A Boy's Love For His Rb20

[DJRIFT]

Sorry I miss read about the 25det crank.

Why the low rev limit. Mark 1 of my 25de revved to 8 and mark 2 revs to 7400 due to fuel supply.

With 320rwkw it was happy to bang limi all day it wasn't revs that killed it anyway.

And there is bugger all difference in the cams mainly the cam timing but that won't stop it revving

[feifongwong3]

Its ok, bro. I know you only went to the dark side to confirm what you already knew. You'll be back in the lap of 2L luxury in no time.

[Roy]

I think its the exhaust back pressure at high rpm, cam timing and cams...a little bit of everything. The RB20 actually makes more power as the new engine falls over after 6,500rpm

So will try new turbo with bigger housing, going for the 12cm2, cam gears, cams etc and I am pretty sure will find a bucket load of top end. Will throw the 20G back on to compare to see if the billet turbo is any better. I think the 20G could be a good thing if we can get it breathing up top and get it to hold onto power. A solid 4,000rpm range of 300 odd rwkws would be pretty solid result

The 12cm housing shall at least enable me to flow plenty and see what the compressors will flow

Yes, the character of the 2L is more fun. Will be interesting to see how is goes for traction at the track when driving in anger

[Interloper]

will be interesting to see how much cams make a difference on the 25, seeing as cams on a Rb20 made no diff...

When's the next track day you're going to?

[Roy]

Phillip Island in late April. Trying to get my new suspension and rear end in for it so that I can throw in my new gearbox. I have to put the rear end in with the gearbox otehrwise will need to do the tailshaft twice. Gearbox feels fine but concerned it will have trouble with the torque of bigger engine on E85 with more power and track work. it has done 210,000kms but at the end of the day not "not going to go" because of functioning RB20 gearbox may let go

[Interloper]

PIARC 28th April? I'll drive down to watch this

you going rb25 box? what rear end mods you got?

[Roy]

Have an R33 GTR rear end but need my new shocks back from revalving before it all goes in. Will likely be doing PIARC with std box. Its the only real original part still in the car

[GTScotT]

Interesting to read you fitting the R32 RB25, unexpected! Valuable info tho.

Kind of glad you made me read for myself, gained a bit I wanted to know lol

[Roy]

If the RB20 didnt split that heater hose then i would never have put this engine in. This was the "too cheap to pass up in case I got EPA'd engine" that I hoped would never get used.

Anyway. So after a Saturday of wasting Racepaces dyno time with fiddling with the 20G and 12cm housing...we are pretty sure we have run out ofcompressor but simply couldnt get thet thing to hold boost.

So knowing the Hypergate only had a piss weak 11 psi spring I have grabbed 3 more springs and should be able to find a good combo to get the gate to hold about 19psi...and us bleed what we want from there.

So cam gears are in. Tomei 256/8.5mm cams are in. 12cm housing on. 19psi springs in the gate and she is rolling onto the dyno still with the 20G as we speak. Plan is to get a good baseline for the 20G to back to back with the T67 and 73HTA.

All this testing is a ball ache, but the engineer in me loves it

[TTT]

Looking forward to the results.

that is results of power and rb20 gearbox internals.

[Roy]

The phonecall I just got from Racepace said they doubt the box will make it through Phillip Island. Mostly due to the twin plate Exedy it now has in front if it....its not the power as RB25s are poop and dont seem to want to make any !

[femno]

Well jump on it! I picked mine up yesterday (running fantastic) and saw yours there.

Im putting my entry in today for PI too.

[Roy]

I must admist I was having long , close looks at your car. I really like how you have done htings.

I think there is a definite thinking to how to build a car when you are a frustrated engineer that wants to drive and build cars for a living Not always the easy way, or the quick way OR the the cheap way....but he cool way

[robots]

Roy, share your results with us

[TTT]

request thread title change to "A boy and his hatred for 350+ rwkw RB25de+t because broken in the head"

[SABBAi]

I've got a fix for the box Bris.

Fire.

Not like it hasn't happened before. Am I right?

[robots]

Roy, check for valve lift ? RB25DE　known to have lousy valve springs.

[Roy]

Engine is meant to have new GTR valve springs. No signs that there is anything wrong with the engine at the moment, Seems all setup related. Not really a problem...just a combo not really working well together....which is to be expected when you throw 500cc at a 2L setup.

request thread title change to "A boy and his hatred for 350+ rwkw RB25de+t because broken in the head"

I am with you...the only thing that helps with the disdain I have for this motor is that its cheap and looks like an RB20, so is 2/3 the recipe of an RB20

[fatz]

go for a 10 minute ride in collins's r31

sell ghay rb25

slap in rb26/30 + -5's then smoke everyone!

[Roy]

Why go for an RB30 when you can have E36 M3 Series II displacement ?