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Guys, i know the R33 rb25det has vct so do i need to do anything about it if im adding a R32 rb25de head? I dont want to go rb30e bottom end as i like revs and my current set up(hks gt2535,gtr injectors etc) would suit a rb25det very well.

Opps i was logged on my sisters account LOL. Also im thinking of using the 25de cams, would they be better than the 20det ones?

IF you select a decent sized turbo to make 'decent' power, throw on a plenum and you will have the rev's.

The plenum appears to be the key for an rb30 to rev, or just use an rb26 head. :miner:

Its about the package.. Either way the gt2535 on an rb30 rb25 head with stock plenum will always go better than on the rb25 due to the higher average power.

Stuff it im going to do it :P just to be different. Hope to have it done this year. I have seen a dyno gragh of a gt2535 on a 30det, boost drops off as it's a small turbo for a 3L. .64 ext housing :P What cams you guys think?

Edited by R31 POWER
Stuff it im going to do it :( just to be different. Hope to have it done this year. I have seen a dyno gragh of a gt2535 on a 30det, boost drops off as it's a small turbo for a 3L. .64 ext housing :ninja: What cams you guys think?

yeh I got a 2535 on my RB30, spools pretty fast and drops off just as quickly and thats with HKS cams too

dont know what RPM the power started to drop off tho as my dyno sheet was in KM/h not RPM

but on my RB25 power peaked at 155-159km/h and on the RB30 it topped at 145Km/h

this is on an Auto R33, if someone could convert that to approx. RPM that would be good

ok guys i asked a question on the last page 239 about timing belt.

stockymcstock posted a pic on how to fix my problem BUT i had allready drilled the hole on inlet side for tensinor so when i went to put the second one above the water put i could not move it far enough to exhaust side to get the right tension on the belt (way to tight) so now my question is if i put a tensinor in the factory position (bottom left) and the put the second one above the water pump on exhaust side would this be ok??

As far as i understand aslong as the pitch and width of the belt is right there should not be a problem i have found in doing it they way i was thinking i would be able to use a 150 tooth belt and get the right tension

but would this work

i've been browsing through this thread over the past 2 or so weeks as i'm very close to doing this conversion myself (as in blown rb25 out and disassembled, waiting on 30 block) but there is one thing i can't seem to find a definent answer on, although i'm sure it must be somewhere in this thread..

the head i'm using is the r33 rb25det with vct, however i'm at a loss as to what to do with the vct.. i read some bore out the oil gallery going from just above the vct solinoid as a source of oil but this dangerously lowers oil pressure throughout the intake cam high pressure side, which is a no no.. others somehow route an external supply of oil to the vct solinoid but i've been unable to find where they tap this into?

if i'm just being a retard and have missed out a very obviouse post then could somebody please tell me so and refer me too it, or could just enlighten me on this subject i will love you long time, i really will :P

had my mechanic drill and tap the head, then put a grub screw inplace of the original vct feed, then drilled and tapped into the front of the gallery behind the inlet cam gear and put a fitting in there for me, all i need now is some braided line to go from the oil hole behind the oil filter to supply it with oil, as the rb25 oil cooler assembly houses the std oil pressure sender, where as the rb30 used the hole behind it.

dont have pics here though

Nemini90: that looks good, shouldn't be any issues. there are, as you have found, a number of different ways to go about it. you just need to make sure you don't drill and tap through into a bore or water jacket or something, it's pretty simple stuff.

so long as the cam timing appears to be spot on, it will run OK. obviously adjustable cam gears with proper dialling in will help to locate the camshafts exactly where you want them. remember with non-OEM belt setups like we all have, the cam timing could really be just about anywhere. while you can alter belt tension on the two swinging tensioners to move the cams, it is not ideal.

cheers

so basically, you're blocking off the original high pressure feed on the bottom of the head which feeds from the block with the grub screw, then you've drilled and tapped another one into that same gallery so as to feed it via an external line from the oil cooler? thanks heaps for your help, much appreciated :(

had my mechanic drill and tap the head, then put a grub screw inplace of the original vct feed, then drilled and tapped into the front of the gallery behind the inlet cam gear and put a fitting in there for me, all i need now is some braided line to go from the oil hole behind the oil filter to supply it with oil, as the rb25 oil cooler assembly houses the std oil pressure sender, where as the rb30 used the hole behind it.

dont have pics here though

so basically, you're blocking off the original high pressure feed on the bottom of the head which feeds from the block with the grub screw, then you've drilled and tapped another one into that same gallery so as to feed it via an external line from the oil cooler? thanks heaps for your help, much appreciated :(

not from the oil cooler, behind it is a threaded hole to the pressure side, which the rb30e ran their oil pressure sender into

I have my engine appart at the moment. So i could take some pictures for you except the engine is at the engine shop. when i get it back (after chrissy) i will take some pics of where it is drilled and the oil line etc and the grub screw.

Also look through this thread more because there is lots of photos of the vct setups from various people.

Guys;

the RB26 hs two crank scraper/windage plates that bolt to the girdle. the RB30 doesn't. what are most people doing - adapting the plates to the RB30 girdle or not?

Cheers

Scooby if i had those crank scrapers to bolt onto the rb30 girdle i would drill and tap the m6 holes required to adapt them. Ive seen a few rb30det build ups by a few workshops who fab up ally crank scrapers and do that...drill and tap holes in girdle so they can bolt them straight on. Plus it was a recomendation by SK too, so its worth while if you have them.

Scooby if i had those crank scrapers to bolt onto the rb30 girdle i would drill and tap the m6 holes required to adapt them. Ive seen a few rb30det build ups by a few workshops who fab up ally crank scrapers and do that...drill and tap holes in girdle so they can bolt them straight on. Plus it was a recomendation by SK too, so its worth while if you have them.

why, what do they do?

Thanks Michael.

Shane they serve to reduce the amount of oil that adheres to/contacts the crank. They are also known as a windage tray.

I wondered if it might be a good idea to leave them out since there aren't any oil squirters, although my conrods have the oil notches in them.

Scooby,

All rods have the squirter's on them to squirt oil on the thrust side of the bore.

---

Towed (tow rope :S) a VN Dungadoor today as it broke down on me when getting my pedal box welded up yesterday.. Towed it unbelievably well. Never needed boost on the flats and up Flagstaff Hill which is a big arsed steep hill it only needed ~3-4psi in fourth gear at 60km/h ~1900rpm.

Was quite surprised at how much torque it really has when you go to tow something with it.

The old RB20DET wasn't able to cruise at 60km/h in fourth gear up flagstaff Hill when not towing anything. :)

Turbo's + Hills + towing = am I towing something?? :)

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