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Sam's 79 RHD 2+2 SR Swapped

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I apologize to all of you who have tried to find a build thread by me earlier.  I thought I had one going that was neglected and I guess it was on another forum.  So this is going to start off with the basic overview and then I'll add in more of the finer details that I can along the way and some eye candy.

 

 

This car was my dad's in the early 80's when he was stationed in Japan.  It stayed in the family until the late 90's when it was sold to a friend of mine who didn't drive it much.  This friend sold it to me for $850 and I drove it from his place in Oregon all the way to my home in Arkansas with no problems (minus the existing A/C charge).  At this time (fall 2006) it was a somewhat neglected original that was starting to show some age on the paint with about 100,000 km on the clock.  I was going to do a SR20 swap initially on a 2000 roadster I had but decided that the ZX would be a more fun daily driver to play with.  I may have been wrong about the fun part on that call later but it's still a blast.

 

I sold the L28, ECU and tranny to a guy from Fayettevill AR for a good price and think he put it in a 240Z of his.  The SR I got crated to my house with the tranny and about 70k km on it for $1700.  It still needed a new water pump, engine wire harness (they cut it, idiots!) ignitor, ECU and MAF.  The good news was that the engine and tranny were in great shape.  I worked over about 2 months on weekends and some week nights to get the engine and tranny in the car.  The only issue on initial start was that it would only run a few seconds before shutting down.  We found out that the MAF was not the correct one and after a good part change it has worked ever since.  The SR has had ARP head studs and rocker stoppers added.  I'm running unorthodox pulleys and no power steering since my body didn't ever have it.  I also have a lightweight flywheel and aftermarket clutch.  Otherwise the SR20 engine, turbo and tranny etc are stock.  I had a portable dyno back in the day showing just under 240 whp and 270 ft/lb.  That's before I had the exhaust redone with 3" mandrel SS and high flow CAT/muffler. 

 

This car gets me about 29-30 mpg on the highway now and is a blast to drive (3.7 gears and 255/40/17 tires, GPS verified).  I've had the swap in the car since fall 2007 and have been racing a the local SCCA course as much as I can around work since 2010.  So far only one HPDE at Hallet.  I've had no real significant issues but a handful of smaller ones.  I'll cover those as the story goes along.  I'll also try to keep this in order as I add in the details. 

 

 

I swapped out the rear diff internals with a KAAZ 1.5 way LSD for a 240sx with an open carrier.  I also purchased a set of turbo ZX flanges and CV's.

 

I installed an aluminum radiator and T-Bird electric fan.  Still working on the sticky solenoid driving the high speed fan setting, but the low is still more than enough.

 

I installed a set of Tokico HP struts/springs all around.

 

I installed a new Polyurethane bushing kit all around.

 

Installed a custom A/C line kit for the SR swap and retrofitted to R-134 (discovered that custom hoses had the high/low ports on wrong hoses w/o losing hands)

 

Purchased a set of 17x9 front Rota RBR and 17x9.5 rears.  Also purchased a set of 17x9 and a set of Hankook DOT-R slicks for racing on.

 

Replaced the stock stereo system and speakers, installed Excelon deck, Soundstream amp and Sony sub....sounds great.

 

Had a shop tint the whole car.

 

Installed a set of Corbeau racing seats on both fronts.  Modded the driver sliding bracket to sit lower and lean back more...still have to do the passenger (left) side.

 

Installed an oil cooler and had the used hose that wasn't the right size blow out when racing at Hallet.  Fixed that problem and haven't had an issue since.

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pics. of everything. I will be joining you shortly for the SR in an S130. Just picked up a running doner car for $2200. the guys dyno sheet read 300whp and a little less tq. Still need to rip it out of the car and strip the shell and get that hunk of metal out of my garage before I go through the block.

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Blue,

 

I just snapped a few pics for you and others to inspect.  I will be getting some better ones of the under side in a month or so when I pull the engine out to replace the slowly dying stock T25 turbo.  The compressor side oil seal is starting to finally leak into the intake side.  I figure I might as well finally switch to top mount, replace the head gasket, switch to solid lifters, swap cams and change out the clutch for the increased power levels expected.  If the tranny deal works out, I'll also bother to switch to a Z33 6 speed.  I'll clean up the engine bay some more with the wiring and hoses.  While it's out you'll get a better picture of what I did to the leading edge of the cross member and motor mounts.  Basically I notched back the front vertical side of the cross member about a quarter of a inch and rewelded in that front vertical surface to create more room between the front sway bar and the crossmember.  This probably wouldn't be necessary if you kept the stock oil sump.  I wanted to use the Greddy one with the extra baffling for higher lateral g's etc. but it was a little tigher of an area to work with as a front sump.  The motor mounts needed to be a little higher etc so I welded on top of the stock ZX mounts on the crossmember some additional 1/4" thick steel plates.  Next I drilled through these where I needed the mounts to sit.  It was a bit of trial and error as the first go was sitting a little too low.  The engine is sitting pretty darn close to where I want it now.  The transmission mounts I cut off the body and then rewelded farther forward on the body...almost started an interior fire in the process but I was prepared for it at least.  I also had to cut open the shifter hole on the body about two inches forward.  I'm guessing if I use the Z33 transmission the shifter will be a lot closer again to the original position as it is farther back than the SR transmission shifter.

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I started a gallery on pictures on here but it won't let me do more than 5 photos on my photo album/gallery.  Is this some kind of daily limit that I haven't read about yet or is it another setting that I need to use properly?  I swear I will eventually learn how to use this forum better for sharing media of the ZX build and projects.

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I'm going to get into one of those ideas you mentioned about an offsite photo online storage location.

 

The SR oil pan is a front sump.  If I spent a lot of time I probably could have rigged up a rear sump.  I guess another option would be to mod it into a dry sump system too but I'm sure that would be pretty expensive.  I've thought about switching out the entire front suspension from a 240sx to inclue the cross member but haven't done the homework to know if it would size up close enough to massage it in.  I'm sure they are very close but need the spec'd out measurements for both cars to have a more educated guess.

 

In the end it was to place the SR20 mid oil pan sump directly over the zx crossmember, place the front sump in front of it but squeezed just behind the sway bar.  It's tight but fits.  I was worried how much this was going to affect the balance of the car and the handling...it didn't matter from what I've seen on the track and with a set of scales.  I've read through a lot of posts about the weight differences and my guess is that the SR is overall a lot lighter than the L28.  I'm sure that helped to make it not a factor in my car for the way the handling and balance is.

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Maybe there is a way to do a dry sump set up instead...although that sounds expensive in the end too and negates part of the fun going SR.

 

My car has been getting neglected lately due to a change in job/income combined with moving & repairing rental properties and the "newsed" house.  I'm really hoping this rental property deal starts to return some of the cash that's been put into it.  Sigh.

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Just another wild thought I had after spending time under my brother's many S13's...maybe you could swap in the entire front crossmember and suspension from an S13 under your 280zx.  This would solve your issue with the oil pan sump as well as the motor mounts.  They look so very similar but I don't have measurements.

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So after doing some of the A/C work the other day, I must have shorted out one of the wires going to the ignitor chip or pulled one of the connections apart.  I'm on the way now to go trouble shoot her where she sits in a parking lot at my work.  She's getting fuel but isn't sparking it seems.  Here we go...

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Well I finally got the head rebuilt after a little drama.  I also learned a lot in the process about degree'ing cams in the process and that Tomei's lobe centerline spec is in reference backwards from TDC rather than forwards from BDC...HUGE difference.  Basically I put in solid lifters & solid style tomei 260 cam's, supertech dual springs, new stem seals, metal head gasket, mang/bronze guides, and titanium retainers.  When I clearanced the shims, I used the slotted guides on both sides of the rocker arms which required a little bit of machining on the rocker tips.  Clearancing the shims was a royal pain in the butt so I just took a long time and triple checked it.  I also had my timing cover still on and found that the chain slipped at one point before reinstalling the cams...contributing to the pain of degree'ing the cams and resetting timing.  I also did a port match on both sides of the head with my gaskets.  After cleaning up the whole affair and addressing a lot of small issues on the motor, I finally put it all back in the car and fired it up about a week ago.  I haven't driven it yet as I need to finish the transmission first and that's in progress as I write.

 

Bottom line the 350z 6 speed is officially mated to the back of the motor using the adapter plate.  I'm going to have a hybrid driveshaft made using the donor 350z slip yoke and the 280zx rear diff plate.  It measures out to 44" between transmission seal to the diff face for my 2+2 with the way I have to motor mounted in my bay.  It seems like I'm going to need at least a 3" diameter steel tube for the critical speed issues on the driveshaft at high speeds.

FWIW, the stock 350z driveshaft (carbon + steel/aluminum) weighed around 13 pounds and the previous 280zx steel 2.5" dia driveshaft about 38" long (not original due to SR swap) was only 6 pounds.

 

I'm going to make a custom transmission mount to hold up the back end of the 350z transmission and leave room for the exhaust to stay more tucked in.

 

I made my own backup lamp switch "plug" for the 350z transmission using small female blade connectors shaved down.

 

Later on I will get a Cable X box and a Kia Sedona ABS ring gear on the differential input shaft to drive the stock speedometer again.

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Hi BumbleZ, sorry I didn't see your questions until just recently.  Yes I did most of the wiring myself.  I found some pinouts of the donor car from the manual and had a donor silvia wiring harness.  Using those two together I worked with the existing zx harnesses and relays to get it working.  You should be able to use the zx ECU relays for running the RB ECU.  I also used the ZX AC relay to run the SR compressor, just had to splice in the SR connector on the ZX compressor wire.  Doing this I lost out on the ECU controlling the compressor which would turn the compressor off during full throttle...something I'm not worried about since my hand on the a/c switch can do the same thing.  The RB ECU might not like the ZX fuel pump relays, but I just ran a hot lead from the ECU relays to the ZX fuel pump to energize just one of the ZX fuel pump relays.  It basically runs the fuel pump anytime the ECU is turned on by the ignition switch...so it runs all the time and maybe costs me just a small margin of fuel economy with the constant cycling of fuel through the return system.  Either way it still works well since I can get about 29 mpg on long highway cruises.

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I also used the ZX temperature wire on the SR sensor.  I tapped the oil pan for the ZX oil temp sensor.  Also used the ZX oil press sensor on the SR oil port near the filter.  I just recently started reworking the tach from what I had before...more to follow on that.  Depending on the transmission your RB has you might just be able to plug the speedometer cable right in to the case.

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Sorry for any of those trying to follow this at all since it's been a while.  I did finish the transmission mount and reworked the shifter coming through the tunnel area a bit.  I ran into a bit of drama with the transmission though getting it to mate with the pilot bushing and the clutch disk, then it was the throw out bearing assembly.  I just had to swap to the SR20 throw out bearing slip yoke since it is a bit deeper on the front side than the donor 350z one, even though the bearing itself is the same.  I also shimmed out the fork pivot ball with an extra washer to push it closer to the disc.  This helped with moving the whole thing closer to the clutch since the first go it didn't even touch the levers of the PP.  All's well now and the clutch works great so far.  The transmission shifts pretty smooth but I also learned that the 350z 6 speed reverse lock out was out of adjustment.  I was wondering why I couldn't "find" reverse at first.

 

My feedback on the 350 6 speed behind the SR20 for driving is AWESOME!  That transmission gear spacing works like a champ keeping engine speed in the sweet spot.  It was a pain but was well worth it.

 

On the Tomei 260 solid lifter and cam conversion feedback...jury is still out for now.  I need to get a tach adapter finally and wire it in to start running the motor with some feedback over just plain hearing and guessing.  It's a lot quieter than I thought it was going to be though for mechanical noise.  For now I'm still running the stock turbo, MAF, ECU and injectors for the SR20 but it's doing well within a low 11 to high 10 AFR still.  I'd like to find a good dyno in the area for just a quick pull and see what she's doing now.  I did a 8 hour road trip up to Missouri a few weeks ago and it was getting right around 28 MPG still using my GPS.  I attribute most of that in my mind to the slightly shorter 6th gear in the 350z transmission which I want to see what RPM cruising gives me once I get the tach adapter.

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After a lot of trying to discern between the wheat and the chaff, I finally purchased the Autometer tach adapter and wired it into the coil harness for the SR20DET.  Now the autometer tach works like a champ with no lying at higher rpms.  PM me if you have any specific questions regarding how this works etc.  It wasn't that bad of an install at all. 

 

I'll be getting the Cable X speedometer box converter soon to get the original mechanical speedometer driven again.

 

A/C is all charged up again and working pretty good given the used compressor that came with the SR20 and the original condenser in decent condition.  I am running the Ford Thunderbird electric puller fan through the 3 row aluminum chevy radiator, condenser and 3" intercooler though on low speed only for now and it's doing a pretty good job on the days we've had in Arkansas so far.  A/C blows at about 53 F on recirc mode with 105 F ambient garage temp.  Good enough for me!

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