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RB20DET Temptation
Posted: Sat Oct 18, 2008 5:30 pm
by Pinkfluffybunnys
Howzit Guys...
Look at this sweat deal (at least I think it sweet). I have come across and tell me what you think and what could be missing , I'm tempted I wont lie.
RB20DET (import Motor,not sure of condition) - R 5000
RB20DET ECU - R1600
RB20DET Wiring Harness - Uncut complete and I mean Complete - R3500
R32 RB20DET Engine Crossmember and Gearbox mount- R 2200
Nistune - R 2600
Total 15600
OK I know this works out to R15600 very expensive but this should be a straight drop in except for the drive shaft and I'm sure the CA18DET gearbox does fit (might be wrong here)
I need the nistune to get my 300ZX airflow meter to work.
its a pipe dream but I thought I would share, I mean I spent almost R13000 on my CA Rebuild but it was a complete forged rebuild
I also Looked into refreshing the RB20DET before it goes in:
(Tell me if I missed anything)
Nissan RB N1 Water Pump - R2000 (imported)
Nissan RB OEM Timing Belt - R800
Upgraded RB Crank Collar - R1000 (A Must for any older RB)
Nissan RB N1 Oil Pump - R2700 (Imported)
Nismo RB Thermostat - R800
Total - R 7300
Then I looked at rebuilding the RB20DET.
Doesn't include engineering ....
Nissan RB N1 Water Pump - R2000 (imported)
Nissan RB OEM Timing Belt - R800
Upgraded RB Crank Collar - R1000 (A Must for any older RB)
Nissan RB N1 Oil Pump - R2700 (Imported)
Nissan RB20DET OEM Gasket Kit - R2700 (imported)
Turbo recon - R2000 (local)
ARP RB20 Rod Bolt Kit - R900
ARP RB20 / RB25 Head Stud Kit - R1700
Piston Rings - R???
Nismo RB Thermostat - R800
Big-ends - R??
Total R 14800
Also I will have the injectors ultrasonically cleaned at work and everything will be nicely painted and prepped.
I will carry some stuff over from my CA18DET like the FMIC after a piping change the electric fans ,nismo FPR and walbro along with the wideband and stuff
LOL LOL well we can dream cant we

Posted: Sat Oct 18, 2008 6:18 pm
by Pinkfluffybunnys
The I looked at modifying the RB20DET
RB25 RB20 Nissan Skyline Super Combo Turbo Manifold Set
R 2300
NEW INTAKE MANIFOLD NISSAN RB20DET
R 7100
Abit expensive might have one made local does the RB26DETT intake fit on the RB20DET ?
Cometic Head Gasket Nissan RB20DET
R2000
Q45 Throttal body - R 800
So all in all the modifications will be 80mm exhaust, Oil Cooler, FMIC, Q45 TB (90mm),Tubular manifold, Down-pipe,Nistune, 300ZX MAF, Nismo FPR, Walbro, Stock Turbo and possible intake...
Not sure what the power out-put will be on such a combination .
Posted: Sat Oct 18, 2008 6:54 pm
by Doctor G
PFB I've also been looking at the rb20det lately.
People say it makes similar power to a SR20DET, but has extra bulk of a 6-cylinder. And extracting the same power will cost more on the rb20 than the sr20, due to parts availability. So for the difficulty of the swap, most ppl advise to get a rb25 which is the same size.
Now, I've looked at your list, and most of the stuff is a bit pricey for my liking.
The oil and water pump, gaskets etc, can all be had MUCH MUCH cheaper. I have the link at work, will post it on Monday.
Another downside is that the RB20det comes with a weaksauce ceramic wheel T28. and most ppl switch to a Garrett of HKS t2835.
Lastly, the CA gearbox is the same, but you will need a RB20 or RB30 bellhousing from a skyline sgli. And the gearlever will be about 1 inch out of std alignment.
What power is your CA18 build making?
Posted: Sat Oct 18, 2008 7:54 pm
by Pinkfluffybunnys
I added a lot of extra over head on all the stuff because things don't work out as peachy as we hope for.
Did a lot of reading on the RB20DET and RB25DET and as much as I would like one it would be stupid for me earning what I earn to switch over to anyone of these motors.
I see it all to often, people plan these swaps save for them then and do them only to sell a few months on or halfway through with saying things like "I got tired of the car" or 'I got bored' or something when the truth is they have ether cut corners and are now paying the price or they cant afford to complete the swap or cant afford the up keep on them including the new gearbox's,failures and so on
It's a pipe dream I never take myself to seriously just thought I would post up on an offer I had today on a RB20DET that got me thinking.
Im sure it could be used as a reality check for anyone on the fourm that might be interested in doing anything like this.
Strangle reading all the things on NiCO the RB25DET has been found not to be as powerful as claimed except the Neo but the RB20DET also seem to last longer then most RB25DET swaps and are a lot cheaper but they are older and will almost always need a rebuilt which it the right way to swap anyway also the crank collar seems to be a must fix thing.
As for the SR thing comparing to the RB20DET everything I have read tells me the same thing , But I'm sure I could match the power with my CA18 it would be more like swapping for the straight six sound and easily being able to swap over to a RB25 with a few changes, I guess its kind of pointless like swapping a CA18DET for an SR20 for the extra 189cc not poking fun at anyone or being rude or asking for flaming (even though I'm going to get it) I just don't see the point but I think this is going in the wrong direction and this is just my point of view
Posted: Sat Oct 18, 2008 7:57 pm
by Sokar
I agree with everything in this except the RB20DET itself.
If you were just going to drop it in with its stock ECU and had no way of tuning it except the normal stuff then a RB20 will be fine, its a good upgrade and is more special than a SR swap, but since you are thinking of a nistune with it, why not get an RB25? a refresh will cost you exactly the same, just the motor cost will be more. You will also kick yourself if you pour money into a RB20 and some guy in a stock RB25 kicks your ass, and the motor just cost him R3000 more.
You will be able to tune for the extra dicplacement no probs, you can keep the CA gearbox for a while as you have a spare, once you start chomping gearboxes look at a RB fatboy.
Posted: Sun Oct 19, 2008 11:22 am
by jon

What happened to your CA loyalty?
Posted: Sun Oct 19, 2008 11:29 am
by mario_200sx
I see it all to often, people plan these swaps save for them then and do them only to sell a few months on or halfway through with saying things like "I got tired of the car" or 'I got bored' or something when the truth is they have ether cut corners and are now paying the price or they cant afford to complete the swap or cant afford the up keep on them including the new gearbox's,failures and so on
SO true what you said there! I was also biting nails about this swap! But at the end I decided to do it the right way or not do it at all!
This swap is not the cheapest of the lot, but I saved some money over the past 5 years and decided to treat myself! I would have loved for a RB25 but that was way out of my reach financially (if I had to do it the right way)!
So I stuck with the sr20 cause I love these motors! Dont get me wrong, I think the CA18 is a monster of a motor! However the SR20 is just a easier route of moding than the CA18!
Hats of to Gary and you for producing great figures with the CA18! It shows the potencial of these motors!
Posted: Sun Oct 19, 2008 2:56 pm
by Pinkfluffybunnys
What happened to your CA loyalty?

I still have it but I guess I just posted what I'm thinking we all have these thoughts at some point when owning a S-13 (someone had to say it)
But then reality kicks in and it sounds so simple and cheap to swap in a RB\SR series motor until you start adding the costs and modifications together then things don't look so peachy after all
Somtimes the costs of the swap outweigh any performance gain because if the same money was thrown at the current motor possibly equal performance and reliability could be achieved we get caught-up in the knowledge that motor we are swapping will benefit more from the performance parts we fit to it and the bragging rights down the line but forget about the initial costs and turmoil of the swap to begin with and normally more often then not we cant afford to modify the swap engine because we are still paying off the underlying expenses from the initial swap and the car doesn't preform as well as we had hoped or where told to believe
I mean take a RB25DET\RB20DET swap, I have gone over build after build on the Nico forums and other RB Sites is stock form the Motor is not a great performer most 1/4 mile time are in the low 15 seconds, High 14 second brackets times easily achievable by the CA18DET or Sr20DET power S14\s14 in the states with a few modification but once you start moding the RB motors then there power potential really starts to show but to get to this point you have already spent an estimated\guesstimated R 20000 if this was thrown into you CA18DET or SR20DET from the start you would have a full forged bottom end and a lot of nice goodies with the correct tune you could see off a lot of cars on the road ask MYPRODOL
Posted: Sun Oct 19, 2008 5:38 pm
by RB25SX
I can talk with experience: Std. RB25DET (Paid R8000 without g-box)
+ Topmount manifold
+ T61 Turbo
+ 50mm Ext wastegate
+ Walbro pump ( std injectors)
+ Big intercooler
262 kw
425nm @ 1.1 bar
In a big R33 Skyline body, I did 13.01 qaurtermile with semi slicks. 13.5 on normal road tyres.
Feels a lot stronger than SR20 with 240kw in a my SX. Was also less expensive than SR20 build.
Posted: Sun Oct 19, 2008 6:52 pm
by Pinkfluffybunnys
RB25SX do you mind posting up the costs of you complete build or just a guesstimation ?
It would go a long way to establish costs..
Also I'm sure you running a management system of sorts an Exhaust and all the small things like filter,intake or porting we forget to mention sometimes not being rude even I forget the mod's I have done when people ask me also are you running the stock CA18DET gearbox with a different bell-housing?
Posted: Mon Oct 20, 2008 9:06 am
by RB25SX
RB25DET - R8000
T61 Turbo - R4500
Topmount manifold - R2500
50mm Ext wastegate - R1200
T-BO EMS - R3500
Custom made intercooler - R1000 (had the core 2x rotary intercoolers)
Walbro pump - R1200
Even used the std BOV from RB25.
adds up to about R22000, add R3000 for int cooler pipes and exhaust: Total about R25000.
Normal pump feul with octane booster.

Changed the inlet manifold for easier piping. Cost about R300.

Posted: Mon Oct 20, 2008 10:44 am
by Pinkfluffybunnys
NO Rebuild or even Refresh on the RB25?
Thats Brave
Also you didnt list the costs for the modification or installation of your, Cross member,Gearbox mount, Drive shaft, Wiring and Tuning was this all done in house by you ?
Also what about the gearbox are you running a fatboy like sokar said or the CA18DET ?
Posted: Mon Oct 20, 2008 3:12 pm
by RB25SX
Straight fit in Skyline,use small box. Will repace gearbox if it breaks with big one. No problems up to now. Most import engines dont need a rebuild, only rebuild it if there is a problem, or if it breaks. I will replace RB25 sub with RB30 in the future. I do all the work myself, exept for tuning, dont have a dyno.
As for fitting RB engines into SX body, it does not cost a lot, just takes a bit of time to line everything up, and build new mounting brackets. Cost is maybe R500 for materials if you do the job yourself.(Skyline crossmember is straight fit) If you use small box, u dont even have to change the propshaft. Most people using High kw SR20's use the small box, so I dont think its a problem under 300kw. As for the crank oil collar, only nessesary if you plan on big rpm, over 7500 like on RB26 that can rev up to 9000. RB25 conversions are getting more popular because the engines are more freely available and not to expensive. I would not go RB20 if you go to all the trouble of fitting a big heavy engine.
Posted: Mon Oct 20, 2008 4:20 pm
by Gary57
Is it possible to retain the Aircon??
What are the specs on the stock RB25 turbo, what power is it capable of??
Do you have to go with a top mount or will the motor still fit with the stock manifold??
Now is there any major advantage to going RB26 instead of RB25, I would keep the twin turbo set up if I went RB26??
Posted: Mon Oct 20, 2008 4:46 pm
by RB25SX
RB26 will cost no less than R25000 if you can find one, and std they are about 220kw. Need to spend money on turbo's to make more power. I have one, will see if it is worth the extra money once its running.
To get back to the crank collar, I want to have some collars made, if anyone is interested let me know, will be cheaper than R1000 for the imported ones.