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Woods247 BrokeFiST Build
- Thread starter Woods247
- Start date
Thread Starter
#1,282
I’ve never had Tirerack heat cycle them but I have used others. It didn’t seemed to work as well as going out for a 20min session at 75% pace then taking them off the car for 24hrs. That’s really hard to do unless you have two sets of wheels and two days on track though.
Thread Starter
#1,284
The car was absolutely rollin’ today even with boost limited to 25.4. Traction wasn’t the best with damp conditions so I ran my rain/cold weather map from Jared at Stratified. It’s still fast but I need to install the hood vents, have Johnny at NineLives rebuild my wing (it’s warped from where there was too much heat from welding a mount), build a functional diffuser and cut a couple of holes in the hatch to vent piled up air in the cabin. I’ll do all that and pull out more of the interior this winter so I can build a full cage. After the cage we will make more power.
Thread Starter
#1,285
I learned A LOT at Barber Motorsports Park today:
1) Unplugging a crash sensor DOES NOT prevent the false crash detection issue.
2) Unplugging the RCM (under the console) DEFINITELY DOES prevent the crash detection issue and ABS is retained. I also think traction control still works but I’ll test that next time we have a skid pad open. The dash is lit up with a wrench, airbag and traction control light while the RCM is unplugged. Pressing the traction control button changes nothing on the dash.
Overall it was an extremely productive day and I successfully lapped for a couple of hours without issues once the RCM was disconnected. Prior to that, I couldn’t complete a single hot lap without the car falsely detecting a crash. I still need to determine if an inertia switch for the LPFP and HPFP are required when the RCM is unplugged. If you choose to unplug your RCM, do so at your own risk. I still do not know if the LPFP and HPFP will shutoff in an actual crash with the RCM unplugged. If anyone knows PLEASE comment.
1) Unplugging a crash sensor DOES NOT prevent the false crash detection issue.
2) Unplugging the RCM (under the console) DEFINITELY DOES prevent the crash detection issue and ABS is retained. I also think traction control still works but I’ll test that next time we have a skid pad open. The dash is lit up with a wrench, airbag and traction control light while the RCM is unplugged. Pressing the traction control button changes nothing on the dash.
Overall it was an extremely productive day and I successfully lapped for a couple of hours without issues once the RCM was disconnected. Prior to that, I couldn’t complete a single hot lap without the car falsely detecting a crash. I still need to determine if an inertia switch for the LPFP and HPFP are required when the RCM is unplugged. If you choose to unplug your RCM, do so at your own risk. I still do not know if the LPFP and HPFP will shutoff in an actual crash with the RCM unplugged. If anyone knows PLEASE comment.
So cool to imagine your build flying out there. Was covering some of the bike events happening there last year (and will be again sometime this year!) and they could really make that track seem small once they were moving. Would be incredibly cool seeing something I actually have a feeling for the dynamics of. That outer ring was a trek in the heat with a heavy as hell camera package, hoping you have some nice pit transportation. 
Good stuff. I have had the RCM unplugged most of the track season because of false crash detection.
But, since the fuel pump will not be cut in a real accident, I put an inertia switch on the fuel pump. It’s worth noting, when you cut the fuel pump (by smacking the inertia switch), the car will still idle for about 45 seconds on the gas still in the lines. I assume this would also be the case had the RCM/crash detection cut the pump.
And the RCM definitely does NOT affect ABS or torque vectoring. The only way I found to completely eliminate TV was to pull the ABS fuse. Doing so makes threshold braking more of a challenge, but overall I was faster because of the speed through the center and exit of the corners without TV.
And yea, I have a Wavetrac LSD. But, the TV was still engaging on me.
But, since the fuel pump will not be cut in a real accident, I put an inertia switch on the fuel pump. It’s worth noting, when you cut the fuel pump (by smacking the inertia switch), the car will still idle for about 45 seconds on the gas still in the lines. I assume this would also be the case had the RCM/crash detection cut the pump.
And the RCM definitely does NOT affect ABS or torque vectoring. The only way I found to completely eliminate TV was to pull the ABS fuse. Doing so makes threshold braking more of a challenge, but overall I was faster because of the speed through the center and exit of the corners without TV.
And yea, I have a Wavetrac LSD. But, the TV was still engaging on me.
“If the engine shuts off.” We have to assume it MIGHT be the RCM that shuts the pumps off; if so, unplugging the RCM would eliminate this safety feature …. do you know for sure?
Fuether, if the engine is still running, it is assumed the RCM will cut the fuel pump in an accident and kill the engine, which could be critical if fuel is leaking and/or there is a fire.
If the RCM is unplugged, an inertia switch, in theory, does the same and has been used by Ford in other cars for years.
Fuether, if the engine is still running, it is assumed the RCM will cut the fuel pump in an accident and kill the engine, which could be critical if fuel is leaking and/or there is a fire.
If the RCM is unplugged, an inertia switch, in theory, does the same and has been used by Ford in other cars for years.
Welp, that would be our answer. The RCM sends a message to the FPDM , then the PCM shuts off the low pressure pump and probably the injector signal.
The HPFP is run from the camshaft, if the engine stops turning, the HPFP stops pumping rail pressure. It will not stop instantaneously though.
The inertia switch may cause other issues unless wired directly to the main power feed for the pump. The RCM, FPDM, and PCM, all communicate over CAN networks.
The manual did note the orientation of the front impact sensors is critical. This could be part of the issue with Wood's car. I am speculating though. I haven't had the issues he is seeing, but I have only done Nashville with the revised mounting orientation of my sensors.
The HPFP is run from the camshaft, if the engine stops turning, the HPFP stops pumping rail pressure. It will not stop instantaneously though.
The inertia switch may cause other issues unless wired directly to the main power feed for the pump. The RCM, FPDM, and PCM, all communicate over CAN networks.
The manual did note the orientation of the front impact sensors is critical. This could be part of the issue with Wood's car. I am speculating though. I haven't had the issues he is seeing, but I have only done Nashville with the revised mounting orientation of my sensors.
Thread Starter
#1,293
They’re on a Deadhook intercooler and have been for many years. Others in the UK experience this with stock crashbars with impact sensors in the stock location. I’ve never compared the location of my crash sensors to the stock location, however. And I unplugged a C-pillar crash sensor to test whereas the UK guys unplug the “sensor under the bonnet”. FWIW, I drove both of these tracks for years with the same IC without ever having an issue. It all started after I got faster as a driver.
Thread Starter
#1,294
The RCM is the restraint control module. From what I understand, it manages airbag deployment, 911 assist and fuel cutoff when it detects a crash. When it’s unplugged there’s a code listed on the AP and ForScan that states an error between the RCM and fuel system. I’ll update this post when I get back to the car and pull the code.
I am concerned about getting knocked out after a side (or rear) high impact collision that ruptures the fuel tank and doesn’t necessarily damage the engine bad enough to prevent it from running until it’s out of fuel. The RCM’s job is to detect that impact and shut everything down immediately without delay (I think). I suppose I’d still be fuct in that circumstance but seconds in a fire matter so I’d like to be 100% certain both FPs shutoff automatically if I wreck while the RCM is unplugged.
I’ve thought a lot about this and even studied both tracks for scenarios where rear impacts are possible. I notify the safety lead of what I’m “testing” too. I’m also installing a fire suppression system to buy a little more time but ultimately I need to find an answer from Ford about how the FPs shut off in a crash. I’m pretty sure that’s the RCM’s job but you’d think the car wouldn’t run without it, if that proves to be true.
I am concerned about getting knocked out after a side (or rear) high impact collision that ruptures the fuel tank and doesn’t necessarily damage the engine bad enough to prevent it from running until it’s out of fuel. The RCM’s job is to detect that impact and shut everything down immediately without delay (I think). I suppose I’d still be fuct in that circumstance but seconds in a fire matter so I’d like to be 100% certain both FPs shutoff automatically if I wreck while the RCM is unplugged.
I’ve thought a lot about this and even studied both tracks for scenarios where rear impacts are possible. I notify the safety lead of what I’m “testing” too. I’m also installing a fire suppression system to buy a little more time but ultimately I need to find an answer from Ford about how the FPs shut off in a crash. I’m pretty sure that’s the RCM’s job but you’d think the car wouldn’t run without it, if that proves to be true.
How do the Bspec Fiestas deal with this situation? I don't think I have heard of issues with this on those cars. Perhaps it has to do with the Ford Performance ABS module?
It would be worth having a conversation with some of the Ford Bspec engineers or at least the prep shops for those cars. Let me contact friend about the issue.
It would be worth having a conversation with some of the Ford Bspec engineers or at least the prep shops for those cars. Let me contact friend about the issue.
Thread Starter
#1,299
Looks like an inertia switch like @cidsamuth uses is what I need.
https://www.fordpartsgiant.com/parts/ford-switch-asy_ys4z-9341-ba.html
This is the switch Ford used in the 99-04+ Focus SVT, its probably the same as all Foci.
This is the switch Ford used in the 99-04+ Focus SVT, its probably the same as all Foci.
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