RB25DET Conversion Guide S13

[Phil LS]

The engine arrived with the crossmember, wishbones, and gearbox all attached, so you may not need to do it exactly like this.

Take a note of the engine number BEFORE fitting it, you'll need it to change the log book with.

Detached Air Con from engine. One less thing to worry about. Very easy to do. Undo 4 nuts on Viscous Fan. Remove Viscous fan. Remove Power steering belt by undoing the nut that holds the pump to the engine slightly, then undoing the nut holding the adjuster to the engine. Then turning the adjuster nut to slacken the belt. Repeat procedure on the tensioner pulley (inbetween Air Con and Crank pulley.) Then remove this belt, and undo all bolts on the air con (there's 2 underneath too). And it's off.

Air Con Removed:



Detached Crossmember from engine, make sure you unclip the wire going to the steering rack. I took the power steering pump off the engine before taking the crossmember off. Crossmember only held to the engine by this wire, powersteering lines, and the 2 engine mounts. You obviously have to lift the engine in the air when taking this off. I wrapped a tow rope under the engine to lift. Lifting brackets would have been nice, but one of mine had been taken off Make sure the crossmember is straight when you undo both or it might strip the nuts on the engine mounts (you need these). I'd recommend putting a jack underneath to lower it slowly.

This is the R33 Steering Rack:



This is the R33 crossmember without the rack.



Detached power steering rack. Once the crossmember is off this is relatively easy. Just undo the 2 feed lines to the rack, and there's 4 17mm bolts underneath the crossmember which when you undo, free the rack.

Removed wishbones. These are held on by 1x 17mm bolt, with a 17mm nut on the other end. You'll need something to hold the crossmember down, or use the girlfriend as a weight as I did as the nuts are done up very tight. I used a 3/4" drive socket set, with a tractor exhaust shoved in the end to extend the bar to about 1 1/2 metres Undo this nut on both sides and the wishbones come off

Removed S13 crossmember. Jack car up. Wheels off. Detach steering columb, I did this by undoing the one nut, in the middle, not sure if it's the correct way (alignment and all that) but i'll cross that bridge when I get to it Undo the arm coming off lower wishbone, joining with the chassis (1x 17mm), and undo lower wishbone from crossmember (1x17mm) Repeat both sides. Detach ARB completely (1 nut each side on bottom of lower wishbone, and the 2 brackets on the chassis) Put jack underneath crossmember to hold the weight. Undo the 2 nuts each side holding crossmember up. Crossmember will now drop off.

This is the S13 Rack on a S13 Crossmember, you can see how different the crossmembers are yet it's such a good fit:



Put S13 rack on R33 crossmember. 4 nuts underneath and the 2 pipes hold the rack down. Undo these and it comes off easily (make sure you don't snap the cover off as your pulling it out, undo it if you have to). Opposite routine of above to fit to R33 (it's a straight fit). You will have to use the S13 piping however since the R33 stuff has the wrong ends on it. These pipes will need some persuation to be clipped in, I had to be a bit vicious and use a vice and all sorts. I'd recommend buying some proper hoses for the job.

Put wiring loom through fire wall. The loom was put through the hole where the cabin vents unequal pressure through (underneath the ABS pump on it's own). We had to use some more gentle persuation to make the hole slightly larger, which involved an angle grinder. A more easy to the eye approach would have been to use one of them electric saw things We're going to leave the S13 loom where it is, without the original ECU, mount the skyline ECU in it's place, and use wires off the S13 loom to send signals to the dash. Then use the skyline loom, again with a bit of modifying to power the engine, but this will need some hacking apart at the end of the loom to get power, and join to the S13 loom (get yourself the R33 GTS wiring loom diagram and the S13 and figure it out) I will post how we wired in my one when it's complete.

R33 Crossmember mounted to engine. Easier said than done. Just make sure that everything is level and it goes straight on. Some pipes may need altering I also dropped the whole lot on a trolley to enable me to steer it around while it's under the car. I strengthened the original trolley that I had with a big piece of wood underneath and lots of bolts. However the wheels still bent on it (RB25 is NOT light )

Car lifted. Engine Crane attached to car by a metal bar underneath the 2 beams that go at 45 degree angles to the chassis and join the front of the car. I had to remove the anti-stone-flickerupper stuff to get the bar in there. Once the bar was on I wrapped a chain around it and attached the chain to the crane. One in the air it was relatively easy to manoevre it into a postion I wanted. My car is lowered about 50mm and when at the height needed the rear bumper was probably about 5mm off the floor It does get the height though. I'd recommend axle stands as a precautionary underneath. I also lifted it with the hand brake off to allow easy manoevring. At this point I removed the wheels to make it easy to get to the wishbones. This isn't necessary.

Slide engine under car. Once the car is in the air this is easy. I removed the gearstick to stop it getting damaged. Also before the engine goes under remove any water hoses and any pointing out hoses as the less the better. But leave the heater matrix hoses on. I just used the trolley that I strengthened and pushed it into position.

Lower car onto axle stands at a low height setting. I did this so I could use a jack to lift the engine into position, but obviously needed some clearence under the crossmember. At this point you have to wary of all the surrounding around the engine (ABS and clutch master cylinder are the main problems). Make sure the water feed hoses do not slip in the transmission tunnel, I pulled them over the engine and will attach them later. The wiring loom was also moved out the way to be put behind the engine later.

Raise engine to mate with chassis. With the crossmember attached it's just a case of getting it into the holes. I used a big screwdriver on the middle hole of the crossmember to align the nuts, then just raised the engine and crossmember with a jack (or engine hoist). Here you will have to raise the gearbox as well to get the right angle for the crossmember to mate with the chassis. It was a lot of going back and forth between the 2 jacks, but again it goes straight in.

Once the crossmember is attached the wishbones and suspension stuff can all be retached and bolt straight on the R33 crossmember. The gearbox mount will need some sort of modification to fit, which I havn't done yet, but will post the specs of any brackets I make.

Wiring. You'll need both the 200sx manual and the R33 manuals. Print off all wiring diagrams you can find. First wire that needs joining is the starter motor wire. Find this and join to the 200sx loom starter wire. Then get both pin-out diagrams for the 200sx and the R33, and join the obvious power feeds, ground the grounds. Once the ECCS is wired up with correct power feeds it's ok. This part is a bit complicated to write so if you need more details pm me.

Power steering. I used the R33 power steering pump and connected to it with the 200sx resevoir. You'll have to rotate the top hose on the pump because it rubs with the radiator. Really a bracket needs making up to hold it in it's new place. The steering arm was a bit tricky to get into the rack, you need to get a bar, and twist the rack, with the 4 bolts underneath underdone, so that it pushes the sleeve closer to the arm, then put the bolt in a do the sleeve up. Don't forget to do up the 4 bolts underneath after

Radiator. Use the 200sx radiator in the standard place with R33 hoses to connect to it. They need a bit of modification to fit nicely (cut them shorter) but apart from that it's an easy fit. You'll need electric fans on the bumper of the rad with a sensor in the bottom hose to turn them on or off.

Lower Engine Water Hose. This is a different diameter to the 200sx radiator, you need a non-turbo 306 diesel radiator hose, which fits to the engine, then converts to the size of the radiator. Then just cut some hoses, use some joiners and it's in.

Speedo / Tachometer. I have spoken to the owner of Thor Racing and he has a module that sits in between the dials and ecu which converts the signals to be interpretted correctly by the dials.

Prop Shaft. Removing the standard prop is a bit of a pig. There is 4 bolts on the diff end of the prop that need taking off. I tried turning by hand with no effect even when coated in WD40. I put a jack under the spanner and lifted this, but the car lifted in the air rather than turn the nut Mr.AngleGrinder came out and the nuts were off in 10 minutes. I'd go straight to this if i did it again and get new high-tensile bolts. Both props have gone in to a company called DynoProp in Romford. Prop shaft has come back and fits a treat. The guy at DynoProp has done a top job on the prop and isn't even 1mm out

Intercooler. While i'm using the standard inlet plenum i'll be using a 200sx standard intercooler in it's wing mounted position with some bodge piping, you just need 2 70mm -> 63mm reducers and some trick piping.

Throttle Cable. I created a plate which extended the throttle cable mount closer to the throttle body. This allowed me to use the standard 200sx throttle cable.

Gearstick. I'm using the skyline gearstick at the moment, going to see if the 200sx one fits instead.....Doesn't fowl on any of the dash or anything as it has a very short throw in 1st 3rd and 5th. I'm 99% sure the 200sx gearstick fits, use that instead of the skyline one.

Gearbox mount. My dad actually welded me up a mount. He cut off the normal mounting positions, and welded on a plate, with some strengthening, and moved the bolt holes 45mm back. Fits a treat. There's a picture of what it basically is on the next page.

Exhaust front pipe from a skyline bolts on to a S13 Cat which allows an S13 exhaust to be used. I did this just to get me to an exhaust place however if you got an S13 De-Cat pipe you could just use this and not get a custom front pipe...... Custom exhaust mount (where it joins next to gearbox mount) is needed to be fabricated which isn't hard.

Bonnet. I put silicone sealent on all the highest parts of the engine. Then tried to shut the bonnet. This would leave marks on the webbing that gets in the way. Then angle grind these bits off, they come off fairly easily. The bonnet will shut with the standard plenum with standard mounts.



Intercooler. Found a pipe that converted from the 60mm to the 50mm needed, and was flexible. So just forced them in

ARB - Mambastu had a good idea of spacing the ARB down so that it clears the sump. I managed to get an ARB that had been tampered with to allow it to fit. Or you can buy a custom one from whiteline....

Custom Front Pipe - Got this made up at a exhaust place in dover. Made a huge difference to the performance of the car, especially at higher revs. Oh and it flames all the time



Then your done.

Finished Article, have since tidied up the wiring

[Stidi]

WOW - i've only read the first half, but... wow
excellent guide

[Spartan]

You make it sound almost easy! Nice guide.

[crackdownuk]

yeah great guide phil how much approx did it cost from start to finish in the end?? and how many man hours??

any thing you would have done differen if you did i again

it really is the business

[Phil LS]

Originally Posted by Spartan

You make it sound almost easy! Nice guide.

It's definatly not easy

Originally Posted by crackdownuk

yeah great guide phil how much approx did it cost from start to finish in the end?? and how many man hours??

any thing you would have done differen if you did i again

it really is the business

Price of engine, box, loom, ecu, crossmember (can vary a lot)

£80 for prop

£xx for custom ARB (yet to sort out a price) expect to pay about £200 from whiteline for one made to fit.

that's it. but then I did a lot of fabrication in house, so it could be a lot more.

If I did it again, I'd try and get the money to change the plenum and get a FMIC before fitting, as it really does restrict the engine.

[mambastu]

Nice one Phil, glad to see another one on the road, maybe we should have a 200SX RB register in the same way the Manta guys have the Manta V8 register

Re: the front anti-roll bar. Don't waste your money on a custom anti-roll bar. Just space the anti-rollbar down at the front edge and then if you want to upgrade you can just go for a standard Whiteline S13 bar.

[Phil LS]

good idea mate, nice one, will try that

[K11SS]

is there a scottish member with this transplant from glasgow/paisley area you know of?

[pauls13]

Originally Posted by K11SS

is there a scottish member with this transplant from glasgow/paisley area you know of?

im in edinburgh and going a similar route

but mine wont be done till next year

Paul

[John Bennett]

Originally Posted by K11SS

is there a scottish member with this transplant from glasgow/paisley area you know of?

nicon_23 on here perhaps?

[K11SS]

cheers john that is who im lookin for

[RB200]

hi im new to the 200 world ive just brought an s13 and plan 2 project it over next few months, ive just seen the giude i was planning on building my ca engine to around 400bhp but on seeing this ive now decided to go for the RB20 DET engine,

[RB200]

^^^^ sorry i meant im goin for the RB25 DET engine

[colchester daz]

Top stuff mate

[Airbog]

Excelent article. Preparing for my own swap and have one question. Did you use S13's prop or R33 one? Must they be shortened or so?

Did I need Skyline crossmember or is it possible to use custom mounts?

Thanks mate.

[Pete C]

You need to get a hybrid prop made using the front of the R33 one and the rear of the S13 one.

Pretty sure you need the R33 cross-member, custom mounting it to the S13 one would be a pain when it's so easy to fit the Skyline one

[colchester daz]

Originally Posted by Pete C

You need to get a hybrid prop made using the front of the R33 one and the rear of the S13 one.

Pretty sure you need the R33 cross-member, custom mounting it to the S13 one would be a pain when it's so easy to fit the Skyline one

Could you use an R33 diff, that way you wouldnt have to custom the prop?

[Airbog]

I'm going to swap Neo engine from R34. This is without crossmember, but I think, that I can use R33 one with this engine. Is it possible to get any (in Lithuania definately not)?
If using custom mounts, local tuning shop can make them. Or I can purchase them from McKinney motorsport. They have driveshafts for this conversion too. So as I see, I need past one for sure.

[bemmerkid]

any more info on the wireing and pictures of the gearbox mount ??

top job phill!!

[Damo]

top job mate not a bad write up at all