535is Homebrew Turbo (ex 633 Callaway) - 2024 Update

[tschultz]

I finessed the intercooler up about 2 inches and shortened the vertical charge pipe in the process. The intercooler piping then is still one of the lower parts of the car, but it is much improved from what I had before. Basically, a hose clamp on either side pulls the piping to sit just below the airdam bracket on either side (near the tow hooks). Here's how the clearance looks and the airflow to the intercooler.

As I mention, maybe in the future euro bumpers are possible, so the setup here shouldn't have to change if I elect to do that. But for now you can see the IC core through the 535is airdam and through the grille. I'd prefer the US bumper not block so much of the cross sectional area, but we are somewhat stuck with what that is. Notice the red elbows on the bottom of the intercooler. This didn't require any additional trimming I'm hoping this is sufficient as far as clearance goes, the red elbows really are no longer visible unless you get down low to examine the front end.

The driver's side is still the low spot, but it is approximately the same height as the bottom of the oil pan. The cooler is ever so slightly offset to the driver's side also.



As compared to:

Also, you can see how my air box and charge piping above the intake manifold is rubbing the hood insulation. I may go with the 1 piece insulation in the future, but I think we have better clearance after adjusting hood alignment a little bit today (1/8" up?).



I have been tuning driveability the last couple weeks and have consistent fuel mixtures from 65-100F and varying levels of humidity. I suspect this means my MAT correction curve and Baro curves are both working well together. I have dialed in some hot restarts and am trying to work on improved smooth idle as well and re-tuning the boost portion of my map. Hopefully some photos and screenshots of my tune in the next couple weeks, as well as maybe some video or sound clips.

Alternator issue I mentioned was the ground strap not making good connection the the block, so the battery was barely charging.

[wkohler]

Wow, you got some work done. Sorry about the accident in the 633 but glad to see this 535is saved. Shame it has gone downhill like that but glad it's back in the game! Good work.

[tschultz]

Thanks Chris. Just a never ending project it seems.

I thought I had been making great progress and took the car up to the mountains yesterday for a verification of my tune and the barometric corrections. As I reached 9000ft, the car was stalling and stuttering running really lean. It seemed that my baro corrections which had worked pretty well previously were suddenly not configured right.

Surging and stuttering was present, confirming that the mixture was lean.

I adjusted the curve mid drive and removed EGO control and noticed a bit better driving as I went back down in elevation. Temperatures we about 70-80F back at ~6000ft, but the car now was running more rich than before. I hadn't touched my fuel map except around the idle region slightly.

Feeling confused and frustrated now for the lack of consistency in my tune. I keep fiddling with settings after base lining and going through a methodical fashion and now the closed loop idle is surging and not consistent. Very frustrated with it yesterday and also today.

Also in alignment last week, found caster and camber different on my passenger side such so it pulls slightly. Not a fun drive yesterday and didn't inspire confidence or enjoyment that makes me want to take it to D4C this august.



At least a new tuning cable has been working in cooler temperatures and not dropping offline like the DIY autotune cable.

[George]

Do the running issues completely go away when you return to a lower elevation or just improve?

What cable are you using? I have the same problem with drop out.

[tschultz]

I used the Ugreen cable here: https://www.amazon.com/gp/product/B00QU ... UTF8&psc=1 (6ft)
and haven't had any connectivity issues yet for the 3 day's I've tried it. I did have issues with the other cable on a regular basis.


I adjusted my idle advance, spark table, and then VE table to be flat in idle region. There is still a strange surging of 2-4 kPa and 100rpm, but it is better than 400 rpm and 6kPa. EGO control also was giving me a strange fluctuation as well so I have shut it off for the time being. Just going to keep messing with it I guess. Don't really want to share a log at the moment.

I did spend some more time realigning the doors tonight. I think I have the gaps and such removed. I also picked up my friend's interior. Black leather with tweed grey inserts. I installed the back seat and door panels and that helped me feel better for the moment. It does look good with the color of the car.




I have to repair the seat harness' to put the front seats in, just haven't gotten to it yet.

[tschultz]

I have been driving the car on my short trips to work so that I can tune in the temperature swings. I have seen approximately 64F-95F in the last two weeks and I have been running with no EGO control and simply my VE map. The plan has been to fine tune the consistency of the table with no closed loop correction before really nailing down the entire map. Once my corrections are adequate, I can fine tune the entire map.
I had reset my baro corrections after my last mountain drive, although I am still fine tuning it. Generally my drive is within 1kpa each day.


So the other factor that adjust fueling is the MAT correction. The green curve is where I am at currently. 80F is my 100% fueling


My current ignition table. A hybrid between settings that have been known good for my crank wheel settings, 91 octane and some of the settings from 2017


I can tell if my tune is about right with baro and temperature changes if autotune suggests the entire map be richer, leaner or about the same. This has been my approach to tuning before really working on as perfect a VE map as I can get.

A few pictures of the car at this time. Door alignment is pretty good and now they close and open nicely. Again, not the prettiest at this moment, the dents and clear coat bother me, but not yet ready to have it repainted.

Wheels are tires were put on for alignment, but it seems the passenger side front strut wouldn't align into spec. It could possibly be bent.

[tschultz]

I attempted to drive the car up to the mountains after DDing it for a week and a half, and unfortunately my clutch pedal started getting soft along the drive, until the pedal went to the floor.

I had to turn around and divert my plans before limping it home without a clutch. I got it in the garage and was able to replace the slave cylinder on Wednesday. That was the problem, although it wasn't obvious (no fluid dripped from the slave).

I also took the chance to replace the cap and rotor and regap spark plugs. About half of them had a reddish tint and I suspect were being overheated due to the small spark plug gap(.025 now back to .032) or the 3.1mS dwell I had been using. Seems like 2.1mS was a little smoother and recommended by Peter Florance.

The last item was to replace the Wideband sensor. Upon inspection, the one that came out had a bit of carbon build up. The new one doesn't seem to fluctuate as much up and down, but that could have been due to misfiring of the spark plugs too...

Maybe I'll get a few pictures, but I have 2 weeks to verify performance and tune at altitude before my upcoming D4C road trip.

[tschultz]

Spent time yesterday driving up to 9000ft and verifying my baro correction. It was simply too aggressive the first time I attempted. Last time, my clutch slave went out. This time I was able to adjust a little bit on the fly but get it working with both change in baro and change in temperature.

I hope a good basis now for performance up to the 9000 ft (74kpa). The road trip next weekend will be up to about 10000ft (69kpa). It is pretty interesting to see the boost gauge showing 0psi and my mixture not reading the 13:1 I am used to. At that altitude, atmospheric is 74kpa, so my map aims for a bit leaner air fuel mixture.

Right now I plan driving from about 60kpa-85kpa. But above 85, the correction I left as theoretical values.



I got stated on installing the power seats I purchased. I had to take the power cable and resolder some of the wires to get adequate length. Once I did that, I could resolder the entire harness back to the cut harness already in the car. I found the power cable (as opposed to the passengers power cable) and soldered it back to the harness. After bringing the seat over and connecting it up, I was very happy to find that when i connected the harness, all seat functions worked!

They are a very light grey tweed with original leather on the outside.


I wanted to make sure that the connections wouldn't come loose or short, so I used heat and zip ties shrink. It doesn't look great but it works!



Instead of connecting the passenger harness (which is cut on both sides), I will likely use the replacement harness I have. For the moment, I'll put it above the carpet as a temporary solution. I'll get to the passenger seat in later this week I hope.

[tschultz]

Time for another update.

I had been preparing the car for D4C 2018 making sure that I could make the 1000 miles, but also have reliability with the varying mountain passes and varying conditions. You saw some of this detail in my last posts. Next up, I finished the installation of the passenger front sport seat which has everything working except the headrest motor.

A great video highlight of D4C 2018 here gives you a good idea regarding the meet itself.

Here's a recap of my trip. Not as many photos as with my M5 last year, but still fun to tell the story a little:

My 2018 route:


Group departure from Denver






Picking up more in Salida, CO


Group meetup in Durango, CO







Purgatory and the event drives























Burt made the group photo too




Travis's M535i


Short hike


Some moisture on the drive back




My brother's euro 3.1L turbo 325iX, also Diamondschwarz



We took a few extra days to explore and I took my wife to Mesa Verde. Neat sculpture on our extended route home.



My beautiful hiking partner









A night stay near Ridgway, CO



Unexpected road hazard!


General check up on the car and setting up the mic before a new mountain road





Neat to see the railroad right next to this coal mine that we got to drive under



Dinner stop at a historic inn




Our night stay near Glenwood, CO







It was over 1000 miles, about 14 passes over 9000', about 24mpg, and the car didn't skip a beat. I did have to adjust a few megasquirt settings for idle at the high elevations, but the cool temperatures really offset the less dense air of the higher altitudes.

Here is a collection of video (sights and sounds) from the trip with my car:

https://youtu.be/K9SahaXkfas


After the trip, I have been readjusting my fuel and ignition maps for driveability now that I know my baro and temp corrections are about right. Very little air temp correction, I suspect because it is coupled with baro, but sitll it is less aggressive than I thought I would need.



EGO control seems to give me more problems that I want, so I decided to shut it off and see about running open loop only. This leads to multiple days of tuning to try to dial in my fueling map. I have touched boost regions but have to continue fine tuning.

Here's where I am at currently.



One of the biggest changes so far was some reading on ignition timing and reviewing my map. I am running 91 octane, but a great short summary I found was here: http://www.autospeed.com/cms/A_109132/printArticle.html

Basically, I decided to add a little timing in the normal driving range up to 3000rpm. This seemed to really wake up the car in terms of response and build boost. I am trying to gauge driveability and feel if the car likes it or not. I haven't touched much in the boost region as I think I really need to get on a dyno to optimize this setup. Still, seems like better driveability and I think it will improve my MPG in normal cruise as well. I have been removing timing when I notice slight bucking and have gotten transitions pretty smooth now.



Here's my MAT retard and TPSdot accel enrichment. Any comments on these settings would be welcome! Sometimes I get lean spikes, sometimes rich spikes for the same TPS and I am wondering if that's why the slider is available for MAPdot.



Lastly, I decided to do a 3rd gear pull on my drive home and see how it compared to my curves in the dense air of January and the initial setup in the 633. Same colors as before. The 535is has a shorter diff, so it is faster, I'm thinking 3rd gear may not be the best for the dyno plot. I still need to dial in the fueling and I am sure I could get it to a dyno and really get the timing set for the boost level... but for now I'm learning by tweaking it myself.



The first run (Orange) was run with my Callaway Log, old noname intercooler and 2" piping at about 6psi.

In warmer weather I had bumped up the boost to about 10psi and taken a log (Green). It probably isn't a fair pull to use in terms of RPM and gear, but an increase of only 20lb-ft torque is all that this plot indicates. Maybe this is due to the richer fuel mixture or warmer temperatures that day, but I didn't extensively test 10psi so I can't really make a judgement on this curve.

Pull without an intercooler (Blue). This is with the TCD manifold (ceramic coated), valve job, and new exhaust flange coming off the turbo. Interestingly this log with increased IAT's still gave number similar to the old setup at 10psi.

New setup with intercooler and larger charge piping (Red) in january 2018. With the same turbo and same boost level this data shows about a 10% increase in performance.

Today's pull (lime) with 535is chassis, different intercooler piping to fit the e28. A very similar boost level and timing values, but I was able to run the curve out almost to revlimit at 5700rpm. With 3000 miles on the engine, I don't often do this with the a long pull. You can see torque and power drop off, so there isn't much reason the exceed this point anyway...
Similar numbers as early January which is encouraging since we are now into summer.

I'm on the fence of tuning for higher boost levels, but I may just leave it as is because if I turn it up, I may not want to turn it down! 10psi (or 147kpa) is really my track use goal for durability.

[tschultz]

A few more minor updates.

I drove my 635 euro for the second time in months after replacing the headgasket and throwout bearing, two of my major projects. I had the wheels refinished and mounted some tires early this year but have only put a few hundred miles on it. I had theexhaust/muffler repaired to keep the unit on there since it sounds so nice yet is also refined.





Went to an e30 meet real quick and was the 2nd oldest car there to my friend's 02 touring.

Now I just need to play around with the distributor and bump up a bit more advance to run with 91 octane. It was fun to run around in that car again now that temperatures make it doable.

But on the 535is:

Car is driving well and I have 2500 miles with this engine in this chassis. I replaced front rotors and hope that has eliminated the rest of the shimmy issues of the previous owner. Brakes feel really nice with E32 master cylinder and bigger brakes.
Playing around with smoother driveability, I adjusted my lag factors and found a bit of a resolution to my response issue. Adjusting MAP and RPM lag factors to be less aggressive seems to have helped with response and a bit less jerkiness. Going through the tuning process, I'm getting about 18mpg in my city commute, but 21mpg overall. I should be able to bump that up I think as I dial in cold start tuning more. I'm fine tuning fueling and am getting good consistency now based on temperature fluctuations and I know altitude correction is about right.

Using only 1% EGO authority right now to basically run off of the base map.

I replaced the rear springs to lift the rear of the car a bit as I wasn't happy with the droopy drawers look. Will take some pictures soon (after it settles). Front is a bit lower than stock, rear is probably just slightly higher than stock, very similar to Charlie with his car Maytag. I think this brought my negative camber closer to where I want it (it was too extreme before).

I'm thinking about a track day at the end of October and also considering some dyno time. For the dyno, I need to find a good tuner and dyno person who can deal with a car without knock sensors and a car that has MS2. Not a high priority as it needs to be the right person.

[T_C_D]

One of my very favorite vintage wheels! I owned a NOS set of 16x8/9 way back in 2001. And as recently as 2008.

[harrypalmer]

Gorgeous wheels, congrats!
Wait, wasn't this car hit on her side and that's why you swapped her engine?
Thank you for sharing your friend's Touring story. One of my favorite all time models.

[tschultz]

They are cool wheels and I stumbled upon them by accident-- very glad the guy was willing to trade for my set of plasti-dipped Style 32's at the time! He put them on his Chevy Sonic for the last two full years:



16x8 Et11 square, I didn't want a set of polished wheels and am really happy with how they turned out. Understated but still attention grabbing enough with the step.

They really work with the early styling of the 635 and I may not even take them off to try them on my 535is.

This car is a different E24, an E12 based euro I've owned for 8 years, not the e28 based 633.

[harrypalmer]

Thanks for the 633 Callaway explanation. Yes, you should leave them on this one, they complement her perfectly. And if I may say so, do not tint the windows she really looks splendid with that tall greenhouse, those yummy seats, wheel arches and these wheels; all portrait a harmonious irresistible presence.

[tschultz]

This story is turning into a bit of a saga now.

Since my last update, I had been trying to fine tune driveability with timing in the transitions and small adjustments. I had upped the boost and In general experienced good drivability. Max I had seen on datalog was 168kpa for a second or two until the wastegate equalizes and I see 165 kpa (10psi for people at sea level).
I did a quick run the other night on my way home from work and was pretty happy with the increase.

Last week, I compared my timing map with other M30's and some other threads and decided to advance my timing in the boost regions.



In the mean time, I painted my BBS RA's just because the spray paint from 8 years ago was peeling. Wasn't ready to really refinish them, but I thought I'd just try this. I changed rear springs and ended up with this height. They are the springs originally from the 633 on page 1. A bit of rake compared to stock (on my 535i), but about right to my eye.


I took the car out for a night with my brother and on the way home I shifted to 4th and hit the gas up the hill towards Boulder. No audible detonation, AFR's in the 11 range and I revved it to about 5200. Soon I saw coolant temp elevating but kept watching it (1 oclock) and then it suddenly started dropping. I looked in my mirror to see a cloud of smoke out the back and soon after the coolant warning illuminate.

We took the next exit and coasted to a stop light. Unfortunately the car wouldn't crank. Got out to see minimal fluid leakage but oil spray all over the engine bay from my (temporary) open breather. This was about 10pm and luckily there wasn't a ton of traffic.



We decided to try to push the car through the traffic light and made it most the way to the next light but needed a break due to the hill. Tried to crank and it seemed to be hydro locked. So after catching our breath, we decided to try round two and push it through the next traffic light to a parking lot. There was a nice hump here as well and we were out of gas getting up that ramp. These bystanders outside an ice cream shop are watching us push and decide to continue eating their ice cream while apparently humming the rocky theme song to my brother who is pushing out back yet losing momentum. Luckily at the point we get to the top of the ramp and I can coast the car to a fairly open lot and park the car.

So what's next? Well my brother and I have a hotel in Boulder and luckily are a little over a mile away for the night. We ditch the car in the lot and head over to the hotel for our commitments in Boulder the next morning. Without a car, it worked out that we could walk to our meeting the next morning, only another mile away north.

So while headed to bed I text a friend to see about a tow Sunday after our commitment ends. Lucky for me, he is available to meet us that afternoon. We hang out in the area and eat lunch before walking the two miles through CU Boulder's campus to my car. In the morning we see that I parked the car next to a no overnight parking sign, but nothing has happened to it in the 14 hours. The bank is closed and we have access for the trailer and winch.

My brother got some pictures and the tow went super easy, at a cost of only $80. My friend even helped deliver into my garage when I can work on it!





Today I looked at the car and found this along with a high oil level.



The engine turns by hand and coolant came out of cylinder number 6.
Cyl 4, 5, and 6 had spark plugs with melted looking electrodes...



The car ran fine for the last 2000 miles with these plugs. Anybody seen anything similar? Do I need a colder plug than stock?

Not sure if adjusting the timing under boost caused my failure, or if it would have happened regardless, I will have to see how it looks when get it apart..
Just for reference, this map my timing map running 87 trigger angle and 91 octane:



Stay tuned for more as I still hope to make Oct 4 track day! Have the HG already here ready for R&R...

[Shadow]

idk what they are but just by looking at that long nose they look super hot.

[tschultz]

Stock WR9LS is what I had been using. No misfire that I could detect. I may bring my cold spark plugs (NGK BPR7ES) to the lapping day and swap them in just before assuming it all goes back together without any surprises.

I'll also remove timing (1deg) above 100kpa and make sure to remove the advance above 4500rpm. I'll keep it flat all the way just to be safe.

Going to start pulling the manifolds off tonight.

[tschultz]

Got the head off tonight and found coolant in #6 based on the headgasket failure blowing out towards the intake side. Apparently I had a failure between cylinders as well although I didn't notice any audible detonation. Time to scale back my ignition timing especially in the uncharted zone on my map above 150kpa. I guess it is also possible that I had over advanced timing in the lower regions of the map and prematurely weakened the HG....

On to the photos


The gasket between cylinders 4 5 and 6 had the damage, but it was very odd to see this between 1 and 2, almost as if the headgasket itself has an inherent weakness at this location... This is an Elring gasket by the way.



Wear on the block side of 1 and 2.


Luckily the cylinder head all looks fine, no cracks or other damage. I was about to wrap up and put the head back on tonight before torquing maybe tomorrow night.

[George]

Tom, you’re a machine. I admire your persistence. You seem to have to the worst luck.

How old are the injectors? New, used? Flow matched?

Given any thought to a block ring?

[tschultz]

I purchased the injectors used but was getting good spark plug readings with these ones installed and they seemed to run good for over 2000 miles. The problems were caused by me reading internet threads about advancing timing at higher RPM after max torque and other peoples maps instead of going with my own tuning methodology.


I hadn't thought about a different headgasket until the most recent detail. I haven't posted because I was done with the car for a little while.

I torqued the head and then reassembled trying to have the car running the last week of October. I got everything together and started the engine only to find that I was idling at about 44kpa and pressure was coming out of the valve cover breather. It also seemed to start idling even rougher than before and wanting to die. I suspected coolant getting into the combustion chamber possibly as it stalled out and then would not stay running without partial throttle.
Either a damaged gasket during installation, damaged rings, or possibly a crack in the block from tightening the ARP head studs. I haven't tried diagnosing yet.

I was sick of the car and needed some time away from it although it has been just sitting in my garage.



In the mean time, I'd like to share something that was fun: I took my 635 out to the lapping day that I had been planning to attend.

Overall it did well. The tires were newer Riken Raptors-- and the wheels are the Rial mesh that I had refinished and will pretty much remain on the car.







I had the timing adjust on me in the middle of the session as my mechanical distributor clamping nut wasn't fully tightened. Once I got that fixed, it was running pretty good until one of the later sessions where it cut out on me. After some research and discussion on first fives, I suspect it is the coil getting overheated or the ballast resistor (never heard of it before) was failing on me.
Eventually we got the car to start and I was able to drive it home.

The built-in resistor wire is buried inside the harness to the coil, you would need to cut back the insulation to find it.

.85 ohms would be fine
If I remember correctly, the voltage at your coil's (+) terminal should be around 11.5 volts or so with the engine running. If it is higher than this then your ballast resistor is missing and you will need the external ballast.
The ballast resistor is bypassed by the starter solenoid when you are cranking the engine so don't bother trying to check the voltage while the starter is engaged.

Also from firstfives:

However there is a control unit for the ignition which has been know to fail. I've put a couple of hundred thousand on them without a failure, but there are stories. On E12s and I think E24s it's mounted down by the washer bottle, a ~3" X 3" X 1.5" aluminum box. Availability seems to go up and down but I've got one or two I could be persuaded to part with if you do need one.

The other potential cause is the Ignition control unit failing (Thanks for the help Mike W.), but the car starts up fine now... I started investigating but haven't determined which is the problem child.


My brothers 318is again with lighter flywheel than the last event



My friends first time


318is following me
https://www.youtube.com/watch?v=mSDz0ZRB_cU

in car footage
https://www.youtube.com/watch?v=Q12EgQKGItQ

[marc79euro645]

I thought the 6 was wrecked?

[Tiit]

What's the cause for blue smoke? Are you slower compared to e30 mostly due tires or something else?

[tschultz]

What's the cause for blue smoke? Are you slower compared to e30 mostly due tires or something else?

Not sure about the smoke, I had new valve guides and head assembled by guru Mark Hutto. It happened on hard right had turns and I wonder if there is a different oil pan or baffle on the e28 cars vs e12 cars.

The first videos shows slicks on the E30, but 318is with 5 lug, bigger brakes, coilovers, light weight flywheel, bolt in cage, and r comp tires (2600#'s).

I am stock with front strut brace and some summer tires (~3400 #'s).

[LeiseyJr]

Throw some gripper tires and eat the edges of the outside on that E24. It's what all the cool kids are doing these days.

[derrith]

What's the cause for blue smoke? Are you slower compared to e30 mostly due tires or something else?

Not sure about the smoke, I had new valve guides and head assembled by guru Mark Hutto. It happened on hard right had turns and I wonder if there is a different oil pan or baffle on the e28 cars vs e12 cars.

The first videos shows slicks on the E30, but 318is with 5 lug, bigger brakes, coilovers, light weight flywheel, bolt in cage, and r comp tires (2600#'s).

I am stock with front strut brace and some summer tires (~3400 #'s).

Yes the baffling is different between the pans. Also m30s tend to fill up the cylinder head at higher RPM. See Murph putting a slight oil restrictor in his build, but not as much as the s38s/s14s. Also winfred’s Copper dish scrubber mods to his m88 to stop the oil burning at high RPM. Might look into a catch can/breather setup between the valve cover and air intake tube before throttle body.