Building RB20 into RB2.2

[Roy]

Sure the RB25 is likely the better basis for more performance. Not wanting to go into RB20 v RB25...its a tired argument. I would just like to point out a few things for those that are ready to throw the RB20 away and bolt in an RB25.

Firstly, the RB25 seems to have weaker ring lands, and whilst its seems to be something that a good tune will see the engine live with at good power levels, more std ECU RB25s with std turbos turned up seem to kill pistons then RB20s. The RB20 turbo also seems more durable at 14psi then RB25s.

It would also seem that the RB25 ECU isnt as flexible as the RB20 when doing bolt on mods, and of course you cant chip the RB25 ECU like you can the RB20.

Next is ppl saying that the RB25 is so much torquier, sure it is, its 500cc bigger but dont forget it is using a different turbo and has 0.5 higher compression. Give the RB25 8.5:1 compression and the RB20 turbo then go and tell me it makes that much more power, or is that much more torquey. Or vice versa, give the RB20 9.0:1 compression and an RB25 turbo, i would love to see the results of that.

So again not saying one is better then the other, just pointing out some things that ppl dont seem to consider when looking at engine / power alternatives.

[Cubes]

My experience is with minimal mods the R32 is quicker.

Not due to the rb20 just the fact the R32 has a lower diff ratio (4.363:1 vs 4.11:1) and its lighter weight. Also the R32 has a shorter second gear.

Hell my ol' R32 has even held on to a Ferrari I sat behind in the next lane while he was gunning it. I was dissapointed with how it didn't really pull away as quick as I would have imagined. + it sounded crappy like a darn motor bike.

He then continued to be a boy racer which is when I left him alone.

[Roy]

Also, if using the RB26 rods with 82-83mm pistons to get a displacement over 2400cc, just remember for give or take the same displacement as as RB25, you are going to have lighter pistons then for an RB25 as they are physically smaller, so when using a forged piston you wll have lighter reciprocating mass and a free reving engine.

[R32 GT]

I hear some whale defending necessary!

You have hardly any other RWD skylines around which can keep up with yours, and from memory the ones that have at all are 33s or 34s (ie, RB25 powered).  From memory the only R33 you have raced at the drags beat you - and all the other 33s around here are virtually stock (at the moment), and all this is with the RB25 in the heavier body.  Also, dyno figures wise - the R33s on average are way higher powered at CF than the R32s, yours with bigger turbo, S-AFC etc was in the middle of the cat-back exhaust and pod filter R33 brigade - so the RB25s are actually making more power too.  An R33 with a road tuned S-AFC and bigger turbo would be in a whole different power/performance class.

The GTSt you mention was doing low 12s on slicks, and needed NOS because with the RB20 was unable to spool the turbo well enough for a decent launch - and has a built RB25 now.

Whale defending? What for? Sorry the GTS-t you mentiond, low 12's i was told by a flatmate it was high elevens, and are you saying a whale would do a low 12 not on slicks? The fact is it was still making 300rwkw on standard internals and he (according to you) just used the nos to spool the turbo but the top end was there from the motor rather than nos. Are you aware of actually how much mods that 33 i raced at the drags had? Considering at the time how much i had spent on my car, it wasnt a very big difference considering you told me yourself you could hardly tell who won... And the 34 with 200rwkw running 14psi was also pretty easy for my old girl to run down, considering i had the front mount on which made it run worse, and was running a huge 10psi ( and still getting to the speed limiter at the finish line) Its mainly the fact the car was cheaper, the parts are cheaper and they are easy to get power out of thats why im sticking with the 32/ RB20 setup

Im not dissing whales or RB25's all im saying is for a ancheint 2litre boat anchor the RB20 seems to go ok, well mine does and its a fun car to drive with it..

Meggala, i agree after taking another look at the tomei option it looks like a good deal, are the pistons they supply to be used with the standard crank/ rods? Otherwise i guess the 26 crank and rods are another option.

Joel, im suprised your car actually was slower on the VG30/ RB25 turbo? Myself and my flatmate run these and find them pretty damn good, i quiver everytime i drive one with a standard turbo now cos they are so damn gutless. I think a good boost controller is a key to getting them up on boost faster and more responsively, which i still need to do.

Sydneykid, i agree with what you are saying about the peak power and power below the line theory, and if i wanted huge power i would more than likely use a RB30 or 26 set up rather than the 20, but i have two complete RB20's sitting there, and want to try the 2.2 setup. And yeah your right i wouldnt bother racing a 33 or anything with a 25 or bigger with equivilant power down the strip, race tracks seem to be better for them when the launch isnt required.

[Lithium]

Whale defending? What for? Sorry the GTS-t you mentiond, low 12's i was told by a flatmate it was high elevens, and are you saying a whale would do a low 12 not on slicks? The fact is it was still making 300rwkw on standard internals and he (according to you) just used the nos to spool the turbo but the top end was there from the motor rather than nos. Are you aware of actually how much mods that 33 i raced at the drags had? Considering at the time how much i had spent on my car, it wasnt a very big difference considering you told me yourself you could hardly tell who won...

All I was doing there was setting the facts straigtht - the only R33 you have officially raced you got beaten by, and the R34 did an ok job considering how few mods it had relative to you given it won the first race - you both had the poor traction disadvantage to contend with. The difference in mods thing (in favour of the R33) is part of my point, you said yours is faster than most of the 33s around - all of those are a lot more stock than yours, and yours is also quicker than the equivalent r32s.... it was a pointless comment.

Also, the GTSt that ran low 12s - you said in your post low 11s (so even if you were told high 11s, you were twisting facts), and ask him yourself why he was using the NOS - and he was using NOS all the way from what I remember him saying. Ask him yourself, he posts as Trust Dunn on Skyline forums.

I didn't realise you already had a RB25DET crank - if you do, then I the 2.2 idea sounds very cool.... if you don't (the only RB25 cranks I know of at your place belong to Mark and Jeff)... I'd considering the RB26 crank, as you dislike Rb25s so much - and given the amount of work you'd have to do etc, a 2.4 would be a lot more rewarding. You can borrow my HPI mag on their build up ideas of an RB24DET (rb20det based) - basically in concept the RB24 would be at least as torquey as an RB25, and still be based on the RB20DET block- so you get your cake and eat it too

[Sydneykid]

Sydneykid, i agree with what you are saying about the peak power and power below the line theory, and if i wanted huge power i would more than likely use a RB30 or 26 set up rather than the 20, but i have two complete RB20's sitting there, and want to try the 2.2 setup. And yeah your right i wouldnt bother racing a 33 or anything with a 25 or bigger with equivilant power down the strip, race tracks seem to be better for them when the launch isnt required.

The last sentence almost covered it, I have personal experience with an R32 GTST with a 225 rwkw RB20DET and then a 225 rwkw RB30DET. I can tell you the RB20 was very hard to get off the line consistently. It was wheelspin or bog down and they were separated by 1 poofteenth of throttle. If I got blocked by another car, it was davasting on the lap times. Drive (power on/off) through corners was very tricky with other cars around. On the other hand the RB30 was so easy, you could roll on and off the throttle and it would make diddly squat difference. Give it a squezze and away it went.

So it has nothing to do with "huge power", even at the same max power there is a world of difference. Like you, I have all the bits, but I haven't done it for that reason.

[R32 GT]

The last sentence almost covered it,  I have personal experience with an R32 GTST with a 225 rwkw RB20DET and then a 225 rwkw RB30DET.  I can tell you the RB20 was very hard to get off the line consistently.  It was wheelspin or bog down and they were separated by 1 poofteenth of throttle.  If I got blocked by another car, it was davasting on the lap times.  Drive (power on/off) through corners was very tricky with other cars around.  On the other hand the RB30 was so easy, you could roll on and off the throttle and it would make diddly squat difference.  Give it a squezze and away it went.

So it has nothing to do with "huge power", even at the same max power there is a world of difference.  Like you, I have all the bits, but I haven't done it for that reason.

Yeap i agree, but for what i personally want out of the car, it suits me fine- Its more than competitive when i race it at track/ drags, and to be honest its nice to be able to have a fast and competitive 32t, as 99% of them are not- Mine managed 2nd overall at the wellington Jamboree in the 2wd turbo class, and at the track its normally right up there, and passed its fair share or Exhaust intake and boost GTR's just cos its light..

But as im not a professional race driver, which your probably closer to than myself and i just have it as a hobby and the love of going fast, which it does quite nicely, it suits me fine. Im not after specific times at the drags, or aiming to beat certain cars i just want something fun that will keep me happy, esp as soon ill probably be driving police cars all day and will want something to lookforward to after a V6 commonwhore or falcon.

Does anyone know if the tomei kit is all compatible with the original rods/ crank? I assume it is, but just want to be sure~

[browny]

From http://www.tomei-p.co.jp

All the piston kit includes piston ring, piston pin, and circlip.  

 

NISSAN RB20DET Forged piston kit    

 

 

Mode   Bore   Part No.          Displacement  

RB22   82.0   1111820112   2207cc 　  

RB24   82.0   1112820112   2334cc    

 

*When using RB24 piston, installation of RB26 crank and con-rod, and engine block modification for escape must have done.

Also....

http://www.tomei-p.co.jp/_2003web-catalogu...36_rb20det.html

[V8eta]

Just out of interest, do the tomei rb24 pistons also work with rb25 crank and rods?

[Sydneykid]

Just out of interest, do the tomei rb24 pistons also work with rb25 crank and rods?

Different part number, due to different gudgeon pin heights in the pistons.

[V8eta]

Ah k, any idea what pistons will fit ie the 2.2 ones or will i have to get customs? Thanks for the help cause there really isnt much info out there on this.

[Sydneykid]

Ah k, any idea what pistons will fit ie the 2.2 ones or will i have to get customs? Thanks for the help cause there really isnt much info out there on this.

Sorry, I don't understand the question?

[Drift-King]

Everyone knows a Rb25 is better then a Rb20, why argue about it ? let the poor guy do what he wants to do and leave him alone.

[R32 GT]

Everyone knows a Rb25 is better then a Rb20, why argue about it ? let the poor guy do what he wants to do and leave him alone.

WTF? read the topic, its refering to a 2.2 build up, so what if you think the RB25 is better? Thats not what the topic is about, not everybody owns a RB25 and considering how much longer we have had skylines there is alot more RB20's and parts around for them, why say such a stupid thing?

[Lithium]

Settle Gretal, he was sticking up for you from the people changing the topic to a vs. conversation.

Worded differently - "All he wants to know is who has done a RB22DET, or how is a good way to go about- because that is what he wants to do".

[browny]

Could someone post up some guesstimates of what a 2.2 and 2.4 bottom end build would cost?

[Roy]

Price using what? 2.2L with std/aftermarket RB20 rods? Std or aftermarket bearings, rod/head bolts, head work in addition to enlarging combustion chamber to suit the new bore (since while the head is off you may as well) etc etc...

Same goes for using the RB26 crank and rods for the RB24... where it is marginally more pricey due to additional machining.

The price can be as cheap as you like, or as expensive as you like....the number i came up with for an RB24 was about $6,500-$7,000 that included thigs like GTR oil/water pumps etc etc and headwork, as the Rb22/24 bottom end cant be bolted back to the std head if you have a 3-4.5mm overbore.

[browny]

What was the rough break-up of the $6,500-7,000

[Roy]

Going from memory, as the numbers are all on my PC in Sydney. (Im in Melb at the moment)

RB20 Block

Bore & Hone block_________________ $140.00

Crank Grind ______________________$140.00

Full balance, rods, crank_____________$100.00

Balance and shot peen rods (set)_____$150.00

ACL bearing _____________________ $200.00

Head rebuild, hydraulic tappets_______ $250.00

Basic Port________________________$500.00

Arias Pistons_____________________$1,600.00

VRS Gasket kit ____________________$250.00

ARP Rod Bolts ____________________ $480.00

So there is approx $3800.

Now you have to buy a set of GTR Rods _$350

Also a GTR crank____________________$400

gtr (Nismo) Water & Oil pumps_________$800

Cams_____________________________$800 (if you go solid lifters then more again, as the head rebuild pricve is higher)

Then there are things like timing belt, perhaps new idler bearings etc etc.

These number are approx, but fairly indicateive of what it would cost. Then you have the whole, should i shot peen/linish and buy new bolts for 2nd hand rods, or spend that little bit extra and get aftermaket rods.... what the point of having 2.4L bottom end and headwork if you dont throw in some cams,

There are savings in the above, and with those savings i would use aftermarket rods, convert the head to solid lifters and put in some bigger cams...but thats me.

I think the thing would rev harder then an RB26, as it will have stronger rods, and smaller (ie lighter) pistons. If you can t make power with cubes then use revs..

Not saying htis is the ultimate or besrt approach, just sharing some numbers/thoughts

[Col-GTSX]

???

Spent a few minutes reading all that has been written... I agree with most but have to point out one thing. It was mentions that they found the rb20 lagger when putting on a r33 turbo. Well i found the exact oppisite, when i put mine on and cranked 18psi under controlled conditions (odviouslly the car was capable of 18psi) i had a smile from ear to ear. The injectors worked way too hard tho and needed upgrading and the ecu had a bit of a hard time too. The only mistake i made was getting too ****y and cranking the boost up and up and up to see how high she really goes.... (BOOM). Now i run 4psi... While my new motor is running in. Have done 7000km now so im ready to crank back to a reasonable 12psi or so.

Also what sort of motor will you get for 300 bucks.....???

Here a head thats been sitting round for years is worth 300....

A good whole motor is over 1200 bucks