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Many of us are here because we like to tinker with our cars, some of us are an amazing resource full of knowledge about functionality and tuning the RX7.
Xavier made is possible for the common guy to better understand things with a high level of explaining things.
I hope that the community can also explain things on a high level for the common guy and then break it down to be more detail oriented for those doing ground breaking work.
1st contribution from me..lol
My motor is super low compression, leaking coolant, and oil internally now. It was a pain in the butt to start until I used the FC-Tweak option to allow negative split under vacuum, now she fires up every time - when cold that is..lol
Little helpful notes for the common guy.
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Great Notes from Dale Clark https://www.rx7club.com/3rd-generati.../#post12595228
Last edited by rotaryextreme; Mar 5, 2024 at 01:27 PM.
I know we collectively have a lot of experiences already with the FC-Tweak tuning software, but it's about to get wild with the new FC-Tweak AFR data logger.
Here is some more things to think about.
FC-Tweak does have pull down menus to configure your car to make the software try to be accurate as possible for your configuration, but I feel the settings need to be played with to find the right spot to have the software tweak the file just right for you.
Example.
I had the Rotary Performance 3 inch High Flow Cat and so I selected RC, (Racing Cat) in the pulldown. I dynoed some good number and the car had a fat power band.
I switch to some random 2.75 inch midpipe with a resonator, I changed the setting to MP, (mid pipe) and I swear the car felt a tad slower and the 2nd turbo did not hit as hard.
True I did change from a Greddy Profec B to the Apexi AVC-R, but I made the same max power at the same psi.
When I reloaded the older tune with the RC selected, using the physical midpipe, the car ran better.
The point is the name does not translate to 100% of the expected results of the part you install on your car.
Another example is the used engine I have was said to have stock intake ports and ported exhaust. I asked Xavier about this and he said to use the stock intake port setting, which is default and you do not select the optional SSP (small street port) or LSP (large street port) options.
I had the car configured minus the engine port selection and it ran fine, but when I experimented with selecting the SSP the 2nd turbo kicked in harder. I'm sure there is a lack of fine tuning on my car, but the point is the settings are a general starting point for us to work with to get the best tweaked baseline map.
So, I think with the exhaust selection, care needs to be taken with the size of the piping and flow vs relying on the name alone.
I can say this about FC-Tweak, I have abused the **** out of my motor learning new things and playing with the settings - BUT - the software always made the changes to keep me out of the danger zone!
FC-Tweak is the only reason why I have not blown my motor up yet - FACT!
Last edited by rotaryextreme; Mar 6, 2024 at 12:32 PM.
Yes indeed 'Air flow mods & porting' selection in the car mods menu offers 8 steps of incrementing volumetric efficiency of your complete setup. There are so many different setups that it would be impossible to fit all combinations in one list, but in practice you'll always be able to find one of the 8 options which greatly enhances driveability. Even a change in exhaust pipe diameter or throttle body size will affect the overall volumetric efficiency. Usually it's either the option which describes your flow components best, or the one next to it, trying it out can't hurt anything. The good news is that this option does NOT affect how the fuel map is autotuned. You may in fact change this flow setup after auto-tuning and still get the same final results. Most often you won't be able to see any difference on the dyno chart, but it will definitely feel much better when it comes to overtaking, during street driving.FC-Tweak uses the flow selection to configure the tables which control the additional fuel injected during tip-in and take-over situations. When correctly set, the PFC is able to predict the amount of extra fuel required even BEFORE any change in boost is actually recorded, resulting in a faster response. The default Apexi map comes with most of these tables disabled, and hence drivability of an out-of-the-box PFC is not great at all, until FC-Tweak does its job on the mentioned tables.
Id love to have this done on my car but i am not going to spend the energy to get to know it unfortunately. Just too busy
With that said, is there a video around where i can get a basic understanding? I checked youtube.
Originally Posted by Xavier Borg
Yes indeed 'Air flow mods & porting' selection in the car mods menu offers 8 steps of incrementing volumetric efficiency of your complete setup. There are so many different setups that it would be impossible to fit all combinations in one list, but in practice you'll always be able to find one of the 8 options which greatly enhances driveability. Even a change in exhaust pipe diameter or throttle body size will affect the overall volumetric efficiency. Usually it's either the option which describes your flow components best, or the one next to it, trying it out can't hurt anything. The good news is that this option does NOT affect how the fuel map is autotuned. You may in fact change this flow setup after auto-tuning and still get the same final results. Most often you won't be able to see any difference on the dyno chart, but it will definitely feel much better when it comes to overtaking, during street driving.FC-Tweak uses the flow selection to configure the tables which control the additional fuel injected during tip-in and take-over situations. When correctly set, the PFC is able to predict the amount of extra fuel required even BEFORE any change in boost is actually recorded, resulting in a faster response. The default Apexi map comes with most of these tables disabled, and hence drivability of an out-of-the-box PFC is not great at all, until FC-Tweak does its job on the mentioned tables.
Id love to have this done on my car but i am not going to spend the energy to get to know it unfortunately. Just too busy
With that said, is there a video around where i can get a basic understanding? I checked youtube.
Closest dealer to you with a licensed FC-Tweak is in NC. But really, you're not going to spend much energy to get to use it, by the time it takes you to drive there you would be done with tuning it yourself. I have got a short video from one of the users on FC-Tweak's FB page, scroll down at : facebook.com/FCTweak/
Results you say? my car has never run better, in fact in ~30 years of driving Rx7's it right up there with any of them, even new ones.
FC Tweak is also one of the nicest pieces of software i've used in years.
i've let the Auto tune have carte blanch, and i'm impressed. its way better at tuning than me, lol
what else? oh yeah it catches EVERY mistake i've made with the car.
The following is a step by step procedure using FC-Tweak to optimize a starting map, for example the Apexi 5.08 map file, to your own car setup. This is a very important pre-tuning procedure that eliminates hundreds of bad/ unoptimized settings, which would otherwise remain in your tune for ever. Once all this is done, full fuel map tuning using real logged data can be performed using FC-Tweak's auto-tune function, to make sure the fuel map is 100% safe.
Step1: load your starting map in FC-Tweak
Step 2: Update the mods list, so that FC-Tweak will optimize all settings tables accordingly
Step 3: Start a file scan
Step 4: View result summary and safety & performance ratings for your original map. In this example FC-Tweak found over 300 settings which need to be optimized to work correctly with this particular car setup.
Step 5: Apply every recommended tweak (unless you have any reason not to). FC-Tweak gives a short explanation of the reason behind that particular setting.
Step 6: scan again to confirm the file is now fully optimized.
Step 7: Export the optimized file and upload it to the PFC
The next step would be log driving sessions and let FC-Tweak auto-tune the fuel map. This is all you need to fully tune any RX7 equipped with a Power FC.
Once you have optimized the starting map (as described in the previous post) ,the car should already drive much better than it was ever before. So, the next step is to fully tune the fuel map. All you need to do is use either a Dataloggit box or a DL-340XB PFC interface to record life data while driving. You will also need a wideband O2 gauge hooked up to the logging interface. This procedure is usually done in 3 sessions, driving at higher boost on each subsequent logging session. FC-Tweak does much more than simply adjust the fuel cells to match the target AFRs. If takes care of the inherent AFR data delay (which is unfortunately ignored by many) and applies intelligent algorithms so as to tune even those cells which do not get logged. With FC-Tweak's auto-tune, you simply drive as you would normally do, for about 20 minutes or so, no special driving procedures like we used to have to do many years ago, when our only PFC tuning tools were just a few excel worksheets!
So, here are the steps which will get any RX7 fuel map fully tuned, using a logfile.
Step 1: Load your Log file
Step 2: Press 'A' to start auto-tuning process
Step 3: Select your preferences for idle, cruize and boost zones. FC-Tweak will automatically generate an optimal AFR target map for you.
Step 4: Your logged data is cleaned up and displayed on a map chart.
Step 5: Press 'A' to auto-tune and 'X' to export the auto-tuned map.
Step 6: View your tuned map. A 'Certified' label will appear indicating that your map is now 100% safe to use at any boost level. Upload map to PFC & enjoy!
Welcome
anyone that still has a Power FC, and especially datalogit, I would highly suggest Xavier's software. My FD runs significantly better with his software.
Is it possible to change the fixed 0.25bar difference between target boost and overboost cut-out? Wouldn't mind being able to target 2.85bar and retain a 3 bar cut-out, my understanding is at present if you set a target above 2.75bar you lose the overboost protection if using Apexi hand controller (and maybe FCEdit too?), is that correct?
Apexi FC-Commander won't allow you to set boost targets above 2 bar, but you can do that using the DL-340XB interface software. The difference between the setting and the hard fuel cut is always 0.25bar, but you can set the target to values higher than 2 bar. Load your file in advanced edit mode, scroll to settings page 7 and adjust as required. Always make sure that your map PIM rows are correctly scaled to include the new F/C PIM value, and that your boost sensor is rated above the F/C boost limit which are shown on the same settings table.
Apexi FC-Commander won't allow you to set boost targets above 2 bar, but you can do that using the DL-340XB interface software. The difference between the setting and the hard fuel cut is always 0.25bar, but you can set the target to values higher than 2 bar. Load your file in advanced edit mode, scroll to settings page 7 and adjust as required. Always make sure that your map PIM rows are correctly scaled to include the new F/C PIM value, and that your boost sensor is rated above the F/C boost limit which are shown on the same settings table.
Thanks, I Waa hoping to keep the 3 bar sensor and just squeeze a touch more out of it while retaining fuel cut but my gearbox and clutch will probably be better of a 2.75bar target anyway. Should still be about 50% faster than it is now once ported and running that boost.
Hello all,
I wanted to add some questions Xavier has helped me with so as to help alleviate some of his workload in responding to our queries.
AFR Reading FSD within FC-Connect AFR Calibration: - A 5V analogue voltage (FSD) indicates very lean AFRs. If you were to use method two like I did, this reading can be due to an improper connection between the Wideband O2 sensor and the DL-340XB. If everything is connected correctly, a consistent reading of FSD can also be due to the air pump still being connected. The air pump should be disconnected throughout the tuning process to avoid artificially lean readings
Smart Map Boost Calibration: - Boost sensor settings should be tackled early on in your tuning process. The information to do that is located within the manual on page 39 and the reading will be displayed in mmHg with the key on and engine off. If, like me, you accidentally did this later than you should have, and your mmhg reading looks like [- - - - ] on your power commander, then driving needs to be avoided until you fix this. Reverting to an older version of the map should fix the issue and display a proper reading. - After you have input the proper offset into FC-Tweak, than your boost should read 0 within FC-Connects real time monitoring tab - Smart Map Boost Calibration only needs to be performed once. Re-enabling it or re-inputting ambient mmHg during subsequent scans is unnecessary and could lead to calibration issues. A boost reading of approximately -8 mmHg with the engine off is normal and attributed to atmospheric pressure variations.
TPS Calibration error while Auto-Tuning:
- I know there have been a ton of posts about calibrating the TPS but I figured I’d add Xavier’s TPS Calibration pdf.
Last edited by 1Coup; Nov 20, 2024 at 06:43 PM.
Reason: Included extra pdf
