Jump to content
SAU Community

Recommended Posts

Ok so i just completed the MOST BUDGET RB25 conversion in the history of skylines (prob not true)

I thought there may have been a problem because the way i was doing it because the guy wouldnt run after it was mechanically finished.

There was talk of INJECTOR RESISTANCE and CAS compatibility but none of that was an issue.

Turns out the Injectors were seized from sitting around to long.

So my conversion cost me:

$700 RB25DE

$20 to have oil drain welded on to sump

$150 in fluids

$200 for 25DET injectors

Total Cost $1070 RB25 Conversion

Parts I used

RB25 Long Motor

RB20 Gearbox

RB20 Clutch/Flywheel/pressureplate

RB20 PS pump

RB20 Alternator

RB20 Loom

RB20 ECU

RB25 turbo injectors

RB20 Turbo and ex Manifold

RB20 radiator

As you all know, RB25det's have NVCS and i will have to go to Jaycar and buy a RPM based switch (maybe a shift light kit) to control the NVCS.

So there we are people, dont be content with your RB20's lack of torque of throttle response. next time you throw a rod, seek out a $1000 RB25 conversion.

Link to comment
https://www.sau.com.au/forums/topic/146057-got-her-running-finally/
Share on other sites

sorry for the stupid questions but im not sure on a few things and am keen to learn about this coz im interested in doing this conversion.

first of all, what is the difference between a long motor and a short motor? does it refer to whether the internals are included with it?

was there any modification needed to fit up the RB20 ex manifold and turbo on? also, did u have to alter the compression ratio aswell?

one last question, did the RB20 loom match straight with the RB25 loom, or did u have to rewire it?

Thanks heaps

Stephen

So you did all the labour yourself? Thats cool but not many ppl can do the whole thing themselves.

Also you are running the std RB20 ECU on a high compression RB25DE with different injectors ( you didnt mention a head gasket)? How does it run?

Also, you havent mentioned the de-gas or re-gas of the air con, are you still running air con?

Im all for doing the conversion, but how good is the finished result? I imagine to get it running reasonably well its going to cost you at least that amount again.???

Very interested in the results and the power it makes. Curious to know if all the talk of the better flowing head actually means it makes more power with the std Rb20 turbo. Expect it to make more power earlier int eh rev range courtesy of higher compression, head design and displacement.But will peak power be any different?

Good luck with it

Stephen, long motor comes with accessories bolted onto it. Pretty much a complete motor.

Short motor is usually the head, block, manifolds... just the actual motor itself. No A/C, no power steering, no alternator....

Stephen: The RB20 Manifold and Turbo bolted straight on with no modifications. I havent modified (dropped) the compression ratio as i feel that any detonation associated with turbocharging this motor can be easily overcome by adding fuel and/or pulling out timing. As for the loom, the RB20 loom was fine for the RB25 save for the soldering of the 6 injector plugs. The RB25 side feed injectors (turbo and NA) use a different plug (generic side feed nippon denso). They were soldered, and insulated onto the RB20 loom. One thing that will pose a problem is that the RB20 loom/ecu has no provisions for controlling the NVCS (which is the variable cam timing on the inlet cam). I can overcome this in a few different ways. PM for details.

Roy: Yeah i did all the labour myself. I cant justify letting a workshop procrastinate on my car for 3 months making excuses all the way like; "we are just waiting on this part"

The CR is standard... 180psi in all 6 cylinders. No metal HG required. It runs RB25DET injectors which are 370cc. I thought it would be too rich, but it seems to be fine.

I never got an AC compressor or condenser with the car when i bought it... some stupid drifter wannabe had removed it. I will be retrofitting it for my driving pleasure.

I anticipate around 170rwkw with a low boost setting. I will have the stock ecu remapped and post results. I fully anticipate this turbo running out of flow around the 6000 mark. The upside to this is it will prob make full boost earlier.

Randy: The motor was technically a long motor, but it was minus alternator, PS pump, brackets, coils, loom.

Sinistagtst: Suck my balls, when you've put in as much effort into an engine swap like this, then you can critise me.

Marki Mark: It idles smoothely but it has not been street tested yet as i havent located any R33 radiator hoses yet and i work 6 days a week!

Andy, nice work!

I done the same thing recently but used a GT3071R running 1 bar.

Im very interested to see how much timing you are able to feed into it before it pings.

Any idea when you will get the tuning side of things done?

ill get a RB25 turbo when one comes up cheap, or get a sliding performance turbo.

i have ordered brand spankers top and bottom radiator hoses for it so add $100 to the cost. They are the last thing before its ready to drift.

ill post results, timing and drivability.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I sense an out of control build thread coming up lololol. That 450kW goal will end up being 600 to 700kW LOL.
    • Nice, thanks for sharing your progress....that's a pretty long list you are putting into it!
    • Decided to upgrade my pressurised plastic coolant expansion tank for a fancy pants alloy version The OEM versions can get brittle, even the new plastic one I got when I first got the car is a starting to show signs of "stress" I wasn't cheap, but it is basically unbreakable
    • Morning all, I have an RB25DET Neo that's in need of a rebuild. Will need new pistons etc due to detonation damage. Would anyone be able to recommend a shop in Southeast Queensland who I could bring my long motor to for a rebuild? Just want someone who knows RBs and whos built a bunch of them before. TLDR - recommended engine shops for RB rebuild.
    • Gday Thought it was about time I started a build thread! As expected this project has snowballed into a huge financial liability, but unless you’re strong willed and responsible, it’s not a surprise. Background -  My first turbo car was an R32 GTS-4, got my full license and then totalled my Au Falcon a week later, so while trying to sell my RMZ450 dirtbike to buy another car a bloke offered to swap the R32 which at the time I felt like I was ripped off but looking back and seeing prices of those now ($40kish) it was a good deal, I didn’t know enough about these cars to appreciate what I had so sold it before the RB20 blew up. Between here and there, out of 12 cars I’ve owned the note worthy ones are a V8 Lexus SC400 (soarer), a couple of XR6 Turbos and my beloved S15 which I had for about 3 years, picked it up for $12500, repairable write off but she was fine, gun metal grey/pewter and bone stock/unmolested until I got my hands on it. Ended up spending about the value of the car and 280kw, 2 demerit points by the time I got defected and sold it for $14500 (also $40kish in today’s market, rip) Fast forward to the present day, I’m in a much better position financially and daily an MQ Triton (great cars, pipe down Ranger Bois), I cruised marketplace and car sales for a few months looking for another R32, the best deal I could find was an absolute rust bucket half finished project for $12000, until this R33 popped up in Port Macquarie for $18k - unregistered and barely running but decent shape, kept an eye on it for a few weeks and the price steadily dropped, $16k then $15k then $14k, that was the point where I was like shit someone’s gonna snatch this up! It was owned by a young bloke who had big plans but him and his missus just had a baby so smartest move financially for them but big gain for me. So 2 days later I’m towing a car trailer to pick this thing up. Roughly 2 weeks and $3500 later I’m cruising around Newcastle in my beat up R33 all smiles and dose noises! It only needed some basic shit to get it going, coil packs and air flow meter, electrical stuff and all fluids changed, 158k kms and running pretty good, nice smooth engine after oil and coolant flush - when I say coolant I mean it had been filled up with tap water, every gallery and heater element was filled with rust, 8-9 flushes later and still had brown liquid coming out but she’ll be right. The car was painted R34 Bayside Blue at some point but whether it was a cheap job or just not looked after is anyone’s guess, clear coat flaking like sausage roll.  Was rethinking my choices and contemplating life, had it up for sale for $22k - still cheaper than any registered R33 but got little interest, next minute I had an opportunity at work - 6 months overseas for good money, so that was a no brainer, fast forward again and here we are with a 50% finished project. Current Mods - 200ish KW according to butt dyno Was tuned with Apexi PowerFC EBC (old school Greddy Profec)  Stock turbo (more shaft play than a Tinder date gone right) 3inch turbo back Varex muffler  Aftermarket injectors of mystery size, Power FC showed 36% duty cycle at full boost so not behd good size Someone had good intentions but stuck with the stock R33 MAF so we had misfires at 6000rpm due to the MAF hitting 5.2V So far I’ve redone the entire interior with carpet form Car Mats Direct, new Seats and steering wheel from Autotechnica, also sound system by Autobarn (mainly Kicker) Also MCA pro comfort coil overs - Hands down best purchase yet, worlds of improvement over the tired 30yrold shocks Goals - 450kw/600hp on flex tune New paint job - Midnight Purple 2 Engine is at the shop getting rebuilt with forged rods a pistons, new valves and springs, ATI Harmonic balancer, Aeroflow 7.5L sump, rear head drain and oil restrictors as per oil control thread* and cam covers modded for larger breathers, other stuff I can’t recall of the top of my head Parts purchased and to be installed once the engine is done -  Engine loom from Wiring Specialties including these options: Haltech Nexus S3 R35 Coil pack conversion  PRP Dual Trigger kit Fan controller  Other Parts -  262 Kelford Cams Turbo - Hypergear ATR43SS3-ProS with T51R mod (whistly boi) 6 boost manifold (high mount) 50mm Turbosmart Pro gate (plumbed back for legal reasons) HKS Super Turbo Exhaust with High Flow Cat Custom 3.5inch dump and front pipe 1500cc Bosch injectors  Fuel Pump walbro 525 Haltech MAP and IAT sensors Haltech Flex Sensor Fenix Radiator with dual thermo fans LS1 Alternator Kit Oil Filter Relocation from EFI solutions and Cooling pro oil cooler Many other things sitting in my garage waiting for that engine to come back. Progress pics to follow -  
×
×
  • Create New...