Skylines Downunder NZ Car Club

Technical => Forced Induction => Topic started by: MOSTDOUBTED on January 19, 2015, 08:47:45 PM

Title: RB25DE+T How too
Post by: MOSTDOUBTED on January 19, 2015, 08:47:45 PM
Hey guys. Any walk through/how too's specific to +T conversions around or on different sites?

I have the idea of how everything goes with doing it. Only things I would be curious about is the water/turbo feed lines and how I fit them.

Also what ECU to run, looking to run all standard 25det parts. Was thinking a S2 25DET ecu would suit as its an S2 motor.

Any links/advice would be great. Cheers.
Title: Re: RB25DE+T How too
Post by: gtsr on January 24, 2015, 03:20:58 PM
Ask Boostinz or R33 400R who have done this conversion.

From my limited knowledge on the subject, I think you use the coolant feed that runs around the back of the head (fit a y fitting like found on turbocharged RB engines). Oil feed, return, etc should be there but blanked off on block and should be able to use turbo engine oil feed, oil return, etc.

I think R33 400R used a Link ECU. Don't know what Boostinz used, but search his post's, as I think he provided photo's / info of the mods he did. But I would think a turbo ECU would be best due to more fuel when on boost (make sure the injectors, AFM are from a turbo RB25DET engine), but would still need to be retuned to suit the engine, as far as I know higher compression engines are sensitive about the tune being correct.

Also non turbo RB engines usually don't have oil squirters on the bottom of each cylinder like the turbo engines do (to cool, lubricate the cast pistons).
Title: Re: RB25DE+T How too
Post by: 4ever_sideways on January 25, 2015, 11:03:56 AM
Don't bother trying to run it on a standard det ecu, you're just killing it slowly. Get a 300zx ecu or a rb20 ecu with a vct controller and chip tune it, you will need to find a series one or rb20 throttle body and tps. The rest is simple bolt on, get a j-pipe and a intercoller/piping. For the water feed follow it from the throttle body to near the rear of the motor, tee into this. For the return there will be a bung on the exhaust side of the block. Use decent hose and fittings here or it will turn to sh*t. Oh plus T can be fussy with plugs and plug gap, ngk BCPR7ES gapped to 0.6mm
Title: Re: RB25DE+T How too
Post by: b00stinz on January 26, 2015, 10:13:46 PM
Yeah as GTSR has said, I +T'd my 25DE out of an R32. I used an RB20DE ECU and chipped it. As 4ever_sideways has said, for your case to keep using the VCT you better get an ECU that can do it. Do it once, do it right is all I can say. I took shortcuts and had to fix up many things to finally have it running well and even then the tune wasn't great as it was a custom on by X-tune to suit the mods I had. He ran it quite rich to be safe so I was missing out on some decent power (still better than N/A).

Water feed, the block should have a bolt that is blanked off for the drain, for supply it is at the back of the head, capped off brass T-piece.

Oil feed is the most important as that is what keeps the bearings cool. The RB banjo bolts and lines are like 0.1mm in diameter to restrict the flow of oil. The mechanic I got to make me some custom banjo bolts drilled the holes to 0.2 "because 0.1 is ridiculously small". I swapped out two turbos because the oil flow was so much greater with just 0.1mm larger that I was getting tons of white smoke out the exhaust and pooling in my intercooler pipes!

Run all the factory lines for oil and water feeds and you will not have an issue. Run both oil and water too as the water will extend the life of the turbo.
As for the oil drain, just a large diameter pipe with threaded fittings to suit both sides, braided should be fine, try look at a 25DET to get an idea of size. There should be a hole blanked off with a bolt for the oil drain near the sump.

Oh also after I turboed my motor, it wouldn't rev past like 4500rpm under load. The coils started failing because there was just so much more going on, they couldn't provide adequate spark:
So be prepared for the same thing. You will also need to run NGK BCPR7ES which is a colder plug gapped to 0.8mm to suit the new operating conditions of the motor.
Title: Re: RB25DE+T How too
Post by: MOSTDOUBTED on January 27, 2015, 02:06:21 PM
Cheers guys. Is there any real build threads on this? I've got the main of idea of how everything is ment to go but being able to see some elses pictures/thread would greatly help.

I'm looking at going for an Link G4 GTS ecu since a friend of mine said its suited his 25+t and its a straight plug in set up? So looks like the way to go.

Also would be kit like this be fine for doing the feed lines? ( If I can't find any second hand feed lines )
Title: Re: RB25DE+T How too
Post by: benji-nz on January 27, 2015, 04:48:18 PM
The Link looks like a good piece of kit. However I did notice that it only has 4 ignition drives so that means batch fire which isnt ideal. Now these look like a real good piece of kit;
Title: Re: RB25DE+T How too
Post by: downtrail on January 27, 2015, 09:30:56 PM
The gts plug in g4s have 8 injector drivers but only 4 ign drivers so will be wasted spark but thays fine. Even batched fuel is fine unless you have super huge injectors.  Have tuned a few only ran into too larger injectors once on a 30 but they were 1000cc injectors.
Title: Re: RB25DE+T How too
Post by: MOSTDOUBTED on January 28, 2015, 10:00:00 AM
I will have a word to my mate who has the G4 GTS installed, met another guy last night I bought my Plus T kit off and he runs one aswell so I'll see what they say.
Title: Re: RB25DE+T How too
Post by: downtrail on January 28, 2015, 06:01:51 PM
To be honest you will be better off doing a wire in and a new motor loom. The looms are old the plug pins have lost tension. That's what id reccomend. Pm me if your like a price for a new loom and dyno tuning.