R31 conversion to RB20DET

[Guest jimmyd17]

has anyone put a RB20DET in a R31? what problems were encountered, and does the R32 GTS-t engine/box bolt on to the existing cross member on the aussie R31?

[R31 POWER]

Ok this is what we did.

- R31 engine mount bracket with R32 engine rubber mount(we used the R32 mount coz the R31 rubber was farked)

- R31 gear-box mount,all lines up,even used R31 gearstick,R31 tailshaft in R32 box.

- R31 power steering and air con pumps,for the power steering pump bracket it was the R31 one and same for air con.You will find the PS pump has a 3 rib pulley and the crank shaft pulley is 4 rib so use 3 rib belt.Use R31 idiler pulley bracket (i think) under air con pump.

- R31 altinator with whole R31 loom from gear box speed senser to altinator,The r31 loom conects to all the same spots as on the RB30e.With the speed senser unscrew it from the RB30e gearbox and put in RB20det box coz RB20det box has a speedo cable where as the R31 is electronic.Also use RB30e oil pressure sender with RB20det.

- Use your temp sender from RB30e and put in RB20det(might have to tap thread)

I have all the wiring info and will post later.If you need any more info fire away.:uh-huh:

[Guest jimmyd17]

thanks heaps for the info,

i was thinking of getting an R32 GTS-t half cut... do you think this is a good way to go? and how did you go about the conversion in the way of buying the parts?

also, how does your sillhouette go? and what mods have you done to it?

[R31 POWER]

Yes I got a half cut so all the parts needed were from the cut or the RB30e.

The only parts I had to buy were heater hoses and the top radiator hose,wich is a ford corsiar/laser hose I have the part number somewhere and had to cut 1.5cm's off each end for a snug fit.

It goes good,down low theres not much pulling power but at around 2500rpm it pulls very good.Btw it is unintercooled,standard dump and frontpipe,2.5inch cat and exhaust with rear muff chopped off and standard boost with a pod.

I have a supra fmic so thats going in very soon and the whole exhaust from turbo back will be made to.

I paid $2200 for the front cut with 55,000km on it but minus all gaurds,bonnet,lights and brakes.

[slip]

After racing a number of rb20det powered cars, I am of the opinion that this is a bit of a waste of money... UNLESS you are going to do it properly and go something like T3, full exhaust, fmic + chipped ecu, as RB20DET's with boost/exhaust in 31's and 32's in highway roll on's are not a lot quicker than me (RB30E with exhaust intake and timing).

If you are going to use a front mount, slightly bigger turbo and the other usual stuff, go for it, but if its going to be pretty much standard, you might be a bit dissapointed after spending all that time and money for a small improvement.

RB20DET + mods + R32 brakes =

[Guest jimmyd17]

thanks for that, i appreciate your imput into the negative side of the conversion, because so far ive only heard good about the RB20DET... out of interest, how well does the RB30E really go? and if i were to go to the RB20DET, what would you recommend doing to for the best results?

[SKY031]

Why not go twin cam with the RB30?

It's all the rage at the moment

[R31Nismoid]

Originally posted by slip

[bRB20DET's with boost/exhaust in 31's and 32's in highway roll on's are not a lot quicker than me (RB30E with exhaust intake and timing).  

[/b]

I dunno about that. I mean... seriously ?

An RB20DET with full Zorst and Zorst will pull up and over 120 rwkw at the Min.

My old dead stock 31... pulled 89 at the wheels on 7psi, but that's with and auto behind it and they suck 9kw out of the package, so manual is basically 100 before mods.

I don't think the RB30 would keep up as they are a low end motor. They don't wanna rev like the RB20DET does.

But with a bigger turbo, it'll go hard.

you can get 180rwkw not problem with just chip/boost/turbo/cooler/zorst

but by that stage you'll need a new diff

[Guest jimmyd17]

ok, cool... what kind of exhaust would you recommend with the RB20DET?

[R31Nismoid]

They ONLY Zorst for a turbo.

3" Turbo back, hi-flo cat.

Where in Melb r u dude ?

[Guest jimmyd17]

I'm in Croydon... Eastern Suberbs.. out ringwood way if u dont know

[R31Nismoid]

i got my car from Chirnside Park... know that area well.

Just got to an Oz Exhaust place... and just get them to make it.

I got one done.. 3" Mandrel from turbo back for $590.

That was not including Cat though... still cheap as.

[Guest jimmyd17]

thanks for that! i'll definately keep that in mind.. out of interest, whats the story of your car? and what sort of difference is there with the RB20det to the 25?

[2fardown]

Swapping over from an RB30E to an RB20DET is a downgrade.

[R31Nismoid]

i did have a 31 ... auto with RB20DET.

put the zorst on... huge torque increase. Made all the difference even without hi-flo cat.

I chipped ECU/boost and it went nice and hard.

Traded it plus $$$ for the GTS-R i have now. The car i brought as is from a private importer who got it here in Dec from Japan.

The car, you can tell, have had a full drift/race backgroud.

The mods include...

RB25DET

5-stud conversion/i think R32 GTR brakes

shortened shift gearbox

coil over suspension that is so hard there is virtually no travel

HICAS has been gutted for weight saving.

extra injectors in the custom intake pipe to plenum

steel braided brake lines

monster clutch

can't think of the rest at present

Also the diff i think has been modded i reckon.

it still has the standard T04E turbo/exhaust manifolds and huge front mount cooler that GTS-R's came with standard.

So its got some balls you could say.

Lovely to drive.... but always wants to go, such is the feel of the car.

But the RB25DET is the be all and end all. In my opinion after having both motors... the 25 kills the 20 hands down in every area.

But the RB20 is good bang for buck though. all you need is a turbo/zorst and cooler and they make quite decent power...

but then you gotta look at brakes/diff and other areas also

[Guest jimmyd17]

thanks heaps for that info, R31Nismoid.. have you had the RB30E? and how would you compare the RB30E to the RB20DET?... is it worth it?

[R31Nismoid]

i have had an RB30ET with a hi-flow t3 running 15 psi...

that was nice, but it didn't wanna rev at all.

Heaps of low end power but the 7500 rev ability of the 20/25 is what i prefer in and engine... RB26 8000+... that's nice

In my own opinion... RB20DET will shit on RB30E for bang for buck.

you can only go so far with an RB30E before you run out of ways to get more power short of going turbo... costly $$$

visit

r31skylineclub.com

we got heaps of this sort of stuff there mate.

[SKY031]

Originally posted by R31Nismoid

i have had an RB30ET with a hi-flow t3 running 15 psi...

that was nice, but it didn't wanna rev at all.

Thats because it was in a Holden :D

[slip]

i agree,

IF you are going to go chip, fmic, turbo back exhaust, t3 turbo, use an rb20det and r32 brakes.

OR turbo + rebuild your RB30 for some wicked torque. Its not peak hp that gets you somewhere quickly, its how much power you have while you accelerate, this is why i was able to sit next to my mate in his r32 gts4 untill he hit top end and pulled on me, then sat dead level again untill he hit high revs in 4th and pulled again.

You are getting a turbo motor, but you are also dropping 1000cc's as well.

[Fast31]

mate i have a 31 with a Rb20 in it, whuch replaced my old RB30e with a big cam , headwork, extractors, 2.5 inch exhaust etc, and the standard rb20 would kill it.

i have upgraded it bit by bit and can honestly say they are a great motor, and in no way a downgrade from a RB30e

first up put on a good 3 inch mandrel bent exhaust, second a good sized front mount cooler, and wind the boost up to 13 or 14 psi.

For not alot of money you are going to have a quick car, worthy enough to scare wrx's and 200sx's.

This is presuming you have a 5 speed. I would also suggest 4.11 diff ratio's.