Skyler's 1990 S13 RB20DET project

[DBL_TKE]

Hello everyone and welcome to my build thread. My name is Skyler and I just picked up a white 1990 240sx recently. I've always liked Nissan for as long as I can remember. My first car was a 1980 Datsun 280zx and I sctuslly still have that car. For the longest time I tried denying myself that I liked and wanted a 240 simply for the fact that most of the owners I've known are always complete dicks that trash their cars.

My last build/daily car was a Montana Green '92 VW GTI with a rebuilt VR6, shaved and mirror polished intake, GM coil pack conversion, 11.5:1 compression, techtonics tuning chip, ported throttle body, techtonics tuning straight piped exhaust, 02J trans, quaife LSD, FK Highsport coilovers, full MK3 k-member/rack/a-arms, Mk3 rear beam, Corrado brakes and 5 lug swap, euro mono wiper, crystal smoked low/high beam headlights/turns/fogs, 6k HID's, Hella euro tail lights, Recaro LS seats, Mercedes Ronal E320 wheels 16x8 with 205/40/16 falkens. There's a ton of other small things but you get the idea. I had that car for three years. I redid practically everything on that car because the previous owner totally hacked everything up. I loved the sound of the VR and it did a 14.3 @ 96 in the 1/4 mile. Pretty decent daily driver but I really don't like FWD cars. Doing a front wheel drive burnout reminds me of when I was a kid with one of those playing cars on the spokes of my bicycle.







After "finishing" that car and driving it for a few months I quickly got bored with it and decided that I wanted a 240sx. Searching Craigslist I finally one that I liked AND he wanted to trade me straight across. So I went ahead with it and got this 1990 S13 Nissan 240sx fastback. It has an RB20DET swap, Megan coilovers, front mount Intercooler, McKinney swap mounts, McKinney down pipe, test pipe, 3" no name catback, S14 seats and a welded diff.



The day I got it I drove it straight home and got to work on it.





There was a horrible exhaust leak so I didn't want to drive around like that. Previous owner told me it was due to a broken stud on the turbo. I quickly found that that was incorrect. The rearmost exhaust manifold stud is actually broken off and recessed into the head. I also found that whoever replaced the manifold gasket left didnt pay very good attention and left the portion of the old gasket still stuck to the head around the #6 exhaust port and installed the new metal gasket OVER that. Thus creating a horrible exhaust leak.





I'm having a hard time trying to get the stud out. I can't seem to be able to drill a pilot hole into the stud. I can apply good pressure and have good new drill bits but they won't do a thing. Very frustrating.

[DBL_TKE]

I finally was able to drill out the broken stud. I ended up having to re tap and helicoil the bolt hole. I was finally able to drive it for the first time since I got the car but I found that there is oil bubbling out from the exhaust manifold gasket for the #6 port. I'm fearing that I may have drilled too far into the head but I can see the oil coming out all around that port, not just from the bolt hole. I'm starting too think that it may be bad piston rings, bad valve guide or valve steam seals. I also noticed another thing now, When I remove the oil fill cap from the valve cover when the engine is running, it will cause the engine to die. I believe that the engine is pulling too much vacuum. Ill be double checking the PVC system and vacuum line routing but I believe it could also be caused by a bad valve.

[xblue__smokex]

awesome
however a rb26 could possibly be better...
twin turbo!

nice car tho
gl

[DBL_TKE]

Originally Posted by xblue__smokex

awesome
however a rb26 could possibly be better...
twin turbo!

nice car tho
gl

You know that's the second time someone has said that to me today, lol. If I had that kind of budget I would. But I'm going to keep this relatively simple. 3-400hp, some nice wheels, Kouki 180sx aero.

[xblue__smokex]

nice
yeah the kouki is always the best even on 240
cool
lower and racing seats too

[soundboy]

Rb20 is a nice engine. Keep it

Sent from my GT-P3110 using Tapatalk 4

[DBL_TKE]

Originally Posted by xblue__smokex

nice
yeah the kouki is always the best even on 240
cool
lower and racing seats too

It may be deceiving buts its already lower than my GTI was, about 1.5" to the frame rails. Recaro's will be in the future.

Originally Posted by soundboy

Rb20 is a nice engine. Keep it

Sent from my GT-P3110 using Tapatalk 4

I plan on it. I may just get a high flowed stock turbo, injectors, and a tune and call it a day... on second thought, that'll probably last about a month at most. I'd want no less than low 12's out of this car.

[BenRice]

Dont know how much you know about RB engines and they seem rare over there, but in NZ we have a facination with them and put a lot of development into them.

Highest outputs were around the 280-300rwkw mark for RB20's before people start shelving them for 25's, 26's or 30's (RB30E block with either RB25 or RB26 head). The 30's are torque monsters, pumping 300rwkw on as little as 10psi with a GT35/40, with most of our Pro drift competitors pushing around the 400-550rwkw out of them. I dont think any needed to be opened all season.

The standard turbo on your RB20 will have ceramic wheels, meaning any boost over ~13psi for an extended period of time will make the exhaust wheel spin off and spit out the back. A good upgrade are the VG30DET turbos as they have bigger housing, bolt onto your manifold, are steel wheeled and can be highflowed to the numbers you want.

I'm running an RB25 in the same chassis (check my build thread if you want). I can tell you running these things low needs 10-12kg springs in the front due to the heavier 6 cylinder engine over the KA's or SR's. 8kg's seem fine for the rear.

If you ever get sick of the "outboard motor" sound of them, look up a company called Sinco Customs here in New Zealand. They make exhaust manifolds that make these things sound amazing and they come with a lifetime no-crack guarantee. Search Zac Pole on youtube, he's running one of these manifolds on his RB30 and it sounds amazing, especially the clip taken of the front wheels.

Anywho, sorry for the novel, just dont see too many RB swapped S13 chassis on here. Good luck!

[DBL_TKE]

Thanks for the info! I've been doing a ton of research on these engines lately. Anyway, there's several issues in having with the car that I'd like to get sorted out. First one I found was that the sunroof leaked badly, I adjusted that and hopefully I won't be getting another shower in the car.

Second, the engine cuts out from time to time. Feels like a complete lose of spark for about a second then piicks back up again.

Another is that the other day when the engine was still cold it would not let me give much throttle once it would build boost. It felt very similar to a rev limiter that retards timing, however if I backed back down to say a quarter throttle it would continue to climb through the upper RPM's. this also felt like a spark issue.

Lastly, the engine doesn't generally just fire right up, it kind of sputters to life. It may be possible that all three of these are related. I still need to research how spark and ignition are run on this engine.

[DBL_TKE]

What's up with that extra wire?

[Yellow4g63]

looks like a ground to me.

[DBL_TKE]

I've gathered that much but obviously its been added on and its coming out of the harness. Is this something that's common with RB swaps?

[Yellow4g63]

Originally Posted by DBL_TKE

I've gathered that much but obviously its been added on and its coming out of the harness. Is this something that's common with RB swaps?

Its a factory ground.