Half-Life | '91 DS 318iS Slicktop | Track & Weekend Warrior

[Digitalwave]

Not a ton to update on the car. I spent a lot of time working on the idle on Megasquirt. I am still having an issue with it idling rich after coming off the track. I have a separate thread for that here if anyone is interested.

I have done a couple of track days, which were a blast. Finally got down to a new personal best time at PBIR (1:34.90).

It's pretty hard to "read" spark plugs, but my stock Bosch Super's were looking pretty baked for being brand new. I switched to one step colder NGK's. Didn't notice any difference, but I am going to run them for a bit and see how they look.





I cleaned all the contacts and reseated the pins on my ICV wiring. Pulling back the rubber gasket, I was surprised there was moisture or oil in there. Weird.





I remembered by chance that when I originally lengthened the wiring for my tucked ignition coil, I did not continue using shielded wiring on the wire from the ECU to the coil. I wanted to re-do that, so I removed as much as I could of the stock shielded wire from my spare engine harness.





This is how I had originally extended it, soldered with normal copper wire.





Made brand new eyelets for the coil using the OEM method, both crimped and soldered. The original eyelets were corroded.





First step is to join the shielding, being extra careful that none of the grounded shielding strands mix with the power cable.





Then join the power cable separately, wrap in foil, electrical tape the whole thing. Then I finished the rest of the harness with TESA cloth tape.





I bought a new SI board, as mine was causing several issues on the cluster. Sure enough, the one I pulled out had some bad traces from somebody using the long trim screws in the wrong place. The board from ProgRama appeared to be brand new, not a remanufactured original board. It was very nice, easy to install, and worked perfectly.





A new project I've started on is cleaning up all my grounds in the car. I also replaced all of the factory ~30 year old fuses with brand new fuses. I am trying to get the voltage system up to snuff. Next up is a new alternator cable and a dedicated ground cable for the alternator from Bavarian Restoration. I didn't realize that the alternator grounds through it's mount, and I spray painted it, LOL. I am going to run a ground cable from the case to the oil pan, and replace the brushes/voltage regulator on my alternator.

I've also been working on engine bay cooling. It gets quite hot on there, even with the ceramic coated headers. The first thing I did was tape up the gaps around the radiator with DEI aluminum tape. This stuff grips well and doesn't show any signs of loosening up yet.

On the track, I did not see any appreciable difference in temperatures, but it did not hurt. I also experimented with removing my hood seal on the track. You could tell the difference in wind noise at 100+ mph, and the wiper blades were getting pushed up, but again, no noticeable difference in temperatures.

I am thinking about drilling holes in my front bumper (a la Sherpaking) and core to get more flow to the radiator, and also considering adding a vent to the front-center of my hood (like Trent did back in the day).













And as usual, here are a couple parting shots of the car on the track:

[2mAn]

you should hit up level motorsport (hes on instagram and has a dead build here). he has a lot of cool stuff he made and is now parting out his racecar. some of the stuff could really help you.

I love that this is still a 2.5L M20 and makes solid power

[varg]

could be a issue with the machine its just strange that it happens at topend. i doubt it is the cap or rotor. id more look at the clearance between CPS and wheel MS (if not already i haven't read entire thread) is notorious for being sensitive to it

The dyno readout being so noisy and weird looking isn't due to the car itself, it's down to the dyno setup or the operator. I don't know how to run the thing so I don't know what caused it, but I've seen plots like that smoothed out with a couple of clicks before. The car pulls cleanly to redline and never loses sync.

[Digitalwave]

could be a issue with the machine its just strange that it happens at topend. i doubt it is the cap or rotor. id more look at the clearance between CPS and wheel MS (if not already i haven't read entire thread) is notorious for being sensitive to it

Ahh, the dreaded VR sync issues! I had those big time when I first installed MS. The car wouldn't rev past 4,800 RPM. I tried different resistors on the VR signal first, but it wasn't fixed until I installed a brand new OEM metal CPS. It is set to the proper air gap. Spec is 1.0mm +/- 0.2 I believe, and mine is set to .90mm.

Last time I checked, my VR signal shows very clean all the way through redline via the tooth logger, but I can check again next time I drive the car just in case. I know that I haven't had any "sync loss" at all since fixing the CPS, since I have the counter on my Tuner Studio dash as well as my tablet gauge cluster in the car. Thanks for the ideas!

[digger]

could be a issue with the machine its just strange that it happens at topend. i doubt it is the cap or rotor. id more look at the clearance between CPS and wheel MS (if not already i haven't read entire thread) is notorious for being sensitive to it

[Digitalwave]

Love everything you've done with this build TJ. Keep up the good work.

Thanks "s13 gangsta" :D:p

Great results though It looks like you have a slight ignition issue based on the plots the output looks noisy almost

Could be (I never rule anything out with this car anymore, lol). All ignition stuff has less than 2k miles (coil, wires, cap and rotor, plugs, CPS). I am going to put a new cap and rotor on just in case, and try NGK plugs (stock or one step colder). I think the jitters are something to do with the dyno though. The AFR graph was doing the same with their LC-1 tail pipe sniffer, even though both widebands on my car were showing nice, smooth, and even. Some of the other charts from cars they've dyno'd looked the same.

Soooooo much want.

Thanks man!

[vtechnik]

Soooooo much want.

[digger]

Great results though It looks like you have a slight ignition issue based on the plots the output looks noisy almost

[e30 gangsta]

Love everything you've done with this build TJ. Keep up the good work.

[wworm]

Good to know. From what I can tell its not a big difference. I'll have to do some more digging

[Digitalwave]

Those numbers are fantastic! Shows what a well sorted M20 can do. I wonder how much the cam and compression is helping scoot you along. I was planning MS for my simple M20 build, but ended up going with a chip instead. You don't have any fancy head work do you other than the springs and 284?

How does the car feel overall with MS vs having the AFM in there?

Thanks! Since it is stock displacement, it is really the cam and compression making the numbers. The other mods (injectors, exhaust) are more standard and probably not as responsible for the power level. The car still made a peak number of 195whp with the AFM/Motronic (and it was pretty lean, too).

The response is great, especially with the 8lb flywheel and 4.10 diff. It is slightly faster out of the corners and down the back straight than my friends FRS track car that has bolt ons and runs E85.

Style 4's are my favorite OEM wheels. Bummed to see that they dont even clear stock e30 m3 brakes without a spacer. Do you have any idea how much more do they stick out than stock e30 brakes? I know the the m3 rotor is 3mm thicker than the non-m rotor so theres at least that

The Style 4's clear the caliper, it's the anti-rattle clip that hits the bulky hub area of the wheel.

[wworm]

Style 4's are my favorite OEM wheels. Bummed to see that they dont even clear stock e30 m3 brakes without a spacer. Do you have any idea how much more do they stick out than stock e30 brakes? I know the the m3 rotor is 3mm thicker than the non-m rotor so theres at least that

[AWDBOB]

Those numbers are fantastic! Shows what a well sorted M20 can do. I wonder how much the cam and compression is helping scoot you along. I was planning MS for my simple M20 build, but ended up going with a chip instead. You don't have any fancy head work do you other than the springs and 284?

How does the car feel overall with MS vs having the AFM in there?

[Digitalwave]

I feel like I have nothing to add to the thread, although a lot of has happened in the last few weeks.

What I thought would be a quick and easy process to switch over to Megasquirt has been anything but. Megasquirt has unmasked a lot of "little" issues with my motor. For instance, the bad CPS sensor as noted before. But, there have still been some little things popping up here and there, some we are still sorting through. A few vacuum leaks were discovered. I also moved the MAP sensor over to by the fuse box as it was getting really toasting underneath the intake manifold where I had mounted it before. It's not as hidden now, but it keeps it cool, and hopefully reading accurately at all operating temps.

In searching for vacuum leaks I found the lines on my intake manifold nipples were leaking. They got zip tied. Redid the PCV lines and put hose clamps on every juncture. Put hose clamps on the ICV elbow as well, just in case.

We "finished up" the tune and I did a track day last week that went well. The tune needs a little tweaking at idle still (which has surprisingly been the hardest thing to tune). We finished up the ignition and WOT fuel map on the same dyno I did my base line run on.

Compared to Motrnic we picked up a good 10-15hp across the powerband. Peak went up about 5whp.


I got the tablet dash mounted pretty cleanly. I tried velcro first which was a major fail (not nearly strong or stable enough). So I used angle aluminum to bend a bracket, mounted it under the cluster, and then used 3M double sided tape to secure the tablet. It's very, very strong and stable as it's mounted. Even track tested now!




















Random picture I found from the last Cars & Coffee:




Until next time...

[ak-]

I want to move my switch to the clutch pedal for no-lift shifting, see eager to see what works for you!