View Full Version : 18LE Turbo conversion

20-01-2016, 07:54 PM
I'm pretty new to the world of Pulsars but have recently got an N13 Q which I picked up pretty cheap. Its a good little car but I bought it with the intention of having a bit of a play about with it. I've read bits of pieces of information on various websites about making a 2litre engine using camira cranks etc. (any ideas where you would get these now!?!) but also lots of references to people having turbocharged the 18le. I can't find any specific information though, has anyone here ever done it or know how its been done? No point in trying to re-invent the wheel if its already been done!

Thanks in anticipation of your help,

Leroy Peterson
20-01-2016, 08:23 PM
I could be wrong, but most N13 owners turbo CA engines. An 18LE would need a custom turbo manifold ??

21-01-2016, 07:09 AM
Thanks for your reply, I have read a little about CA18 swaps as you say, but I have also seen reference to 18le turbo conversions but no details. I'd be more interested in sticking with the 18le, not looking for massive power, I'd be happy with fairly low boost.

Thanks again,

Leroy Peterson
22-01-2016, 10:25 PM
And what exhaust manifold are you going to use? And which ECU?

23-01-2016, 05:26 AM
That's the sort of details I was hoping people here could help with. I think the standard ECU can be reprogrammed reasonably easily and I believe there were versions of this engine turbocharged by GM in other countries. I was pretty hopeful that someone here would have details on how the conversion has been done in the past.

Leroy Peterson
25-01-2016, 06:56 AM
I think the standard ECU can be reprogrammed reasonably easily
That is very rarely the case with Nissan ECUs.

Sorry I can't help further but be sure to let us know if you come across any further info.

25-01-2016, 07:42 AM
That is very rarely the case with Nissan ECUs.

Sorry I can't help further but be sure to let us know if you come across any further info.

Thanks for your reply. The N13 uses a GM/Holden ECU because of the GM family 2 engine.
If anyone else has any further info please feel free to chip in.
Thanks, Jonathan

23-02-2016, 03:11 PM
Hey Jonathan,

Back in 2008 I custom turbocharged a stock 18LE with great results — it made 120.1kw/atw @ 8psi (basically doubled stock power).

At the time I was sticking to a tight budget and was able to achieve the whole job in the $4,000-$6,000 range. This being; all research, sourcing parts and fabrication work untaken by myself except for the installation of the aftermarket ECU and good tune.

Unfortunately I currently don't have time to write up exactly what is required and the process (hopefully in the near future I can do a proper write up) however I can give you a enough for you to think about and go from.

Keep in mind that a stock 18LE engine is only really good for low boost applications. If you are re-building the engine, components suited for turbo applications would be recommended, and that way more boost could be run reliably. To give you an idea, my stock 18LE only lasted under boost for about a year before one of the pistons blew out around the rings, and that was with a good tune and I looked after it.

Basic 18LE+T Requirements


– Spark plugs, 1 stage colder spark plug than stock
– High-flow fuel pump (high-flow Walbro in-take is ideal)
– High-pressure fuel hose (doesn't hurt swapping all rubber fuel hoses with ~180psi hose, pretty inexpensive item for the piece of mind)
– 440cc + fuel injectors (Ford XR6 injectors fit the 18LE manifold and fuel rail)
– 2/3 bar MAP sensor
– Upgrade coil (optional), a MSD 8226 coil is a great plug and play option and will supply a more fatter spark thank stock. At the time I didn't do this and stock was fine. However if I would run more boost, upgrading would be recommended)
– Aftermarket ECU (at the time I went with an Adaptronic as that was what my tuner recommend for my application and it was also a reasonable price)


– Custom exhaust manifold or you can source a Pontiac C20GET (LT3) low-mount exhaust manifold (I custom made a high-mount using steam piping and laser cut flanges sourced from Liverpool Exhaust)
– T25/28 turbo
– Custom 2.5" exhaust, turbo-back
– Custom turbo oil and water supply (oil can be T'ed from the oil sensor, water from the coolant/heater lines) and oil drain into sump
– Oil catch can
– Intercooler, custom intercooler piping, air filter setup (pod or custom airbox) and BOV
– Upgraded thermo fans (2x 12" fans)


– AD22VF calipers and rotors


If you are only going for a mild boost setup, the bellow are defiantly not needed, the stock components are more than enough.

– Upgrade fuel regulator
– Upgrade ignition management (eg. multi-coil ignition system)

Basic 20LE/20LE+T Requirements

If you were planning on rebuilding the 18LE engine, you may aswell bore and stroking it to 2Ltr (making it a "20LE") as the parts and process is fairly straightforward.


– Holden JE Camira 2Ltr 20JD crankshaft and pistons (source a second hand 20JD crankshaft from wreckers or online)

From memory the 20JD connecting rods are the exact same as the 18LE (centre to centre rod length, bearing journal dimensions and thickness etc.) so sourcing the 20JD rods mightn't be necessary.

MILD UPGRADE AND RECOMMENDED (but definitely optional)

– Turbo cam from a Pontiac C20GET (LT3) (for a 20LE+T setup)
– Opel C20LET/C20XE connecting rods. These are beefier than 18LE/20JD connecting rods and are a great upgrade if you are undergoing a 20LE/20LE+T engine build. They share the same rod length and bearing journal dimensions as 18LE items, however they use a floating style piston. This may seem like a complex upgrade, however it is relatively straightforward. All that is required is machining of the pistons to accommodate the floating pin and grooves machined for the locking pin clips. Most good engine builders will be able to either do this themselves or send them to a machinist to get done. Or just get custom forged pistons made haha.
– ARP 109-6001 connecting rod bolts for the C20LET/C20XE are a good option to keep the bottom end secure (these fit the 18LE connecting rods aswell). The only slight modification for using these bolts on either the C20LET/C20XE and 18LE connecting rods is to have the connecting rod end caps chamfered slightly to accommodate for the chamfer that is evident under the head of the ARP bolts, again an easy task.

In Conclusion

It may seem like a fair bit of money to spend on a car that is ageing and worth less than the amount you would end up throwing at it, however it's a fun learning experience and the result is something a bit different. Looking back, I am glad I spend the money on it instead of just going out there and buying a WRX or something (for a bit more of course), as what I had learnt through the blood sweat and tears cannot be bought. My main advice is to research and plan everything as it will make the build process a breeze.

Hope this helps!

23-02-2016, 07:36 PM
That's an awesome reply Chris, thanks so much for taking the time to write, exactly the sort of information and encouragement I was hoping for! I have a spare (stuffed) engine to start playing with and was already looking at the Pontiac manifolds (is the 'sunbird' the one to use?).
Thanks again, would you mind if I sent you a PM or two as and when I have specific questions?

Thanks again,

24-02-2016, 09:36 AM
Yes the C20GET (LT3) engine came in the following cars apparently*:

– 1987-1990 Pontiac Sunbird
– 1987-1989 Pontiac Grand AmSE
– 1987 Buick Skyhawk T-Type

The other GM SOHC Family II engine that is the basically the same as the 18LE is the C20NE found in Opel's in the UK. There is a surprising amount of aftermarket parts (cam gears/vernier pulleys, camshafts etc.) for these in the UK.

Do as much research you can on all the related GM Family II engines as it will surprise you what parts are available for each engine, which are generally interchangeable with the 18LE.

When searching for the parts on eBay for example, I find it best to go to the relevant countries eBay page and search from there, as not everyone sets international shipping (making it appear on the Australian eBay search results) and most of the time they are willing to ship it over for you.

US – ebay.com (http://www.ebay.com)
UK – ebay.co.uk (http://www.ebay.co.uk)


* Sourced from Wikipedia: https://en.wikipedia.org/wiki/GM_Family_II_engine#LT3
Note some info could be wrong such as the name for the Holden Camira engine that is currently listed on that page. It's listed as a 20LE when in actual fact the Holden Camira engine number is 20JD (20LE is a made up engine number referring to an 18LE being bored and stroked to 2Ltr)
I also just discovered this page, with good information on the LT3 engine, from a footer reference of the above Wikipedia page: http://lt3engine.i8.com/specs/LT3.html

Zak Critsilis
08-08-2019, 09:48 AM
Please contact me mate if you can