I'm new to this forum and megasquirt but not RX-7's. I have a few questions and appreciate everyones input. First a bit of info on my car to help understand what I'm looking to accomplish. The car is a 1982 RX-7 with a 1987 6 port 13B. The 13B has a cartech turbo kit on it designed for 6 port 13B's. I have a GSL_SE gas tank and high volume bosch pump. I just ordered a megasquirt kit and daughter card with the dual Im1815 circuits. I have 4- 720cc injectors. I understand adding the pull up resistors,and 99% of the wiring needed to be done. My questions are as follows.
Do you completely remove the mass air sensor?
If so what MAP sensor to use in its place?
The throttle position sensor I have loses contact at 1/3 throttle...fron reading your posts it looks like the turbo throttle sensor keeps contact thru full throttle?
If so will that sensor bolt on or will I need to fabricate a bracket?

I know some of this may be old news to some of you but I did read through the forums and saw nothing on these topics. Thanks again as everyone's already been a great help. custom13B

 

If you are going to use the MS for full fuel and ignition then you can remove the AFM.

The MS comes with a MAP sensor that is good to ~21 psi of boost, just use that unless you plan to go higher on boost.

Your TPS is a S4 sensor so yes it is only good for part range. The S5 cars have both part range and full range sensors. To put an S5 sensor on an S4 engine I think you will need to switch over the TB + UIM + LIM--not really worth the effort--unless you just have that laying around. I don't know of anyone that tried to convert a S4 engine to use a S5 sensor (other than mentioned above).

I have the same problem, but I will try to use the mapdot feature instead of tpsdot for accell/decel enrichment. The part range TPS will still be good for some features so I will still leave it in. I've heard there may be problems using mapdot on a turbo engine, however, it may work out just fine--I'll know soon.

If that doesn't work out then I'll be forced to install a full range TPS--probably a GM or Ford unit.

HTH,

Scott

 

I'm pretty sure mazda doesn't use the full-range TPS for anything other than controlling the OMP on S5's and 3rd gens.... They use the narrow range for enrichments and such... The point is, when I megasquirt the S4 turbo and S4 NA that I have waiting.... I'm going to use the narrow range and try to set everything up so that works well... I'm pretty sure that I'll be able to get proper enrichments with just the narrow range...

My reason for this is that when using the full-range TPS, tofuball and I noticed that most of the enrichment is needed at lower revs when going from closed throttle to any open throttle state.... but at most other times during engine operation, having accel enrichment enabled causes the engine to go super rich for about half a second or so... and the values that work at lower revs don't work from about 2000-3000 up... I don't think any enrichment is needed above the point where that tps loses contact... So I'm going to test this on both of the S4's over the next few weeks and if I get it to work the way I want, I'll probably just use the narrow range for all the cars I tune.

Ken

 

Its not hard at all. The S5 throttle body bolts straight up to the S4 equiptment. Thats what I'm using for my RX7.

 

Thanks guys I appreciate your input. I'll keep my eyes open for a S5 throttle body with sensor. I have a spare S4 but that does me no good. I may try running it as you both suggest and Mazda does with the stock sensor. The megasquirt will be here anyday now I cant wait! Been wanting stand alone for years. Also have new injectors coming so if anyone needs a near new set of RC 550cc injectors PM me or I'll ebay em. Thanks again Im sure I'll have more questions.