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RX-7 1st Gen Specific (1979-85) RX-7 1979-85 Discussion including performance modifications and technical support sections

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Old 06-15-2009, 10:29 AM   #16
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Quote:
Originally Posted by StumpDrummer View Post
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.







Last edited by Rogue_Wulff; 06-15-2009 at 10:31 AM..
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Old 01-11-2010, 06:22 PM   #17
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Originally Posted by Gravity Fed View Post
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)
Q: i just got a 1983 rx 7 thats in real bad condition and im redoing the wiring system on it for one and two i cant find an air intake hose anywhere wondering if anybody can help me out with that and im brand new to the site so still learning how to work it so any other tips would be good thanks
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Old 03-30-2010, 03:46 PM   #18
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sounds like you just need a shop manual with the schematics and im not clear on the air intake hose thing.
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Old 07-29-2010, 09:42 PM   #19
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amazing


http://www.blcrushers.com/
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Old 07-29-2010, 10:45 PM   #20
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Old 08-29-2010, 11:50 PM   #21
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so any thoughts on the value to a set of 79 limited wheels?
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Old 10-14-2010, 04:12 PM   #22
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Default Redline Water Wetter is safe for rotaries

I finally read parts of your informational thread. Over all excellent for documented information.
I do take exception with:

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)

Do know know which scientific studies you have access to.
I have been using Redline Water Wetter since it was introduced back in the 80's.
Use it in all client vehicles, race vehicles (from IT stock motors to full Bridge GT motors), Generators, AC, with no problems that could be related in anyway to water wetter.

When it was first introduced it did not have the protection for aluminum, and they recommended that some, at least 5% glycol be used in motors that contained aluminum parts. The product has contained aluminum protection for well over 20 years.

Redline worked with Mazda to formulate chemical products that are safe to use in the Mazda rotary. Unfortunately they still could not come up with a synthetic that could be used in meter system vehicles.

I continue to use it and recommend that any vehicle that is exposed to or will be used in extreme conditions use it. Also recommend that the more extreme means to change oil and coolant more often.

I change the coolant in my clients vehicles every 3 years or 30K miles, max, as per Mazda service schedule.

My experience is that most coolant related failures were due to either tap water, lack of service, incorrect mixtures, repairs or odd ball chemicals introduced. These generally lead to inevitable overheating. A couple were related to "improved cooling" modifications incorrectly done to housings. Tap water failures were actual housing failure due to corrosion.

Otherwise good work.
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Old 11-22-2010, 02:00 PM   #23
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Can we talk a little more about simple spring/strut combos v. coil over setups? I have an 85 1st gen and she is tilting in the back (which I think may have compressed the brake line, no bueno). I took the wheel off and jacked it up, nothing is visibly broken, but it's getting a little crusty and I was considering replacing the shocks and either the coils or looking at a simple spring/strut combo. I have read through the manual and see how to make the swap, but in shopping for parts (the readily available ones sitting at autozone of somewhere of the like) I see that shocks are easy to find, but coils are not, would it be easier if I looked for the spring/strut combo?

I drive the car as a daily driver and with less than 60k original miles I would like to continue to do so for a while, so I am considering replacing shocks + coil or coil/strut combo in at least the rear of the car, perhaps front and rear.

I 'think' I understand how to make the repair, but I would love some advise on solid parts suitable for everyday driving, and maybe not a million bucks

Thanks,
Sarah
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Old 11-22-2010, 03:07 PM   #24
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Quote:
Originally Posted by sarah View Post
Can we talk a little more about simple spring/strut combos v. coil over setups? I have an 85 1st gen and she is tilting in the back (which I think may have compressed the brake line, no bueno). I took the wheel off and jacked it up, nothing is visibly broken, but it's getting a little crusty and I was considering replacing the shocks and either the coils or looking at a simple spring/strut combo. I have read through the manual and see how to make the swap, but in shopping for parts (the readily available ones sitting at autozone of somewhere of the like) I see that shocks are easy to find, but coils are not, would it be easier if I looked for the spring/strut combo?

I drive the car as a daily driver and with less than 60k original miles I would like to continue to do so for a while, so I am considering replacing shocks + coil or coil/strut combo in at least the rear of the car, perhaps front and rear.

I 'think' I understand how to make the repair, but I would love some advise on solid parts suitable for everyday driving, and maybe not a million bucks

Thanks,
Sarah
This isn't really the thread for that question, but I'll help you out.

For a strut/coil combo you have a few choices. You can get some Tokico's or KYB's. There are more expensive stut/shocks out there, but those will do fine for what you want. Racing Beat makes some excellent springs for what you want as well.

But, for all your first gen needs, contact Billy at RESpeed.
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Old 11-22-2010, 08:13 PM   #25
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Thank you and I wont be offended if you delete my question and your response, could it maybe be split into a new thread?

I might have some more questions
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Old 11-22-2010, 09:03 PM   #26
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I think if a Mod were to see it, they might be able to help you out with that. Or just copy and paste to a new thread in the first gen tech section!
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Old 09-02-2016, 12:05 AM   #27
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Whizbang. I don't remember if I asked this yet so here goes. I'm tearing down my 12A. Where can you point me for info on how to properly do the ports? It'll be my first time and I don't want to grind away too much. Only looking for around 20-30 hp. More would be nice but my FB will be daily driven, with aircon, in hot and heavy stop and go traffic, so I need reliability. I'm going to put headers and I've already got instructions on how to mod the Nikki. Any help as to where there are any instructions, would be helpful. TIA.
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