The 18R-GTE reference manual ...

[egamirrorim]

Can you provide some more information surrounding the emissions and engineering required?

Considering there were no factory turbo 18RGs, what reference/limits was the setup tested against?

[o_man_ra23]

Emissions was based on ADR27a (same as it was when the car was complied in 1977). Test is an IM240 emissions test, done at either Lane Cove or Penrith RTA testing facility (no charge). Basically they run your car through a speed up, slow down cycle on a dyno with your exhaust going through a sensor which measures unburnt hydrocarbons, CO, CO2 and NOx levels (total quantity, not percentage). If your cumulative quantity over the test cycle is below the limits specified in the relevant ADR, then you get a pass.

For the engineering specific to EFI and turbo mods, the Engineer wanted a pass on the emissions test, charcoal canister connected and plumbed to intake, catch can plumbed to intake, cat converter installed, noise test pass (to ADR of 1977), air filter boxed. That was it. He didn't care that the ECU tune wasn't locked. Also had to pass a general road test. Plenty more testing and compliance for all the rest of the mods (6 page report). Even did a platronics brake test (70/30 front/rear brake split - awesome!)

[Omegaman]

O_man, did they ask to have the fuel filler converted to accept Unleaded only. they did for me a long time ago.

[o_man_ra23]

Nope. Can't buy leaded fuel, and its an 18R-G so leaded motor.

[73GTV]

i wanted to see this thread again and it was gone, I needed to review the progress now that I have an 18RG turbo exhaust manifold to experiment with.

Thanks to all of these guys who has done this before me, I hope I learn enough to post progress on a future build. Now to source the pistons, I have Ross Racing Pistons in Mind to make mine. A while ago their was a set on Yahoo Japan that someone had ordered new and I missed bidding on that set. Now I guess going to the source will be better than NOS Racing stock off someone back shelf.

I also read where ITB are a waste of time and hard to maintain, I hope to prove this statement wrong.

[73GTV]

My Turbo Manifold, Cast iron for an 18RG that I bought from Ebay:

[JadeEstevez]

Are you making these?

[73GTV]

Are you making these?

No, I do not have that kind of skill. This was a recent purchase from Ebay from a guy in California who was liquidating his old 18RG Parts. It cost me shy of $500.00 bucks in Bidding. I have fitted the manifold to make sure it did fit and will be sending it out for Ceramic coating to preserve it. I may have the Black Ceramic coat rather than the silver coating.

[JadeEstevez]

Damn, I thought someone was going to cast these A mate of mine in Germany reproduces cast iron and cast alloy parts for BMW's, even whole cylinder heads.
I'm trying to convince him to make 152E's, haha.

[73GTV]

Damn, I thought someone was going to cast these A mate of mine in Germany reproduces cast iron and cast alloy parts for BMW's, even whole cylinder heads.
I'm trying to convince him to make 152E's, haha.

No, I also know a friend of a friend who has made their own twin Cam head for a 280Z L-28, having casting poured for that head in Florida. I do not have the specifics

[RA23GT]

Is there an ideal CR for the GTE? I'm looking at about 15PSI-ish using a Haltech Elite ECU on 95. 92mm pistons. Not after big HP lots of torque and a nice street motor.

[Javal]

Is there an ideal CR for the GTE? I'm looking at about 15PSI-ish using a Haltech Elite ECU on 95. 92mm pistons. Not after big HP lots of torque and a nice street motor.

There's no right answer to that question.

VERY generally speaking, an engine with a higher compression ratio, running a lower boost pressure, will be more responsive than an engine with lower compression running higher boost pressure - and that's not accounting for turbo sizing / efficiency. Gotta give thought to cam profile and ignition systems, static vs dynamic comp etc too. There's SO much to consider.

For reference, factory turbo engines with (comparatively) rudimentary EFI systems (late 80's / early 90's) used to run lower compression (8.0:1 ish, sometimes less) with well sized turbos to help prevent pinging / knocking / detonation under instances of high intake temp and high load. Nowadays, with more advanced management systems, better sensors and better turbo + turbo control technology, manufacturer compression ratios for turbocharged engines can be 10.0:1 and greater, even in our land of high ambient temperatures.

Lots of things to consider, but a modern and comprehensive management system with a knock sensor(s), individual coils etc should theoretically be able to handle a more modern level of compression with boost.

But really this is something you want to talk about with both your engine builder and tuner.

Also, RE: 95 octane fuel... there's almost no point short changing yourself by choosing 95 over 98 octane. How big is the fuel tank on a RA23? 50-55L? With a price difference of 15c per litre, it's about $7.50-$8 a tank more for 98. If you daily drive the thing and fill the tank once a week, you might save $350 per year in fuel, or... $30 a month, break it down however you like, it's not a huge amount when it comes to playing with old cars and tractor engines. But WHY you really should be paying that premium is the higher octane rating - not for more power, although that can be a bonus - but for the protection higher RON fuels' resistance to knocking.

[RA23GT]

What was I thinking, of course 98 (facepalm) she barely runs NA now using 95 so no way I'll use anything less and possibly water injection. Thinking about it 8.5 with the possibility of going for higher boost once I mature the ignition. I may start with running LS1 coils. Will mod my Hall effect dizzy to make it a cam position sensor and fit a 36-1 timing wheel for crank. Will run a Haltech Elite 100 or 1500 not sure which, and a modern top shelf twin entry turbo with appropriate manifolding.

[JustenGT8]

Hey Kev,
I can give my old experience and suggest that newer ECUs and better fuels can only result in a better output and ability to push boundaries a bit more.

So my setup was a fully 'built' 18RG with biggish cams, simple Haltech F7 ecu, regraphed electronic dissy with boost retard. 7.5:1 comp. big old school TO4B...can't recall the wheel trims.

Never really dynoed lol but sub 5 sec 0-100 and low 12. 1/4's on street tyres and a very firm track suspension. Let's just say performance was solid

Drive ability was great, off boost performance was fine, spool was pretty good. No issue at all keeping on boost through the twisties and power was there on demand. I'd run 18psi day to day but saw as much as 30psi no problem (other than stretching head bolts which is the only thing I couldn't find a fix for at the time).

With a modern ECU I'd build something similar but with 8.5 or even 9.0:1. Run 20-24 psi on 98 day to day and try not to die controlling 250ish rwkw A multitude of turbos to choose from that will deliver that power and still be response on a big 8 valve 2 litre. Can't go wrong really

[RA23GT]

Hey Justin, been a while mate, I run into Roger every so often. Finally getting my RRRRs into gear an getting the old girl done up. Will go for a Haltech Elite level ECU (with knock control) and a good twin entry turbo. Liking the look of the EFR series, might need to some reading for sizing.

Looks like 8.5 CR is the go and I can play with boost a bit. Ordering Arias pistons today actually.

250kw would be heaps of fun, will justify the KAAZ LSD I have ready to install !!