I just got my 7th 7 all sorted in stock form, and am interested in trying an aftermarket/modded ECU such as an Rtek. I am quite naieve about the tuning aspect, as I have never been to a dyno, but have tuned many past cars with carbs/injection with a Gtech and a wideband.



Questions are:

1.) What kind of improvements can I expect from a properly tuned ECU change while keeping a mostly stock S5 6port NA that is used mainly as a highway cruiser that is driven "spirited"?



2.) I understand tuning WOT on the dyno, but what about tuning part throttle to retain drivability?? Is it done the same way without flooring the car on the dyno?



3.) I'm not after a racecar, as anyone with a NA finds out sooner or later, but instead, I am after better fuel economy, better performance climbing hills and such, and generally a better running car, especially in the upper rpm range, where my car seems to get waaayy rich.



On top of everything, I am sick as **** of 1980's FI. It sucks, and want something that I can play with.



Thanks!

Jim

 

I doubt you'll get much improvement in an n/a by going aftermarket ECU. I've heard you can pick up a little midrange torque by leaning out that area of the map, but this can be done with a piggyback like the S-AFC. If you feel the need to tinker, then by all means, but you'll probably find that it will take a good deal of time and effort to get a map as good as the stock one.

 

best thing about the rtek is that you START with the stock map. so when you plug it in, the car will run the same as it did before.



1. you can expect a bunch more top end power, stock ecu is really rich up top (11:1ish over 5000rpm), leaning it out even to like 12:1 feels HUGE, power actually goes UP after 5000rpms. additionally the stock ecu can be a little lean under 4000, so you might be able to pick up 2-5hp there too



3. since you can adjust the whole map, you can prolly get the idle low speed range a tad better, lean out the cruise a tad etc etc. this depends on the other stuff you have done to the car. if the car is 100% stock, the stock ecu isnt too bad, but when you mod it, the stock ecu's usually compensate the wrong way

 

I stand corrected!

 

Well, that is kinda what I am after. I have gone the "porting a 6 port" route before, and while it did make a difference, having to see the red side of 7000 to notice it was not really worth it. The S5 isn't really exciting fast, but it is decent, and the VDI thing is really cool to feel. I MAY do headers when my hearing deteriorates a little more, and this time, AFTER I buy a RB exhaust. I have an intake that I made out of carbon for it, and I run the timing a little advanced, but other then that, I want to keep the thing fairly stock and reliable.



On a sidenote, does anyone have a S5 Rtek they want to sell?? I have an extra CPU to send in, but if someone has one already done up, I would be interested.



Thanks again!

Jim

 

Well your in luck with having an S5 N/A to play with and considering buying an Rtek, right now they are in their testing phase of their S5 N/A Rtek 2.X which is suppose to incorporate AFM Deletion. Id expect them to be ready to have it on the market later this year.

 

Hmm, Im glad I looked at this forum I might go with the Rtex as well instead of a complete standalone