My First Generation Informational Thread

[Whizbang]

UPDATED: 4-3-09

General Suspension Questions

Q: What are the rear suspensions revisions in 1984?

Q: What are the differences between front struts?

Q: What can i do to improve the handling?
A. Many options exist here.

• Odds are your original dampers and springs are worn. This is the best place to start. You can go with simple spring / strut combos, or coil over setups depending on your needs and budget.
• A good set of tires is probably THE most important variable in have a good handling car. If your tires can stick to the pavement, then all your other modifications are moot.
• One upgrade that is also not too hard on the wallet is upgrading the sway bars. Options from vendors such as RE Speed, Racing Beat and Suspension Techniques are good choices. For some information on installing sway bars, see this thread --> ST Sway Bar Install
• An easier on the wallet, but somewhat time consuming process, is replacing the worn stock busings with a good polyurethane bushing set.
• For those with greater handling needs, there are many adjustable and spherical bearing components from vendors. See Re-Speed.com for a good selection.

General Engine Questions

Q: Where can i find the Factory Service Manuals online?
A. here are the First Gen. Manuals:

http://www.wankel.net/~krwright/cars/rx7/manuals.html

i download them to ensure they if the site goes down, i could rehost them or possible the RCC server could.

Q: How ratio do i use for premixing?
A. Generally a 1oz to 1 gallon ratio works well but this can vary on your application. Most forms of low ashing 2 stroke oil will work.

Q: Can i lower my coolant temps with additives?
A: A few small studies have shown that Redline Water Wetter, and the like, are corrosive to coolant seals and are advised against. Redline being the worst. Its recommend to aviod their use and if you do, flush it out as soon as possible. (provided by TitaniumTT)

Q: Where can i get internal engine parts coated?
A. http://www.jhbperformance.com/

Q: Can i use the later style FC plugs?
A. Yes of course! The same BUR9EQ for the trailing and BUR7EQ for the leading are a fine choice.

Q: There is a strange, mustard like substance in my oil cap and filler tube?
A: Those in the know, call it "lung mustard". Essentially, your PCV system is faulty and the crankcase pressure is not being vented. Common after people mess with the emissions systems during a rats nest removal. There are a few solutions to this.

• Reconnect the PCV system per the FSM or Haynes manual.
• Connect a line from the filler tube to a vacuum source. A check valve is needed for turbo cars.
• Drill about a 1/4" hole in the oil cap. Cheap but effective.

Q: Can i use an FC AFm on my GSL-SE?
A. No. The GSL-SE may have had a 13B engine, but one major difference was the EFI controls. The SE AFM was a 0-12v system. The later S4 AFM was based on 0-5v signals.

Q: Is the GSL-SE 13B engine like the FC3S 13b?
A. In some ways, yes, but there are numerous differences. They are as follows:

Eccentric Shaft:

• Eccentric shaft seems to lack the hole for the oil bypass for the thermowax pellet.
• Any 13B eccentric shaft can be used as a replacement with concern given to balancing.

Intake Manifolds:

• Lower has coolant passages.
• Upper has no ports for secondary injectors, smaller runner diameters, and a smaller throttle body.

Irons:

• The irons have aux. ports with sleeves.
• The coolant jacket is the same as a 12A and is not capable with later 13B irons.
• The coolant seal groove is not located on the irons, unlike the later 13B.

Rotors:

• Rotors have 3mm apex seals.
• Any 13B rotor can be used as a replacement with concern given to balancing.

Rotor Housings:

• The rotor housings lack the restrictive diffusers in the exhaust sleeves the later 13B 6PI has.
• There are coolant passages for the intake manifold unlike the later 13B 6PI.
• The coolant jacket is the same as a 12A and is not capable with later 13B irons.
• The coolant seal groove is on the aluminum rotor housing unlike the later 13B.

Q: How can i make my 12a faster?
A: The 12a is the most common engine from the first generation rx7, but the last one sold was over 22 years ago, so they are now starting to become less common. With this in mind, one of the first things you want to do is give the car a complete run down. Get a service manual and check everything for specs and replace the wear items. This is the best performance mod you can do!

Once you get your car were it SHOULD be, then you can start looking into your options for more fun. A few of the many options are below.

1. The Exhaust. The stock exhaust manifold is not a great flowing piece and its very heavy. Replacing it with one of any number of tubular headers is a great modification and should be one of the first ones made. From here, you can replace your header back exhaust with an even greater variety of after market parts. Figure out your goal, then buy accordingly.

2. Carb Upgrades. The stock carb is a very effective unit and some tricks can be done to improve its performance. In addition, there are kits to use Holley, Weber and older Delltoro carbs, as well as others. These upgrades usually require additional modifications to the fuel system, such as fuel pump upgrades and fuel pressure regulators.

3. Changing the final drive ratio. There is some decent content on this site on how to change out the final drive gear on the 84-85 rear ends in favor of a number of options. Alternating this will yield greater acceleration at the cost of a higher cruising rpm at a given MPH. The extent of the effect varies depending on the gear selection.



Q: How can i make my GSL-SE faster?
A. The exhaust. Get a header, do what you can based on emissions standards for the cat, and get the best muffler you can stand to hear. This is essentially the best modification per dollar.

B. Running the stock AFM basically limits what the intake system will allow for. Running a cone filter will not yield any appreciable difference in performance and may actually be ADVERSE since its prone to sucking in the hotter air. Run a K&N replacement for the stock air box. If you are hell bent on the cone filter, you can get fancy and find way to prevent the hotter air from getting at the inlet, but the flow is still going to be limited by the AFM sizing.

C. Gearing! the 4.44 and 4.778 gear tricks can work here as well. See this thread HERE

D. Porting is another great option if your rebuilding! Remember, 12A four port irons work with GSL-SE rotor housings!

****NOTE: any form of SAFC or other piggyback unit will probably not work with the stock GSL-SE engine management. The system is on a 0-12v basis and a piggyback with normally only work on 0-5v systems.****

Q: Can i turbo my 12A engine?

Q: Can i swap a 13B turbo engine into my FB?

Q: I want to upgrade from a 12A to a 13B engine, what can i do?

General Chassis Questions

Q: Are all fuel tanks the same?
A: No. The tanks do have some differences. Year compatibility is as follows:

• 1979-1980
• 1981-1983
• 1984-1985

Also, the GSL-SE equipped with the 13B using EFI had a small difference to the tank. There was a cup in the bottom where the pickup sat. While you can use a 84-85 12a model tank in a GSL-SE, you may have issues with fuel sloshing. A surge tank is recommend to resolve this issue.

Q: What fuel pump options are there?
A: Several. Most common of which are the Walbro 255lph models. A Walbro ordered for the 1983-1989 Chrysler Conquest is a direct fit and has 2 copper washers, the bango fitting for the PD from stock pump, both aluminum washers to install PD, and the 12mm fitting for the fuel pump feed. (Thanks to "3rd and final 7" for this information)

[Whizbang]

Base specifications of the SA/FB

The best way to look at this is from a year to year perspective.

1978 / 1979

At first there were only two trim levels, the S and the GS. The "S" was the base level with the 4 speed manual transmission, at a price of about $6,300. The "GS" trim level consisted of a 5 speed manual transmission, a rear sway bar and a wider 185 tire width for an additional $600. Many opted for the alloy wheels and the rear spoiler. Earlier models only had a driver's side view mirror.

Japanese models had a backseat as a standard option to avoid certain taxes. US models did not in order to have a required crash bar to pass safety standards.

Specifications

Wheelbase: 95.3 inches
Length: 168.7 inches
Width: 65.9 inches
Height: 49.6 inches
Ride Height: 6.1 inches
Track: Front 55.9 / Rear 55.1
Curb Weight: 2,420 lbs

17 city / 26 highway
14.5 Gallon Gas Tank

*The engine was a carbureted 12A four port engine with a 9.4:1 compression ratio. Rated at 100 HP @ 6000 and 105 ft/lbs @ 4000.

*There were three transmissions available; 4 speed manual, 5 speed manual and 3 speed automatic.
Manual gearing was as follows:
1st: 3.674
2nd: 2.217
3rd: 1.432
4th: 1.000
5th: 0.825 (5 speed only)

*All rear ends had final drives of 3.909 with an open differential.



1980

The only note worth changes in 1980 were the addition of the "LS" or "Leather Sport" trim level which included leather upholstery, sunroof and alloys.

The rest of the car remain mostly the same less the increased antenna height, a rubber piece added below the rear bumper and most semi-important, electronic ignition as opposed to the points system. Also, the optional sway bar was 18mm as opposed to the 15mm for all other years.

Specifications

Same as 1978 / 1979 model years.



1981 / 1982

In 1981, Mazda brought the Rx7 out with some new appearances, namely in the front and rear locations. Also, the GSL trim level was introduced which included disc brakes, sunroof, and alloy wheels. Leather was now an option.

We also see the "shutter valve" come into existence as well as the addition of catalytic converters and a split air system.

The price also stepped up to almost 12,000 dollars base.

Specifications

Wheelbase: 95.3 inches
Length: 170.1 inches
Width: 65.7 inches
Height: 49.6 inches
Ride Height: 5.7 inches
Track: Front 55.9 / Rear 55.1
Curb Weight: 2,360 lbs

21 city / 30 highway
16.5 Gallon Gas Tank

Manual gearing was as follows:
1st: 3.674
2nd: 2.217
3rd: 1.432
4th: 1.000
5th: 0.825 (5 speed only)


1983

Speedometer was changed from 85 mph to 130 mph per loosening of government regulations. Effective front mounted oil cooler was replaced by the "beehive" oil cooler.

A limited model was released. Very similar to the GS but only came in Arctic Silver with a red pin stripping and a 14" wheel.

Specifications

Same as 1981 / 1982


1984 / 1985

With sales starting to slow and Mazda about to release the second generation rx7, some attempts were made to keep the first generation rx7 in the public eye. The biggest of these was introduction of the GSL-SE in the States and the 12a Turbo in Japan.

Specifications

Wheelbase: 95.3 inches
Length: 170.1 inches
Width: 65.7 inches
Height: 49.6 inches
Ride Height: 5.7 inches
Track: Front 55.9 / Rear 55.1
Curb Weight: 2,350 lbs (non GSL-SE, m/t)
Curb Weight: 2,590 lbs (GSL-SE)

21 city / 30 highway (12a)
16 city / 23 highway (13b)
16.5 Gallon Gas Tank

12a engine Manual gearing was as follows:
1st: 3.674
2nd: 2.217
3rd: 1.432
4th: 1.000
5th: 0.825 (5 speed only)


Q: What is special about the GSL-SE trim level?

A: Several things.
*The engine was a fuel injected, 13B six port engine, 9.4:1 compression, 3mm seals. Was similiar to the 12a with the water seal grooves in the rotor housing. Engine performance was rated at 135 HP @ 6000 and 133 ft/lbs @ 4000. It used two, 680cc injectors, mounted at the primary ports on the intermediate iron. The beehive cooler was also left on the shelf and a front mounted oil cooler returned to the FB.

*The transmission was a beefier model than the previous 12a transmissions, also using an improved clutch assembly. Gearing was as follows:
1st: 3.622
2nd: 2.186
3rd: 1.419
4th: 1.000
5th: 0.758

*The rear axle was a live axle similar to the 12a equipped cars but sported a 4.076 final drive ratio, vented disc brakes, Limited slip and a 4x114.3 stud pattern (as opposed to the 4x110 with lug bolts).

*The front suspension also used a 4x114.3 hub. The steering was also modified with 3.4 turns lock to lock, and a turning radius of about 32.8 feet.

*The wheels were a 14x5.5 inch wheel withe 205/60R14 tires.

*Weight was listed at around 2650 lbs. I bit more weight than the previous rx7s.

*The price tag? Just tipped the scales at 16,000 dollars.

Wheels Options for the SA/FB

The 1979 "Limited" wheel. Should the rarest of them all. 13" 4x110


The 1983 LE or "limited edition" wheel. 14" 4x110 (thanks to P71)


The "Rotor" Wheels from the top of the line Savannah GT limited. 13" 4x110 (thanks to -xlr8planet-)

[Whizbang]

General 12A Turbo Information

Q: What about the Japanese 12AT then?
A: Well for starters the 12AT was found basically only in Japan. The engine was found in more than just the Rx7, but also the Cosmo and Luce.

Some stand out OEM features (aside from obvious engine items) are:
1. Red cooling fan, Red spark plug wires
2. Gauge cluster with boost gauge
3. "Turbo" wheels
4. Badging
5. EFI style airbox (similiar to GSLSE setup, only have a "turbo" sticker)

There are quite a few other things that is dose share with our GSL-SE. Namely, the suspension. Both cars have the 4x114.3 lug patterns, differentials and brakes. I also believe the transmissions to be the same. While the port timing is somewhat different, the GSLSE intermediate plate might also be adaptable for a 12at.

Rx7 with the 12at

[Rogue_Wulff]

Nice. But, near the bottom of the 1st post you state this:

*The rear axle was a live axle similar to the 12a equipped cars but sported a 4.076 final drive ratio, vented disc brakes, Limited slip and a 4x114.3 stud pattern (as opposed to the 4x100 with lug bolts).

The bolt pattern is 4x110, not 4x100.

[Whizbang]

Vin Number Information

The 1st - 3rd digit of the vin number will be "JM1" indicating a Mazda passenger car.

The 4th / 5th digit of the vin number orients to the series of Rx-7. This is "FB" for all 1st generation models from 1981 to 1985.

The 6th / 7th digit of the vin number orients to the following:

• A Japanese imported coupes will read 33.

The 8th digit of the vin number orients to the engine selection.

• 13B 6PI : 1

The 10th digit of the vin number orients to the year of production.

• 1985 : F
• 1984 : E
• 1983 : D
• 1982 : C
• 1981 : B

The 11th digit of the vin number orients to the plant of production.

• Hiroshima - 0

The remaining 6 digits is the unique serial number in order of production.

Paint Code Information



Production Numbers

First Generation (471,018 total):

• 1978 - 72,692
• 1979 - 71,617
• 1980 - 56,317
• 1981 - 55,321
• 1982 - 59,686
• 1983 - 57,864
• 1984 - 64,959
• 1985 - 33,562

Grand total of 811,634 RX-7s produced

[Rogue_Wulff]

Eh, I saw it right after you posted, but delayed in pointing it out, in case you caught it.
Just how long are we able to edit our own posts?

[Phoenix7]

forever. It's not like other places where they take your intellectual property and don't allow you to remove it/edit it.

[-xlr8planet-]

amazing



thanks for taking the time to do this

[Eatmyclutch]

Good write up.

[Whizbang]

i am reorganizing the thread to make it more user friendly in additional to adding more information!

[Whizbang]

Updates:

10/16/2008

[SAW32rally]

hey low impedance, i just registered like you said. i think i am going for a 13b non turbo swap. which engine will get the best results for the price? thanks.

[3rd and final 7]

Hey if you dont mind id like to add something. i have talked to Greddy in the past about putting the Emanage on a GSL-SE and they are telling me that you can install the Emanage on a 12 volt fuel system you just have to set the switches accordingly

[StumpDrummer]

Hey L I do you have the info on the differences in the struts for 79-85 I gotta get some coilovers or replacement struts very soon!!

[Rogue_Wulff]

Originally Posted by StumpDrummer

Hey L I do you have the info on the differences in the struts for 79-85 I gotta get some coilovers or replacement struts very soon!!

I didn't see this till just now, but here's the quick run down on the differences.
The 79/80 strut housing uses a different insert than the 81-85. The 81-85 insert can be made to work, but you must use a ~1" spacer under the cartridge.
The lower spring perch is also positioned a little lower on the 79/80 housings. This can cause tire/spring clearance issues when running different tire/wheel combos. Most of these same combos will work on the 81-85 12A without problems.
The 81-83 strut housing can be directly swapped onto a 79/80 using the brake rotors and calipers from 79/80, or you can upgrade to the 81-85 calipers by using a custom made brake hose. The 84/85 strut housings can be swapped onto a 79/80, but you will need the matching 84/85 rotors and bearings, as they have different outer wheel bearings. The 79/80 calipers can be used on the 84/85 struts/rotors, if desired.