I'm thinking about 'upgrading' my R32's RB20DE engine to a neo one which should give me some better fuel efficiency, cleaner emissions and _slightly_ more torque(186.33 N*m / 4400 rpm vs 184.37 N*m / 5200 rpm) . I'm having a hard time finding information about the engine and what differences there are with a non-neo engine. I'm wondering if i could get away with swapping just the head/loom/ecu and using my current block/internals or if its a lot more extensive than that (eg full engine transplant required).

If anyone could point me in the right direction that would be great.

And no RB25 or turbo is out of the question at this stage (damn you insurance company )

I'm thinking about 'upgrading' my R32's RB20DE engine to a neo one which should give me some better fuel efficiency, cleaner emissions and _slightly_ more torque(186.33 N*m / 4400 rpm vs 184.37 N*m / 5200 rpm) . I'm having a hard time finding information about the engine and what differences there are with a non-neo engine. I'm wondering if i could get away with swapping just the head/loom/ecu and using my current block/internals or if its a lot more extensive than that (eg full engine transplant required).

If anyone could point me in the right direction that would be great.

And no RB25 or turbo is out of the question at this stage (damn you insurance company )

RB20 neo would not be worth all the trouble. Wouldn't it be worth paying a little more for insurance and getting an RB25DE Neo?

RB20 neo would not be worth all the trouble. Wouldn't it be worth paying a little more for insurance and getting an RB25DE Neo?

Like I said, rb25 isn't an option. As I am under 25, my insurance company will only allow me to insure a car 2 liters or under. My insurance company currently gives me very good rates as the rest of my family use them also. Then on top of that I would have to get a certification done (government requirement here in nz) if I used a larger engine - about $450. Believe me, I would love to plonk in a rb25 - but its just not viable atm.

Anyways, less whys - more how-tos

do you know what 2 NM extra torque would feel like?

you could get better fuel efficiency by buying a $350 brand new Apex SAFC and leaning out the mixtures a bit. you'd even get better power and torque from that also.

And guess what, you wouldnt have to rip the motor out!

do you know what 2 NM extra torque would feel like?

you could get better fuel efficiency by buying a $350 brand new Apex SAFC and leaning out the mixtures a bit. you'd even get better power and torque from that also.

And guess what, you wouldnt have to rip the motor out!

You can see that it also peaks 800rpm earlier - which may be more noticeable and possibly improve the drive-ability (so gutless down low ). There is also quite a significant fuel consumption drop between neo and non-neo. Plus I enjoy taking things apart

As for the SAFC, I'm planning on getting a second hand one already. I figured using it with the neo head should give some good benefits.

Thanks for your suggestion tho.

Edited May 4, 200719 yr by Sinturion

Just 2.4 stroke with individual throttle bodies...and stay NA....shell go better then

so you wont a bigger n/a hey.

well nuthing beats displacement so why not go and get an RB30E and put a rb25de head on it. this should be good for around 130wrkw and plenty of tourqe. should be pritty simple to bolt in the rb30e block and then get the head wired up.

aslo witht he rb25/30 you will need to get the rb25de pistons to have the right comp ratio and if you deck the block i believe it is .74 thou you will have a 12:1 compratio.

this in my opinion would be the best path to travel and then if you wont to go turbo all you do is pop in some turbo pistons (get rb25det head if planing to do so) and wack on a tubro of u'r choice.

hope this helps brentt

he wants to keep it 2l though i dont think its worth it and id imagine it d be hard to source a rb20de neo

what about just modifying your current rb20

Mate in all honesty, considering your position my suggestion would be forget about modding the engine & concentrate on suspension mods. You'll learn a lot & by the time you hit 25 you can get the car you want & go nuts on it. HP isn't everything.....

Mate in all honesty, considering your position my suggestion would be forget about modding the engine & concentrate on suspension mods. You'll learn a lot & by the time you hit 25 you can get the car you want & go nuts on it. HP isn't everything.....

as above, you can get about 100 at the wheels out of them, and with a lean tune it should be pretty good on fuel, then go suspension etc

that said, they dont have to know you have a 25de in it, you can even go as far as changing what the block says (to your current 20 engine's details) if you want to be dodgy... never be the wiser

other than that, its a 20 give it some cams a good tune, timing compression, flow in and out, and then just let it rev, should be fun enough for now

Hehe

While I appreciate the advice - I would really like to know what the physical differences between the rb20de and rb20de neo are. I think the rb20 neo is more common in NZ than in AU. One of the main factors for doing this is also the learning behind it, so that when I build my rb30de I have a clue what I'm doing.

Btw, just brought a secondhand SAFC2 - going to pick it up in a minute or two

I've been reading the R34 engine manual. Apparently the RB20DE Neo has variable valve timing control, as well as variable air intake control - both which claim to increase torque at the lower and middle ranges. It also has 'air swirl jet control' which has something to do with making combustion more stable. More reading required!

If I was doing this, I would do the 2.4 stroker conversion. That would give you the torque increase you want, and there is no way the insurance company are ever going to know.

I would also fit a power FC, and then get the car properly dyno tuned. The whole thing should then run pretty well, and the engine still looks completely standard and original.

I was reading about the rb23/24 last night conversions last night. Seems like there might be some expensive machining work involved to bore it out to 81/82mm?

I can't find alot of info about an NA rb23/24 - just the turbo ones. What kind of effects will it have on the compression ratio if i used 4age pistons and a RB25 (or RB26) crank?