Djays12

Hi all, I finally decided to register and start getting all the parts and info I might need for my swap, that I will do during next winter.

The swap is a LS2 with a T56 Magnum coming out from a '07 CTS-V and it will be going into a Nissan S12.

I've had this S12 for 10 years now, the car is driven on the street but mainly on the track (HPDE and autox). I've done a lot of work on the car already, but mostly in the suspension and geometry department... now I'm getting a bit bored with my 140whp output so I decided to go with some american muscle instead of boosting a I4.

Here's a quick round about what have been done to the car:

Suspension and chassis:
-Megan Racing coilovers
-Customized front control arm (heim joint and length adjustable)
-Customized Techno Toy Tuning 280ZX caster rod
-Customized infiniti M30 upright for camber adjustment
-Caster plate
-Nissan 180SX front brake swap with HP+ pads all around
-Techno Toy Tuning roll center adjuster
-Progress adjustable front anti-roll bar
-Aftermarket tie rod (mix of S13 off the shelf and house made parts)
-Customised rear semi-trailing arm with heim joint. Camber and track width adjustable
-Quaife R200 rear differential
-Nitto Nt01 225/45r15 tires... I will probably upgrade to Maxxis RC-1 245/40R15 with the torque from the LS2.

Engine, I will not get into details as there is no wow factor. It's a KA24DE from a S14 with some work to it.

The LS2 swap I bought came with a CXRacing swap kit for a 240SX... the S12 and S13 are pretty similar especially in the engine bay, so I believe I will be able to use or modify some parts to make it work. I'll start by getting the engine as close to the firewall as I can and then work from there. I'll probably fabricate my own headers, maybe notch/reinforce the crossmember and massage the transmission tunnel.

The remote shifter from the CTS-V will have to be modified as it will be to far back. Right now I'm looking at the possibility of modifying a MGW V2 meant for a GT500 TR6060. I'm not worried about chopping and making it fit. The shift linkage inside the T56 magnum should be the same as the TR6060 so I don't see why it wouldn't work (given some work).

Anyway, here is a picture of the car to tease a bit.


Cheers!
Jerome

Djays12

I just realised I haven't updated this at all but the swap is completed.

I made a build/how to thread on the S12 forum, thought it would be nice to have it here aswell.

Djays12

PART II: Other custom fitment needed

REVERSE SOLENOID:
The T56 have a device called a reverse solenoid. How it work is that under about 5mph, the ECM send a signal to that solenoid so it stop blocking you from going reverse. Without this it is possible to get into reverse by accident.

If you can still keep this functionning with your swap you don't have to worry about it really. If you can't (My GMPP ECM kit doesn't have this function), you have to find a way that suit you to feed 12V to this solenoid when you want to go into reverse.

Or if you really don't want to mess with it, it is still possible to go into reverse without sending 12V to the solenoid, it just requires more force to fight the spring loaded gate in the transmission. It isn't that bad honestly.

HEATER CORE:
Next issue you're going to face is the heater core port ending up right behind the right side head. If you don't care about keeping the heater core it's not a problem. I wanted to keep it.
So you will have to take the heater core out and make a new hole in the firewall for the ports about 4'' outward. Then extend the copper line on the heater core that same amount and find a longer hose for the lower port. Since you have the heater core in your hand, you should remove the lower ducting. It won't fit over the new bigger transmission tunnel anyway.


The top copper tube of the heater core have been extended by 4''


here you can see on the left the new port of the heater core sticking out. A blocking plate has been tacked to the firewall to fill the original hole.


now it was time to fill some unused holes in the firewall and engine bay. I kept the throttle cable hole for the harness and deleted the speedo cable hole since you can't use one with the newer T56.


The result once sanded and painted.

Now just one last note on the heater core, from the reading I've done during the swap, the LS engines need to have a coolant flow through the heater core ports on the water pump in order to have the thermostat to function properly. Which mean you can either simply loop the ports together if you don't want to run the heater, or you have to provide a way of keeping the coolant flowing even when you set the heat control to cold. In our case, this shut a valve on the heater core and prevents that flow.

There are some LS swap heater bypass block that are sold for about 75$US but I decided to made my own since I had all the material needed at home ( an old pair of ski poles and a 2x3x4'' bloc of aluminium).


LOJkits sell a LS swap heater bypasse block


Here my house made bypass block. The tubes are longer to fit the hose I already adapted to the water pump ports.

HEADERS AND EXHAUST:
Now that part is a headache too. I’ll talk about what I had to do to fit my CXRacing headers. The fitment is probably different from other swap headers. I would still recommend to start from some S13 swap headers as these are probably be the closest to fit.

First issue would be the frame rail fitment. Our engine bay is slightly narrower than a S13. In my case the left side header contacted the frame rail and needed some massaging.
Now, why massaging the headers and not the frame? After watching this video ( ) I figured out it was much easier to do this without any effect on the performance of the headers.

It also contacted one starter bolt on the right side (hammered the header there also) and slightly touched the steering column (same deal again).


Right side header, there is plenty of room clearing the frame rail.


Left side header, you can see where it was hitting the frame rail. It have been hammered and now provide about 3/8'' of clearance.


Once the header have been massaged enough, it finally clear the frame rail.


The steering column go right between the runners on the left side header. To install the header you need to remove the steering column, loosen the left side engine mount and lift the left side of the engine. Then you can slide the steering column inside the header and bolt it back.


Here you can see the starter bolt that was touching the header

Next is the bottom of the headers that need to be modified. Again, just like the transmission, I didn't want anything hanging below the frame rails. The CXRacing headers exit in 3'', are too high and aim at our floor pan.


header exits aiming right at the floor pan.

So I bought some 3'' to 2 ½'' conical reducers and chopped the header outlet. I then shaped the reducer on an angle to orient the exit below the floor pan. Reducing the diameter to 2 1/2'' made it easier to go around the T56 without going lower than the car already is.

There is not much room to spare around the big T56. Instead of using some V-clamp like the header used to had, I just made some straight exit. Some band clamps will take care of connecting the headers to the exhaust line.


A glimpse of the conical reducer temporarily held by some masking tape

The tightest spot to fit the exhaust on the S12 IMO is where it goes above the rear subframe. Due to muffler choice and the space you have to pass the exhaust in there, I went with a Y pipe dual 2 ½'' to 3''. For a muffler, I only have a Dynomax VT which is supposed to be quiet like a stock muffler and open up a flap once you step on it.

Well for now I'll just say that this is still loud, and that was to be expected since there are no cats and no resonator in the exhaust line. I'll experiment with a side branch resonator to bring the noise down in the 1500-2500 rpm range.

Djays12

FUEL SYSTEM:
The fuel pump obviously needs to be upgraded. A walbro 255lph fuel pump is the minimum I would use with 400hp.
The main difference from other swaps is that the LS engine need a constant fuel pressure, not a vacuum referenced pressure like Nissan did at the time. Luckily this also mean a cleaner engine bay. The corvette already uses a fuel filter that integrates the pressure regulator. (WIX P/N 33737)
This filter will regulate the fuel pressure to 58psi.


Since there is now a header on the right side, I decided to install the filter/regulator under the floor. That way, there is only one fuel line going up in the engine compartment. There is a hump in the floor pan that make it fit nicely. I then added a metal shield to protect the filter from road debris.


Fuel filter/regulator in it new location


Fuel filter/regulator protected by a shield made of aluminium.

The fuel lines size has also been upgraded to match the fuel filter. I don't know if that was really a necessity but mine were starting to be rusty so I didn't take a chance.

OIL SYSTEM:
The oil filter on the LS engine screw onto the oil pan. I don't think any aftermarket oil pan have it setup that way. This mean that you have to run a remote filter. I placed mine next to the frame rail, under the battery tray. I already had thermostatic sandwitch plate and an engine oil cooler on my setup so your might be different.


The oil filter, along with the factory CA20 oil pressure sender and a aftermarket oil temperature sender

DRIVESHAFT:
In my case this was a headache because of the CTS-V transmission. I contacted driveshaftshop with the measurement between the differential and transmission flanges and had a custom driveshaft made. The driveshaft in question is a 4'' aluminium with a CV on the transmission end. The CV will allow the driveshaft to plunge.
If you have a Camaro T56, all you can do is get a Camaro driveshaft, have it shortened with a 240SX Joint in the back and get it balanced.

CLUTCH:
This part of the swap goes just like any LS to S13 swap. I used a Sikky clutch master cylinder kit. This includes the line to the slave cylinder, a ¾'' wildwood master cylinder and an adapter plate to bolt it to the firewall.
I highly recommend buying a remote clutch bleeder kit. The slave cylinder in the T56 is shaped like a doughnut and is inside the bellhousing. The factory bleeder barely sticks out at about 2 clock on the bellhousing, making it almost impossible to reach. The remote bleeder is a must to be able to easily bleed the clutch.
If you have a CTS-V T56 like me and want a lighter flywheel (OEM is in the 40lbs range) you need to use a corvette C6 slave cylinder, which is higher. A lot of clutch setup need you to measure the gap between the slave and the pressure plate. I went with a kit on tickperformance.com (18lbs aluminium flywheel, monster stage 1 clutch and C6 slave) that do not need any shimming.

CLUSTER:
To run the OEM cluster, you will need to do some work to get the speedometer and the tachometer to work.
For the speedo, I called Abbott and had a Cable-X custom made with a spare speedo cable I have. In short, the Cable-X is a device that receives a VSS signal and then drives a small electric motor that will run a shortened speedo cable. I installed my Cable-X where the radio used to be. The Cable-X has a dozen dipswitches inside to change the conversion from the VSS to cable rotation. This way, you can adjust the speedo reading if you change the rear tire size or the differential ratio. The cable-X will take the signal directly from the vehicle speed sensor on the transmission and NOT the signal coming out from the ECM.


The cable-x fitted in the radio deck holder. The shortened speedo cable will simply loop inside the dash and go to the cluster.

For the tachometer, you will need to build a pull-up resistor circuit. This circuit is nothing really hard, it's just a resistance of about 1kOhm that raise the ECM tach signal to 12V when that pin on the ECM is floating. When the ECM ground the signal it will draw the 12V down near 0V. Once you have boosted this signal, you need to boost it again to simulate the voltage peak of the ignition coil discharging (the Tachometer is looking for pulses of 55V+). I tried to make my own signal booster from an automotive relay but it didn't worked. I ended up buying this signal booster from ebay that worked nice. There is to way of wiring it, you need to wire it for active low operation.

http://www.ebay.com/itm/TACHOMETER-S...-/142171581596
(If the link is dead, look for TACHOMETER SIGNAL BOOSTER / SPARK COIL SIMULATOR it is made by widget man)

POWER STEERING:
The LS pump flow much more than the Nissan one. You need to restrict that flow for the steering to feel right, other than that it will be over assisted.

Turn One make a restrictor for the LS power steering pumps with a hole sized for Nissan racks. This restrictor come out with a AN fitting.

The CTS-V pump also output a higher pressure than the Camaro and Nissan pump. 1700-1800 psi versus 1100-1200 psi for the Nissan and Camaro. For now I haven't done anything about it. The full pressure is only present if you are on the steering stop and trying to steer some more. This shouldn't happen if you are careful or in road racing application. If you plan to drift the car this is an issue.

The funny thing that I will look into is that the CTS-V pump is made by Toyota (Well, Toyoda, which is in the same group). It look very close to the 2003-2008 Toyota Corolla power steering pump. I still have to measure one at a junk yard and if it have the same dimension, get one and test what the output pressure is. This could be an easy way to lower the max pressure.

I don't see the Corolla having as high of a pressure than the big heavy Cadillac. This part will have to be updated eventually.
I found the pump data on a toyota matrix FSM (same pump) and it pump the correct pressure for us (about 1100psi) so I say we are up to a good start with this.


CTS-V pump


Corolla pump

Djays12

The LS2 looking right at home in the bay!


Now I still have to get used of driving this thing again! I'm really happy with the outcome of the project!

Djays12

So I took the car to the dyno. The numbers were above my expectations!

382whp and 388 lbs of torque

AnotherWs6

iTrader: (17)

Good stuff. That thing is a sleeper for sure.