Proyect Ationbstard RB25det

[actionbstard]

Hi. I am about to get some internals for my rb25det and wonder if theres some one who have experience with this engine and its capablities.the project aim is for 700hp. first my head set up:
port and polish
270 cams
solid lifters
valve springs and retainers
valves
valve locks
oil restrainer
cam gears
multilayer metal head gasket
head studs
the head its already port and polish but missing internals.
what do you guys think?
my turbo set up is gt42 850cc injectors
alcohol injeccion kit,plus a walbro 255 plus a external fuel pump(aeromotive fuel kit)
im not looking to go further then 700hp

[Skym]

There's a dude in the UK that ran a high 9 sec with a RB25DET in a R33. He has a spec list on his website and includes photo's of the setup -

http://www.projectgtst.com/spec06.php

I think he now has a modified RB26 engine, as he wanted to see how fast a rwd GTS-T could go.

To see the latest spec sheet, click on 2008 that's at the top left and then click on spec link at the top right.

Here's a videoclip of the car in action -

http://www.youtube.com/watch?v=1kUsgDrkNJU&NR=1

[actionbstard]

well its a start,I cant afford Jun stuff sow mines are different brad.I wanted to know the cams duration like 270 or 280 which I prefer ect? he spooled up the turbo with nos guess I got to get some nos.thanks bro

[Skym]

You're welcome.

Trying to spool up a GT42 turbo. Isn't that a 1000hp turbo???

1000hp turbo + 850cc injectors. More like need at least 1000cc+ for 1000hp turbo???

Maybe a GT35R, like on this Subaru might be better??? -

http://www.youtube.com/watch?v=48QRiae0FFE

I would contact Turbonetics and talk to them (check out the video clip of the turbocharged doorslammer at the top of link below) -

http://www.turboneticsinc.com/

They might be able to help you in eliminating some of the lag from turbo, but produce the same power output.

Best to talk to a cam / head specialist about cam specs, as cams have to match the port size, valve size, etc. Saying that cam will work might point you in the wrong direction, which I don't want to do.

This is an example of the questions they ask you (cam / head specialist downunder that makes import, racespec V8, etc cams) -

https://www.safe.net.nz/kelford_co_nz/designshop.php

[actionbstard]

the port and polish is mild I didnt over size the valve since my aim is for 700hp the problem I thought about was aire flow specialy on the exhaust side.so I can slap on a per of aftermarket cams and be done,maybe later I'll buy a head and over size every thing.the money left is to reach the 700hp mark or close to it.yeah im shopping for new injecctors 1200cc.spooling the turbo with some nos.
I dont know how much power the stock internals on the head can take?

[Skym]

I think R.I.P.S in NZ was producing around 700hp at motor and running low 10sec 1/4 with a upgraded N/A RB25DE head on RB30 bottom end.

Here's a 770hp engine (RB30 bottomend) with RB25DET head that was built by R.I.P.S -

http://www.ripsracing.com/images/ima...ns_r33_lge.jpg

If you rev engine higher than stock revlimit, change to Tomei solid lifter + shims and upgrade the valve guides, valve springs, retainers, etc. Basically upgrade everything in the head.

From what I understand around 700hp (at motor), probably would be looking at a dual external fuel pump, duel fuel filter setup, FPR, etc. That means fuel rail wise, one fuel pump feeds feeds the front, one fuel pump feeds the rear of aftermarket fuel rail with a single exit for fuel in the middle of fuel rail.

I think Sard make these dual entry fuel rails -

http://www.more-japan.com/files/d_1068.jpg

Also might look at a surge tank setup (to prevent fuel starvation when cornering, etc) in the boot with a lift pump or pumps to get fuel from main fuel tank to surge tank. Then have the two external fuelpumps taking fuel from surge tank and feeding the dual entry Sard fuel rail.

R.I.P.S surge tank -

http://ripsltd.com/images/images2/Ad...uel-system.jpg

R.I.P.S -

http://ripsltd.com/products.html

Up to around 700hp, probably stay with stock fuel rail and just upgrade to Nismo injectors, Nismo fuelpump.

You want injectors to run at 85% duty or less (to prevent overheating problems with injectors) if you are racing the car. So 85 / 100 of say 800cc injectors = 680cc. 1cc = roughly 1hp, so 680hp.

Then find a fuelpump or fuelpumps that supply slightly more hp than injector max HP (800hp) to be safe.

[actionbstard]

I mean..what if I go for the 600hp to 700hp range?The car would not be able to move foward if I go above the 700hp range man.I am going with the valves ,springs,retainers and cam,but do I have to upgrade to solid and the valve guides?i mean Im not going above 800rpm my port job is mild just intake and exhaust,No oversize valves since my aim is for low 600hp high 700hp.

as for fuel I liked my 2nd. set up that was 850cc injectors,walbro 255,tomei fuel regulator,aem o2 wide band and apexi power fc.this was to be used with a
GT40 t4 flange and twin ex. 42mm waistgates,to run on low boost oh with a zex dry kit 25 fogr.

what I mean is not that Im aiming for higher then 700hp man ,no high revs kicking all gears for that I will get another head and build it slowly as another fuel set up and then I go for the big dog gt42.

What do you guys think?

[Skym]

I would do it right the first time and fit upgraded parts that can be used for the next stage. You'll end up spending more than you should with 2 rebuilds.

From what I understand it depends on the duration, etc, but cams can shift the powerband (peak torque, peak power) up the rev range, so have to rev engine more to get to peak hp and have more lift, etc hence why you need solid lifters as hydraulic lifters don't work well at higher revs with more lift, etc. The engine becomes very peaky and lacks bottomend, which is the downside of very high hp import motors. One V8 I have seen has a good powerband, even with around 1400rwhp and can run a high 6 sec 1/4 + can be driven on the road.

This a rough list (stage 1), but can support stage 2 with a few modifications like cams, turbo, wastegate, duel fuel pumps, braided lines, fittings, drysump, etc -

In the trunk -

Aeromotive 900hp fuelpump -

http://www.streetperformance.com/par...524-11104.html

Custom surge tank (can make yourself if you can weld aluminium or make the templates and get someone to make in aluminium and weld them for you).
lift pump
Braided lines + fittings

Head -

Sard fuel rail (with bung in centre return line for stage 1 600-700hp)
Sard 850cc injectors
Sard FPR
Braided fuel lines + fittings
Tomei or custom 260 or 270 duration cams
Tomei valve springs, retainers
Tomei solid lifters + shims
Tomei valve guides
Tomei camgears
Tomei headgasket
ARP headbolts

Bottomend -

Arias pistons + piston rings + gudgeon pins
ACL race bearings
Eagle or Spool conrods (includes upgraded ARP conrod bolts)
ARP main bolts
Jun crank collar
Jun oilpump
N1 waterpump
Tomei baffle plate (sump / pan)
Tomei oil restrictors
VHT block filler
ATI damper

Cooling -

Nismo low temp thermostat
Triple core radiator + silicon radiator hoses
Engine oilcooler with thermostat inbuilt into sandwich plate.
Greedy air separation tank + bottom hose fitting

Drivetrain -

Tripple plate clutch (Nismo, Excedy, Osgiken, local made clutch, etc)
I think upgraded clutch cylinders for lighter pedal feel + braided line
Aftermarket engine, gearbox mounts

That's just the engine, not including intake manifold, exhaust manifold, turbo, wastegate, etc. Also brakes, etc that probably would need to be upgraded to support the power.

It gets expensive very quickly.

[actionbstard]

suspension,tranny and rear end,fuel I went for a 2 liter surge tank,aeromotive 1000,dual fuel filters and still running the walbro in tank.Injectors are 850cc tomei FPR,im still shopping for a fuel rail.Also I have cover the block.about That list of parts for the head????.man your talking about tomei...thats top dollars man.lol.Im planning to sell the car after done.600hp its overkill.Cant go more then that since with 300hp to 400hp I was having some grip problems.I upgraded the suspension to Megan ST coilovers and traction bars.lower the back tires pressure and the shock adjusted more to the soft side so it should give me more grip to handle the 600hp goal.remember my rb25det its on a 200sx sow its more light then the gtst.Its strip and has almost every thing in carbon fiber and fiberglass.Ill say its weights got to be in the 2500 non less.

But dont get me wrong man.I also favor your idea of building to take all you can throw at it.But this one just cant handle that much hp.thanks for the help guys

[Skym]

You're welcome.

Most turbo engines are not run on high boost setting all the time including F1 turbo engines. Some use high boost for overtaking, like with the turbocharged Lemans racecars.

Don't have to use Tomei with valve springs, headgasket. Probably could use local made parts -

Ferrera valve springs (scroll down to Nissan Skyline 6 cyl valve springs) -

http://www.ferrea.com/general-result...tegory_id=6084

Cometic headgasket -

http://www.tweakit.net/shop/product_...oducts_id=6008

Not sure about local made cams, valve guides.

Also probably want to go with a bigger 4 core radiator with around 1000hp.