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Premium Member
8,244 Posts
Discussion Starter · #1 ·
Since search function on this forum isnt' the best outthere and a lot of people don't tend to do some search :gc-Smiley-UseSearch, we've decided to make a thread of FAQ on our 3.8 Genesis Coupe ECU reflash.

If you've been directed to this link means we are helping your lazy a$$ :) j/k

This is what I can think of right now but as we get more questions, I shall update on this.

3.8 V6 SFR ECU Reflash F.A.Q

- What does it exactly do?

1. Throttle response

Since Genesis Coupe has E-throttle body that is controlled by sending signals

with ECU, there are some delay/hesitations with throttle body. It also has to

do with notorious rev hang issues we've seen and experienced especially with

automatic tranny. With SFR reflash, we can control the timing and

responsiveness of throttle body remapping the logic of the throttle body.

Reaction time will be a lot quicker and all the lag that used to be with stock

tune will be gone. We don't want it to be too touchy especially for the

customers located in East coast where they get snow in winter, so we've put

it in the safe range. Going into full throttle (80% opening) is going to be

much faster resulting to reach desired RPM faster than stock tune. It also

saves gas mileage since car will be more responsive with throttle (with less

amount of gas on the foot moves the car... Injection = amount of foot to the


2. Unleashing torque management system

There is a torque management system built into Delphi 3.8 V6 ECU that is

limiting the power to the ground (Even with traction control off). It also has

to do with traction control/tire pressure sensor that ECU will automatically

limit off the power if it detects any loose tractions. We program the torque

management system to turn off the traction controll fuly when it's OFF.

Traction control will work just like stock when it's ON.

3. Advanced timing

We give out timings depends on what octane rate you are running the car.

The higher octane you are running with the car, the more aggressive timing

we will be given to each flash.

MAF based 3.8 sensors/o2 sensors/ECU are very sensitive that slight change

in Octane/MAF flow rate will affect very easily. We recommend to stay with

flashed octane as always (You can go up but you can't go down on the

octane rate) in order to avoid on the misfiring issues.

Also note to use legit brand named Gas stations to get octane rate as


Giving more timing will make more power throught the RPM, and the customer

definately feel the aggressiveness of power and torque.

We recommend one step colder spark plugs for 93+ (octane) tunes (especially the custom tunes)

4. Trimming A/F ratio

3.8 ECU is targetted A/F ratio map that ECU try to adjust to the A/F ratio we

set at. It's little harder to adjust with some aftermarket intakes that

bypasses MAF sesnor some air (ex. INJEN) since ECU is not monitoring the

right amount of air coming in. However, after all these years of experience

we know exact what to give for such modifications/combinations with

exhausts and other aftermarket bolt-ons.

Giving out more aggressive A/F ratio will generate more power in desired RPM

range (or all range) but there is a risk of misfiring or shorten the life of motor.

Our canned tune is set at more than safe range.

5. Rev limiter/Top Speed governor

We can only change the rev limiter on Manual tranny cars though auto

tranny can go up to desired rpm in 5th and 6th gear.

The usual and proven RPM bump is @ 7200rpm. Neutral RPM rev limiter is still

@5000rpm like stock. We can always change this but in case of dealers

checking things out with possible alternations, we didn't want to put

anything too obvious. Top speed governor will be taken out and there will be

no limit to the top speed.

- Dyno vs Performance/Drivability gains?

Dyno gain on canned tune on 3.8 V6 is about 5-20 rhwp (dyno peak powers)

range ONLY.

If you break it down some areas (RPM), it would be around 10-40rhwp gains

and 20-60lbs of torque.

A lot of people are so crazy about making some useless peak powers on the

dyno but as we stated above it's all about the drivability gains for 3.8 V6


Our canned tune for each octane rate is set at more than safe range of A/F

ratio/advanced timing that can be performed right without getting into

problems. Giving more aggressive timing or leaning out A/F ratio might yield

few more hp but it will not make a big difference and have more chance of

getting into problems (ex. Limp mode/misfiring/etc)

This is also one of the reasons why we've been suggesting our canned tunes

that will increase in overall performance and drivability while it's problem-free.

With canned tune, it's already proven by bunch of members to shave at

least .5- a second on the quater mile which is hard to believe while gaining

only such numbers on the dyno. This proves enough evidence that it's not all

about making useless numbers on dyno but tune must be targetted more

towards to drivability on 3.8 V6 ECU.

- Automatic vs Manual?

Performance gains on both tranny would be about the same. Due to increase

in response of throttle, people with manual tranny will have to relearn where

to engauge the clutch( it should not take long). Once you get the feel of it,

throttle is right there. Especially people doing some high skilled

drifiting/Touge/time attack should have advantages doing heel n toe/power

shifting/etc. Automatics have less chance to mess up on the shifting so

advantages on the flash is more towards to the transition on the shifting.

Due to throttle response changing gear would be faster/smoother. Going

on/off on the throttle will be much faster and responsive. (ex. You had to

downshift in order to pass somebody on the highway,

now it's just instant foot the pedal and power is right there)

We've seen avg of .7 seconds with manual tranny and .5 seconds with auto

tranny on quater mile times.

- What parts to buy/what mods to do?

We have brands and parts to recommend in order to maximize the outcome of

the reflash. We've done quite many custom tunes for certain brands and

combination. Some wrong modifications such as taking out all catalytic

converters will loose power (Your car isn't 80's Honda civic). o2 sensors not

only monitors the amount of o2 but the temperature of the cat and etc that

if it is not reading right bascially A/F ratio map on ECU that is connected to o2
sensor would also get messed up resulting high risk of running extremely lean

or rich. If it runs lean, ECU will pull timings resulting loss of power as well as

running rich. So please contact us for any modifications prior or after the ECU

flash. We'd be more than welcome to help out selecting parts as well as

locating and giving the best pricings as possible. We'd refuse to tune certain

cars that have the parts already on the car we aren't really sure about. I

- Retune?

If you are only putting in some bolt on parts such as intake/exhaust/etc, you

don't need the retune. Flahsed ECU will act just like stock ECU that will

relearn itself overtime. It only takes few seconds to reset the ECU by pulling

the ECU fuse in the fuse box located near the battery. No you will not loose

the flash by disconnecting the battery or pulling the fuse out. ECU flash is

permanenant. ECU will go back to when we first flashed the ECU after the


If you are coming with other tuner's tune, we will have to charge extra to

returning ECU back to stock first to get the basedata made. So far we are

the only vendor that reuses the ORIGINAL stock data converted to tuned


- Warranty

We don't guarantee anything about Hyundai's warranty with ECU flash. Get

this at your own risk just like any other aftermarket parts you put on.

However, it's not obivously seen or detected compared to any visible mods

such as intake/exhaust/etc.

We always use original stock data pulled then modified to tuned data, so all

the calibration data and other ECU functions remains exactly the same as


We also have just started offering the ECU core for those of people who are

really worried about their warranty, and you can keep you stock ECU and

tuned ECU.

Then, basically switch them out when you go to the dealer for any services.

- Feedbacks

As of today 09/26/2011, we've done little over 350 Genesis coupes ECU flash

(both 2.0T and 3.8 combined) since July 2010.

We've been getting bunch of positive and "WOW" responses, but feedbacks

are all over the places that can't get all of them at one place.

We've been collecting some of feedbacks that we can find and it's here:

(Please read through the initial thoughts and impression that fellow Genesis

owners have experienced)

Thank you

Take 'em Fei!
9,280 Posts
Woot woot! Love my tune!

2,012 Posts
Great idea posting this, it sums it up perfectly.

376 Posts
Great post.

☜(゚ヮ゚☜) ¯\_(ツ)_/¯
235 Posts
Can't wait to be tuned again :D

Yeah budday!
237 Posts
:wtc: beautiful write soon as the wife let me, I'll be getting it real soon. Good info Jay...

3.8gt auto
137 Posts
.5 sec ....that Awesome...Cant wait Jay...

Genesis 1:1
1,150 Posts

For all those that don't know how to use search, this is bad-A.

Hopefully we wont see anymore useless threads asking for info!

Excellent write-up and I cant wait to experience the tune.

2,297 Posts
Much needed info as most people do not like to search ;)

I love my SFR tune :D

Wants to go back to Cali
1,365 Posts
I didn't know us east coast guys get 80% opening on the throttle. Well in the near future when I go back to Cali for good, can I have it switched to 100%? :p

152 Posts
good info!
I can't wait till Oct, the power cut between 2-3 shift is one of the most annoying thing that makes me dislike the car

Blumagic Fanboi
80 Posts
Thank you sooo much for this! Really appreciated! So the ECU does intervene even when the Traction Control is turned OFF and your re-flash does disable it 100% if you push the button! Brilliant!!

Compact Parking Space
101 Posts
Thank you for a great writeup!

Couple more questions:
1) What's the best way to collect engine parameters to send you for a custom tune? I have a Bluetooth OBD2 reader, which can be connected to an Android phone/tablet running Torque, or to a PC.

2) Do you guys offer an ZF automatic transmission flash? I heard somewhere that it can be tuned for faster (if rougher) shifts, which actually REDUCES wear, since the transmission spends less times with two gears engaged simultaneously.

311 Posts
Hey Jay, or any other member that has the link to the YouTube video of the demo car on the dyno showing the before and after results of the tune. Can someone place it in this thread. I have seen the video three tines, but I am unable to locate it now. Go Figure. The video is showing the car with no rev limited and no speed governor.

Sent from my Autoguide iPad app

☜(゚ヮ゚☜) ¯\_(ツ)_/¯
235 Posts

311 Posts
Thanks, been trying to find it, but now I know why. This video has not been made available on mobile devices. I was searching for it with my iPad. Thanks again.

Sent from my Autoguide iPad app
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