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RB25DET 280ZX


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January I purchased my '79 280ZX for 700 bucks shortly after getting it home we pulled the L28 out and started thinking of engine choices.

 

post-16512-089678600 1304208401_thumb.jpg

 

After many ideas were thrown around I decided I would go with the RB25DET and so the money pit begins. A loan and ebay visit later the motor was sitting at my house.

 

post-16512-055225700 1304208506_thumb.jpg

 

The loan covered engine purchase, oil pan, greddy style intake, and engine mount kit from mckinney motor sports. Now to switch gears a bit, with limited adjustable suspension choices for the S130 as well as brakes to handle stopping the RB, I decided to do something different and swap subframes from a S30 chassis. Surprisingly there isnt much difference between the subframe areas of the S130 and the S30, after a visit to the junk yard I had the subframes from a 240Z. Here is a picture of the front.

 

post-16512-023431200 1304209382_thumb.jpg

 

To further explain the need for the swap, I went to ArizonaZcar.com and saw that they had a fully adjustable control arms, shock/spring assemblies and the brakes I was looking for. My over all goal is to build a RB powered S130 that goes around corners. The rear A arm set up for the S30 will have to be partially fabbed to make it work and after a few measurements I believe that this swap will work very well. The front subframe initial fit went well the mount points for the subrame will have to be cut and a wider plate will be welded in to line up with the holes from the frame. I will throw front fitment pictures up tomorrow. I am open to any advice on the build over all , I will keep this thread updated every few weeks.

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Yea I had read a few of those threads previously and its not that I didnt want to use the newer set ups (Z31,Z32,S13) refering to the struts ect, but I wanted to get away from the stock trailing arm and go to a normal lower A arm which the S30 has.

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I want to mainly circuit track the car at least thats the over all goal. With the trailing arm design the car will/may not handle properly under acceleration out of turns as in the rear will squat to far changing camber and throw the chassis off balance. I had read a few places that the S30 rear set up was better than the trailing arm, granted I havent seen a S130 with an RB go around a circuit track so all I have to go off of is what I have read and the S30s I see at our local track super laps every month. I also want to try something different that sets my car outside the norm for S130 builds. The arizonazcar control arms would give me full adjustability on the control arm side allowing me to have full control of how the car handles. I understand that the control arm isnt the only factor in how the car handles and the AZC kit that I am looking at covers the other parts of the equation.

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Dude i love your goals .. BUT:

 

You dont need a mckinney motor sports mounts, a rb25 bolts into a s130 with just the motor mounts of a r31 skyline ( look on ebay australia for those) Then the stock RB gearbox even bolt into the oem mount in the back ....

With the fabwork needed to make the front full adjustable, you can also buy the Techno toy tuning adjustble tension rods and make your on heim joints on your a amrs.

What you really want for handling is more caster than the stock set up gives you anyway!

 

 

Next point WHY in the world use the rear arms of a s30 it doenst handle any better .. the whole trailingarm bs is a myth.. the Bob sharp cars show why. if that doenst convince you! look at the BMW e30 m3.

Like you state in your post; "had read a few places that the S30 rear set up was better than the trailing arm" Have you experianced it ? and are you good enough of a driver to notice it ?

I think you are taking a complete wrong set of choises and you should read, and understand handling more before you start swapping. As like this you will have your ass handed to you by well sorted ZX in a blink of the eye!

 

However if you really hate the trailing arms with a passion, go s13 or s14 if you want a real upgrade! Plus you get wider better part availability.

 

Same goes for Brakes for the s130.. there is so much available that is fairly bolt on, and an s13 coil over kit fits with very little fab work!

Edited by frank280zx
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I'd listen to him, Frank280zx saved me a fair bit of fab work on another guys car. The R31 mounts are like $20 AUD and then the rubber mounts can come from nissan if they are cracked and need replacing :> and on the rear to me a S13 rear makes so much sense both financially and modification wise.

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You're doing the same thing I am. Except I'm going with an S13 conversion front and rear, which I should be picking up some of the pieces tomorrow. I like where you're headed. Also because I have the exact same goal for my ZX.

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Well Forcer your idea makes sence a s13 is a good multi link desing and has a huge aftermarket following when it comes to parts!

Going from a niche market car to another does not, especially since the front geometrics of a s130 are superior over an s30 from a desing point of view.

Thoug like mentioned before, they give far to little caster for serious racing... The Turbo Electramotive and Bob Sharp cars had tubular front ends with allot more caster than the stock front end gives.

 

I modified my strut towers in fashion that it gives me allot more than stock. It alterd the handling of the car in a very pleasant manner!

I dont claim to be mister know all, but i do have my share experiance with s130's as i personally love them more then a s30.

So i guess that and actively tracking and developing my s130 makes me fairly experianced with things that work on a s130 and things that do not.

 

BTW Forcer if you go s13! talk to 260DET

Edited by frank280zx
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Well Forcer your idea makes sence a s13 is a good multi link desing and has a huge aftermarket following when it comes to parts!

Going from a niche market car to another does not, especially since the front geometrics of a s130 are superior over an s30 from a desing point of view.

Thoug like mentioned before, they give far to little caster for serious racing... The Turbo Electramotive and Bob Sharp cars had tubular front ends with allot more caster than the stock front end gives.

 

I modified my strut towers in fashion that it gives me allot more than stock. It alterd the handling of the car in a very pleasant manner!

I dont claim to be mister know all, but i do have my share experiance with s130's as i personally love them more then a s30.

So i guess that and actively tracking and developing my s130 makes me fairly experianced with things that work on a s130 and things that do not.

 

BTW Forcer if you go s13! talk to 260DET

 

 

I have no doubts in your experience, I actually look at yours as an inspirational build for mine. And I fully intend to do the S13 swap. Just picked up some of the peices today to start mocking up the front. I should have a rear subframe in about a month. Once enough of work has been I'll do a build thread. I can't wait since I've had the car for 6 years and I'm just now doing anything with it.

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Thank you Frank for the input, haha actually I had been looking at the S13 rear subframe over the past week and I will be picking one up today hopefully from a salvage yard. I knew about the R31 mounts and had attempted to get a set from rawbrokerage but he was out of stock so I moved on....I have not yet purchased the mckinney set, so I will hit up the other Ebay to source a set. To be honest I had gotten tired of failed searches for the topics I had questions about and jumped to the first thing that I found that made sense which probably isnt the best thing to do. I look forward to hearing your input as I continue the build.

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I say that s13 is your best bet! You can cobnvert the front with either z31 or s13 parts. whereas i used z31 struts to keep it simple.

 

As for the mounts

 

Talk to the aussie guys here or do as we international folks need to do all the time.. Ebay...

 

http://cgi.ebay.com.au/Nissan-Skyline-R31-6cyl-engine-mount-NEW-PAIR-/350459962253?pt=AU_Car_Parts_Accessories&hash=item51990aa38d

 

http://cgi.ebay.com.au/Nissan-Skyline-R31-engine-and-trans-mount-NEW-manual-/270735101699?pt=AU_Car_Parts_Accessories&hash=item3f0911cf03

 

They state Australia only but shoot them mail and ask if they can send them.. otherwhise ask one of the guys above friendly ;)

Edited by frank280zx
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33621_10150103645904992_508404991_7590971_5356582_n.jpg

 

Thats with R31 rubber mounts (I am pretty sure the rubber bit is the same between all of the models) and R31 metal brackets approx 1 inch off the fire wall and 3-3.5 inch from block to crossmember (those numbers are from memory...) the R32/R33/R34/C33 etc are a more forward mounted engine so I believe the mounts will sit your engine about 5 inchs more forward (don't quote me on that)

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  • 2 weeks later...

Engine bay about done and ready for paint, I had it stitch welded yesterday after work it looks pretty good. I seem to have misplaced my camera cord so when I locate it there will be pictures. Currently cleaning up some rust issue, there was a bad repair on the left rocker to quarter panel area which caused water to eat some metal away. I cut out the old stuff just need to pick up some sheet metal. Thats all for now.

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  • 3 weeks later...

Alright went to the junk yard last weekend and cut out a S13 rear subframe mounting points, also got S13 front subframe control arms,spindles,shocks and brakes. Started today on cleaning up the mounting points and prepping for the swap. Did some measuring for shock placement and came up with the best option to get the S13 shock to mount to a S130 shock tower while still keeping the correct amount of travel for the suspension. More to come on the shock placement we are currently trying to get the angles correct for the shocks. Subframe install should happen within the next month or so due to money...

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Now, here's a question. Would the S14 rear subframe work better, since it's bout an inch wider than the s13? I have seen the s13 under a 260z, but our cars are a wee bit wider, and with the fender flares I personally have planned, well, y'know. Also, I've heard rumors of a 280z (not zx) with an R32 rear subframe under it, anyone can corroborate this?

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