Ok I just purchased a Stock 1986 Automatic Rx-7. I wish it wasnt Automatic but its the only one around here so. Any ways I was wondering if you guys new some cheap ways to make it faster.

 

Unfortunately, "cheap" and "RX-7" don't belong in the same sentence. However, if you don't know the car's history and pedigree, then you need to do a full tune up. First, check the engine's compression on all rotor faces. If the compression is not good, you'll never get the most out of it and you will be facing a rebuild before too long.

Then, Plugs (NKG's), Plug Wires (8 or 8.5mm's), fuel filter, hoses, belts. Set the TPS and idle to spec; set the timing to spec.

Change out engine oil and the oil filter. Use Castrol GTX or Havoline in 10W-30 or 20W-50. Use a good quality filter, not the el cheapos. Transmission and rear end oil. Use a high quality synthetic 75-90 gear oil. Neo, Redline and Royal Purple. First check to see whether your rear end is LSD and use an oil for LSD differentials.

You're out of the cheap things to do by now. Best mod for the most power gain is in the exhaust system. RX-7 stock exhausts are a bit restrictive. Cat Back exhaust and freer flowing mufflers will free up the most HP. Probably cost you at least $500 though.

Take out the stock air filter box and replace it with a cone filter and fabricate a heat shield box around it. This will only cost you the price of the filter and AFM adapter. Look on E-bay.

Then start reading the posts on this forum and in the archive forum. Read the post and responses on "building a beefy N/A". Do your home work.

 

Intake, exaust, bareblock, fivespeed swap, wr, those are about the cheepest I can think of but before any of that do all of the standerd maintence, that will go along way. oh and read the stickeys at the top. good luck

 

Checkout and test your 6pi (aux ports), they help with your top end.

 

Full tuneup. Plugs, wires, filters, fluids, TPS adjustment, etc. etc. etc. Proceedures are in the Haynes and Factory Service Manuals.

 

unfortunatly, automatic rx7's are pigs....... their redline had to be lowered due to the torque converter (if i remember correctly)...and the auto tranny robs horsepower..... so, the first thing i would invest in is a 5-speed swap..... auto rx's are for casual drivers who want the looks of the fc, not the performance, cause performance was sacrificed the second that auto tranny was put in ....... and im not biased, i have an 88 gxl w/ an auto tranny, and a 91 w/ a 5-speed...... i just know first hand

 

Thanks man. I dont know alot about these cars other than the fact there absolutley my favorite car. So exaust is the first real mod to put on it other than the other small stuff?

 

yeap, also redground the engine, seems to be a common problem.

 

btw guys, what is the stock HP for a Automatic Rx-7

 

its rated the same 146 hp..., getting a full exhaust system( including header, like a racingbeat system) , and a performance air filter would be a good performance increase, as well as the recomended tune up procedure

 

here are the first mods i did on my automatic 88:
1. rebuilt motor
2. swapped in full manual drivetrain

an old motor with 600 dollars in mods will likely get stomped by a fresh well built motor. as far as the manual swap the straw that broke the automatic's back came when i was burned by a pos base model eclipse because the JATCO automatic in these cars CAN NOT LAUNCH and coupled with the 3.9 rear end i prolly would have had... let me stop, i hated my automatic but that doesn't mean you can't like yours... but let me tell you the day i drove that motor to 7k and heard those gears wind up was a damn good day.

if you do decide to do the swap beware of the write up that is in these archives. it is strictly for series 5, 89-91 transmissions/rx-7's, though it claims otherwise.

 

Thanks for the advice man.

 

you might want to look into how to do a compression check..it's a bit different than a piston engine compression test..( a manual or sticky up top will give you the info )..welcome to the world of rotary...you will never be the same!

 

doing a tune up actually increases horse power and makes the car (and you) feel better. and far as free horsepower you car remove the a.c. if it has power steering do the same. also maybe a junkyard electric fan will free up some of the horsepower as well. remove filter( though not recommended)advance ignition timing( manufacturers tend to set them onta conservative side,some not all)remove exhast system(depends where u live)low temp thermostat (never heard of one for rx but maybe they do ?)bags of ice on intake mani.(before running it in a ace or something) and also using higher octane gas will help. (I use 93 on my tii) These were all taken from an issue of TPI magazine so if anything i said was wrong or for a ****-on( I meant piston) engine you know why. Erik

 

yeah, don't take your air filter off.

 

Ok thanks again for the tips guys. All are welcome.

 

A/C only sucks power when it's turned on. If you turn it off, you have your power back.

If you are going to do this, make sure to do it properly by swapping on the manual rack.

No it won't. http://www.aaroncake.net/rx-7/efanmyth.htm

That's terrible advice. If you remove the filter all kinds of junk will be sucked into the engine. Install an aftermarket filter...

Not easy to do past a few degrees on the FC, also might require shifting to premium fuel. Not worth it.

Right....If you remove the entire exhaust system, the engine will be ungodly loud and you will likely lose power due to lack of exhaust velocity. Just dropping the rear half will help a little, but again it will be super loud.

Why? Engine runs richer when it's cold, and thus makes less power.

NO! NAs should run the lowest octane you can find. Stock TIIs should run 87/89, and modified TIIs should run a higher octane.

 

1. Do a compression check to make sure its gonna be worth doing any mods, FIRST!!
2. As mention in your other post exhaust and air intake are the first things you should do to your 7.
3. do the 5 speed/miata swap.
4. do away with your cats, when you replace your exhaust your gonna have to convert your ports to electric/ run them off of the airpump(do a search they are both cover in this forum) , being your not going to have the backpressure pipe anymore off the old cats.
5. all this is gonna cost you so be prepared.

 

No it won't. http://www.aaroncake.net/rx-7/efanmyth.htm




well thanks Mr. Cake. Sorry for bad advice did learn though ! good thread! and if you read on mine; all that info was taken from a magazine I was just throwing it out there like I said.thanks.erik

 

Yeah, but boost is better.

 

What does that mean?

 

I replaced the three stock cats with a single RX-7-specific high-flow cat. It activates the 5th/6th ports the "stock" way, and I still pass Chicago-area emissions.

 

i have a 91 rx7 vert w/ manual trans. i love it but it runs rough at about 40mph and up. can anyone tell me what it might be thats causing this problem?

 

Probably be best to start your own thread (no "thread-jacking" ).

But, if you DO start your own thread, be VERY specific about the 'speed related' issue otherwise it's unlikely your question will get much response.

 

A good intake system will help the exhaust flow better from what i hear