Other than a cooling system upgrade, the only mods on my car is a free flow intake. I do not take the car out on the track and do not push my car. I am looking at a Racing Beat double tip cat back and a 3" stainless steel downpipe. I am hoping to avoid remapping the ECU. I have read conflicting articles and am uncertain if I really need to do this and would rather not purchase a remapped ECU. My car just turned over 40K miles. The catback exhaust is necessary. The downpipe is not, but while I am already working on the exhaust....

 

no

just dont put a midpipe on yet

 

^^What he said. You should be just fine. Replacing the downpipe will help clear some of the heat away from the motor/turbos.

 

If you want to play it smart, install a boost gauge before the exhaust mods. You should see 10psi.

Then install the exhaust mods. You should still see 10psi. If it goes at all above 11psi (test it when it's cold) then you need to do something. The easiest/cheapest solution is to install a boost controller and get it back down to 10psi. Or if you're really cheap, take a 3/32" drill bit and drill thru your wastegate pill. That should put you around 9-10psi.

Remapping the ECU can cover the problem but you still won't have any control of your boost, and tuning/mapping is misguided if you can't keep your boost where you want it.

Dave

 

Yes it is. Removal of the pre-cat is an important reliability modificatication.

 

The mods you have chosen are all good for performance and reliability. However, you WILL see boost levels rise to unsafe levels. As Dave mentioned above, keep the boost at 10 psi maximum (with some sort of boost control) , and you won't need a rechipped ecu.

 

I have a boost gauge that reflects 12psi when I push my car. I suspect that my gauge might need recalibration because I had a good mechanic test the boost and he would get 10psi. In any event, with respect to a boost controller, do you have any recommendations as to which one I should purchase and how difficult is it to install one?

 

search under 10 psi rule. lots of info here.

Jeff

 

Your safest bet is to put a manual boost controller set to 10psi. With the racing beat exhaust your safer since thats more restrictive then some of the others.

 

Manual boost controller will be your cheapest/simplest option. It is pretty simple to tune/ install. You will find a writeup in the FAQ for the install.

 

Keep the boost at 10 psi and you'll be fine. I would recommend a power fc as the cars run much smoother with it and you will have both monitoring and tuning capabilities for later.

 

what about rising boost only during tough races? for example i have to race somebody, i have only reliability mods and boost set at 10psi by electronic boost conroller. can i rise my boost to 11-11.5 temporarly for couple of races and than put it back at 10? will the engine suffer hard because of this?

 

It only takes detonation once at hard running to ruin something.

The stock fuel system does not support above 10 psi properly. Stay at that level.

 

^^ what he said. my first motor lasted 3 months. second motor 6 months. third motor still going strong after alot of reading, research, and whole lot of down time.

 

The FAQ doesn't show anything, no matter what I search...Kinda dumb how I can't just look through it (maybe its broken)? I'd REALLY like to know about this manual boost controller; so far what I've read about ecu's is really scaring me away from them... at least the kind you're supposed to program yourself.

My 2 cents: dropping in an aftermarket computer to control what is already a perfectly tuned machine sounds ridiculous from a reliability standpoint. Even a clean sounding smooth running end result isn't enough to justify the aftermarket ecu's remapped settings. You need long-term testing, the kind I'm sure Mazda spends much more than just a couple hours on.

 

my boost spiked to 1 bar once i installed dump pipe and kept hitting fuel cut. Installed Profec B on the weekend and all is good again.

Another question. Can you run mid pipe once you have PFC? I herd you cant with out modifying the gates, is that true?

 

I give you credit for searching and bumping an old thread instead of just starting a new one.

Try this. http://www.fd3s.net/how-to_turbos.html

one600: You'd need to have the waste gate ported before you can run a midpipe, because the stock wastegate is insufficient to control the incresed volume of air flowing through at that point.

 

It's there, under 'M': https://www.rx7club.com/3rd-gen-archives-73/my-boost-control-setup-perfect-10-8-10-pattern-178136/
Here's another one that might help: http://www.rx7.org/Robinette/boost_controller.htm

Consider that for better or worse, the aftermarket "re-flashed" ECUs have been field-tested now for well over a decade and feedback among the users is out there.
Many also go with a programable engine management system with more flexibility and those are all pretty well time-tested too....again for better or worse. Like most things, there are advantages and disadvantages based on use of the car, current or anticipated modifications and of course, cost. But IMO, none are "ridiculous". My .02.

 

Mazda was most concerned with emissions, cost, and reliability at stock power levels over the life of the car with any fuel. Mazda had to assume the owner was an idiot.

Programmable ECUs allow higher power levels and better fuel economy if properly tuned. It helps that the aftermarket programmable computers have more computational power too. If tuned well and run in a well sorted car, they are in fact better than the stock ECU in just about every way.

Dave

 

The factory ECU isn't exactly the FD3S' best feature.

 

By today's standards having an 8 bit OBD I ECU that's probably true. But was it so bad for the time.....15 years ago?

 

my friend bought RX7 it has 94K kilometers on it.
from what i saw, the car has only catback and dirty stock air filter. tested boost on sunday and it was over 10psi, aproximately 11.5. we were testing in BARs it showed 0.8-0.5-0.75