[GenXG87]

I got my DME back from Femto!! WOW that was fast. Took 4 days to get to them, they shipped back same day and 2 days to me.

I loaded in BM3 Stage 1 multimap to get the ball rolling. I thought something was wrong because it only took 10 seconds to flash. Way faster than initially on our N55 M2.

First impressions.. pretty good. Compared to JB4 map 2, butt meter says it pulls harder. But for those wanting something easy to install, the JB4 is definitely the best bang for the buck.

Light throttle the car is noticeably different now. So much so, I will need to tune down the throttle response for track us.

This gets to the next step. No doubt there are good tuners out there that can get things pretty good remote, but since I am continually tinkering on the car I want to be able to tweak the tune as needed.

I am starting to dig into all the tables and wanted to see if there were other DIY tuners looking to get some technical discussions going.

My background:
I've been away from tuning for quite some time
My experience is mostly GM but did some Ford stuff back in the day.
- Tuned Port stuff using DFI. Imagine having a 16x16 table for injector pulse width TPS vs RPM. The easy days, lol.
- Old Holley gen 1 stuff
- Reversed GM LS1 in the early days. Desolder, chip read, burn and solder
- Early HP Tuner.

Anyhow I tuned a couple LS2, LS3 cars and actually have my HP Tuner around somewhere. I had a 2016 C7 Corvette so I used it to tune.

So now I'm perusing the BM3 tables. There's a lot going on. So my first step is to do simple change comparison. Unfortunately there aren't a ton files available.

Anyone up for getting some discussions going? My goal would be to start small and to document.

[x622]

Looking forward to your updates, curious to see what kind of timing it's pushing and can handle for sustained track abuse. I'm gonna get mine sent out to femto as well.

You have any mods? I'm just doing a full turboback on it, and maybe some cooling mods then of course wheels/tires/brakes

[GenXG87]

I haven't started digging into the tuning yet. I have a track event next weekend and am working on suspension and alignment tweaks. But I am doing some testing and comparing.

I am running the Stage2 OTS tune 93 pump Costco gas. Definitely pulls harder. Pre boost is stable @ 25-26psi. AFR 12.3-12.5 Timing around 9 degrees on avg though cyl 1 seems to consistently pull a bit out though there is no knock detected.

Not sure how lean these Direct injection cars can run. Back in the day that would be aggressive on boosted cars. I need to read up, but my guess is these cars can handle leaner mixtures.

One of the issues was seeing a lot of throttle angle changes when I ran the JB4. I know that 'throttle' is not really throttle anymore and is handled with valvetronic/vanos and the TB is a back-up device. But whatever the computer is interpreting it was fighting with the spoofing. With the tune this is much less of an issue and only see the throttle change in the 4800-5500 rpm range. The rest of the time it reports 99+% My guess is the EWG tries to hit target and then the computer adjusts valve timing/lift to keep it at target torque.

Comparing some old JB logs. Map 2 ran less pre-boost. Around 21psi. It also took longer to reach boost. However, it's not apples-to-apples cuz I do have a mid-pipe and CAI now which could help spool time.

The JB A/F was similar but timing was around 14 deg. Expected with less boost.


I tried stage 2 multi-map but burbles stopped working. I don't want a lot but none was weird. I'm going to reset everything on the map and test again. I like the idea of have some options on a track session.

The other nice feature is remapping the throttle though that will be one area of interest with custom tuning. It seems that the exhaust valve max angle is linked to sport/sport+ but they also make the throttle more aggressive. That is the opposite of what I want on the track. I currently have sport at -25 and sport+ -40%. Sport feels good, sport+ still has too much tip-in response. When I do a custom tune I will literally copy the comfort throttle mapping over to sport and sport+ to start.

I will do more extensive logs on the track to see how the car comes on and off throttle.

[x622]

Originally Posted by GenXG87

I haven't started digging into the tuning yet. I have a track event next weekend and am working on suspension and alignment tweaks. But I am doing some testing and comparing.

I am running the Stage2 OTS tune 93 pump Costco gas. Definitely pulls harder. Pre boost is stable @ 25-26psi. AFR 12.3-12.5 Timing around 9 degrees on avg though cyl 1 seems to consistently pull a bit out though there is no knock detected.

Not sure how lean these Direct injection cars can run. Back in the day that would be aggressive on boosted cars. I need to read up, but my guess is these cars can handle leaner mixtures.

One of the issues was seeing a lot of throttle angle changes when I ran the JB4. I know that 'throttle' is not really throttle anymore and is handled with valvetronic/vanos and the TB is a back-up device. But whatever the computer is interpreting it was fighting with the spoofing. With the tune this is much less of an issue and only see the throttle change in the 4800-5500 rpm range. The rest of the time it reports 99+% My guess is the EWG tries to hit target and then the computer adjusts valve timing/lift to keep it at target torque.

Comparing some old JB logs. Map 2 ran less pre-boost. Around 21psi. It also took longer to reach boost. However, it's not apples-to-apples cuz I do have a mid-pipe and CAI now which could help spool time.

The JB A/F was similar but timing was around 14 deg. Expected with less boost.


I tried stage 2 multi-map but burbles stopped working. I don't want a lot but none was weird. I'm going to reset everything on the map and test again. I like the idea of have some options on a track session.

The other nice feature is remapping the throttle though that will be one area of interest with custom tuning. It seems that the exhaust valve max angle is linked to sport/sport+ but they also make the throttle more aggressive. That is the opposite of what I want on the track. I currently have sport at -25 and sport+ -40%. Sport feels good, sport+ still has too much tip-in response. When I do a custom tune I will literally copy the comfort throttle mapping over to sport and sport+ to start.

I will do more extensive logs on the track to see how the car comes on and off throttle.

You touched on one of the biggest things I felt was wrong with this car - that throttle tip in. I find it kind of hard to manage maintenance throttle in a corner in sport+ because any little bump will send substantially more power than I want back to the rear wheels which will induce oversteer currently.

Sending my ECU to femto next week, but I will have a full turboback on the car. How are temps looking?

[GenXG87]

Originally Posted by x622

You touched on one of the biggest things I felt was wrong with this car - that throttle tip in. I find it kind of hard to manage maintenance throttle in a corner in sport+ because any little bump will send substantially more power than I want back to the rear wheels which will induce oversteer currently.

Sending my ECU to femto next week, but I will have a full turboback on the car. How are temps looking?

Just the simple % adjustment on throttle with BM3 makes a big difference. I used to run in sport but once I added the mid pipe the throttle was touchier.

I haven’t tracked it yet with the tune but with the JB4 oil temps never more than 215 on 90+ temp days.

[TwinWhistles]

This is a very interesting thread, but way over my limits of modding capabilities. I'm curious if anyone knows of other companies trying to crack the ECU besides Femto. It would be nice to be able to go back to the Cobb Accessport days of some off-the-shelf maps and the ability to get a custom tune without having to ship off the ECU.

[DrewNewM2]

Agreed. I have had Cobb accessports on Subarus since 2007, but custom tuning only. Great company that supports many makes, including some BMWs. Need S58 support!

[TwinWhistles]

Originally Posted by DrewNewM2

Agreed. I have had Cobb accessports on Subarus since 2007, but custom tuning only. Great company that supports many makes, including some BMWs. Need S58 support!

I transitioned from a stage 2 WRX to a BMW 335i, both tuned on Cobb AP. It was awesome to be able to get pro-tuned once the stock maps didn't match the mods.

I also remember the open-source project a group worked on for the Suby's to crack the ECU. Those were some fun times.