scott01hickey

I'm looking at getting a RTEK 1.5

I currently have a rev2 exhaust and a corksport tid. Everything else is stock. Can anyone tell me what to expect with the 1.5 version, or should I bite the bullet and upgrade my injectors and go 1.7?? I'm just looking to get a little more kick out of the car, and I am wondering if this will do it.

Thank you,
Scott

Sudowoodo

iTrader: (1)

I'd recommend the 2.1 honestly. That way you have FULL control.

AGreen

iTrader: (11)

2nd Generation Fuel Calculator

Looking at the calculator, the max duty cycle of the FC injectors, as limited by the stock ecu, is between 58 and 63%. At 63%, max expected flywheel HP is 199.7. Raise that to 68%, and it's 15 more (available max) HP. So 215 flywheel HP. Granted, the 1.5 does have a built in FCD, but that doesn't mean it's still safe. Safer, yes. But with a stock, non ported wastegate turbocharger, you can easily boost creep up well past the limits of the turbo and injectors. You need to port the wastegate to prevent murdering the engine. The Rev2 exhaust and a free flowing TID will make things get out of control quickly.

If you are looking for more fun with the added comfort of safety then I would recommend upgrading your secondary injectors to 720cc and use the rtek 1.7 or 1.8. I feel as if the 1.5 is for completely stock engines with a stock exhaust. Seems like the 1.5 is more like what the stock computer should have been.

And if you are going to spend that kind of money on the 2.1, you might as well spend the same amount on building a megasquirt ecu. $450 for an ecu that you still use a flapper type AFM and 1980's era technology (and wiring... eek!) is absurd in my book. For that price, I got a whole new wiring harness, sensors, and a FULLY programmable ecu. And I do mean fully programmable.

scott01hickey

AGreen,

Thank you for your smart & educated answer. I do have the racingbeat fcd in my car. You are right with the free flowing tid I boost creep like crazy. The car pulls strong and then once boost kicks in (9-12psi) it literally feels like someone cut off fuel to the motor. I wonder if I got a dud fcd from racingbeat. Do you know what resistance I should see from the fcd? I would like to make sure it is working properly. I have owned other rx7 turbos with the same setup and they pulled like a bastard, but this one wont. It literally has a major dead spot when boost(9-12psi) hits. I have had the car for about 4 years now and it runs so good that I never changed anything on it... ie.. plugs, wires, fuels pump etc.. If i go to the 1.7/8 route should I upgrade the fuel pump as well? Years ago I lived in S. Florida (Boca Raton), I had great mechanic, Perry, at Rotary Performance. Now being in RI I have no one that I can bring the car to. I am a diesel mechanic, not a tuner, I work on heavy equipment. I feel like I should know more about this stuff, but I guess like anything else experience is key.

Sorry to be so long winded. Thanks again.

AGreen

iTrader: (11)

Ok, so 10 psi max is all I'll ever recommend out of the stock turbo. 12 and up and you are too far out of the efficiency range. At that point, heating of the air becomes the bigger concern and your AITs get to the point where detonation is likely. You don't need to pull the turbo to port the wastegate. If you just drop the downpipe and pop the wastegate actuator off, you can get in there to port it no problem. The stock size is 11mm. I had to use an old lawnmower exhaust valve as the wastegate flapper since I ported mine so big. There are all kinds of threads about WG porting on this site.

Now, as for your dead spot, it could be a couple different issues. I would check out that AFM to see if it has a hang up in its movement. Or maybe you did get a bad fcd. In either case, don't try hitting boost until you have figured the problem out.

Thinking back to my stock ecu days, I remember something about the fcd being nothing more than a voltage clamp. It prevented the ecu from seeing boost pressure higher than like 8.6 psi or something. So the map sensor, which is nothing more than a pressure transducer, sends a voltage to the ecu that corresponds to a specific pressure. It's like a diaphragm with a variable resistor attached. So let's just say for instance that at idle with approx 18" Hg applied, the map voltage is 0.7 volts (out of a max of 5v). At 8.6 psi it might read 4.2v. (These are just made up numbers... for example purposes). If the voltage goes higher than 4.2v, the ecu flips **** and cuts fuel to the rear rotor. Now that's a bad day. So what racing beat's fcd is supposed to do is clamp that voltage at or below (say) 4.2v.

So here's a test you can do. Look at the wiring diagram and see which wire sends the map signal to the ecu. Test voltage at that wire. Hook up a pump to the map sensor and watch the voltage change. Somewhere around 8.6 psi the voltage should start staying constant with the fcd installed. If not, you got a bum fcd.

scott01hickey

great advice thank you

DR_Knight

iTrader: (23)

At least 1.7 personally would recommend at least the 1.8 but timing gets scary if you start using safc. So as said, rtek 2.0 2.1 is the way to go if not going ems

jjwalker

I looked at rteks website yesterday and at least for the S5 NA version, you aren't required to upgrade injectors. Not that I dont recommend doing so on a turbo car, you could at least get away for a bit tuning it conservatively and setting the injector values to the stock flow rates.