Building a reliable RB25 ?

[Paulpen]

Hi guys

Basically im building a Onevia to house my RB25 that I had in my S13 but id like to make it right first time.

Im not that clued up on turbos, tuning etc so thought id ask the great knowledge of the internet

Im looking for about 400 - 450bhp but would like it to be driveable power much like the engine in standard form (not alot of lag and a wide powerband).

Ive read so much about oil restrictions / draining modifications, turbos inlets etc and so many different views on everything that I dont know where to start.

I would prefer to run stock internals due to cost and dont really want to touch the rev limit. Top mount turbo is an option but again I have no iea of the real benefits of it other than looking good :doh:

Would anyone be able to spec me a setup that they think will be close to my needs or is there anyone running a setup that is quite like what I think I want ?

Thanks in advance

Paul

[Coolwhip]

400-450whp setup:

Turbo - GT3076R
Injectors - 700cc+
ECU - your choice just get a good tune
Intake manifold - Greddy or similar (not required but makes things easier)
Z32 Mass Air Flow Sensor (if remaining MAF based)
Adjustable Fuel Pressure Regulator

You'll need the obvious supporting mods:
Upgraded clutch
Upgraded exhaust - any 3" for your car will work plus custom downpipe from the turbo
Upgraded cooling system
FMIC
Intake

You'll be able to do that with a stock long block. However, reliable is only relative to how you define it. You may want to consider the following parts to upgrade:
Cams - Tomei poncams are drop-in cams and serve this setup pretty well
Oil Pump upgrade
Oil cooler upgrade - depending on car use and climate

Then there is the "other" parts that should be addressed some time, some where, some how, through your swap and upgarding process:
Timing belt job (idler, tensioner, spring, hardware, and belt)
Water pump
Misc. gaskets
Spark Plugs

Inspect and replace as needed common trouble items:
Harmonic Balancer/crank pulley
Coil Packs
Faulty coil pack harness

And what most people mess up when doing high horse power builds is the lack of "car build" so don't forget to build your car (and driver) for such power:
Tires
Rear Diff
Suspension
Cooling ducts
Brakes (and brake fluid)
Proper monitoring system for engine vitals
oh... and tires

all part of a complete balanced breakfast

We sell all these parts so if you need more guidance or need any parts, let me know... http://rawbrokerage.com

Good Luck

Ricky

[sviellvoicae]

Nice response! All my buddies have rb's and always used to talk about this place called rawbrokerage and I used to think it was an mma fighting site lol. Thanks for the info ill take it into consideration. I just swapped a 25 into my 240 and so far its the best/smoothest running motor I have had in it when compared to my old ka, ca, and sr. My only question is (and sorry for a little thread jack) it seems powerless. Maybe cause I went from a 24psi and great tuned sr to a stock rb lol, but compared to an sr with mild upgrades and 10psi I dont stand a chance does this sound right?

[Cjmartz2k]

??? Dude, what are you even asking? 24psi on what turbo? You sound like you don't know to much for somebody who has had 4 different motors in his car. Quit whoring up the OP's thread.

OP-sounds like you've got a lot of research to do. Read people's build threads on here and other forums, see what kinda numbers they make, times the run, and problems they have. Spend some time learning what other people have done. The top mount thing just has to do with fitting a certain size turbo. Especially on LHD 240sx's, you aren't going to be able to fit a 600hp+ capable turbo bottom mounted. That's why people get top mounts. It does make things easier to work on though. How much money do you have to work with?

[Paulpen]

Awesome reply

Bearing in mind that I know nothing about turbos but names and numbers when would you expect that turbo to kick in and reach full boost ?

I will be doing an injector upgrade but am unsure wether to go top or side feed so any input would be great

Intake, MAF and FPR will be getting done for sure along with clutch, exhaust (maybe external gating on standard manifold) and cooling will be oil cooler, uprated radiator and the viscous fan if it still fits

Oil pump currently looks like it will be a new standard Nissan unit as ive heard N1 pumps can cause too much oil in the head leaving the bottom dry.

Can I ask why you advise uprated cams for reliability ?

All service items will be replaced along with the headgasket and all associated gaskets. Ive also got new coilpacks and have re soldered the pack loom

Harmonic Balancer - I was thinking this but was then wondering would I need it if I had the complte bottom end balenced ?

Tires - Will be new with the wheels. All I know at the moment is 17" and pretty wide at the rear lol
Rear Diff - Ive got the GTST diff with the S13 backplate at the moment to keep the gearing correct
Suspension - COilovers, all adjustable arms, uprated roll bars (sway bars), uprated steering arms and ends, every suspension bush replaced with poly
Cooling ducts - As for the brakes ? Im still not sure how im going to do this yet
Brakes (and brake fluid) - R33 GTST callipers, Ferrodo Ds2500 pads, R32 GTR discs
Proper monitoring system for engine vitals - WIll be going for boost, oil temp, oil press and water temp gauges


Many thats for the great post. Im already hoping to have one of your powersteering hose kits but ive got to get you to look into shipping and RHD fitment as im in the UK ;)

[Zacho2]

I've got a gt3076 .82 on an rb25. Full boost is reached around 3700-3850 in 4th on the dyno. It will fully spool by about 4100 in third. Very streetable turbo in my opinion, and it is why I chose it.

[email protected] psi on pump (91) and [email protected] psi with a 60/40 mix of pump/race.

I have some 256 cams, tomei oil restrictor, rb26 rods, new oil pump, tomei valve springs. thats all my engine has. some 540cc injectors. But there are tons and tons of other little things...

The little things are what will ruin your wallet such as:

AN fittings
AN hose
downpipe/dump tube fabrication
flanges/vbands/gaskets/seals/bolts
ignition upgrades (if nessecary) etcetcetc list goes on and on

I can't stress enough in your adventure, spend the money on GOOD MANAGEMENT. Don't get a piggyback, NO fuel controllers etcetc. Spend the money on a good tune too. You can build a motor as strong as you want but a tune will make/break it.

[Bigalow311]

I can't stress enough in your adventure, spend the money on GOOD MANAGEMENT. Don't get a piggyback, NO fuel controllers etcetc. Spend the money on a good tune too. You can build a motor as strong as you want but a tune will make/break it.

What do you recommend as far as 'good management?' I just agreed to buy a car with an RB25DET and managed by AEM FiC. Riding in the passenger seat and driving it made me feel like it has a bad tune.

[Coolwhip]

I can't stress enough in your adventure, spend the money on GOOD MANAGEMENT. Don't get a piggyback, NO fuel controllers etcetc. Spend the money on a good tune too. You can build a motor as strong as you want but a tune will make/break it.

What do you recommend as far as 'good management?' I just agreed to buy a car with an RB25DET and managed by AEM FiC. Riding in the passenger seat and driving it made me feel like it has a bad tune.

http://rawbrokerage.com/Haltech-Platinu ... 055001.htm