

[Marko R1]

well i know with 26 i used to get 450km to the tank, street driving.

with my old rb30 i'd be lucky to see 300km to the tank.

anyway, if u want fuel economy, buy a hybrid

[Simonster]

well i know with 26 i used to get 450km to the tank, street driving.

with my old rb30 i'd be lucky to see 300km to the tank.

anyway, if u want fuel economy, buy a hybrid

ha ha, i'm getting around 430 a tank with the 3litre.

Don't think for a minute i'll be selling the car just because it's not getting 10km/L! Fuel economy isn't synonymous with any RB engine- just interesting to hear what other people were getting, for the sake of interest.

So now, need to change the cam timing and see what happens.....

[Marko R1]

i must have a heavy foot then (or u drive like a girl )

[TiTAN]

spot on 14.7

That is pretty much highway driving, with a very small amount of "traffic" but it's pretty constant with 3 stops. That was why i was of the opinion it wasn't that great.

My tuner spent quite some time on light load fueling as he know's i do a bit of highway driving.

on the highway 15.5-16:1 AFR mine gets 9.5L/100km

[Simonster]

on the highway 15.5-16:1 AFR mine gets 9.5L/100km

Interesting, i'll have to check that out next time on dyno then- cheers

[rockabilly]

having now owned both versions, firstly a forged rb26, 264/272 cams hks 25/30,s and rb26/30 gt4094r,270/280 cams i would say this

on the road the 30 is much more road friendly, leave it in top and just press the go pedal, whereas the 26 was a bag of crap below 3200 and not much happened until 4000 onwards, then it went.

on track a well sorted 26 with 600bhp will hold its own against a well sorted 750bhp 30,dont ask me how but it does. this is why i was following simon,s thread. i have modded my exhaust housing on my gt4094r to aid spooling, now if this does not help then twins will be going on.

senario. 2 x 33gtr vspecs, rb26/600bhp twin 2859r,s-- verses rb26/30 750bhp gt4094r single on track very equal.. why?.

at .52secs we are going down the main straight you can here the external wastegate opening and shutting at 1.5 bar thats full chat 750bhp and he,s pulling away?.

on the above clip both cars were taken to 7500rpm,s. yet i could not catch or gain on nick in the white car.

also both cars were brimmed with fuel and did the same amount of track time, 2 sessions of 20 mins each. the 26 used a 1/4 tank fuel the 30 used just over 1/2 tank?

i, as marko may go back to the 26 at some piont as the milage i do a year and the price of the fuel difference is enormous..

Edited May 8, 2011 by rockabilly

[Marko R1]

having now owned both versions, firstly a forged rb26, 264/272 cams hks 25/30,s and rb26/30 gt4094r,270/280 cams i would say this

on the road the 30 is much more road friendly, leave it in top and just press the go pedal, whereas the 26 was a bag of crap below 3200 and not much happened until 4000 onwards, then it went.

on track a well sorted 26 with 600bhp will hold its own against a well sorted 750bhp 30,dont ask me how but it does. this is why i was following simon,s thread. i have modded my exhaust housing on my gt4094r to aid spooling, now if this does not help then twins will be going on.

senario. 2 x 33gtr vspecs, rb26/600bhp twin 2859r,s-- verses rb26/30 750bhp gt4094r single on track very equal.. why?.

at .52secs we are going down the main straight you can here the external wastegate opening and shutting at 1.5 bar thats full chat 750bhp and he,s pulling away?.

on the above clip both cars were taken to 7500rpm,s. yet i could not catch or gain on nick in the white car.

also both cars were brimmed with fuel and did the same amount of track time, 2 sessions of 20 mins each. the 26 used a 1/4 tank fuel the 30 used just over 1/2 tank?

i, as marko may go back to the 26 at some piont as the milage i do a year and the price of the fuel difference is enormous..

that is odd but does not surprise me as well bernie & if anything your car should be quicker as it would sit in the slipstream of your mates gtr.

the rb30 makes its power mid range whereas the rb26 makes its power top end...on the circuit you are sitting on top end revs most of the time & this has actually been proven on motorbikes.

for example, when i had my kawasaki zx10r & was racing my mate with his suzuki gsxr1000, i was down close to 10hp which is a lot on a bike (like having a 100hp delta between 2 cars), however, we were neck and neck & this was running on a long road from 100kmh to over 300kmh. fyi, zx10r lacks mid range (like the rb26) & the gsxr1000 lacks top end (like the rb30). How or why? Must be something do with where the engine makes peak power, after this it drops off...

when i 1st built my rb26, i gave my brother in law a good fright but when i built the rb30, the 1st thing he said to me was “your rb26 felt a lot quicker” & i guess that is because the rb30 is much more linear, doesn’t have the same top end & doesn’t have the same snap/rush as my rb26. my rb30 had 405awkw, my rb26 had 362awkw.

Its good to see a gtr in its element on the track

[TiTAN]

having now owned both versions, firstly a forged rb26, 264/272 cams hks 25/30,s and rb26/30 gt4094r,270/280 cams i would say this

on the road the 30 is much more road friendly, leave it in top and just press the go pedal, whereas the 26 was a bag of crap below 3200 and not much happened until 4000 onwards, then it went.

on track a well sorted 26 with 600bhp will hold its own against a well sorted 750bhp 30,dont ask me how but it does. this is why i was following simon,s thread. i have modded my exhaust housing on my gt4094r to aid spooling, now if this does not help then twins will be going on.

senario. 2 x 33gtr vspecs, rb26/600bhp twin 2859r,s-- verses rb26/30 750bhp gt4094r single on track very equal.. why?.

]

at .52secs we are going down the main straight you can here the external wastegate opening and shutting at 1.5 bar thats full chat 750bhp and he,s pulling away?.

on the above clip both cars were taken to 7500rpm,s. yet i could not catch or gain on nick in the white car.

also both cars were brimmed with fuel and did the same amount of track time, 2 sessions of 20 mins each. the 26 used a 1/4 tank fuel the 30 used just over 1/2 tank?

i, as marko may go back to the 26 at some piont as the milage i do a year and the price of the fuel difference is enormous..

you can also hear massive amounts of compressor surge under throttle which isnt going to be doing any good in that video yet in this one with the white 33's owner driving your car its not there (i have noticed mine does this if you aren't 100% full throttle)

[rockabilly]

ah well spotted so light throttle is a no no and full beans is a must lol

[Marko R1]

Regardless of compressor surge, drivers ability or any other factors such as even gear changing, it is evident that bernie's gtr is not gaining on nick's gtr on any straight in his vid.

Bernie - are both setups running the same boost level and have both been measured on the same dyno?

[sucram]

you both have different driving styles which will result in different speeds. Rock squeezes out of corners where the in the above embedded vid (different driver?) squares the corner.

So exiting a corner driver (A) is at 40% throttle gradually squeezing it open and at the same point driver (B) but is at full throttle.

Same thing in a roll on race even if you have a bit more power then the guy next to you, and he gets the jump on the start you cant always claw your way back.

At the end of the day put driver (B) in both cars and he will always have a faster speed at the end of the straight then driver (A)

Marko- never under estimate driver ability/experience. Otherwise we would all be driving F1 cars and we will be all lapping within a tenth of each other

[dorifticon]

My fuel consumption in the rb26 was around 10L/100kms and increased to around 15L/100km in the rb30 build (but that build also significantly upgraded the cams and different clutch as well, so heavier mass to rotate on the crank).