ok im new to rotary so i have some questions, i have a 1987 rx7 with the 91 turbo motor swaped in, what is the max boost i should push on stock internals, also what performane upgrages can i do, thanks and all opinions and suggestions are wanted.

 

Max boost on stock internals? Well the limit to this would be the limit of the turbo's efficiency, the fuel injectors, the fuel pump, intercooler. If you have a bigger turbo, you can run less boost to make your power, if you got a smaller one you have to run higher boost to get that same power but then you get to a point the air coming in is way too hot and your pushing the efficiency of the turbo.....

Basically if you have everything stock, the first thing to get would be a fuel cut defender. The rx7's will cut fuel at a certain amount of boost (forgot the number), if you search you will find the information on this. This will prevent that from happening. I believe the stock turbo can push you up to 250whp easily though possibly more...

Once you get that though, those fuel injectors will be pushing it, you need to upgrade. Then next thing you know you need more fuel coming in with a better fuel pump. Then now you are going to want a way to control fuel via a SAFC or stand alone or RTEK.

The internals can hold up to anything on these engines. If you want to upgrade the internals though you can get thicker apex seals if you are going to be pushing alot of power out of it. This will give you a safety margin in case the engine starts to detonate, you won't shatter your stock apex seals, but with a good tune you will be fine. If the engine is high milage though (100k) you might want to start looking at rebuilds. This engine is very simple, only 3 moving parts, I much prefer having a rotary to work on than a piston engine any day. Good way to test the condition/health of your engine is with a compression test, search this and you will find info on it.

Other upgrades, suspension, wheels, usually brakes are left alone maybe some stainless brake lines. Upgrade to a nice fuel pressure regulator, cold air box, ect....

Hope you get where I am coming from, read the FAQ, and search. There is so much information here that everyday you will learn something new.

Welcome by the way.

 

by the way do you know the stock turbo specs or where to find them

 

I found this by searching titles only, in the second gen section "turbo specifications":

https://www.rx7club.com/showthread.p...specifications

Hope this helps, look into the FAQ on the top of the 2nd gen forum it has lots of information.

 

ok i have other question, i see people sayin, i has the s5 whats and s5, and what do people meen by vert, sorry if its a dumb question

 

its in the FAQ take a look at it and your questions will be answered there......

s4=series 4 - 86-88 FC3S
s5 = series 5 - 89-91 FC3S
vert = convertible (best looking FC's by the way)
FC3S = 2nd generation RX7

 

Search for a hitachi ht-18. That's the stock series 5 (89-91) turbo.

As far as I know, the fuel cut defencer prevents the ecu from cutting fuel at 8.6psi. It does this by tricking the ecu into thinking boost is lower than it actually is. It is literally a small plastic box with a plug.

 

"Vert"= convertible.

The second gen RX's are divided into two series...S5's are 1989-1991 and S4's are 1986-1988.