This car is a 1987 FC3S RX7 TurboII (Second
Generation RX7), It's owner is Chito in Los Angeles, California, USA.
The car was originally left hand drive (as are most cars in the US, except
postal delivery vans) but was converted to right hand drive using parts
from a wrecked Japanese import. The engine that has been fitted is a 20B
engine from the Eunos Cosmo. (There are pages about both the 20B and the Cosmo
elsewhere on this site).
The original 13B TurboII transmission was used, with the
original transmission cross member bolted at all the same original places.
The 20B flywheel was replaced with the original TurboII flywheel although
using the 20B counterweight.
The original TurboII starter motor was also used.
In order to fabricate engine mounts, the transmission was bolted to the engine and to the body, thereby leaving the engine unmounted
at the front.
The 20B engine mounts are located to the rear of the engine (on the cast
iron housing between the rear two rotors).
The original engine cross member is used in a modified form, cut and welded
towards the back of the cross member to accommodate the original 20B engine
The standard RX7 TurboII drive shaft and differential are used.
Other engine mounting issues:
As the 20B is about 7 inches longer than the 13B TurboII
engine, the original radiator was replaced with an aluminium one
located further forward (and necessitates using some big electric fans).
In this case, with the large intercooler, there was significant modification
towards the nose of the car to accommodate it.
Furthermore due to a lack of room the Air Conditioner cannot be used and the front
sway bar need to be adapted because the 20B engine will hit the sway bar.
Turbos, fuel system and exhaust:
Due to the complex layout of the 20B's original
sequential turbos, these were removed and replaced with a single large
The original 20B in the Eunos Cosmo generates a stock 280hp, up
to around 350-400 with minor modifications.
With the T-64 turbonetics single turbo, the target is at least 500hp.
550cc injectors have been used on the primaries and 1200cc
injectors on the secondaries. Given that, the engine should be capable
of 10 - 12 lbs boost with a little left over in injector capacity so it
does not lean out.
The exhaust is custom made, with a 3.5 inch downpipe to
a 3.5 inch Borla stainless steel resonator branching into two 3 inch pipes
and two 3 inch exhaust, all made from stainless steel. Evidently it sounds
Two electromotive TEC1 engine management systems are used,
with two sets of three coils each, one spark plug per coil (the other
side of the coil is grounded).
(3 rotors x 2 plugs = 6 plugs, 1 coil per plug)
Two crank angle sensors are used, which are 180 degrees
apart, one for leading and the other side, trailing. These sensors were
installed inside the original 20B crank angle sensor. (The 20B crank angle
sensor is located at the same place where the 13B distributor is).
The TEC units manage the ignition timing as well as fuel
injection, with the main computers mounted in the polished aluminium compartment
and the coil packs mounted on the suspension tower (TEC II units combine
the computer and coil pack into one unit).
3 rotor 2nd generation RX7:
Mazda's early multi rotor engines had problems due to
the design of the eccentric shaft. When this was overcome in the mid 1980s,
Mazda started to build them mainly for racing. However the engineers tried
several modified production cars with these engines.
Firstly a 1st generation RX-7, then in 1988 (the RX-7's 10th anniversary)
a 2nd generation RX7.
This car was taken to the USA (Mazda's biggest market), for a number of
automotive writers to evaluate. This caused speculation that a multi-rotor
RX-7 may well be produced.
The car pictured below was fitted with a naturally aspirated
3 rotor engine, which probably would have been a 13G 3 rotor engine (Note that
13G was never used in any production cars, however the related 20B was).
As the 13B 2 rotor fitted to the RX7 of the day was 654cc x 2 rotors = 1308cc,
146bhp@6500rpm , 187Nm(138lbft)@3500, one would speculate that the 13G
with 654cc x 3 rotors would make 220bhp/280Nm(207lbft) at the same RPM, however
this is only an estimate.
Thanks to Chito for the pictures and information about his
conversion. His email address was firstname.lastname@example.org
however I have since tried to contact him on several occasions without success.
Further reading and acknowledgements:
* Books (RX7 by J. Yamaguchi, 2nd edition - Factory 3 rotor RX7)
Other relevant reading at Craig's Rotary Page (Please go via the INDEX
* 20B Engine (The engine used in this RX7)
* My 1994 USA trip (Rod Millen's 20B RX7)
* Books (RX7 by J. Yamaguchi)
* 13G engine (The engine used in the Factory RX7)
Other relevant sites on the Internet (Please go via the LINKS
* There is an extensive page about this swap at FC3S PRO
* Team FC3S (Extensive collection of information related to this model RX7)
* Search for Chito
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This page last updated 19/8/2005
19/8/2005 - Added FC3S PRO link
26/3/2001 - Renamed from PG02.HTM to PG25.HTM and all images to PG25_XXY.ZZZ to
make room for site admin pages
17/3/2001 - Changes to More Information section
16/3/2001 - Converted all text to new standard (Headings as Heading1, Some
sub-headings (e.g. tables) as 14 point normal bold italic, Most text as Normal,
Internal page links at top not all uppercase)
11/3/2001 - Minor content update (Spelling mistakes, tidy up). 'More
information' section in new format. Changed from Netscape to
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changed to PG00_02B.JPG
10/9/1997 - Previous known update (May have been some before this)
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