R33 Rb30 Conversion

[kastin]

R33_racer,

so your getting about the same power as your old turbo? or is this just a mild tune?

Cheers

Jon

[r33_racer]

yeh it is the same power....but with no water/meth injection...however they are two different dynos....so there could be some difference. With the old turbo and water/meth the knock at this power level was alot higher and getting close to unsafe...however now there is no knock at all...not even at the track. So its not bad....but i can feel the need for more coming on soon.

[Sydneykid]

ok here are the sheets.

Just got back from first day of the first round of the state championship round at QR. Was good, but I was expecting more cars to be there...seems alot of people pulled out at the last minute....odd.

We need a good boost controller. And a better setup suspension.

It's a race car, lean it out to 12.25 to 1 and add 2 psi of boost. There's another 50 bhp in there, just gotta find it.

cheers

[dontfeelcold]

yeh it is the same power....but with no water/meth injection...however they are two different dynos....so there could be some difference. With the old turbo and water/meth the knock at this power level was alot higher and getting close to unsafe...however now there is no knock at all...not even at the track. So its not bad....but i can feel the need for more coming on soon.

Any reason why it was knocking more when using water/methanol injection?

[kastin]

Any reason why it was knocking more when using water/methanol injection?

He just upgraded the turbo, on the old setup he was at it's limits with the water injection, with the new setup he gets the same power without running things on the edge and he's still yet to add the water.

[r33_racer]

What kastin said....Cheers mate.

[Cubes]

So what do you think Michael..

Did you prefer the gt3040 for the better low gear spool especially considering the gt3540 hasn't 'yet' made more power?

Or do you prefer the gt3540 being a little easier getting the power down out of low speed corners?

[r33_racer]

gt35/40 for sure. The power isnt so savage...the gt30 equaled alot of wheelspin and power/throttle induced oversteer which makes traction harder to maintain. Good thing with the 35/40 is there is still more room for power...which SK has pointed out already. However that turbo has blown...but is getting rebuilt asap. Plans have upgraded bigtime now:)

My opinion is GT35r fo shizzle!

[KISIN]

I've decided my RB20 is no longer going to cut it and I'm keen on breaking my engine building cherry

The basic plan is a RB25DE head with GTR valve springs and a standard RB30e bottom end. The car (R32 GTS-T) already has a RB25DET box

Just so I'm under no disillusions before I start to collect parts -

Can a non rebuilt RB30E bottom end be expected to last at 270-300rwkw?

Is a metal head gasket and o-ringing a requirement for this kind of power with some reliability?

Can I skim the head (RB25DE/DET) a little to raise the compression closer to mid 8's without upsetting the quench zones? Likewise skimming the block to run a zero deck height?

Is it worth replacing the bearings and rings to after market items or will something else break first (rods?) making it a waste of money?

Will I need after market head studs like ARP's or will OEM do for this kind of power?

I think thats about it...

I know a lot of the reliability has to do with tuning but stock parts only last so long before they let go at high power levels. I'd honestly be happy with a responsive 250rwkw from a 'on the cheap' RB30 build but 300rwkw is my goal and probably the absolute limit for a R32 GTS-T anyway. I could probably do it from an RB25 but I want the extra torque to make a bit of a motorkharna weapon

Thanks in advance for the advice

Interested in these answers as well...Might be building a "budget" rb30det. Maybe get forgies/rods package and maybe some cams to crack 300 ?

Also what would you guys recommend on an RB30 ROUGHLY running 16psi (maybe lil more). A GT35R or GT40R ? (keeping in mind that you might go for a higher power figure down the track, with a more complete rebuild, so i dont want to change turbos)

[WebR33]

Hi guys, i know this is an old thread, and everything i want to know is more than likely covered in it, im up to like page 18 i think, slowly getting there!!!! I pretty well need a quick detailed description to give to my mechanic who is putting this conversion together for me. Me and a mate were going to do it all ourselves just to get my skyline goin again and make a good engine on the side as i got money, but as it is, ive got 5k so am just going to put forged pistons and rods straight into the rb30 block ive already got and get it done first time.

Using a rebuilt rb30 non turbo bottom end with the head off my rb25det. Im Using Arias Pistons as they have a model specifically made for the 30/25 conversion. The part No. through rocket industries is AP332105 - .40 or AP332104 - .20. I was wondering what Rods other people recommended to use, rocket have only the one set that are quite expensive as they are some alloy or somethin i dont need. I dont really want to go with a no name brand, as id prefer to get a brand that is proven to be of good quality as im going for reliability at the moment so i can focus on power later

What have people with R33's done to counter the extra height of the rb30, how much work is involved in dropping the engine mounts 15ml?

In regard to rods i have been asked a question by one person if i need a 21 or 22 ml gudgeon pin, ive got no idea! Also do i need to get anything done to the crank or anything else while the engine is all apart as id prefer to spend a bit more now n get it all sweet so i have no problems later. Another question is with forged pistons, im going .40, am i going to need an aftermarket computer, well even just having the rb30 bottom end will change ratios etc thus putting the RB25det computer out???? Sorry if im asking whats been answered 500 times over, but im reading thru all this and getting confused on some parts so figured better to just get one straight answer. All the oil feeds etc that need to be changed are all in that PDF rite?

Oh one last thing, what will the CR be roughly with the bored out forgies, and what can i do to adjust it to a more ideal CR of.... Also from what ive gathered, if i have VCT, i ditch it and use cams is that right? Thanks guys.

Edited March 28, 2007 by WebR33

[shanef]

Hi guys, i know this is an old thread, and everything i want to know is more than likely covered in it, im up to like page 18 i think, slowly getting there!!!! I pretty well need a quick detailed description to give to my mechanic who is putting this conversion together for me. Me and a mate were going to do it all ourselves just to get my skyline goin again and make a good engine on the side as i got money, but as it is, ive got 5k so am just going to put forged pistons and rods straight into the rb30 block ive already got and get it done first time.

Using a rebuilt rb30 non turbo bottom end with the head off my rb25det. Im Using Arias Pistons as they have a model specifically made for the 30/25 conversion. The part No. through rocket industries is AP332105 - .40 or AP332104 - .20. I was wondering what Rods other people recommended to use, rocket have only the one set that are quite expensive as they are some alloy or somethin i dont need. I dont really want to go with a no name brand, as id prefer to get a brand that is proven to be of good quality as im going for reliability at the moment so i can focus on power later

What have people with R33's done to counter the extra height of the rb30, how much work is involved in dropping the engine mounts 15ml?

In regard to rods i have been asked a question by one person if i need a 21 or 22 ml gudgeon pin, ive got no idea! Also do i need to get anything done to the crank or anything else while the engine is all apart as id prefer to spend a bit more now n get it all sweet so i have no problems later. Another question is with forged pistons, im going .40, am i going to need an aftermarket computer, well even just having the rb30 bottom end will change ratios etc thus putting the RB25det computer out???? Sorry if im asking whats been answered 500 times over, but im reading thru all this and getting confused on some parts so figured better to just get one straight answer. All the oil feeds etc that need to be changed are all in that PDF rite?

Oh one last thing, what will the CR be roughly with the bored out forgies, and what can i do to adjust it to a more ideal CR of.... Also from what ive gathered, if i have VCT, i ditch it and use cams is that right? Thanks guys.

My suggestion, get a mechanic who know's what he is doing

To answer a few:

- 21mm gudgeon pin will be fine (only custom pistons and rods use 22mm pin)

- get an aftermarket computer so u can tune it

[WebR33]

My suggestion, get a mechanic who know's what he is doing

To answer a few:

- 21mm gudgeon pin will be fine (only custom pistons and rods use 22mm pin)

- get an aftermarket computer so u can tune it

in regard to the pins, would the arias pistons be classed as custom pistons seeing as they were made specifically for the rb30/25 conversion? If i dont get a computer straight up is the engine gunna run like a bag of shit on the rb25det computer, or will it be alrite for a while till i get an aftermarket one? Also does anyone know where i can get hold of a power FC, i know EVERYONE wants them, why did apexi stop making them for skylines, idiots!

[shanef]

in regard to the pins, would the arias pistons be classed as custom pistons seeing as they were made specifically for the rb30/25 conversion? If i dont get a computer straight up is the engine gunna run like a bag of shit on the rb25det computer, or will it be alrite for a while till i get an aftermarket one? Also does anyone know where i can get hold of a power FC, i know EVERYONE wants them, why did apexi stop making them for skylines, idiots!

no they wouldnt, they'd still be a 21mm pin.

if ur spending the money on a forged bottom end, ud be silly to run it with the std computer, and risk wrecking it and having to start over! i'd suggest u wait til u have the money and put a power fc in it (or similar) and get it tuned properly.

[WebR33]

no they wouldnt, they'd still be a 21mm pin.

if ur spending the money on a forged bottom end, ud be silly to run it with the std computer, and risk wrecking it and having to start over! i'd suggest u wait til u have the money and put a power fc in it (or similar) and get it tuned properly.

Thanks, yeh i got an FC lined up, was just saying that like if i have to wait a few weeks cause im not gunna get it n short change myself halfway thru the rebuild. but i'd have it not long after its finished regardless.

Using a rebuilt rb30 non turbo bottom end with the head off my rb25det. Im Using Arias Forged Pistons .40. Ive been looking into the rods, so far only ones im keen on are ones made by Argo, anyone heard about them??? I also checked out Spools website and saw the ones they have advertised.

What have people with R33's done to counter the extra height of the rb30, how much work is involved in dropping the engine mounts? Its gotta drop 15ml or 30ml?

All the oil feeds etc that need to be changed are all in that PDF rite?

Oh one last thing, what will the CR be roughly with the bored out forgies, and what can i do to adjust it to a more ideal CR? What ended up being the best result if i have VCT, ditch it or rig it back up somehow?

[r33_racer]

get an aftermarket plenum for the height, thats easy to do instead of stuffing around with dropping the mounts/crossmember.

the only oil feed you need to worry about is the vct feed.

you need to work out what your cr will be using one of the online compression ratio calculators. inputting stroke, bore size, hg bore size, combustion chamber cc, hg thickness, piston height in the bore, and whether the piston has any valve reliefs or is domed.

Street car.....keep vct. Its fark all work to make it run.

Argo rods are great and Spool rods are great. Both come recommended.

[humz]

oil restrictor question.

my builds nearings its end, i remember some where that oil restrictors are recommended

can someone enlighten me on why?? i would say its due to the 30 and 25 blocks having differant oil restrictions etc but not 100% sure

and what size restrictor is needed?? theres 2 in the block isnt there?

do you use a differant size restrictor if your using an n1 oilpump on a 25/30.

ALSO

jun crank collar, does this need to me machined to fit the 30 crank or is it a straight fit.

also any secrets on fitting it?? or you just push it over the crank.

[rev210]

The oil supply to the head on RBs is over the top and causes the bottom end to wait too long for it's share to get back down from the head. An external return feed in the back of the head to speed return of oil and restrictors to the head help prevent this potential for spun bearings at high rpm.

[r33_racer]

humz seach the forums or maybe within the thread for details on installing a jun collar....the crank will need grinding and holes drilled and tapped for grub screws. Its not so simple, machine shop job.

Edited March 29, 2007 by r33_racer

[shanef]

Th influx of people recently asking questions that have been answered and sometimes with great decsription and detail in this thread is getting beyond a joke.

If you can't be bothered spending the time reading this thread, and the pdf, dont post in here!

[Adriano]

^^^^^^Agreed