Technical Emails
Here is a collection of my responses to some of the technical
emails i have received, this page will be updated over time. Keep
in mind that I by no means claim to "know it all" when it comes
to engine building and so on, i have just put this page together
in the hope that what i have learnt from the work i have put into
my Corolla may be of use to others...
"The 4A-GZE Turbo Setup"
"20v Conversion"
"Supercharge or Turbo?"
Hi steve,
I shall be short to waste little of your time.
Ruffly how much should one budget for to do the conversion like
yours?
What sort of results are you getting?
thanks
James.
Hi James,
Here's a rough estimate of what mine cost:
Engine & intercooler : $800
Turbo & manifold : $600 (second hand)
ECU : $500 (second hand)
Exhaust: $750
Radiator, inlet manifold, coil, distributor, thermo fan, etc :
$500
Gaskets, seals, belts, piping, silicon hoses, fittings, oils,
etc : $500
Total : AU$3650
I was fortunate in that i found the manifold, turbo & ECU second-hand
... if buying this stuff new you would probably budget another
$1000 on top of that. If you needed someone to do the installation,
i'd guess budget close to $2000 for labour. I have a friend who
is a mechanic and he helped me with the difficult stuff, such
as fabricating the dump pipe & intercooler piping, for a small
amount.
I should also mention that i have spent more since the original
installation, i had the turbo rebuilt (and made into a hybrid
using the compressor housing from a big 13b turbo), and i've also
put in a gze LSD gearbox and a heavy duty clutch. All this came
to nearly $2000
The first time on the dyno showed 185hp at the wheels, which,
working on a loss of 15%, comes to around 215hp @ flywheel - an
improvement of about 50hp on a standard GZE. The car was in a
very average state of tune at the time and only running 8psi,
it is now setup at around 12psi and tuned a lot better - i haven't
had it back on the dyno yet, but it feels as though it would have
to be making over 200hp @ wheels now.
Unfortunately i haven't yet managed to achieve the car's potential
on the drag strip, with a best time of 15.1 @ 95mph, due to some
niggling problems ... the 95mph indicates it should be doing low
14's (UPDATE - the corolla has since run 14.4@100mph).
I will be fitting a new intercooler soon, and once everything
is sorted it should be good for 13's.
Sorry about the essay - i guess the short answer to your question
is, budget $5000, expect 200bhp :-)
Steve.
Hi, my name is Dain Smith. Ive been considering doing a 20v
conversion into my toyota ae92. I read from the tech forum in
www.4agze.com that you have done the same conversion and i throught
i could ask acouple of questions.
My car has the carby engine. I was wondering about the fuel system
problem. i heard if you change over the tank and lines to a sx
fuel tank and lines, this is all you need to convert the fuel
system over from carb to efi. Is this correct? Are the fuel tank
and lines out of the csi 4afe suitable aswell? Do you have to
change the lines or can you get away with just changing the fuel
tank? Can the carby lines that run under the car in the black
plastic tray (the steel ones) handle the efi pressure? The carby
engines also have a fuel return line, does this need to be up
graded to a larger diameter? i heard 5/16 is the size needed,
or is this the size needed for the inlet fuel lines? Any advice
would be greatful. How did you find the wiring? Im going to get
a front cut so i can label all plugs and wires making it easier
to wire back up. I have also got the wiring diagrams and pin outs.
Can the driveshafts from the carby engine handle the 20v? Or would
you recommend changing to the 20v driveshafts? If so are they
a bolt in fit? What about the mechnical speedo? Is that a easy
fitment to a 20v? I heard that the 20v uses a light to indicate
oil pressure. Is this also correct because the carby engine doesnt
have a oil pressure sender unit like the sx model, which works
in my favour if correct. Lastly what can you recommend me doing
that you found out could be easier if you did the conversion again?
Thanks for your time if you reply back to me and congrats about
your successful 20v conversion.
Hey Dain,
Good to hear you're thinking about doing the 20v conversion -
it is a very worthwhile swap. I should tell you firstly that i
no longer have the 20v in my car - i now have a turbocharged 4AGZE.
Please don't let that make you think the 20v is no good, it was
just a choice i made in the search for ultimate power. The plan
was to turbocharge the 20v, but with all the difficulties involved
it ended up being easier to do a turbo GZE instead. The 20v has
been put aside and will probably one day be installed in a sprinter.
I should also mention that i didn't actually do my 20v conversion
(that was a couple of years ago when i knew little about toyota's),
however i have since done the GZE conversion so i can still help
you with most of your questions. Here goes:
Fuelling - Yes, you can use the SX fuel tank, or a tank from any
of the EFI ae92's. Mine came from a CSi if i remember correctly.
You can change the lines if you like but it is not a necessity.
I ran around with the 20v on the original carby lines for over
a year without any fuel flow problems - in fact i still have the
smaller lines on the current engine and they are still flowing
enough fuel! I think (not 100% certain) the carby'd corolla lines
are 6mm and the EFI ones are 8mm. If you do upgrade the lines
you can use the original feed line as the new return line.
Wiring - I didn't do the 20v wiring so I can't tell you for sure,
but having "un-wired" it (albeit rather quickly) it doesn't look
overly difficult. I only found about half a dozen wires which
needed to be spliced in between the new "engine loom" and the
original "body loom", and of course some for the dash. Having
the diagrams & labeling all the plugs like you mentioned will
make it nice and easy. If you do run in to troubles, you can contact
Jason Purcell on the twincam16.com forums and he'll be able to
help you out.
Driveshafts - The carby'd engines shafts will handle the power
no worries - they are the same diameter as the 20v ones. Some
of the 20v ones (but not all i believe) use a half shaft on the
longer driveshaft, to reduce torque steer. If you get a front
cut, you will just use the 20v shafts, as they fit up to the ae92
hubs no worries.
Speedo - You can use the mechanical speedo with the 20v gearbox,
however the problem is that if the ECU doesn't get the speed signal
(ie - from an electronic speedo), it will set itself into "limp-home
mode". Don't worry, it's not as bad as it sounds - what it does
is set the rev limiter to around 7500rpm instead of the factory
8200rpm.
Oil pressure sender - Correct, 20v just uses a switch (to switch
on the light), so that will work fine with yours. Only the SX/GTI
corolla guys with the oil pressure guage need to swap over the
original sender.
Recommendations - Can't give you anything specific as i didn't
do the conversion, but may i suggest you take the opportunity
to do new timing belt, plugs, leads, filter, etc (i guess you
probably already figured that). Also, don't be lazy, crack that
gearbox off and check the clutch! :-) Odds are it will be almost
due for a new one, and believe me - it's a lot easier to do before
you put the engine in the car!!! The flywheel might need machining,
and check the rear main seal, too. Allow yourself a week to do
the swap. You'll probably have the old engine out and the new
one in place within a weekend, but the wiring will take some time
and patience, and you don't want to be rushing to finish it.
That's about all i can think of at the moment. Hope it helps.
Steve.
Steve,
My name is Hayden and I'm looking to replace a 4a in my AE82 with
either a 4AGZE turbo, or a 4AGZE supercharged motor. Could you
please give me the pros and cons of each engine, an approx price,
and places where I could pick one up. I'm also interested in meeting
others who have done this to their corolla so as to see and get
a feel of whats to come for me, maybe a corolla club.
Any infomation you can send me will be very much appreciated.
Thanks, Hayden
Hayden,
Ok, as i see it, the advantages of a standard (supercharged) 4agze
are:
- good low-down torque (good for street driving)
- fairly straightforward conversion
- reasonable fuel economy
- reasonable reliability
- easy power upgrade with a bigger pulley (to give 12 - 14psi)
The disadvantages include:
- limited potential (once you've done the pulley, you won't get
a lot more power out of the s/c)
- expensive insurance
The advantages of a 4agte (gze converted to turbo) are:
- huge power potential
- huge power potential
- huge power potential
- and a huge grin on your face every time you put the pedal down
:)
The disadvantages of the turbo include:
- takes longer to come on boost than a supercharger, so not as
responsive on the street
- not so good fuel economy (unless you run low boost most of the
time)
- maybe reliability problems, depending how much power you are
making (though the GZE & it's drivetrain is pretty strong, so
you shouldn't have too many problems)
- more work to do the conversion
- expensive insurance
By the way, did you realise that the 4agze has to be converted
to turbo if you want it turbocharged? The GZE never actually came
with a turbo from the factory.
Any jap importers will be able to sell you a 4agze front cut,
so if you just want to do the gze conversion it's easy... you're
looking at about $1800 for the frontcut, plus another $700 - $1000
or so by the time you add up the cost of a clutch, modification
plate, and the extras bits n pieces you will need to get it running.
If you aren't doing the conversion yourself, you need to allow
another $1500 or so for labour.
If you want to do the turbo conversion, you need to add another
$2000 or more on top of that, depending if you want to use the
standard ECU and what sort of turbo & intercooler you get, etc,
etc.
As a guide, my turbo conversion cost about $5000 all up....
Hope this hasn't confused you more!!
Where are you located? If you're in brisbane, you're welcome to
come out on our next cruise and meet myself and many other guys
who have done similar conversions.
Cheers,
Steve.
