Does anyone out there know of a good fuel additive for rx7 engines?

 

Additives are not worth the money.

 

Search this forum for that same question. Has been discussed NUMEROUS times, and they always come down to the fact that they are NOT worth the money.

They work off the fact that MOST people think that a higher octane = more HP. WRONG. The truth is that LOWER octane fuels make MORE HP. All these dumbasses pumping 110 octane race fuel into their cars thinking its giving them 15+ HP are soo wrong. Higher octane fuel does nothing more than raise the flashpoint. Higher octane fuels are used in high compression engines, turbocharged and supercharged engines (again because of the higher compression).

Not worth the money. They don't even raise the octane more than .2

 

I have heard good things about marvle mystery oil added to my rx fuel but I cant say it does anything helpful besides give me a warm fuzzy feeling about my fuel injectors.

Haven't you always wanted to feel warm and fuzzy about your fuel injectors?

 

i was wondering if anyone knew of any good engine additives for rotary engines?

 

YES, its called oil - change it regulary. The only other one you will see recommended is MMO. Do a search for it.

 

I used Microlon on my engine in 1988, and it looked great when it was opened up 10 years and 150K miles later. However, I cannot necessarily attribute that condition with the Microlon. I'm not sure if any of those treatments are really worth the trouble.

Here ARE some things that I can absolutely attribute to good engine health over time, based on actual results:

1) Use DISTILLED water in the cooling system. Even though this is specified in the Mazda factory service manual, some of my friends laughed at me for using it in my cooling system. After seeing that the water passages are nearly spotless upon disassembly as opposed to the massive nasty deposits in their engines, my friends stopped laughing.

2) Use good oil, and change it per the Mazda factory service manual schedule. Castrol GTX has had the best results in my experience.

3) Make sure that you accelerate the car on a regular basis so that the secondary injectors get some use. The worst engine I have ever seen was destroyed by a guy who thought he was being "nice" to the engine by always accelerating as slowly as possible and short-shifting. The result of his actions was that the secondary injectors were totally clogged up, and the engine went lean upon acceleration and blew multiple apex seals in both rotors. This engine also had the most deposits I have ever seen, and the 5 & 6 ports were totally jammed and packed with deposits.

 

Whoa thanks for the tips evil! I would have never thought about the secondary injector thing. Now I have an excuse to go fast !

 

I'm not saying it is your fault, but his car was running fine until it was thrashed.

btw, I'm searching if there is a way to insure clean injection without dismantling everything.


SpeedFreak, he just said the car got destroyed after being 'waken up' out of slumber. So how do we find out if running it in is good or bad. It is different if you grew up with the car versus getting a used model.

 

I thought turboed and nitrous fed engines ran lower compression.....

Yup, NA = 9.4 Turbo, 8.5

 

Turbo engines run lower compression ratios because of the forced induction. The high pressure air being fed in has to be offset by the lower overall ratio so the 87 octane pump gas will burn efficiently. All gas has basically the same potential energy, but the various octanes burn at different temps.

Ideal gas law: Pressure = R(gas constant)*Temp / Volume

High pressure applications will produce higher temperatures, which will require a fuel that burns best in that temp range.

 

No, the car was obviously running lean and slowly cooking the motor for quite some time before the engine blew. Also, it is unsafe to drive a car that can't accelerate on demand without blowing the motor, and I don't think too many sports car owners would consider this an acceptable condition.

FYI the engine was not blown due to "thrashing". The original owner simply accelerated to pass another car and the engine blew up.

The cleaner in the bottle doesn't work so well. It is easy to pull the injectors anyway. Also, the air bleeds will be full of crud, so clean those too. Be sure to use new grommets.

 

1)+1 for Distilled water! I also like to add a bottle of Redline's Water Wetter.
3) This type of behavior is frowned upon in the RX7 community!
Obviously this guy is more suited for a GEO!

 

By using only a distilled water, will it make the car water temp higher than using a coolant???

 

^ I think he means distilled water with antifreeze. It's to prevent sediment buildup. See below.

Engine Oil: Use only API certified oil. See the FAQ for recommend synthetics. They are better, but expensive and not at all necessary. Always great for the tranny & diff tho, since you change those less often. A good engine oil has all the additives you need. Most/all other oil additives are snake oil. Many are ridiculously thick and thus seem to slow leaks & oil burn in old engines... until that molasses causes excessive friction and wear.

Gas: See www.toptiergas.com. A good gas has all the additives you need. Some bottled additives are good (and the same as what they put in good gas), but others are snake oil.

Coolant: Use roughly 50% ethylene glycol antifreeze that's safe for aluminum and 50% distilled water. More water will run slightly cooler, but also reduce boiling protection. More antifreeze will increasing boiling protection, but it'll run slightly warmer. It makes little if any difference, and 30-70% is okay. NEVER RUN PLAIN WATER. It will cause rust and eventually destroy your engine. Even if it's distilled when you buy it, it won't stay 100% pure for very long. Antifreeze contains anti-corossion additives. Change your coolant & thermostat (with OEM) every 12-18 months to keep corossion away. You can buy more anti-corossion additives to extend the life of your antifreeze, but I'd just change it to be safe. Water wetter, purple ice, etc. do lower your temp slightly, especially when you use more water. Still use at least 30% antifreeze and change your coolant more often b/c you have less antifreeze.

 

regg25, I merged your two topics together since they were virtually the same question.

As others have posted all additives are junk. Piston or rotary, doesn't matter.

 

I have had really good luck with lucaus fuel treatment. It seemed like the car ran smoother after I added it.

 

See the above post by ericgrau. Also see the factory service manual. Many of the questions posted on this forum can be answered by simply reading the manual.

 

the best fuel additive for a rx7 I can think of is 2 stroke oil