The 18R-GTE reference manual ...

[MnToyGuy]

Dan, I didn't mean to be rude, just blunt. How much boost? RGEU pistons will work for low boost apps. Stay under 9:1 with forgies for moderate boost. 8:1 range forgies with high boost. What are your goals? ECU? There are too many variables to answer directly.

We love to help, but also to not have to answer the same basic questions repeatedly, and to summarize all the posts made previously. Sorry if I offended.

[Little_Rolla]

Its ok, its just ALOT of reading to take in at one time... considering i only wanted to know about the pistons mate

Boost, well, it will be low boost, Unsure on ECU as yet. want to get motor all complete and sitting in bay, and go from there. Im not out to make the fastest 18RG-TE, just something with a bit more poke then the 18RC, and is fun to build up

Was considering Low Compression forgies, will see how i go

And i like Blunt, straight to the point

[roadkill]

Hi,

i would have just kept it simple by saying something in the ballpark of 6-8 pound boost. They should handle that fine. But every engine is different, old pistons can be crap blah blah blah. If you want really high boost you could get some new 18rc pistons, machine them for valve clearances and put 30psi in

bEn

[MnToyGuy]

Gather info and plan your system as a whole. The parts all work together (or against) each other. Approached like this, you'll save money time and headaches.

[Little_Rolla]

well im unsure as yet,

I admit this is my first turbo build up, but i have a few mates who have worked on turbo cars ect.
And im more then willing to build as much as i can, and sent the car in for the final touches to be done

So far Ive got the parts cheap enough so it hasn't really set me back much. And if i decide against the turbo idea Ive always got a set of extractors i can chuck on,

Block is in getting a clean, and the bores honed... hoping i wont have to bore them out and use bigger pistons.

And so what your saying i could grab over sized RC pistons, machine them for a lower CP and valve clearance and could safely run 12psi with them?

[roadkill]

Hi,

maybe.... I'm not sure on the thickness of the top of the piston and how much you would have to machine out of them for valve relief. It will also depend on your cams..... The unda presha 18rg drag car has forged fj20 (i think) pistons. about 1mm oversize i think and static compression is something silly like 6:1. Hence why it'll take 38 pound boost! He just cracked his first one a few months ago after about 18months of racing. Not bad if u ask me.

At the end of the day, measure it all up. Drill/machine/cut an old rc piston and find out how much meat is there. 12psi might not be enough though to make up for low loc compression....

Dunno much about turbo engines though so don't take what i say as gospel

bEn

[Little_Rolla]

yeah, well the plan is 12psi

So guess ill have a chat to me engine builder and go from there.. im guessing somewhere in the vicinity of 8 to 5? or so

[roadkill]

im guessing somewhere in the vicinity of 8 to 5? or so

Huh? I assume you mean 8.5?

If you want to run 12psi you would be best to reverse engineer it. Keep that as the constant figure. Find out what compression with 12pound boost will be best for engine performance, longevity, reliability and decide on what fuel you will be using too. That will all effect the compression ratio you look for. Once you've found out that info start looking at what pistons will provide you with the right ratio. You'll probably find something somewhat stock, close to what you need. You may then find you need to use a higher octane fuel to compensate etc etc. If you have constants you want to stick to look at what variables you also have and how they can effect things.....

Also people, go and fiddle with Engine Analyzer Pro 3.5. It is the shizzle with figuring out possible hp as well as weak points in your system. You do however need to know just about everything there is about your engine but it is well worth smashing it in a simulator than in your car. Haven't found a crack for it yet but still looking. There is a limited use shareware version out there. My mate that works for one of the v8 racing teams uses it amongst his mates. Very accurate!

bEn

[Little_Rolla]

Cheers for that mate

Going to talk to me Engine Builder and see what he reckons,
Im guessing ill be getting it running NA first and read a bit more into the Turbo side I have the manifold and turbo purchased, and a few other bits... and the fuel system is nearly sorted

Regards
Dan

[Norbie]

Back on topic. Have any of you converted the 18RGEU fuel rail to accept AN fittings for the input and return? I can't seem to find the right adapters, especially the M18 x 1.00 FPR hole. Weld and tap? That just scares me with such a scarce part.

Weld and tap for sure. If you're not confident get a good machinist to do it for you. It's a straightforward procedure for anyone who knows what they're doing.

Also, can MSII support a cold injector, or should I just plug that hole?

The cold start injector is redundant when you have real engine management. Plug the hole.

[RA35GT]

Alex, you are correct, $150 ea per set (we hope)

Karl, great info, I'll remeber to do that.

Yellowrolla - 2
JustenGT8 - 1
O_Man_RA23 - 1
Steve M - 2
Witzl - 1
RA 28 - 3
7M GTE MX73 - 1
Sagluren - 1
Norbie - 1
Timbosaurus - 1
Floppy - 1
River - 2

So right now we have 20 sets overall. I'll hit the guy up next week for a status and let him know I have this level of interest.

Tks for the reps everyone!!! I just hope this works out out so I actually deserve them!

So if/when we set up a group buy what are the forum rules? Roadkill mentioned on the 1GC forum (for his door hinge bushing GB with Cary) that you need to request permission from the board.

Back on topic. Have any of you converted the 18RGEU fuel rail to accept AN fittings for the input and return? I can't seem to find the right adapters, especially the M18 x 1.00 FPR hole. Weld and tap? That just scares me with such a scarce part. Also, can MSII support a cold injector, or should I just plug that hole?

Hey dood,

Put me down for two oil pumps.

Thanks
Rudi

[The Witzl]

Im hoping for above 200rwkW with my setup - or wheelies
However my engine is a bit more serious than River's - I have H-beam crower rods, forged pistons, modified rod:stroke ratio and a large turbo.


Dan - i wouldnt bother doing a turbo 18RG unless you are going to use an aftermarket programmable ECU. Without one, your engine will self destruct.
Im using an Adaptronic on mine.
With that, and a good tuner, you should be able to CONSERVATIVELY tune the engine with low boost using the 8.9:1 18RGU pistons..... but you will DEFINITELY need good ignition timing control, and a good tune, and hopefully a healthy engine, and the ability to resist increasing the boost.
Even then i would be prepared for a piston to lunch itself.

[Little_Rolla]

aftermarket ecu is on the cards mate, aint that silly,
And i want to run around 12 psi safely, hence why i asked what sorta pistons will do the trick

[o_man_ra23]

The 8.9's of the 18R-GU will work fine with 12psi if the pistons are a quality make, and are not flogged out, and you don't drive like a tool. That being said, you will need to start it on restricted boost and work your way up once tuning is good. Any detonation without a forged bottom end such as teh Witzl's will lead you to a lunched engine when running that sort of boost on a previously NA engine.

I am using a set of 8.3 ART (they manufactured the pistons for Toyota originally) 0.5mm oversized pistons with my CT26 turbo (similar output to a T25) with stock rods and a Toyota head gasket, and can't see a lunched engine any time soon. I am also restricting my boost to about 7psi to start with, and eventually about 10psi, and will restrict the RPM to 6000 to prevent instant climate change. That said, this isn't my first engine build (though it is my first go at turbo), and I haven't set very high goals for the engine. Plus I am restricted by the sticky tyres and weak diff combo which will likely let go before a piston does.

Although you may have a life outside the net, if you want to have a go at this sort of build, reading threads such as this, and the member's rides of those who are/have built that sort of engine should save you time, money, and heartache by the end of your build (unless you are a pussy like River and pay somebody to do it all for you )

MnToyGuy, Norbie is right, the cold start injector is defunct. I couldn't find an off the shelf M10x1 blockoff for the fuel rail so I left mine mechanically connected, but didn't put anything electrical to it. Eventually I will replace it with blockoffs though.

[Little_Rolla]

ahhh well,. times will tell what will happen
I enjoy the tinkering, and this isnt my first engine build, but yes my first turbo. and obviously have a bit to learn.

Im in the process of buying a second 18RG, if thats the case, one will be done NA as a daily runner, then i can spend more time researching a turbo build for the second one .

Aint no dreamer either, can post pics of progress, and the car

Take it easy guys, Night

Dan