Installing a RB20DET into your R31

RB20DET (R32 Silvertop) into S3 R31 Executive

This article needs a bit of work, if you can help out, please do!

Parts needed

• RB20DET with loom
• ECU
• turbo
• dump pipe
• etc (engine package)
• Gearbox (R31 auto wont hold up too long) I used the RB20det manual box
• Speedo sender from Aus R31
• clutch pedel, master cylinder, slave cylinder
• R31 manual crossmember
• R31 Manual Tailshaft
• all new fluids (oil, coolant, gearbox oil)

replace hoses (if you got spare money replace all of them, if you dont, just replace suspect hoses) Replace belts (timing belt, power steering belt, air con belt, etc) maby new clutch (im using one that came with RB20 as its a Nismo clutch with 50% left on it)

Removing the RB30E

Take radiator out, it will be much easier without this in the way.

The following steps can be done with gearbox attached or not attached, i tried doing it with the auto trans attatched and couldnt, (only took 15mins to undo the auto trans) undo all hoses, from engine, (dont forget charcole canister and accelerator cable). It is easier to remove the engine and gearbox as one piece if you have a propper engine crane.

Undo gear selector rod, disconnect speedo cable, can leave other wires connected just make sure they are undone from the engine side of the loom.

disconnect/cut trans lines running upto radiator (i undid one and cut the other as i wouldnt be needing them)

unbolt tailshaft and remove

unbolt gearbox crossmember now everything should all be undone ready for engine and transmission to be removed,

we removed the trans by jacking up the frount of the car, tying a rope around back of trans, and yanking from the back of the car, after about 3 yanks it came undone. <=-DODGY, needs re-wording

now for the engine, undo ECU from kick pannel, and feed wires through to engine bay (need to take out plastic grommet to fit the plugs through) (there are 2 more plugs becides the ECU plugs that are in the cabin which also need to be undone.) undo all other plugs in engine bay remove starter motor from the engine We removed the power steering pump and air con pump from the RB30 and left them in the engine bay so we could bolt them onto the RB20 when it is in, the power steering fluid doesnt need to be emptied if you do it this way.

place chain through lifting points on the RB30, undo engine mounts, and lift engine out (removing the bonnet is a good idea)

would be best now to install the clutch pedal as its easier to do while engine is out. to install the clutch pedal i had to disconnect a heater hose that goes under the drivers side foot well, once this was undone the clutch pedel fitted nicley, now bolt the master cylinder into the engine bay. you will have to cut or change the brake pedel as the auto brake pedal is too wide for the clutch pedal to fit.

Putting RB20 in

remove air con pump and power steering pump if the engine has them.

Take engine mount brackets off RB30 engine and bolt onto RB20 while lowering in RB20, bolt P/S pump and A/C compressor onto RB20, this could instead be done once the engine is bolted in.

place engine into engine bay (we did it with out gearbox connected, it could be easier to bolt the gearbox onto the engine first), bolt engine onto rubber engine mounts.

I used the RB30 Power steering pump, had to use some washers as spacers for one of the bolts, as the rb20 pump bracket has abit of a knob on it, and used the RB30 PS belt. didnt connect the A/C

Putting gearbox in

take out the old auto shifter, have to undo center console and undo a few screws and it will pull out. You can take out the auto trans computer which is under the passenger seat, or leave it in (i will be taking it out to put an amp in its place) put Aus R31 speedo sender into Rb20 gearbox

we jacked all 4wheels up and put jackstands under the car. placed gearbox under car, and turned it upside down (with out shifer in gearbox), put rope around back of gearbox (where shifter goes) then put a crowbar in the car accross where the hole where the shifter goes. and wrapped roap around crowbar got a mate to site in the car holding roap, put a jack under frount of the gearbox, got the bloke in the car to lift the back of the box up as high as it would go, then jacked up the frount of the box. got it linded up into position, then slipped the spline in, lowered jack and put it under the back of the gearbox undid roap then turned gearbox up the right way, slipped it in the rest of the way and bolted it up. and put the manual gearbox cross member in.

EDIT If you are putting an RB25 into a r31 s1 and using the 31s1 auto make sure you change the flex plate as the rb30 hole centres that bolt the torque converter onto the plate are diffrent to the rb25 hole centres. I suppose its the same with the rb20 I didnt check and now have to pull mt motor out to change flex plates Wolfie

Tailshaft...

Manual tailshaft bolted straight in,

Radiator

I used the Aus RB30 Radiator, i used the RB20 bottom hose and cut a RB30 hose for the top. and i used the RB20 fan

Intercooler

I have the standard RB20 cooler placed where the standard airbox goes with the pod underneath it, my RB20 didnt come with cooler piping, so i have to get some custom made.

Other crapola

Boost gauge, i installed mine where the cigarette lighter goes, its a 2" gauge and fits in nicely i have 3 other gauges (amps, Oil pressure and water temp) i will be installing these where the 2 middle air con vents are.

Exhaust

my RB20 didnt come with dump pipe, so im using a standard RB25 dump pipe, and i have the flange that comes off it im welding a pipe between dump pipe and the cat so i can use standard exhaust till i get some $$$ saved for a full system

Compiled By

Harolto