RB25. where 2 start!!!!

[Wilso R32]

Rite b4 i start id like to say sumthin.........

Ive done searches...........

ive done the usual.............

and ive spent 3 days readin about 134 different posts on the subject in three different owners club!

Im lookin to do an RB25det conversion on a r32gtst, but rather than do the install and then moddify HEAVILY, id rather do the foundation work now 2 save rippin the engine out at a l8ter date.

target bhp for now is 350-400bhp at fly/crank.

And yes, this is gona be a long thread!

I need advise on everything, from a how to guide on the conversion, to what mods shall i use to make the power and where to source the parts.

Next.... Im in the UK and will be the first to do this conversion on English soil and the grage (who will use it as a demo car) reputation is on it.

350bhp @ the wheels is a startin figure, i intend to make more at a l8ter date, but also reliability is a big issue as the car will also a daily drive. Im not realy interested in bhp to be honest its more torque i want as torque wins races.

i will also run 50hp kit of nos on a regular basis.

And lastly.......... i have to use as many standard nissan parts as possible!

so heres my first set of questions.

are gtr internals a good upgrade for the RB25? are they stronger? are they worth the expense hastle? i.e. crank, rods, pistons ect?

will the car make more power with them?

Any suggestions to make this power with a complete parts list would be appritiated, and remember it will be driven HARD, advise on wich ecu to use would also be helpfull

Nice 1

Wilso R32

[tomj]

bare minimum if its going to be belted with nos is forged pistons - rb25's are known to have weak ringlands - so keep that in mind - allow the rest of the ppl to offer you more advice then that

[Mase]

are you going to rebuild ur engine yourself? If you take it to a workshop make sure you take it to a reputable one. I've had two mates, one with sr20det and another with rb20det who took both there engines to seperate mechanics for a rebuild and they were both stuffed up. I'm off to work so someone with more time can answer that list.

[Craved]

http://www.skylinesaustralia.com/forums/sh...ead.php?t=44435

check that thread about the rb26 internals should answer a few questions!

was it 350bhp? or 350rwhp?

if looking for about 250 -300 kw at the flywheel, that can be achieved at the wheels on standard internals..

also look here:

http://www.skylinesaustralia.com/forums/sh...ead.php?t=44571

http://www.skylinesaustralia.com/forums/sh...ead.php?t=34717 for results of B-man's setup with GT3040 - around your target power!!

there is more out there for you though!

good luck with the conversion.. they can get tricky sometimes!

[Wilso R32]

bhp, brake horse power, neva used kw??? thanks for the info, but with regaurde to the pistons, i read the thread but no one realy said wether or not there stronger?????

[Sydneykid]

Rite b4 i start id like to say sumthin.........

Ive done searches...........

ive done the usual.............

and ive spent 3 days readin about 134 different posts on the subject in three different owners club!

Im lookin to do an RB25det conversion on a r32gtst, but rather than do the install and then moddify HEAVILY, id rather do the foundation work now 2 save rippin the engine out at a l8ter date.

target bhp for now is 350-400bhp at fly/crank.

And yes, this is gona be a long thread!

I need advise on everything, from a how to guide on the conversion, to what mods shall i use to make the power and where to source the parts.

Next.... Im in the UK and will be the first to do this conversion on English soil and the grage (who will use it as a demo car) reputation is on it.

350bhp @ the wheels is a startin figure, i intend to make more at a l8ter date, but also reliability is a big issue as the car will also a daily drive. Im not realy interested in bhp to be honest its more torque i want  as torque wins races.

i will also run 50hp kit of nos  on a regular basis.

And lastly.......... i have to use as many standard nissan parts as possible!

so heres my first set of questions.

are gtr internals a good upgrade for the RB25? are they stronger? are they worth the expense hastle? i.e. crank, rods, pistons ect?

will the car make more power with them?

Any suggestions to make this power with a complete parts list would be appritiated, and remember it will be driven HARD, advise on wich ecu to use would also be helpfull

Nice 1  

Wilso R32

Hi, I read the "long post" (it's pretty short actually) and I can't see where it says what you are going to use the car for. Is it a road car, a drag car, a circuit car, a dyno car, a demo car or a combo of those?

Because it makes a difference to the spec that I would suggest.

[Wilso R32]

i going to re- build the entire engine once i find one so replacing pistons ect wont be a problem, need to no once the engines stripped, were should the money be spent??? i dont want a laggy turbo at all, i ant it to come on nice and smooth and let the Nos do the rest. how much is a set of forge pistons then?

nxt will be h/gasket, 1.4mm do?

[Wilso R32]

a combo m8t, it will be a demo car yes as it will be slapped up in rally slag graphics with the garage colours on. Mainly track and drag, camber ect will be adjusted to suit.

will also be used on the road. my end target will be 400bhp@ the fly but i need the torque more than anything, want to use gtr internals just for reliability more than anything.

[Sydneykid]

a combo m8t, it will be a demo car yes as it will be slapped up in rally slag graphics with the garage colours on. Mainly track and drag, camber ect will be adjusted to suit.

will also be used on the road. my end target will be 400bhp@ the fly but i need the torque more than anything, want to use gtr internals just for reliability more than anything.

OK Wilso, thanks for filling in the gaps.

You have probably read the posts about 450 bhp form RB25's being OK on standard RB25 internals. We have built 3 and after 20 months the first is still going strong, very low leak down, no oil comsumption and the same power as when it was built. So you don't have to open the engine up to achieve your target of 400 bhp.

This is my favourite RB25DET spec for a combo car, gets driven every day in city traffic, rain, hail or shine, does 4 or 5 ciruit events per year and a few trips down the 1/4 (11.9 at 120 mph).

GCG Ball Bearing hi flow of the standard RB25DET turbo

Standard R33 GTR Intercooler

Alloy pipework 63 mm from the turbo to the intercooler and 75 mm from the intercooler to the standarrd throttle body (and inlet manifold)

HKS BOV (plumb back)

Alloy pipework from AFM to turbo (it kept sucking the standard one closed)

Power FC with boost controller (we use a Datalogit for tuning)

POD with CAI and heat shielding

Tomei 256 Poncams

Sard 550 cc Injectors

Bosch 044 in tank fuel pump

Split dump pipe with 3.5" hi flow cat and exhaust

Electric fan

OS Giken twin plate clutch

The engine has not been opened and makes 265 rwkw (355 rwhp) on our Dyno Dynamics roller dyno, that's around 435 bhp (at the engine).

I have driven (and own) Skylines with more power (in some cases much more) but this is the best all round 2wd for my requirements. The GTR, being 4wd, can handle a bit more power and still be liveable under all conditions.

Hope that helps

[Craved]

bhp, brake horse power, neva used kw??? thanks for the info, but with regaurde to the pistons, i read the thread but no one realy said wether or not there stronger?????

thats cool, hope some of that info helped

just wanted to confirm your targets since bhp is at the flywheel, not at the wheels. thats all

as SK has confirmed, you can do what your aiming to achieve without opening the engine up.. that was what i was trying to point out, NOS shot will change a few things but if your not running much NOS then a good supply of fuel with the NOS will keep things alive for a while!!

[Wilso R32]

Nice 1, thanks for the info, yeah see your point about nos, thats why id be runnin a wet kit,

sydneykid, any chance u can email me that spec with a price list on parts? U are the first person in weeks to give me a straight up, no shit list that even looks like it'll work! just out of interest but what sort of ecu tunning went on to achieve that power, and what sort of boost were u running? would a h/gasket be a good idea? mite make slightly more power than that here as we use higher octane fuel on the road.

any chance of sum engine bay pics?

[Sydneykid]

Nice 1, thanks for the info, yeah see your point about nos, thats why id be runnin a wet kit,

sydneykid, any chance u can email me that spec with a price list on parts? U are the first person in weeks to give me a straight up, no shit list that even looks like it'll work! just out of interest but what sort of ecu tunning went on to achieve that power, and what sort of boost were u running? would a h/gasket be a good idea? mite make slightly more power than that here as we use higher octane fuel on the road.

any chance of sum engine bay pics?

Many questions....

On ECU tuning, we spent 2 days tuning it. About 1/2 day on power and the other 1.5 days on driveablility. I don't know how to describe it other than "so it runs nice". It is driven every day so it has to start every time, hot, cold, wet, dry. It has to run in city traffic or on the freeway at low load and high A/F ratios. The air con and power steering have to work without any distress from the engine. All the stuff that you would expect from a standard car, that's what I demand from one with double the standard power.

Boost is 1.3 bar, all day every day. I am not a believer in multiple boost settings.

I am not a believer in lowering the compression ratio, I prefer to get the power without simply "turning up the boost". Lowering the compression ratio hurts the response, so I don't do it. With the technology we have available, tuning equipment and the fuel, it is simply no longer necessary. The car below runs 9.5 to 1 compression ratio and makes over 1,000 bhp. The Gibson GTR's made 625 bhp on 9.3 to 1 at 1.9 bar, and that was 10 years ago.

An Australian price list would be prety much useless to you, since I did all the work myself, and labour is the expensive part. From what I remember following are the costs;

GCG Ball Bearing hi flow of the std RB25DET turbo $1800 (it was 2 years ago)

Standard R33 GTR Intercooler $600

Alloy pipework 63 mm from the turbo to the intercooler and 75 mm from the intercooler to the standarrd throttle body(and inlet manifold). It uses a 120 degree bend at the throttle body $400

HKS BOV (plumb back) $80

Alloy pipework from AFM to turbo (it kept sucking the standard one closed) $40

Power FC with boost controller $1200 (we use a Datalogit for tuning $400)

POD with CAI and heat shielding $80

Tomei 256 Poncams $1200

Sard 550 cc Injectors $800

Bosch 044 in tank fuel pump $400

Split dump pipe with 3.5" hi flow cat and exhaust $1400

The exhauts is heat wrapped from the turbo to the cat $80

Electric fan $50

OS Giken twin plate clutch $1300

Total ~$10K, sounds about right.

Engine bay pics would be a waste of time, it looks standard, the POD is in a black box, the manifolds are standard, the cam covers are standard. The only thing that isn't standard looking is the intercooler pipework. The power is on the inside, not the outside. PM me your email address and I can send you a photo or 2.

Hope that helps

[noods]

why not consider a rb26 conversion?

[owned]

rb26 conversion prolly cost more than what sydneykid posted, not to mention the lag before boost then stupid amounts of torque and power through the rear wheels when on boost. Try driving that every day.

[JasonO]

U are the first person in weeks to give me a straight up, no shit list that even looks like it'll work!....

....as we use higher octane fuel on the road.

Dude, Where are you asking your questions, cos there is plenty of info available in the UK, and I know of at least three 400+rwhp RB25 builds in the UK already.

You're certainly wrong about our fuel though, we are in the same boat, if not worse than our antipodean counterparts

My car has been built in the UK and I expect to see an easy 400+rwhp from it, unfortunately it costs lots.

£4k+ for turbo kit.

£1k+ for the supporting act. (oil cooler / gaskets / piping etc.)

£1k+ for intake.

£2k+ for ECU, WBO2 and software.

None of the above takes account of the labour hours !!

With the power figure you have in mind, RB26 internals won't be necessary, and if you are going to go down the route of new pistons, you may aswell spec some proper ones from the likes of Tomei rather than making do with 2nd hand RB26 ones. There is plenty of discussion on this site, and on SDU and www.gtr.co.uk about the various crank / rod / piston options, yu'll just need to use the search engine to find them. (Sorry I know it's a pain in the butt, but it's the only way to find it all.)

Good luck with your project

[Wilso R32]

i use the gtroc for a lot of info, and also the skyline owners club, didnt bother cos u always get the same reply, may as well buy a gtr, wats the point, get a gtr, go see abbey (and ur bank manager), it takes u a week 2 get sum decent answers, plus look at what parts we have avaiable in the UK. theres more of a selection down under and for half the price. plus alot of the tunners dont experiment another for fear of damage and so u get, no it wont work, why bother, where as here its, yeah tried it, works good, or nah it dont work.

i no there many highly tunned 33gts in the UK, local bloke (portsmouth) is pushin 450bhp, but, look at the money spent, ive been offered the same mods on here for half that, duty isnt a problem, will pay 8% as is for a buisness and ill claim it back.

wen i said id be the first in the UK i ment 2 do an 32gts RB25 conversion.

No ofence to the gtroc or skylineowners.com, but alot of the people talk shite, and are extremly negative, where as here i get nothin but answers and yeah it has been done, tested and heres the proof on the down under sites!

ive been in contact with a couple of shops in NZ and they have told me variouse things, gone to another and they say it wont work and that this is better. both shops have 10 second gts 32's and both have different opinions on how 2 do it. just tryin to get as many angles as i can without shellin out £K's where i dont have to.

P.S. none of this is ment to be a dig at u, i appritiate ur tryin to help, any opinions welcome!

[JasonO]

WOW you've managed to slag off the complete UK Skyline scene in one post.

Congratulations you'll go far :thumbdwn:

[Wilso R32]

Well thats wat happens wen u here sell up and get a gtr everytime u ask for sum info!

[JasonO]

Well thats wat happens wen u here sell up and get a gtr everytime u ask for sum info!

Can you show me the url of your thread on the www.gtr.co.uk forum where you were advised to buy a GTR ?

I'll be surprised if that response went unchallenged.

[400kwgtr]

by the time you do this conversion you could have sold te gtst and brought a gtr, alot less hassel and in the end you have GODZILLA......