livevil904

1. What's the curb weight of a 1988 rx7 convertible? I've heard numbers from 2600 to 3000+

2. The previous owner, an arrogant 22 year old, told me to never use high octane gas (only use 87) because it was hard on the engine. Is there truth to this?

3. He also told me to add a small bottle of 2 stoke motor oil into the gas tank every month or so. He said it cleans out the engine. What are some opinions on this?

4. How often should I change the oil? The manual says 7500, but that seems pretty long. I know this really isn't that important of a number but what are some opinions?

5. What are some easy and cheap i.e. less than $100 modifications I could do to improve performance? I am no mechanical expert, but I'm confident in myself and my dad has worked on cars all his life so he could help me out. I'd be very interested in cutting weight, but its still my everyday car. Possibly someone could refer me to a thread for this.

6. How important is it to let the engine warm up before driving? Previous owner said it was VERY important.

gracer7-rx7

iTrader: (16)

I'm sure some 2nd gen gurus will come along soon but in the meantime read the 2nd gen FAQ to learn more about fuel, premix oil in the fuel and oil change intervals.

misterstyx69

iTrader: (142)

1: about 2800 lbs..Specs are on a sticker inside the driver's door jamb.
2: NA Fc's like a good 85-87 octane..anything higher is just a waste of cash.
3: putting a small bottle (like 3 oz) in the tank won't hurt the car,But IF you Omp is working you are just adding Money into the engine to get burned,,again.(you can call it a precaution to add 3 oz per tank though,just in case the omp craps out)
4:.5000 miles is a good number to shoot at when changing oil.
5:Good air filter..(COLD air intake if you can swing it).good brakes,good shocks,good wires,plugs,fuel filter,,all good suggestions...later TIRES.(I know more than 100 bucks..lol!)
You don't have to wait until your beard starts growing before you can drive the car,just don't Goose the **** out of it until it has gotten up to normal operating temp.
I hope that helps..
Welcome to the Forum.Cheers, Styx!

livevil904

the only reason i asked about the octane is because, where I live, all gas is 10% ethanol except for a few stations that sell 100% gas at 91 octane. that would be the only time i would get high octane gas

misterstyx69

iTrader: (142)

Gas here also contains 10 percent ethanol..no big deal..
run the stuff and enjoy the car!

livevil904

i know its not a big deal, but E10 does steal horsepower and mpg, not much but some. thats why i sometimes get the 100% gas

so the question still remains - is it bad to use high octane gas?

the inside of my door did not show curb weight but it did show "max load" (680lbs) and gross vehical weight (34xx) so i guess you got curb weight by subtracting them? I will most likely just take it and weight it sometime (i'm just the type that likes to know these things lol)

Evil Aviator

As per the original 1988 brochure that I am holding in my hand... 3003 lbs.

No, that's not true. A stock 1986-89 RX-7 is rated for a minimum of 87 octane with no more than 10% ethanol, and no amount of methanol. If your car still has the original owner's manual, you can find this information on page 1-4.

Higher octane fuel will not hurt your engine, but it will cost more money, so there isn't any point in using it unless your engine is in such poor shape that it is pinging with the lower octane fuel.

There are a lot of misconceptions about high octane fuel... it will make your car faster, it burns too fast and ruins your engine, it burns cleaner, it gets better gas mileage, it gets worse gas mileage, etc. This is all BS. The octane rating is simply an anti-knock rating, and that's all. The octane rating is not necessarily related to gas mileage, burn rate, or energy content.

Similar to a 2-stroke piston engine, the rotary engine requires oil injection of some type. The stock configuration has an Oil Metering Pump (OMP) [or Metering Oil Pump (MOP)] that takes engine oil and injects it into the engine combustion area at the rate of approximately 1 qt per 3,000 miles. If the OMP on your car has been disabled, then you will need to add oil to the fuel tank at the rate of about 1/2 oz per gallon. If your OMP is still working, then there is no need to add any oil to the fuel tank. Some people think it helps, but I have not seen any proof that pre-mixing plus the OMP makes the engine last any longer than the OMP alone.

Its probably best to use the "Unique Driving Conditions" schedule in the manual. Personally, on my convertible I tend to hit the time before the mileage, so I just change it twice a year. If you put a lot of miles on your car, then I think the most efficient method would be to change the oil/filter every 6,000 miles and add 1 qt at the 3,000 mile mark between changes. I assume you are not racing this car on a track.

My recommendations: Castrol GTX oil in the engine, a Fumoto F106 Regular Valve oil drain valve to replace the crummy stock plug and annoying crush washer, a good synthetic (Red Line, Amsoil, Royal Purple, etc.) for the manual transmission and differential, and Castrol GT LMA or ATE Super Blue / Typ 200 brake fluid.

I also recommend that you install new oil filter pedestal o-rings. These tend to crack after about 50,000 miles or so, causing oil to seep on the upper heater hose, which then develops a pinhole leak that is really annoying. Plus, the upper radiator hose is rather expensive, so it is no fun to replace it. The o-ring part number is 9954-10-1601, you need two, and the cost is about $5 each. If you don't want to replace them then I recommend putting something like aluminum foil over the upper heater hose to protect it from the seeping oil.

Other than engine porting, there really are not a lot of cheapie performance mods for a non-turbo car. If you are on a tight budget, then it is probably better to just replace worn/broken parts with aftermarket performance parts that tend to be about the same price or even cheaper than OEM. Other than that you should probably just spend your money on regular upkeep. The convertible RX-7 is one of the nicest convertible sports cars ever built, and unlike a Honda Civic it doesn't need a bunch of aftermarket junk to make it better.

Here are some items that I have on my convertible that I added when the OEM parts needed to be replaced or serviced:
- Cat-back exhaust (performance exhaust is the best bang for the buck on these cars, I prefer the Racing Beat brand)
- Performance air filter (I like K&N because it is good for 10 years or 1 million miles)
- Performance springs and dampers, new bushings (I like the Racing Beat springs and KYB AGX dampers for street/autocross use)
- Good battery (I like Optima Red Top and Interstate brands)
- All-aluminum radiator (I have the Koyo, the stock radiator sucks because the plastic end tanks split and may even explode)
- New OEM pulsation damper, new rubber fuel lines, cleaned and "rebuilt" fuel injectors
- 89-92 OEM stereo surround and AC grille to replace the brittle 86-88 stereo surround that cracks after about 5 years.
- Mazdatrix shifter bushing rebuild kit
- Good tires (I have Falken Ziex ZE 912 tires on my convertible because they are an inexpensive, good all-weather touring tire that also handles fairly well for autocross)

* Read here about the pulsation damper problem:
http://www.mazdatrix.com/c-pulsation.htm

Other common mods:
- Performance clutch
- Light flywheel
- Full performance exhaust system
- Upgraded alternator if you have a big stereo system
- Performance brake pads
- Short shifter
- Sway bars
- Front strut tower bar

I do not recommend:
- Underdrive pulleys

Long thread about various power mods:
https://www.rx7club.com/forum/showthread.php?t=31410

Good vendors to browse for parts and FAQ:
http://www.racingbeat.com/
http://www.mazdatrix.com/

There are several engine rebuild videos available that will come in handy when the time comes. Your dad will be a great help with this, even if he has never rebuilt a rotary engine.

Not usually important. The stock Accelerated Warm-up System (AWS) is just there for emissions, and if you press the gas pedal it will drop the idle back down. When it is really cold outside I like to let the engine warm-up a bit because the engine is an aluminum/iron sandwich design, but other than that I just crank the car and go.

livevil904

Thank you

Just so we're clear, I know that high octane gas will not benefit my car. The non ethanol will though.