Disclaimer: take everything with a grain of salt. It's just my $0.02.
I try to give some good advice here, but take no responsibility if you blow
your engine up. Ask for more opionions before doing any mods
if in doubt, the toyota-mods mailing list would be a good place to start.
7M-GTE 230hp HKS: max 450hp
3 liters + turbo = lots of power to be unleashed!
Beyond about 350hp turbo upgrade is A Good Idea.
Many people have achieved 550-650hp while keeping it
streetable. But do retorque the head gasket! 90% of
problems with these engines come down to the head
gaskets, which blow because the head bolt tension
is too low. See supras.com for more info.
7M-GE 200hp HKS: max 218hp
Trade it for a 7M-GTE Supra turbo ;)
Unless you're satisfied with around 250-260hp, which is
as high as you'll get with 7M-GE.
5M-GE 160hp HKS: max 174hp
Not too many performance parts are available. The Celica Supra
was tried in rallying but abandoned quickly (even the Celica
was heavier than regulations required even after extensive
lightening of all possible parts). Consider putting in
a 7M-GTE instead, as several people have successfully done.
3S-GTE 200hp HKS: max 283hp
Your wallet puts the limits on what you can get out of this engine ;)
Performance parts are available but may be expensive beyond a
certain level.Still used in world championship level rallying in
the Celica GT-4. The stock turbo should be upgraded or modified for
over ~250hp. The stock intercoolers aren't that effective,
especially the 87-89 GT-4 unit is poor. After these have been
attended, 350hp should be possible.
5S-FE 130hp HKS: max 144hp
Not designed nor used for serious racing. Air filter, exhaust and
ignition are all you're going to find for this one.
4A-GZE 145hp HKS: max 186hp
Larger pulley for the supercharger will raise the boost.
The bottom end is much stronger than the 4A-GE, therefore
a few people have turbocharged it with good results.
4A-GE 112hp HKS: max 168hp
Maybe THE most popular Toyota engine used in racing.
Think of any part for it, and you can be sure it does already
exist! The European spec engines (-1990) had no cats and higher
compression ratio,so they produced 122-125hp. The TVIS system
was dropped and hp went up to 130, and later VVT was added
with noticable power increase to 160 without loss of low end torque.
The old versions are still very much used in national level
rallying (Corolla GT), and Toyota Atlantic series. The VVT
version is so far only available in Japan. The earliest
(up to late 87 or so) 4A-GE stock bottom end is only good
for about 160-180hp. Stock fuel system is good for 150-160hp.
Over 200hp is possible, but expensive.
3S-GE 115hp HKS: max 126hp
Later versions of 3S-GE are MUCH more powerful, up to 175-180hp
for 1993-1996 models. BTCC (and other 2.0l touring car classes)
versions have around 300hp@8500rpm.
4K 58-65hp
Nothing in its design suggests that it could be used for
racing, but it has been! That's due to it being put
into such ultra-light car as Starlet. Still, you can
get 100hp out of it which makes a 700kg pocket rocket.
With 5K block close to 1500cc.
2JZ-GE 225hp
Buy the turbocharged version, or get a turbo kit + lower comp
forged pistons.
2JZ-GTE 320hp
What, you need more? ;)
If you could afford one, you probably can also afford
upgrading it to 600-700hp as many shops will be happy to do...
This engine is superior to 7M-GTE because of its ability
to rev higher reliably (fully balanced crankshaft = 12
counterweights). Comes stock with metal head gasket so
that problem was addressed already by Toyota.
Engines not widely imported to US:
2T/2T-B/3T/3T-E 75-105hp
Despite being pushrod engines, these have potential for
some 150hp naturally aspirated. Can be bored to 89-90mm,
which with 3T crank yields close to 2 liters!
Turbocharging is also somewhat popular for street (up to 200hp),
but the more serious ones use one of the twin cam versions
instead of these.
2T-G* 110-125hp
Same comments as above, but these are twin cam versions.
If you don't know how to distinguish a twin cam Toyota engine
by its code, here's the guide.
3T-GTE 160hp
Racing versions (4T-GT) were used in Group B rallying and Group C,
but weren't available for too many private teams.
The strongest block, crank (8 counterweights, rumours say it would
be forged as well) and rods of the T series. Lacks intercooler
and blow-off valve in stock form, these should be first in
the list of upgrades along with boost controller.
The stock CT20 turbo is worth its weight in junk iron,
and should be replaced if you want reliability and/or over
210hp or so. At this point, also an injector upgrade is in
order. I have modified mine up to 310hp@1.4bar, limited
by the 50-trim T3 turbo. With a more suitable compressor
side and more aggressive cams, 350+hp should be no problem.
18R-G* 120-145hp
290hp has been squeezed with turbocharging for street use,
or some 180-200hp naturally aspirated.
1G-GE 140-150hp
1G-GZE 160-168hp
1G-GTE 185-210hp
Any of these three engines would be fine for a street car
if you're satisfied with stock output or a modest increase
to some 260hp for the 1G-GTE. None of these have been used
for racing.