R33 Rb30 Conversion

[GiJOr33]

when does it spool up? My HKS turbo doesn't give full boost till about 4200rpm... so it should be a pumping turbo for the RB30 block. Should have it spinning by 3300rpm i reckon!

The RB30 block is 25% bigger, so will move 25% more air than an RB25 at the same RPM. So you'd expect the turbo to spool up 25% earlier too...

[B-Man]

It starts spooling at 2200 and full boost at 3500 on the 2.5L - I'm thinking that it might run out of puff/efficency at like 6000-7000.

I've been told that it is efficient up to 26 PSI - but I don't like the idea of running that much boost. (I will be doing forgies and the rest though)

[GiJOr33]

you won't need to rev the engine much harder the 7000rpm, cos that's moving the same amount of air as an RB25 revving at 8750rpm. So even if you reved it to 7500rpm you're moving more air than an RB25 doing 9370rpm... Give it a go, if it doesn't do what you want it to, then change it

Your turbo should be boosting pretty hard at 3000rpm, makes it nice and streetable.

[DennisRB30]

An interesting thing about spooling turbos is, its not just the capacity of the of the engine that counts. Remember Workhorse wakeup in Zoom, where they put 2X RB20 turbos on a 4 litre ford 6. You would expect the turbos to spool up the same fast as on a RB20 becuse they are fed by 2L each. In practice it was not the case, they reported almost zero lag, they were on full boost somwhere around 1800RPM from memory. It was somthing to do with the large stroke pushing out exhaust gas with a much greater force than an RB20, even though the size per turbo is the same. So I recon that the extra 20% size the RB30 has might do more than just a 20% increase in spool time....?

[25t]

hi Guys

ive been driveing my rb30det for 2 weeks, i suggest that its an ideal conversion for a 25t as ive used all the standard parts from the 25 and retained the vvt, Just as Sydney kid has written

this motor was only the third engine rebuild ive undertaken and really its quite a simple motor ,the only thing which is a bit of a drama is fitting a oil hose from the oil sender port to the vvt /front inlet cam bearing

im running the standard 25t series 1 turbo ,injectors with 25 deg advance ,no shit this thing is way faster than the 25t,NO lag just full boost all the way form 1500rpm (bleed valve)

i had to remove my struct brace(no name brand)

Guilt-Toy

try around pages 5&6 Joel posted a link which showed the vvt/cam feed hose mods

Guys stop talking/start doing, its cheap and easy horsepower

cheers

[Cubes]

So with the RB20 Turbo I worked it out to get on full boost by 1300rpm

50% increase over a 2ltr..

[GiJOr33]

but it will run out of puff at 5000rpm!!! and you've still got 2500rpm to play with!

[Guilt-Toy]

I really want more information on practically getting the VCT hooked up.

also do you need oil squirters? how hard are they to install? can you get away without it ?

[JNR24]

bahh, dont need oil squirters!

if 9 sec VLs run without them youl be fine. Just make sure you have a good oil pump. & youl be laughing!

[Guilt-Toy]

can someone give me the link for the VCT setup please ?

[JNR24]

http://www.users.bigpond.com/allanreynolds...enewtwinvl.html

Explains it in here.

Cheers,

Trev

[GOT BOOST]

holy sh*t what a read

youve just bout talked me back out of the rb26 transplant

ive already got someone buying the rb25det head i bought earlier

it was my intention to biuld rb30det. but the rb26 was to good to turn down.awesome info though. cheers

[SXTACY]

Wow!

I have just spent the last hour or so reading through 14 pages of posts and would have to say this is by far the best post of all time. The amount of information, co-operativeness and tracking sets this post in a league of its own!

Now I have a question... please excuse me if I should be posting it somewhere else:

I am starting a RB30DETT conversion. The main reason is I have bought 2 x 2530 HKS turbos with wastegates which I think would really get up and go with the 3.0 litre capacity.

From the posts, I image this is what I'd use:

Block: RB30 N/A Series 1

Head: RB26

Head Gasket: RB30 (?)

Pistons: RB30 (forgies) to equal CR of 8.3:1

Rods: RB30

Oil/Water Pumps: RB26DETT

Cams: RB26DETT (possibly aftermarket with timing gears)

Exhaust manifold: RB26DETT

Gearbox: RB25DET

Clutch/flywheel: ?

Inlet Manifold: ? (Aftermarket?)

ECU: ?

As above, my questions are:

* Will the RB26DETT head fit on a RB30 N/A block (I think yes)

* What ECU?

* What clutch/flywheel to suit RB25DET box?

* What inlet manifold?

* If I wanted a twin turbo, is the RB26DETT head best or should I TT on the RB25DE or RB25DET head?

Lastly, would it be too insane if I decided to put all of this into an S13 Silvia (because the older ones don't need compliancing in Australia if older than 15 years)?

Any issues of clearance/fitting considering an RB25DET engine drops straight in with the right dkyline engine mount?

Skyline Kid, I noticed you are in the process of such a build, do you mind if I hit you offlist with a few questions?

Once again, keep up the great work and let's see some more results!

Cheers,

SXTACY

[DennisRB30]

I think you will have some probs closing the bonnet as the RB30 block is taller than a RB25. I remeber someone on another forum seeking info on how to close the bonnet of his silvia with a RB25, I would only assume that it would be even harder to close with a RB30DETT, but I'm sure its nothing some well thought out mounts wouldn't fix.

[SXTACY]

Thanks Dennis.

The current issue of High Performance Imports (HPI) has an S13 with an RB25DET in it and it said that it was as simple as locating the right skyline mount and dropping it in so I wonder if the RB30DETT might just need some modifed mounts?

If someone could help anwer the questions in my first post I'd really appreciate the help Thanks.

[lowlux]

yes for the twins the rb26head is alot easyier in the way u already have the manifolds for the turbos,and yes the head will fit on just as easy as the rb25 head. Clutch i rekon u should go atleast a good quality twinplate, the inlet manifold u could just keep the rb26 one as its been shown it flows very well and alot of the japanese tuning shops still use them. Then the ecu you could use anything really but youd have to look in other threads about them,they are all very good at the moment

[Nismo_Boy]

Originally posted by SXTACY

Thanks Dennis.

The current issue of High Performance Imports (HPI) has an S13 with an RB25DET in it and it said that it was as simple as locating the right skyline mount and dropping it in so I wonder if the RB30DETT might just need some modifed mounts?

If someone could help anwer the questions in my first post I'd really appreciate the help Thanks.

Thats my olds mans car. The car now forged pistons etc, and has been twin turbo'd. specs and pics will be in another upcoming HPI.

and to answer you question in your above post, would it be insane to put what you wanted into a S13? yes it would be, my olds mans car is damn scary!

[Cubes]

Well.... my rebuilt RB could be as close as 2 weeks away before its sitting in there purring away.

What I need to know before I go ripping everything apart to reduce off road time (that I cannot afford to happen for to long) is...

Can.. I use the RB20DET inlet Plenum?

Can.. I use the Stock RB20DET ECU if I use the RB20DET inlet plenum/injectors? or is there a little problem with possibly slightly different coils or something I don't know about?

If I can use the RB20DET inlet plenum that means I could have the RB30DET running with the stock turbo until I get the money together for the turbo. Basically similiar to a R33 Conversion just swap the bottom ends over and off you go.

hrmm.. I really hope I can use the inlet plenium or more importantly its the injectors that will cause problems.

Can I use the RB20DET injectors in the RB25DE Head?

Please tell me yes.. Thinking about 2 weeks gives me an anxious feeling, sleepless nights etc..

[Steve]

The injectors are the same impedance as RB25, but they are top feed - I have been told the RB20 fuel rail will fit on RB25 with top feed injecotors, but not sure exactly what is needed to make it all come together - Those injectors will be a bit small I would have thought anyways.

[Cubes]

I have 370cc Injectors in mine for some reason. But yer it is just to get it on the road and run in.. then bigger turbo new LT-16 Microtech (when it is released and if it definately has the Closed loop)

I imaging the RB25DE non turbo injectors would be smaller than the RB20DET injectors would it not?