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Location:
Rocklea qld
Registered:
February 2003
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turbo or supercharger and info
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Sun, 30 November 2003 10:14
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i have an 18rgeu and was considering turboing it, but was told that its not really worth it as turboing them tends to cost alot and theres a big risk of melting the pistons unless u add little gets into the block to cool the pistons. Can anyone shed some more light on this for me or tell me what work is involved in putting a supercharger on. This info is from a mechanic at a motor import shop so i gather he does know a little about the subject. Please any help would be appreciated
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Registered:
November 2002
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Re: turbo or supercharger and info
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Sun, 30 November 2003 10:56
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He has paraphased just one of any number of problems that you could get when turbo-ing any car. Nothing is available that directly bolts onto a 18RG so you are looking at custom stuff all the way, and $$$.
Do yourself a favour (Molly Meldrum) and read the tech articles on this site and then consider a 1G-GTE/GZE instead in your TA23.
Cheers,
Mitch.
RA23 (1G-GZE Soon)
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Location:
Brisbane
Registered:
May 2002
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Re: turbo or supercharger and info
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Sun, 30 November 2003 22:23
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An 18R-GEU can be turbocharged quite successfully without melting the pistons, but Mitch is correct, you're looking at custom manifolds etc to make it work. If you can get this done cheap go for it, otherwise as he said you're better off doing a 1G conversion.
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Location:
adelaide
Registered:
May 2002
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Re: turbo or supercharger and info
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Mon, 01 December 2003 01:21
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Hey Norbie, how is your 18R-GTEU project coming along??
I am probably going to go down the same path with a series5 13B turbo, and possibly the S5 injectors also.
What internal modifications/upgrades/improvements would you suggest if one was to turn the efi NA motor into forced induction?
I was planning on doing a full bottom end rebuild, but i can only get standard parts. should i use aftermarket stronger/hardened bearings and other bottom end bits? or will the stock bottom end parts cope with higher stress?
I will probably use the stock pistons (-88250 small dome, 8.7:1),
and do a bit of head work like porting... but will i need hardened valve springs etc?
Also oil presure in my 18RGEU is not the greatest 100% of the time, Is this a fault in all 18RG's? When i let the motor idle the oil pressure guage slowly falls to around 2/3rds.. and sometimes even half. is this worrying? should i try and modify a larger pump if i was going to go turbo? especially if it will need to flow oil through the turbo aswell..
Cheers,
Guy
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Location:
Brisbane
Registered:
May 2002
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Re: turbo or supercharger and info
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Mon, 01 December 2003 03:25
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I still haven't got off my arse with Project 18R-GTEU, but hopefully once the Supra is back together with its new suspension etc I'll be able to make a start on it.
The 18R bottom end is tough as nails; unless you're going absolutely nuts I wouldn't upgrade anything except the pistons (ie forgies), and even that isn't necessary with mild boost. I plan to keep the stock cast pistons as I'll only be running 7psi or so. As long as your engine is well tuned and you have a good intercooler, the cast pistons will hold up fine.
Your oil pressure problem probably isn't much to worry about; if your engine is a bit worn this is to be expected. After you rebuild the bottom end and get the bearing clearances back to spec, the oil pressure will right itself. The stock oil pump flows plenty even with a turbo, but it's a good idea to shim the bypass valve to increase the oil pressure a bit. Apparently this is pretty easy to do when the engine's apart but I have yet to chase up detailed instructions.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: turbo or supercharger and info
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Mon, 01 December 2003 03:27
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| blackRA28 wrote on Mon, 01 December 2003 12:21 |
I was planning on doing a full bottom end rebuild, but i can only get standard parts. should i use aftermarket stronger/hardened bearings and other bottom end bits? or will the stock bottom end parts cope with higher stress?
I will probably use the stock pistons (-88250 small dome, 8.7:1),
and do a bit of head work like porting... but will i need hardened valve springs etc?
Also oil presure in my 18RGEU is not the greatest 100% of the time, Is this a fault in all 18RG's? When i let the motor idle the oil pressure guage slowly falls to around 2/3rds.. and sometimes even half. is this worrying? should i try and modify a larger pump if i was going to go turbo? especially if it will need to flow oil through the turbo aswell..
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fwiw, your crank should never ever touch the bearings, so there should be no need for hardened/stronger bearings.. the soft metal is there just in case you lose oil pressure.
hardened valve springs? all springs are hardened steel  . depending on what revs you are aiming for, you may need dual springs, or just stronger singles..
oil pumps tend to have lower pressure at idle, since the gap for the oil to escape from (in bearigns etc) stays the same, but idle oil flow volume is low. it is normal for idle and off idle oil pressure to be maybe down to half of full pressure. a friends MX5 reached full pressure at 4000rpm....
high volume pump is a good idea. you could try the hybrid pump idea, since K,T and R oil pumps have same diameter rotors, but different thickness. grab a K pump rotor and attach? to the R rotors, then extend the housing a similar thickness.. more flow 
Cya, Stewart
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Location:
Perth
Registered:
September 2003
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Re: turbo or supercharger and info
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Mon, 01 December 2003 04:32
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the hitachi turbo off the 13B realy isn't suited to the 4cyl exhaust pulses. given, a compressor IS a compressor, but you'd be better off with an ex-7MGTE CT26 or the like if you want to step into that size of turbo.
trust me on this one! it will work, but it won't feel right driving. it's odd...
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Location:
Rocklea qld
Registered:
February 2003
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Re: turbo or supercharger and info
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Mon, 01 December 2003 09:28
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Norbie....are u saying that if i only put like 7 psi or so of boost into my motor i wont really need to modify and internals. How exactly is the best way to regulate the boost i get. should i do any head work to help it along
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Location:
Brisbane
Registered:
May 2002
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Re: turbo or supercharger and info
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Mon, 01 December 2003 11:01
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1. Yes.
2. Use a wastegate.
3. Head work helps but don't expect much of a gain as the stock head flows very well from the factory.
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Location:
Brisbane
Registered:
February 2003
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Re: turbo or supercharger and info
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Mon, 01 December 2003 12:29
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even if you dont modify the engine internals (lower compression pistons, machine head out and cam-grind to suit a turbo)...
you should consider water injection (on from a few pounds boost) and/or boost-retarding of timing (you really don't need all that advance during >4psi boost)
plus having gone down the path of turbo 18R requiring custom and modded bits... go EFI ... so you can control your fuel a little better - the carbi experience has been painful.
charles.
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Location:
Rocklea qld
Registered:
February 2003
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Re: turbo or supercharger and info
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Tue, 02 December 2003 10:05
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I already have an 18rgeu but i think it is all stock. Should i just do some cam grinds or something. Ive already sorted out how to do my manifold to bolt a turbo on and im going to loose a little power out of it ( not much though ) so i should bne right to put a little extra boost into sjhouldnt I. What sort of 18r did u turbo. If i put bigger injectors in do i need to upgrade my computer and should i do all this for turbo. How do i tell what is the right amount of boost to be putting into my engine. I want as much as possible but not to much to blow my engine.
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Location:
Brisbane
Registered:
October 2002
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Re: turbo or supercharger and info
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Tue, 02 December 2003 12:10
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he has a 18RC turbo'd, go to his site, its cool
hey chuck, r u gonna sell the manifold
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Location:
Brisbane
Registered:
February 2003
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Re: turbo or supercharger and info
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Wed, 03 December 2003 03:23
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hiya phil,
i am still looking for someone to make my manifold - so the existing stays for the time being. i intend to replace part of the intake side soon - but i'll probably keep the exhaust and repair/modify as needed.
i keep getting these respones like "...why don'tcha put a newer engine init' mate? ..."
which leads me to wonder if they heard my original request "...can you, for money, fabricate a manifold to my design..." which they must of interpreted as "whataboutanewmanifold ... mate?" - unless it's imported, costs more-per-kilo than coke and the sticker's are surfboard size, they sometimes don't seem interested... (or maybe it's my cheery personality)
people100: a stock 18RG might only handle up to 5psi or so of boost - possibly even less. if your sticking with the factory dizzi, you might want to get mechanical advance modded to start at higher revs (2500rpm) and provide less total mechanical advance (about 15 degrees) so when the vacuum advance kicks in you don't get engine-destroying pinging at high boost. you'll also need bigger injectors otherwise you'll run lean on boost. i don't think the factory ECU will give you enough fuel on boost - could you adapt an ECU from a motor that knows boost?
might be worth your while talking to some of the turbo companies in BNE (do a yellowpages search for turbochargers) about what your planning.'
charles
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Location:
Brisbane
Registered:
May 2002
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Re: turbo or supercharger and info
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Wed, 03 December 2003 03:46
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Charles, if you're looking for someone to make a custom manifold I know a bloke from the Gold Coast who might be able to help.
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