Hey guys, I am a bit new to the forums and RX-7's and I had a few questions.
I am looking to buy my first RX-7 it's a 88' my concerns are:

How common is it for there to be a bit of an oil drops after sitting for a few weeks?

The guy has upgraded the turbo to a newer turbo S5 from an 89+ as well as bigger injectors the 720cc's as well as added a piggyback chip to it. Should the car be custom tune, I was wondering if the piggyback chip could cause it to run lean. It does has an aftermarket air/fuel gauge and it appear to run around 12.5 and would drop some when the turbo spools up. I thought 14.5 was normal or idea for air/fuel.
It has a bigger FMIC and turbo back exhaust.

With the rotary engine are there items I should look for to tell if its a good buy?

Thanks in advance for the help.

 

Well, the car is 25+ years old.

Common leak points are the oil pan, metering oil pump, turbo oil return and the oil filter pedestal o-rings.

14.7 is the stoichiometric ratio for gasoline/air, but the car will only run that ratio under light load cruise.

What do you mean by "drops" from 12.5? If it then drops into the 11s as the boost rises, that is exactly what you would want to see. The fuel needs to be richened up during boost and 11s for a stock turbo car is right on the money.

How To Buy An '86-'92 Non-Turbo RX-7
How To Buy An '86-'92 Turbo RX-7

 

I thought the s4 t2's ran 8.5:1???

 

I think you are referring to compression ratio.
The poster is asking about Air fuel ratio.

 

I am a proud owner of a '88 FC T2, and have some advice that might help you out. Oil leaks are a common sight with rotary engines, i just had a major tune up done two weeks ago and now leak again. Try to see where the leaks are coming from, if it is directly under the housings then i would worry. If it is toward the front of the engine bay then it is one of the oil cooler lines which often give out on S4 models, and an easy fix. View the car in a well lit place and see if you can visually inspect the whole engine bay. As far as the tuning goes, the engine has to run perfectly or it will die!!!! Rotaries are not like any other car, any changes will have to be tuned properly, a "piggy back" chip is nothing to the rotary. When you change injectors on a rotary you have to keep in mind that the primary kick in right off at low rpm, and the secondary at higher rpm, if your experiencing odd A/F ratios it means the ecu is not up to date with the injection times that it needs to run properly, also a stock ecu will not have the computing capability to calculate what is needed. I would recommend changing the ecu to a Haltech and having it tuned by a professional, this way you will have the right A/F ratios kicking in at the right time. When tuning it make sure to keep the boost of the turbo at low psi, without any upgrades to the cooling and oil system of the car you will blow the housings, but by using the Haltech when you choose to upgrade then you will have a bad *** set up.
I know its a lot of info all at once but it can definetly help to give you a picture of what work your looking at, and its only the beginning.
Thanks for reading, let me know how it goes.
Marco

 

If you're seeing higher than 12.0:1 under WOT then pull out and do some diagnosing haha

 

To nitpick a little....

Technically, any engine will need to be tuned if you make changes. However some are more forgiving, and some OEM EFI systems are better than others at adapting to changes. Interestingly, AFM based systems like L-Jetronic used on the FC are pretty good at dealing with engine changes. To a point, of course. :-)

A Haltech is certainly a quality and well understood standalone, but a standalone isn't always necessary. For minor upgrading, an upgraded stock ECU like the RTek is a more economical and perfectly capable choice.

It is possible to read your statement to mean that the primaries are turned off once the secondaries are brought online, which isn't true. Both the primaries and secondaries operated together.

Apex seals blow, not housings.