Stage 2 in mods on RB25DET

[sweetr33]

Hey people basically im at the stage where im going to stage 2 shall we say in the modification realm. My delemar is im not too clued up on turbo selections for my application, u hear about big turbos chasing big hp but in my case im not after all that. My target is 280 rear wheel hp anything over would be a bonus. Its my daily drive car so i cant go too silly. Basically it dyno's at 213rwhp at the moment which is ok but the additional 70+ hp would be sufficient for me performance wise. I still retain the standard turbo, cooler, computer and injectors. I have a mate who can get me a new front mount which brings me to a question.

For the application im after(280ish rear wheel hp) Is a bar and plate cooler going to be benificial over a tube n fin? Also the standard turbo is blowin abit of oil into the stocko cooler so an upgrade on the turbo side is another question i would like some advice on. Something alittle bigger that offers good throttle response and power when needed. I would like to be running around 14-18 psi MAX as i would like to retain the standard ecu but can make changes if neccessary. Any advice, preferrably positive would be much appreciated, any additional questions or info feel free to ask. Thanx. By the way i have tried search but it doesnt come up with what info im after for my particular application !!

[Sydneykid]

MMMMMMMMMMM a search would have gotten you this post of mine from a couple of days ago.....

Hi Steg33, it has been our experience that you can get to 250 rwkw on the standard RB25DET injectors. I'd spend the money on a set of 256/260 Tomei Poncams instead. That will give you a better spread of power than the standard cams.

A ball bearing hi flow of your standard turbo will also get to 250rwkw as well. This saves a lot of hassle and expense with water, oil supply, intercooler and inlet air pipework. All the standard stuff bolts straight back up.

A standard GTR fuel pump would be cheaper than a Bosch and will handle 250 rwkw as well.

I'd save money and buy the Boost Control Kit with the Power FC rather than have a AVCR. They both use the same good quality solenoid, so boost control is equal.

For 250 rwkw you won't need to lower the compression ratio, so a thick head gasket is unnecessary. In fact you don't need to open the motor up at all for 250 rwkw. We don't even think about that until well over 300 rwkw is the target.

and a real search would have found this one from last week...........

this is what we do for 400 bhp with the increases from each part shown in (brackets)...........

* Power FC with Boost Control Kit & Commander (20 rwkw)

* Split dump with mandrel 3.5" exhaust & hi flow cat (25 rwkw)

* GCG ball bearing hi flow RB25 DET turbo (20 rwkw)

* Tomei 256/260 Poncams (15 rwkw)

* Z32 AFM (0 rwkw)

* Pipercross panel filter in the standard airbox (5 rwkw)

* But upgrade the ambient air feed (on a hot day 20 rwkw)

* Standard R33/34 GTR intercooler (20 rwkw)

* 63 mm pipework from the turbo to the intercooler (goes with I/C)

* 75 mm pipework from the intercooler to the throttle body (Goes with I/C)

* OS Giken twin plate clutch (O rwkw)

* Electric fan (remove the standard fan) (4 rwkw)

More importantly, what we don't do...

^ Standard internals are fine

^ Standard compression ratio is fine ie; don't need a head gasket

^ Standard inlet manifold is fine

^ Standard coils are fine

^ Standard exhaust manifold is fine

^ Don't need an adjustable exhaust camshaft pulley, the Tomei Poncams are timed perfectly out of the box

We follow this plan, tune it properly, run 1.3 to 1.4 bar and we get 220 to 240 rwkw (400 bhp) every time, as long as the engine is in good nick to start with of course.

Now if you add all those increases together it ends up more than 220 to 240 rwkw, that's because you don't get the full effect of one without the other (eg; the PFC helps to release the extra rwkw that the turbo produces). And some things, like the Z32 AFM, don't in themselves give any more rwkw, but without it you can't tune the PFC properly. The whole lot is of course useless if it doesn't make it to the wheels, hence the clutch upgrade.

If you want an order, do the exhaust first from the turbo back, the panel filter and then the PFC. It doesn't matter what order you do the rest in. You just have to tune it after each major mod.

There are probably 10 or so more post of mine that would answer all of your questions, let alone other peoples, but I think I have made my point.

Hope it helps

[sweetr33]

Ok, hiflowing the standard turbo cost roughly how much? I am getting a pwr tube n fin fmic and am probly going to get a forward facing intake plenum aswell. I already have a turbo back exhaust. Its 3 inch with high flow cat and one muffler at the back. I got a k&n pod which was on the car already when i got it and dont have a stock air box to play with. $$$ on those cams?

[MRK25T]

Tomei 256/260 Poncams

Where can I get the Tomei Poncams, what sort of price are they going for, and what would you expect a mechanic to charge to fit them?

I asked Nengun mid last year after you personaly recommended me getting them after I queried you in a pm and he said he doesnt sell them.

[RBVS]

MRK25T: for tomie cams go to Hi octane racing web site they have a link to the tomie web page and deal them, prices on tomie site are in yen.

Sweetr33: make sure you read the big thread on front facing plenums, theres very good reason to keep the stock one. you cant miss it on a seach

[MRK25T]

MRK25T:  for tomie cams go to Hi octane racing web site they have a link to the tomie web page and deal them, prices on tomie site are in yen.

Sweetr33: make sure you read the big thread on front facing plenums, theres very good reason to keep the stock one. you cant miss it on a seach

I'm at Tomie's website: http://www.tomei-p.co.jp/_2003web-catalogu.../efr_index.html but I cant see any prices or products. Is it because I dont have a Japanese OS?

Could you quote some prices for the poncams for the rb25det please?

[dojobi]

You're looking at 64,000 Yen for the pair. Alternatively, you can buy procams for 32,000 Yen each and customise it a little (e.g. 260 in, 270 ex).

[HKSgtst]

sydneykid,

what do you mean by electronice fan ? i dont get it ..

care to elaborate ?

[Bobjones]

You remove the standard clutch type fan and replace it with something like a Davies Craig fan that is electronic and works only when a soloniod is activated by a certain temp, they are used in all FWD cars and performance cars as it reduces the load on the engine...

They are often also more efficient at cooling thus their use in motorsport...

Also you can get the cams from

www.mercurymotorsport.com.au deliverable to anywhere in oz, and they are on special this month and I am yet to find a cheaper price delivered...

[benm]

A good condition RB25DET will get close to 208rwkw (280rwhp) using the stock turbo if you offer it the right support such as:

* 3" Turbo Back Exhaust

* K&N Panel Filter

* Power FC+ H/C

* Boost controller (12psi)

* Ex Cam Gear

* Bosch Fuel Pump

* FMIC

Using my limited knowledge I reckon you could get away with all of that for about $5,500 drive away. I believe alot of people upgrade the standard turbo way before what they should (if you have an aftermarket turbo on an RB25DET and your only pushing 200-220rwkw I honestly believe you have wasted your money).

If you really wanted to get a new turbo just get your standard turbo hi-flowed to 450hp for about $2,000

[sweetr33]

yeah i am thinking about the Hi-Flow option. The whole take off and bolt back on side of things is the main eye catcher. And plus the no hassle with connections for water line, oil line etc.

[Kaido_RR]

 If you really wanted to get a new turbo just get your standard turbo hi-flowed to 450hp for about $2,000

for that price you can get a HKS gt20

[TrevR32GTS-T]

Great thing about Power FC is when you upgrade your injectors.

The frist thing I got was a FMIC and HKS SSQ BOV. Next, (when I get my car fixed) is a manual boost controller then fuel computer for my 550 injectors and t-28 turbo (cheap upgrade).

[MRK25T]

You remove the standard clutch type fan and replace it with something like a Davies Craig fan that is electronic and works only when a soloniod is activated by a certain temp, they are used in all FWD cars and performance cars as it reduces the load on the engine...

They are often also more efficient at cooling thus their use in motorsport...

Also you can get the cams from  

www.mercurymotorsport.com.au deliverable to anywhere in oz, and they are on special this month and I am yet to find a cheaper price delivered...

I could only see HKS cams for silvias on special for $750

[Bobjones]

I could only see HKS cams for silvias on special for $750

They were up there last month on special,

Email Trent as ask for a price I am sure he will do very close to the price they were on sale at (unsure of price)...hit him up for free delivery as well... :Bang:

[Gradenko]

Sweetr33: make sure you read the big thread on front facing plenums, theres very good reason to keep the stock one. you cant miss it on a seach

As the creator of the big plenum thread, I have to ask what that reason is? I've been running a factory front facing plenum for some time now and have had nothing but positive results.

[RB Fairlady]

You remove the standard clutch type fan and replace it with something like a Davies Craig fan that is electronic and works only when a soloniod is activated by a certain temp, they are used in all FWD cars and performance cars as it reduces the load on the engine...

Something popular in the states is to get the fans off a Ford Tarus from a wrecker. I believe they were sold as Falcons or Fairlanes... FWD family car sold sence ~88 to present... They are really plentyful in wreckers here, and the fans are big and efficent.

[RBVS]

As the creator of the big plenum thread, I have to ask what that reason is? I've been running a factory front facing plenum for some time now and have had nothing but positive results.

Reason: the stock setup can still provide the goods and

a good range of information, why not read it?

a friend of mine has done the conversion and also got good results but their could be a chance it might not so could be a good idea to read the thread and get more info

[benm]

* Electric fan (remove the standard fan) (4 rwkw)

What electric fans do you recommend (got a url?) and approx what are they worth?

[Sydneykid]

What electric fans do you recommend (got a url?) and approx what are they worth?

Try

http://www.daviescraig.com.au/

You can get them at most autoshops, Repco, SuperCheap, Auto One, AutoBarn, Auto Pro etc.