Few Questions About An Rb20 Powered S13

[osiris23]

Hey guys. Im currently selling my R33 as i need to get a 4 door car for work. On the side i am going to probably start an S13 with an RB20det in it. I used to own a 180 with an RB20 and loved it want to do another. I want to do it my self though so just getting a little info before i start.

Ive been told they are basically a bolt in conversion just swap the cross member and basically everything bolts up. How true is this and i was also told to get an Auto one as the tranny tunnel is larger.

will i need to use different a different drive shaft or diff or modify anything on that end of it. I was told the CA18 diff has good ratios for the RB?

When i had my RB 180 i blew the motor (due to detonation ) and replaced with a 4wd cefiro motor. as i can remember i had to change the sump and that was basically it. If i use a GTS4 halfcut is the cross member going to be different and is it only the sump i have to change as i have a GTST sump already anyway.

Any troubles i will run into that i should know about or anything that needs to be customised/modified or is it basically a straight forward conversion.

My 180 was pretty heavily worked as well so how is it going to go as a basically stock RB20 for a while running stock ECU etc?

Please if you have done the conversion or know about the conversion please tell me everything you can as i want to be prepared for anything before i start.

Thank you

Edited April 26, 2006 by osiris23

[osiris23]

Anyone?

[rb26s13]

doesnt matter which one you buy.. if your only goin to be putting a rb20 gearbox into how ever if your goin a rb25 gearbox be better to buy a auto silvia are 'suppose' to be bigger how ever i havent been able to notice a difference in size between the manual tunnel and auto tunnel side by side seeing as my so called auto tunnel still needed a big of modifyn to fit the rb25 gearbox

just simply buy a r32 gtst front cut the cross member between gts4 and gtst would be different due to 4wd setup and wat not

its not an overly hard conversion to do buy yourself how ever find someone who knows the wiring for these cars as ive run into a problem with wat i would call a underskilled workshop i guess you could say

my old rb20 ran just a stock computer and all i had was a custom 3inch turbo back exhaust along with a rb25 turbo (series 1 r33) and it went quite well for a year or so untill i blew a headgasket(i think thats wat went wrong i just pulled it out and stuck it in a corner)

[osiris23]

doesnt matter which one you buy.. if your only goin to be putting a rb20 gearbox into how ever if your goin a rb25 gearbox be better to buy a auto silvia are 'suppose' to be bigger how ever i havent been able to notice a difference in size between the manual tunnel and auto tunnel side by side seeing as my so called auto tunnel still needed a big of modifyn to fit the rb25 gearbox

just simply buy a r32 gtst front cut the cross member between gts4 and gtst would be different due to 4wd setup and wat not

its not an overly hard conversion to do buy yourself how ever find someone who knows the wiring for these cars as ive run into a problem with wat i would call a underskilled workshop i guess you could say

my old rb20 ran just a stock computer and all i had was a custom 3inch turbo back exhaust along with a rb25 turbo (series 1 r33) and it went quite well for a year or so untill i blew a headgasket(i think thats wat went wrong i just pulled it out and stuck it in a corner)

Thanks mate. Yer just all on the drawing boards at the moment. The reason i am leaning more towards a 20 is obviosuly the price. i have priced some RB20 cuts for about $2500 and in the 25s couldnt find much under the 4 grand mark. Would love a 26 powered s13 but then again alot more money and im sure it would be alot more work.

The wiring isnt a hassel as my mate is a auto elect and would do it for a case of piss. He is good at wiring up cars and just finished our mates VR wagon powered by an RB20det

Reason also for an RB20 is i used to own a 180 with an RB and ive got a few parts at home for them like a metal head gasket and a complete bottoms end bored out etc.

Anyone else got any imput?

Do i have to do a custom tail shaft as i was reading the mods of a RB180 and it had a custom 1 piece tail shaft and i remember my 180 had a custom tailshaft as well.

Anything else i would have to watch out for? or any recomendations?

ALSO just one more quick thing i had been considering an RB30DET in an S13. How would that mount in there or would it be alot more messing around again. obviosuly the whole rebuild etc and finding a DOHC head etc but could be interesting at the same time.

[neil_se]

-You just use a tailshaft from a manual ca or sr s13, it's the right length for the rb20 manual gearbox.

-Slot the mounts if you want the engine to sit lower, especially if its going in a 180sx.

-Front swaybar needs to be spaced about 1cm down or use a whiteline swaybar that is extended forwards.

-The rear of the power steering pump needs to be modded if its going in a non-hicas s13.

-Use the rb20 radiator and twin thermos.

-Only a few wires need modifying, its the ones on the loom near the airbox.

-Use the rb20 air con lines.

[DRFT 14]

You will need a 6cyl engine crossmember (I used A31) - Engine mounts do not need to be changed (RB20).

Gearbox crossmember is a perfect fit (unlike 25t Gbox).

As mentioned above use RB20DET Radiator and to electric fans

I used an R32 driveshaft and got it modified into a one piece as per leangth from GB yoke to Diff

Its a pretty streight forward conversion indeed. I did however face an over heating problem at the drag strip. It would overheat by the end of the strip each time, but didnt do this during street driving (even though i got the radiator cleaned before installation). Perhaps dont go with a 100mm thinck IC like I did and avoid the crossover IC piping configuration?

Apart from that go for gold

[osiris23]

Cool thanks for your help guys. Need to sell my R33 b4 i can start anything but the plans are getting more together now

My mate has an RB20 onevia and had a big think aluminium radiator, thermos, and then the cooler is vertical fins with the inlet and outlet on the same side. Strange set up but i guess its better

[neil_se]

A few other things

-the speed sensor will need to be machined down to fit into the rb20 gearbox

-i used the original power steering lines but i hear the rb20 ones will fit better

-you need to swap the tacho mechanism from the s13 to r32 one to get the tacho working

-r32 dump/front pipes tend to hang very low for an s13 so i had them modified shorter

-its not a bad idea to fit the r32 brake master and slave.

I did 27 quarter mile runs in the middle of a very hot day with no overheating problems, but many people do get overheating on idle.

[osiris23]

cool sounds good ill print off all this stuff and give it to my mate who will be helping me do the conversion and wiring it up for me.

Cheers guys thanks for your help.

[osiris23]

just out of curiosity how hard is an RB26 conversion in an S13. im sure it would be alot of work?

[carl h]

for rb swaps into s chassis cars may i sudgest a few websites?

www.racebread.com <-- nothinb but rb related swaps into s chassis cars

www.nicoclub.com <-- dedicated rb engine section, covers most stuff you need for a swap.

www.240sxforums.com <-- again another forum with a rb section, good faq.

[MK2]

I'm passingly familiar with someone that managed to squeeze an 2.7stroked Tomei RB into an S13 chassis and its not mucking around.

http://forum.silviansw.com/viewtopic.php?t=21253

It would be very amusing to own thats for sure.

Apart from that, just curious as to why the RB20?

The SR20 is usually the weapon of choice from most ex-CA18 owners that want to upgrade to something thats got some nuts and more bits and pieces than is probably sensible for getting power out of them. Just tends to make them a bit nose heavy with the 6cyl engines in them and throws off the nice balence they have

[osiris23]

well im wanting to build up a street registered track drift car. ive always wanted to get into drifting but the cars which i have owned are always my dailys and my last 2 haveing customs paint jobs and kits etc never even wanted to take it drifting at all incase i stuffed something up.

Which is why im buying a 4 door daily for a new job and on the side im going to build up a S13 (probably make a onevia).

Reason for choosing the RB motor is i used to own a RB20 powered 180SX. Loved the car and i want to build another with the same kind of power. I have never owned an SR but 2 of my mates have S14s and i just like the feeling of the RBs better. Guess its the torque i dont know.

About the front end weight problem i have read it is only about 60-70KG more or so and just read on the NICO forums 95% of people wouldnt even notice a change in the handeling after the conversion. Also read some where with the right coilover set up it can compinsate.

Thanks heaps for those links as well Carl there is some good info on there.

[MK2]

The S14's are a little bit heavier and have (IMO) a bit better suspension setup to start with so they are a very different car on the road. Guess theres lots of alternatives really if youre keen on dropping an engine in, might even be worth saving up the money for an RB25 half cut I guess if you want the extra torque and think it can be ironed out with suspension but it might be worth doing some more research.

Red tops are a decent SR20DET though for the price and I guess the easiest thing about them is the loom and ECU pretty much drops in, but if you've had some experience with getting a transplanted RB20 into an S13 and making it work then thats what you know (and I cant tell you what you like!)

[osiris23]

i havent dont the conversion or seen the conversion done my self i bought my 180 with the rb already in the car. my mate how ever has helped someone do the conversion so i shall be getting his help if i di end up going through with it. having thoughts now about just keeping my R33 for awhile longer. Got to sort out what i want to do haha.

Thanks heaps for your help everyone