i have a bnr stage 2, t3/4 turbo, fmic ,3rd gen pump ,havent decided on what injectors yet ...now i,want to put this altogether but as i read on this forum always go standalone when adding a bigger turbo ...so i would like to hear from rx7 members there pros/cons when they went standalone ...or even if they had a rtec ...and your install was it hard or did you have a tuner install it

 

In a nutshell the cons are initial cost and time (time mainly in building the wiring harness yourself. If you have someone else do it its just even more stacked on costs).

Pros: You can do whatever the hell you want as long as the mechanics of your car can physically support it.

 

i hear good things with the rtec 2.1 piggy back anyone with good results...also what standalone models are you guys using

 

I have a Haltech Platinum Sport 1000 but not currently in the car since the engine that its going on isn't in the car yet.

 

Can't you just use a simple piggyback fuel computer with the BNR Stage 2?

Piggyback fuel controllers still use the crappy old stock ECU as a base. However, if all you need is a simple $400 piggyback fuel computer, then there isn't much point in going through all the trouble and expense to convert to a full standalone EMS.

My racing friends always go standalone with NO turbo, lol.

The installation itself is not that hard in most cases, but it depends on your EMS. For example, the new Wolf and Haltech models have plug-in adapters available which make them about as easy to install as a new in-dash stereo. Most EMS models install with a flying lead wiring system that you either need to wire to the stock sensors, or wire to new sensors that you may need to drill and tap into the engine. Some EMS models require more work, such as the Electromotive EMS which involves installing a 60-2 ignition wheel and its own coils, or the old Wolf EMS models which required modifications to the CAS.

The hard part is initially setting up the parameters of a universal standalone EMS to work with the 13B engine. This is not required in application-specific EMS models such as those from Microtech, or in plug-in models which are pre-set with a base map. Other than that, the rest of the hard part is the tuning. Contrary to popular belief, owning a wideband O2 meter does not make you a tuner.

The functional downside of an EMS depends a lot on the model. Some do not have closed-loop O2 sensor support, some do not idle well, some do not work well with air conditioning, some do not work well with the S5 OMP, etc. Nearly every standalone EMS is intended to run in speed-density mode on street cars, which means that once tuned, the engine must be re-tuned for modifications or aging effects which affect the airflow efficiency. The 86-91 RX-7 stock mass airflow system will automatically compensate for minor differences in engine efficiency.

The functional upside of an EMS on an FC RX-7 is the elimination of the 3800rpm hesitation problem, elimination of the overboost fuel cut, elimination of the airflow meter, elimination of the computer-induced flooding problem, and most importantly the elimination of the 1980s technology stock ECU. To give you an example of the better tuning possible with a standalone EMS, I was able to drive a FC RX-7 in a parking lot in all 5 gears without ever touching the gas pedal. That same car averaged about 30mpg on the highway in open-loop. Other advantages, depending on the EMS model, may include datalogging, turbo timer, security system, electronic boost control, extra and/or larger injector control, N20 injection control, ADI control, radiator electric fan control, etc.

 

You don't always have to make or rewire your own harness. You can get the PowerFC and it plugs straight in to the harness that is already in the car. Also, if the harness that is already in your car sucks you can get one from Corksport.