While the engine was getting a minor refresh, we decided to use HR head gaskets to open up the coolant channel at the back of the DE cylinder banks, which are typically closed off. This should allow for more uniform heat transfer and minimized hot spots at the back of the cylinder banks.
Area opened up circled in red:
Closer look:
Also digging deeper with an exhaust leak, found there was a crack at the collector of the passenger side 370Z header:
Cleaned up and welded. Hopefully it holds up:
Also got some fresh exhaust wrap on them. The existing stuff basically disintegrated off:
Engine back in the car with some new freshness:
Here's the finished up BMC firewall brace. This worked out pretty well with a definite reduction in firewall flex using the eye test. This can be made more effective if you pickup mounting points that are further apart. As is, you can actually see the strut tower contort a bit when applying the brakes.
'meh' welds:
Finally the MK60 E46 M3 ABS system. I think we are 1 of 2 S-chassis in the world that have this ABS system implemented. We ended up mounting the module and all necessary components on a panel I made up on the passenger side rear seat deck. The engine compartment is way too busy as is and I already have enough weight hanging over the front axle. The obvious con being a large run of lines.
The hard-lines are nickel copper alloy and all flares are 37 degree AN flares with tube sleeves and tube nuts. Then quite a few AN bulkhead fittings. I'm using banjo-to-AN fittings at the master cylinder. Since the master was a non-ABS, the middle port had to be plugged. For this I also used a banjo-to-AN fitting and then just capped it off with an AN cap (pic below). Working great.
ABS module and lateral/yaw sensor mounted on the plate to the right of it:
(**EDIT - added some completed pictures**) Here's in process line routing without seats in the car. Looks better than this now:
System needs two 15amp fuses and one 5amp. The 5amp can be switched to reset the system while on the move.
2 supply lines from MC, and 1 return to the front left caliper:
Master Cylinder:
SO, once everything was installed and I started testing. There were rear wheel speed sensors faults being thrown. There were really slight drop offs in wheel speed when logging them that was enough to fault the system:
Thinking that possibly it was an air gap issue, I tried reducing the air gap by milling the diff cover. Nothing. I removed the steel sleeve that protrudes from the diff cover that the sensor resides in thinking that maybe there was some interference. This circled in red:
To this:
And still the same issue.
At that point, I didn't have anymore time before our test day on 4/1 to sort it out. The ABS worked very intermittently and then would basically throw an error after the first time ABS was activated and then would stop working. The good news is that when the ABS throws a fault, the brake system behaves as it did without it. I managed to top my personal best at the track and we got within 0.2 seconds of our best ever at the track with 18 hour old Hankook RS4's, where our previous best was set with NT-01's.
Obligatory test day pic with new Core4 BBK's:
(OH, and the diff. Definitely an improvement. Noticeably easier to move and roll around the paddock and garage. Still plenty of capability to kick the ass end out under power as well. Did I notice less of a tendency for the car to want to track straight when off the throttle? Perhaps a little, but not as much of a change as I was expecting. It did make less noise though if there was ever any rear lock up and in general. But, more on the diff later in my next post about the Watkins Glen event. )
So, with basically less than a week from the Watkins Glen event, resolving the ABS was priority number one. So while troubleshooting, I had somewhat of an epiphany. Although it was difficult to do while installed on the car, I noticed the signal would get better if I moved the sensor around and held it in a different position. I then simply looked at a picture of how an E46 M3 rear speed sensor actually mounts on an M3.
Notice the orientation. The mounting bolt is inline with the direction of rotation of the wheel/tone ring.
Just to refresh your memory, here's the Nissan diff cover which mounts the sensors 90 degrees from the rotation of the tone rings:
Now this seems pretty obvious, but I assumed this was how the E46 sensors were mounted also. When I realized the 90 degree difference and brought it up to company that makes the custom harnesses for these, they said "they believe it shouldn't matter." Since it wasn't a concrete answer my gut knew that this was the issue. I never thought orientation would matter for these things, but it does!
SO, because there's not really material on the diff cover to just rotate these and have material to drill and tap, I welded some material and milled it flat (I'm getting pretty damn good at removing diffs now!). I did this very quickly with whatever material I could find so it looks a little shitty:
Buttoned it all back up, hooked up the scanner and let it run in gear for about 15 minutes. ZERO FAULTS. Game on for Watkins Glen!! Here's what the speed signals are supposed to look like:
Butter smooth:
In hindsight, perhaps it would've been better to just use the Z33 rear wheel speed sensors. The only customization required is that they need to be shimmed away from the tone ring since they would interfere as is. The depth of the E46 M3 sensor happens to be perfect. Again, pick your poison.
Watkins Glen event is finished I will post the results of that soon. But, our next race is this weekend (5/17) at New Jersey Motorsports Park.
Last edited by gills; 05-14-2019 at 08:33 AM..
