Rb25 Vs 25/30

[Adz2332]

Hey all

currently in my track car have a rb25

360kws (graph below)

Mods

HTA3076R turbo with .82

Trail wastegate

dump and screamer

6 boost manifold

G4+ link computer

plazamaman Plenum

Yellow jackets

1000cc injectors on plazaman rail

Decent fuel set up

E85

Im thinking about bolting it all onto a rb30 i have thats in good nic.

will give the block a clean up, put new head studs etc with it.

is it worth going to the trouble? Whats gains would you think id see?

[KiwiRS4T]

More torque, more power.

Frankly I wouldn't bother until your engine blows.

I was assuming that your track car was AWD which means an adapter plate but if its 2wd it not so hard.

You are making good power for a 3076 and to get the most out of a 3L block you might need a bigger turbo (maybe not).

But if you are keen by all means go ahead - you will go faster!

[Adz2332]

I should have mentioned. i was going to forge the engine... so i can either forge the 25 bottom or the 30.... so at the end of the day the engine is coming out regardless

[Dose Pipe Sutututu]

Is your VCT working? does seem a little laggy for all the gear you have.

[Adz2332]

ive had the laggy problem through 2 tuners now. this curve MUCH better than the last

[Dose Pipe Sutututu]

I honestly think the VCT isn't working, it looks like a RB26 power curve

[Adz2332]

might take it in, again. and ask specifically to check it

[Adz2332]

this was the first tune

[Dose Pipe Sutututu]

yeah do it dude.. I am 100% the VCT isn't being triggered properly.

I do recall it is off by default in the Link G4 and you need to assign the output and set it to turn on.

[Dose Pipe Sutututu]

very similar setup, note the difference, this is Matty's car

[whatsisname]

Shaun is highly experienced with the entire RB engine range so it would come as a surprise if he hadn't identified VCT wasn't triggering. But stranger things have happened.

I drop by the workshop most Friday's, I'll ask him about your car tomorrow if you'd like?

As for your original question, it is a no brainer... yes to the RB30 option every time!

Here's my HTA3586 .85 RB30 25DET @ 22psi on the same dyno:

Same ECU and plenum too.

Your RB25DET is producing approx' 85kW at the wheels at 3700rpm vs. my RB2530DET 180+kW

At 4400rpm 135kW vs 330+.

Car goes back on the dyno Tues to complete the tune - yet to add timing and still rich up top - and wind boost up (~30psi)

[Adz2332]

thank you mate that would be awesome.

impressive figures. cant wait to start hoarding parts then. lol will start writing a list

[KiwiRS4T]

Yep if you're going to pull the engine out definitely go the 30.

Here's my power curve with the 30 - less top end than yours but more power early and that's with a 3582 turbo (NB the torque curve - not so much the numbers - they mean nothing to me but more the shape of the curve and early peak torque):

[whatsisname]

No problem at all mate, happy to help out. He is no doubt flat-out preparing Terry's yellow RX2 (630kW rear wheel craziness!) for the ANDRA Finals this weekend but I'm sure I can squeeze in a brief chat.

That's the spirit! [emoji4][emoji106] It is well worth the effort and expense. You won't regret it.

[Piggaz]

[Ad's]

Im doing exactly this but building a forged rb30 with a spare head whilst keeping the current 25 rolling. Ill swap my cams, turbo, exhaust manifold oil and water pumps across before dropping the 30 in.

Using four different RB's to create something unique:

Rb30 bottom end

Rb25 head

GTR intake

GTSR exhaust manifold

<3 the dirty 30

[jet_r31]

ive had the laggy problem through 2 tuners now. this curve MUCH better than the last

got a boost graph aswell?, is it on kill? power is shit if it is

cheers

darren

[Adz2332]

do you think the 3076r will run out of legs on a 30?

[niZmO_Man]

http://i1068.photobucket.com/albums/u457/Ptriffitt/2375B80B-2EB9-45FF-907D-72513DFC83FE_zpsegyt1yuh.jpg

Post of the month.

[Dose Pipe Sutututu]

then let's all have a sads...

A stock 2JZ-GTE VVTi with say a GTX3582R bolted to it will out perform a mildly built RB30 lol... they will happily shit out 450kW on E85 stock the works.