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Danzi754

180sx engine conversion

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Within the next few years I'm going to be doing an engine conversion on my 180sx. Currently it's running a silver top sr20 n/a. I'm going to either swap in a turboed sr (blacktop topnotch version) or a rb26det (single turbo conversion)

 

The goal for the car is to be a daily but semi show car. I'm not looking for massive amounts of power but I will be rebuilding the engine, forged internals, cams, etc etc.

 

The at I assume will be easy, out with the old in with the new basically. And the rb will take more work, R32 front front end, ecu, wiring, tail shaft, gearbox, sump, brakes, and a few other things. Has anyone done a rb26 in a 180 in this forum that's can help out with pros vs cons and questions about it?

I'd like the car to be clean have a working aircon, reliable, and handle like its on rails. Cheers in advance

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There is only 1 pro and con.... Money.

 

If you can afford to, do it.

 

If not go SR

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A lot of people on here would suggest an RB25 Neo over an RB26. Cheaper and pretty much better overall. The pros and cons should be really obvious if you hit up the slew of build threads here and conversion guides on the net:

 

Pros

  • More displacement
  • More cylinders to spool a bigger turbo
  • More torque
  • Less lag with a modest turbo
  • Easier and safer to make 300kw+
  • Sounds better than an SR20
  • No need for a conversion bellhousing/adapter to run an RB box

Cons

  • Less space in the engine bay
  • Cooling issues due to it being so close to the radiator
  • More weight in the nose
  • Having 6x the parts instead of 4x makes the cost of everything greater
  • Coilpacks seem to crap themselves more often than SR20 units, and the oem RB ones are far more expensive than SR20 coils pound for pound
  • Belt instead of a chain, so it will have to be replaced where the other mostly won't
  • Needs $$$$ spent on a custom tail shaft
  • Have to spend $$$ on a quality radiator
  • Have to upgrade to R33 brakes due to the increase in tare weight
  • Possibly bonnet clearance issues depending on the mounts you use
  • Likely have to swap or modify the sump or oil pan to suit the crossmember/rack location
  • Needs engineering which would likely be more expensive than for a drop-in DET swap
  • Have to run an FMIC because you have zero space for a midmount or WCIC, so possibly get heat from the popo
  • Have to fart around with loom modification, cluster adaptation or a stack cluster, speedo correcters, etc
  • It's a lot of work for a car that doesn't need massive power
  • We've all seen RBs in RPS13s; they're cool and I'd take one over an SR, but it's nothing that would turn heads in a show

As for handling like it's on rails... how much are you prepared to sink into this? Clean out the Hardrace catalogue with regard to their adjustable arms (or go vulcanised rubber on the stock arms all round), LCA bushes and perhaps subframe bushes. DIY weld or install a Nismo Power Brace, change all balljoints and tie rod ends with Chinese shite, new rubber/poly swaybar bushes, MCA Blues (or something decent) with higher spring rates/valving at the front to handle the extra weight. 9" or whatever wheels with non-shite tyres in non-shite sizes, probably a corner balance due to the fact that the nose is so much heavier, and a non-silvia-republic-spec wheel alignment.

 

I didn't go down the RB path myself (started with an SR20DET), but I did do all the handling stuff. Never kept a tally of the costs but faaaaaaaark it adds up so quickly dude.

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Have had both. Rb conversion is good when done right. I have sunk big $$$$ into mine to get it right and redone things I did in the past. Cooling setup is a big thing.as pmod said Neo 25 is the way to go, Solid head with vct.

I've replaced all bushes with urethane, rose jointed adjustable camber, castor and toe arms with tein coilovers 5 & 4kg springs and whiteline sway bars. Drives great on the street.

 

If I had my time again I would have gone a vct sr20, small cams, gtx2863, e85 with all the other supporting stuff.

Spend the money on genuine parts, a quality panel beater and enjoy it.

If you go down show car route no point having lots of power and what ever your thinking of spending triple it.

Edited by robbo_rb180

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the easiet way ive seen to do it is to buy an R32 half cut. that way i can get the subframe, radiator, loom, and heaps of other gear all for about 5-10k depending on the location and condition, whereas most rb26 engines by themselves (with gearbox) are about 6k upward. most of the labour i can do myself, there will just be little things i will have to get a profession to do. i dont mind about money too much, ill be pretty set up by then but ill still try and reduce costs as much as possible without cutting corners.

 

as for the handling im going tyo do some work to improve it but not ever mod under the sun. im mostly going to pick and choose the most effective mods and work down the list till im happy.

 

This project is still a few years away but i am 100% going to turbo the car. i just love the look of the rb26, the sound the power capability and the flexibility of it as well as the idea of it being in a light car that will have the greatest power to weight while still handling beautifully. in saying that i already know roughly what im going to do with the engine setup wise.

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RB25DET NEO motors are better IMHO..

 

VCT is magical, will provide better low down torque, will allow you to spool turbos earlier (due to more torque, more torque means more exhaust flow), no need to cut and shut any sumps, more economical as it has a better combustion chamber, uses GT-R rods, uses solid lifters will happily crank out 400kW in completely stock form (of course with the appropriate bolt ons).

 

Anyone considering a stock RB26DETT over a stock RB25DET NEO should be dropped on their head LOL

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as for the handling im going tyo do some work to improve it but not ever mod under the sun. im mostly going to pick and choose the most effective mods and work down the list till im happy.

 

The chassis is 20 years old... they're all effective mods. My car was in decent condition when I bought it and yet every original control arm bush was cracked, the swaybar mounts were floppier than a donkey's balls, and the swaybar link bushes were small, rock hard and resembled an abstract art project.

 

If you want to save some cash and do the most impactful/necessary mods in the most efficient way, from my personal testing, this is the path to follow:

 

First batch (to do at once):

The reason this should be done first is because it allows you to actually get a good alignment, and if you do things right, the front alignment really doesn't change by the end of the process and the rear is a simple touchup. Having tried China arms and Hardrace, I can't rate the rubber adjustables enough, as the build quality is fantastic and there's basically no extra NVH. 100% worth the cash, don't cheap out here and go for pillowballs on a street car.

  • DIY weld bracing to your stock caster rod bracket (home powerbrace copy ftw)
  • Hardrace Rubber Caster rods
  • Hardrace Rubber Camber arms

 

Second batch:

This is by far the cheapest step, but potentially the most annoying to do, at least it was for me. Changing all the swaybar bushes fixed so many squeaks and transitional issues for me that I strongly recommend it, and the bushes are pretty cheap. The rack/shaft bushes improve steering feel a tonne, so get on that too. If the eBay rubber cylinders don't fit the oem swaybar rods, just run a drill bit through them to rough up the inside and they'll fit.

  • Urethane swaybar mount bushes
  • 8x new swaybar mount bolts that are around 25mm long iirc, as the urethane bushes don't compress enough for the thread of the oem bolts to locate
  • Rubber/urethane rack bushes
  • Alloy steering wheel spacer

 

Third batch:

Tightens the who feel of the car up, but unless you have broken bushes, the other items will make a more noticable difference. Definitely worth doing where money/time allows it.

  • Hardrace/Megan vulcanised rubber bushes for LCA/Toe/Traction
  • Fleabay china-spec balljoints
  • Cheaparse fleabay rubber swaybar link bushes
  • Pay to have the bushes and balljoints installed, unless you have a press or a better quality bench vice than me

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You need to workout you min required power goal, and then cost required parts for each enging sr/rb (rb cost would include engine swap).

 

If your not emotionally attached to your 180 sell it and buy buy a skyline.

Somthing like a R34 GTST will give you better drive ability with more torque for a given power out put with less mechaincal stress.

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Even if you get a 32 gtr front cut you can't use the crossmember, or the gearbox without cutting off the transfer case, then you need to cut the front diff off the sump....

 

So much hastle compared to a neo 25 and newer too

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