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

[tschultz]

Good Point^^

No major chunks in the oil or oil pan. We didn't do an extensive look at the pump, but nothing looked out of the ordinary...


In other news, last night I installed the BEGI 2025. I mounted it just under the coolant reservoir, pretty much where the return line runs.

First thoughts: Throttle delivery felt smoother, especially in the midrange and getting off idle. Really with this old-tech turbo @8psi on a stock engine, it gets going much faster than I could have anticipated!

I ran down the street and back, fine tuning the part throttle AFR's and adjusting the gain and main pressure of the begi. Cruising is just about 14.7, which will decline depending on the vacuum/intake pressure. I feel I have a nice stock pressure setting at about 40psi, and it barely creeps up when at atmospheric. I haven't run my gauge through to the windshield yet, but I imagine I'm at no more than 55psi max at 10psi (see calculations in an earlier post). I'll double check this when I get some time.

Now I have it in a nice place where slight acceleration/load brings the AFR's from 14.7 towards 13-13.5 near atmospheric. I think 12.5 is a good target here, so I might increase the gain slightly.

When it reaches boost, the number continues to creep down towards my target of 11.5:1. I am happy with the feel of all of this. The car will really get going at 3/4's throttle once the turbo spins up; before it just wasn't as smooth.

There is one caveat to all of this. WOT signal from the TPS throws everything out of whack and way rich. My gauge shows 10:1 at anything less than atmospheric into the intake.
As I understand, this is too rich, and is a result of the 24# injectors and stock WOT fuel map dumping more fuel than it thinks.
What I'd really like to do is disconnect the WOT Pin of the TPS and see how it all responds. Of course this means I'd rely on the BEGI for all fuelling needs in boost, but I practically am right now anyway.
All the switch does is activate Idle circuit or WOT circuit-- nothing in between. You can disconnect it and the car will still run, but returning to idle may be tough for the car.

So basically I'd keep it to activate the Idle circle only, just like the automatic cars do. I don't think I want to tune the RRFPR to have less gain as there will still be a segment of the fuel curve that is too lean for the condition, and a segment too rich (WOT).

Thoughts always appreciated...

[LeiseyJr]

http://www.mye28.com/viewtopic.php?f=9&t=17345

[tschultz]

So time for another update. D4C has come and gone, so I have a bit more time to continue with small progress (hey I warned that it would be slow!).

I started driving this car to work and have put approximately 1000 miles on it. To start with, I was mainly tuning the mixtures and experimenting with the FQS switch.

Where I have it now seems to be reliable and I haven't touched it for over a week. First, I jumpered the TPS to the harness, only connecting the GRD (middle pin) and Idle pin. For the moment, WOT is not used because I was getting super rich conditions while under vacuum and full throttle.


**Slightly adjusting it seemed to help, along with cleaning the ICV and Throttle body with carb cleaner-- highly recommended**

The FQS switch is set to Position 0 or 2, which is either standard or -3% fuel. I think this just adjusts the duty cycle of the injectors slightly and holds them closed. This gives me idle AFR's of 14.7-15.3 depending on ambient temperatures.

The RRFPR is set with the gain needle all the way out, and the center screw maybe 2/3's of the way out. However, I found out that I don't have the restrictor required for this device, so I may need to continue tweaking when I install the new turbo.

Last night, I installed a Walbro GSL392 inline pump in replacement of the stock external pump. I like reversible modifications, so if I ever wanted this could be reverted back to a standard Bosch pump, or it could be repaired on the side of the highway if ever needed.
I found a great write up on the subject, which I will save and share below for somebody else's future reference.

Follow the pictures how to swap from your old 130lph vane type inline pump to a modern 255lph gerotor design from Walbro that flows more at the same pressure. The gerotor squeezes fuel from in between to gears up to your rail versus being pushed with the old vane style. This allows the pump to be small, light, quiet, etc. Everything you want to ease your mind while zipping down the road.

First step it to verify you have all the tools and knowledge to do such a repair. This entails safety glasses, wheel chocks, hoses, drivers, clamps, etc.

Here is what you need:

1 - Walbro 255lph inline fuel pump (I used Walbro GSL392)
1 - 8mm barb - 10mm x 1.0mm male (Walbro P/N 128-3024)
1 - 12mm barb - 10mm x 1.0mm male (Walbro P/N 128-3025)
1 - Few meters of 8mm x 13mm fuel house (BMW P/N 13311722262), 5/16" works fine.
1 - Meter of 12mm x 18mm fuel hose (BMW P/N 16121176440)
1/2" will work IF you can locate high pressure EFI line.
1 - New hose clamps, ABA or style that does not cut into hose



1. First, secure car on ramps or jack stands and chock wheels. Disconnect fuel pump relay when vehicle is running (if you have it) or let pressure bleed off after a few hours. Then identify the fuel pump beside the filter.



2. Here is your new high volume at high pressure Walbro with fittings installed. 12mm on side to lift pump, 8mm on side to filter.






3. Next, go ahead and disconnect the old fuel lines. You will spill fuel, so put that stogie out and locate a suitable container to catch this fuel.




4. Remove 10mm bolt from bracket and nuts that secure power wires. Should be 7mm and 8mm.



5. Compare new pump to old. You will notice that the dampening unit needs to be swapped over. You need simply a short length of 12mm x 18mm line, around 2".



6. Loosely tighten clamps on dampening unit and new hose. This device can be removed, is so, just replace with an elbow fitting, or run the large fuel hose straight to the pump.



7. Slide new pump into position. Attach lift pump hose to dampening unit and pump supply to fuel filter. Attach pump wires, brown is ground and green is 12V.




8.. New lines at lift pump. I cannot show with pictures what to do, but simply slide the new lines down the top of the tank and they will come out the opposing side. Cut to length.



Jump fuel relay and verify no leaks. If none found, go ahead and start the vehicle on up with extinguisher handy. Let idle for a few moments and go over all connections as vehicle idles.

If all checks out okay, lower car from ramps or stands and wash up. Congratulate yourself as you now have sufficient fuel supply to make massive power and one less headache to worry about.

The old pump had been having issues at 5+psi boost of going slightly lean. It was strong otherwise, and will remain a backup for my other two NA cars. I think it was not able to keep up with the higher pressures at the required flow rate as asked by the RRFPR. Static, it was good to 80, but in the required condition, it seemed to be limited to about 60psi. Somehow, the bracket had been missing some hardware, allowing both the pump and filter to wiggle freely, held in place only by the fuel line. I was able to round up the required hardware and mount both properly and secure it all.

I need to continue some tuning as now the AFR's are a bit too rich (10-11) when approaching atmospheric and 1-2psi. I realized I needed to install the restrictor to delay this rise in the BEGI 2025. Since mine didn't come with one (Bell references P/N: F2815-301), I will use a smaller I.D. vacuum line and see if that helps.
I only drove it around the block, but initial trials suggest AFR's of 12.5 in 3rd gear under boost. Excellent. Before, this was the point where the numbers would go lean and the stock Bosch pump couldn't keep up.

Next up will be to continue 'shakedown' progress of the car. In the near future, however, I will plan to upgrade to the TCD 60-1 turbo--I was waiting partially for the fuel pump, but also pending results of daily use.
Sort of reserving the use of the WOT signal, in case the RRFPR can't keep up with the flow capability of the new turbo. Will explore more at that time, but the idea would be to use a 1psi pressure switch with 8psi check valve that opens when the RRFPR can't keep up. Then the WOT signal means the ECU opens the duty cycle of the injectors to get 20% more fuel when at 8psi+.

I have a small leak on the valve cover, by the ICV. It seems like coolant/oil, but is always gone by the time I look at it in the morning. I think the Valve Cover Gasket is leaking coolant, so I may do a valve adjustment and valve cover gasket first, before changing the turbo.

[9mil]

Coolant from the valve cover? maybe the duck gasket in the back of the head... but there shouldn't be any coolant under the valve cover.

I am at this stage currently trying to adjust the AFM spring and the FMU to get acceptable fueling. I have wicked rick tip-in dropping into the 9's and 10's - I suspect the TPS (which was new) so I am having them replace it again. interesting note on that, I ohmed it out and it appears there is no WOT circuit in the one I had. I can see the idle circuit and when swapped to the WOT pin, nothing- no change at WOT.... I hope this played into my problem, in that it was seeing WOT all the time off idle. Ill test the new one before install.

I have the Walbro and 30lb injectors and I am thinking about dropping to a set of 24's I have just to see if that will help with fueling (after the new TPS is tested of course)

Good job keeping up with the thread and keep the posts coming!

[tschultz]

It a mystery for sure, so I think it would be a smart idea to take a look around and maybe replace banjo bolts and do a valve adjustment while I'm in there.

9mil,
As I understand, the AT cars came with a TPS that didn't have the WOT signal-- it was controlled by the TCU (Transmission Control Unit). Maybe this is what you had on your car? I have a spare or two around, maybe I'll check mine out to see if they are good still, if you need one.

I haven't touched my AFM spring, instead allowing my unopened AFM's to not mask other running problems. Using the ECU FQS switch allowed me to dial back fuel throughout the range up to -6% (too lean for my liking). It might be worth a try for you, as I mentioned, I like the reversibility.

Sounds like the WOT signal is what's causing your way rich condition in combination with those 30#'s. I'm curious to hear how you fix it. Weren't you originally planning to do MS2?

I'll have to share some pictures soon as I also took off the autozone red stripes!

[9mil]

Yes- I went MS2 but have since taken 2 steps back and tried to take some variables out of the mix. I didn't have the time to digest the steep learning curve of MS and got frustrated and things weren't working- it was always some sensor or wiring that made something else happen that set me back yet again... I am trying to keep it simple now yea right!

my car is a 5spd so I only have the 3 pin TPS - I have 3 of the auto ones should someone need.. my new one just got here and it tested correctly. resistance on the idle switch, nothing then resistance at WOT.

I am a little embarrassed to say that I dont know much about the FQS, but I have done a little researching and cross referencing with the 944 today and it sounds like it might be worth a go. I have a TCD chip in retarding the timing, so I want to make sure I don't undo that- some seemed to say it was affected by adjustment- some didn't.

There is no way mine would run without tighting the spring up. I am hoping to get out and do some tuning on the FMU tonight or tomorrow. I hit 12.6 on boost... so I like that, but I know I cant have my cake and eat it too! Ill have to compromise to get this thing out of the 10's and 11;s- it just shouldn't be there.

I clamped off my cold start valve too- just incase. and will be putting in fresh plugs, new CTS, I have 2 AFM I have been playing with to keep them honest, ICV is in there, just not sure what else it can be.

Whats your intercooler strategy going to be?


Found this: http://www.motronic.ws/fqs.htm
Looks like I might want to try position 3 and 4 .... Just that easy, right!

[tschultz]

Indeed, I have a photo of it on Pg 3 part way down the page. It's obvious with the ECU cover off. I have kept the cover off for now until I am done messing with the switch. Makes it easy to change if required (I always do it with the car off).

Your 30# injectors are almost double the stock size. So the FQ switch may actually give you -6% or -12% fuel if only the duty cycle changes. I'm not sure if this adjusts the entire map, or just portions of it. From my experience, I think it just reduces the duty cycle by a fraction across the entire map.

Establish a baseline:
I'd suggest trying a test run at 2/3 throttle (ignoring WOT signal), you should be able to get to a few psi and see how the AFR's look.
Then repeat with a WOT short run and see if the numbers go rich or if they are pretty close to the first trial.

For me, I had been getting super rich when still under vacuum WOT(not safe) and then under boost, the AFR's were close to the target with the additional air. As I have done, try the RRFPR with the gain needle all the way out so that you get the least amount of gain possible. Adjust the center nut so that atmospheric AFR's are close to 13 (I used this number from looking at various dyno plots). Once that is set, you continue with the gain for additional fuel under boost conditions.

[9mil]

Its another adjustment to add the mix!
When you say atmospheric - you are saying as you pass into boost from vacuum, correct? Or are you meaning just pulling the vacuum line at idle and adjusting to 13.0?

[tschultz]

Its another adjustment to add the mix!
When you say atmospheric - you are saying as you pass into boost from vacuum, correct? Or are you meaning just pulling the vacuum line at idle and adjusting to 13.0?

Correct, while passing through into boost.

You may be somewhat limited by your large injectors and may actually want to reduce your FPR from a 3bar(43psi) unit to a 2.5bar(36psi) as found on the earlier cars. This would be another work around to help with idling conditions only.


Will be curious to hear how you get yours running to your liking. I noticed that based on temperatures, the Motronic 1.0 likes to run slightly more rich than it needs in the colder weather. 50degree mornings give me idling AFR's of about 14, where warmer weather puts me near 15.5.

[stoney]

You certainly saved this car! great job so far.

I'd be looking into the oil pressure thing a bit more too, and start with a correctly sized restrictor rather than the one you have just fitted.

The best way to find out what size restrictor you require is to remove the turbo drain line, and measure how much oil comes out in a minute (capture it in a bucket) and compare it to manufacturers specs. Too much oil can damage the turbo seals and cause drag on the bearings, and if you do have to fit a smaller restrictor then that should also help with increasing your engines oil pressure.

It's a quick task to measure the oil drain through the turbo to know if you are getting enough flow with the restrictor in place.

Granted ball bearing turbos need less oil than the journal equivalents, and my GTX3582R runs a 1mm feed line fitting. What size was yours again?

Do you know your turbos construction - ball bearing or journal bearing?

[tschultz]

Good points. I was going to replace with a TCD turbo, standard journal bearing I think.

My restrictor is .090" ID, where a 1/8" NPt restrictor can go as small as .030" or .065" ID.

Since my pump never goes over 65psi, even when cold, I didn't see the need to go with a smaller restrictor and risk under-lubricating.

anybody else have suggestions on this topic?

[9mil]

Might want to hit chuck at pure turbos up- he said he had turbos that don't like anything above 65psi... But that is usually only at cold. I have an inline gauge I used to check and I wasn't really getting anywhere close. Happy to send it to you to play with-

[stoney]

Its possible, as you said, that due to not small enough a restrictor you are having the oil warning light issues at low rpm, so my suggestion was purely based mainly around fixing that issue. Seeing as when you fitted one as opposed to not having one, the oil light stays off a bit more often. My turbo runs a 1.0mm restrictor, but it is a ball bearing centered GTX3582R, so that's noticeably smaller than your current restrictor.

Added benefits of limiting oil flow can be increased boost response as well, but obviously not restricting so far as to starve the turbos needs.

[9mil]

Alright... I needs my updates!

how's it rollin'

[tschultz]

Hey 9mil,

Thanks for the bump. I haven't updated this in a while, and unfortunately haven't made a ton of progress, but a lot of little things.

I had replaced the external pump with a walbro. Fortunately this has cured my lean problem in high revs, and even made things slightly rich. After thinking more, I have decided to go forward with a TCD turbo in the near future before getting the exhaust completed. This will push more air and hopefully bump up the fuel requirement into a range my RRFPR can be used. Right now it is all the way open, and I still have fuel pressure rise too quickly.

The other benefit of the turbo, I think will be reduced back pressure. Right now the light weight flywheel and such doesn't seem rev very feely and I think this is due to the small turbo and high backpressure. With the larger turbo, I want to reduce this back pressure. In addition, the new turbo spins so much more freely than the Rotomaster. It feels very noticeable by hand when spinning the two. I imagiune this will be a huge upgrade in spool time and overall response. Right now, the response it press the gas, count 1...2...3.. and then it starts to go...

Progress stopped mainly because i realized that the welded "fix" did not solve my problem. Upon closer inspection the under body is cracked, almost like the rear wheel was taken off a jump, and the subframe mount cracked the underbody. You can see it in the images previously posted.

I had some other issues with some of the other cars and some personal stuff, so I took a break working on the car. The heat of the late summer didn't help for work on the car after work. Now it is cool, so I am just starting the progress again. I actually put the car in the air tonight and took off the exhaust. Tomorrow and Thurs, I plan to try to drop the rear subframe so the welder can come back on the weekend.

I spent some time tightening up the front spoiler to the nose, so it is a much better fit.

I also found that my radio power cuts when I turn on the lights. I have to take that out and rewire it, along with unsticking the temp control knob. It got stickier and stickier for the mornings that I actually was driving the car.

In the mean time, I decided to remove the ugly red pin striping and the horrible window tint. I got stuck on the back window with the glue separating from the tint layer. not sure how to remove it without cutting the defroster units. Maybe worth paying somebody?

In the mean time, I replaced the engine bay fuel lines on the euro 635 (M90). Got that back together which was handy, and snapped a photo of the euro car next to the (super dirty) turbo car :
The turbo car looks worse paint wise, but is in better condition rust-wise.

[tschultz]

So I continued progress today in removing parts from the rear end. I have everything ready to go for removal, minus the shocks on either side, the brake lines, and the diff mount.

Speaking of which, how do I remove rusted brake lines? I think I need to remove the hard lines so the assembly can be lowered and rolled away for repair access.

What is the best way to take them apart without damaging them? On a search, I read heat may be the best way. any suggestions?



I loosened it tonight to make sure the assembly would move as I suspected.



Fortunately it dropped down slowly on the side I am concerned with. More pictures to come when it is fully off. But you can see the crack, which is maybe 50% around the mating parts:





This photo shows how part of the underbody is torn enough so that it is pulling downward slightly from the weight of the loosened assembly.



I have replacement subframe mounts here ready to go, however I am unsure how to remove the old ones... At 150k and their current condition I'm half tempted to leave them alone--- Of course on the other hand, I don't want to be in here again on this car if possible.

Any suggestions or bookmarked threads on the actual removal?

Here's how the driveway looks. The M5 front end is apart as I'm fitting a euro valance. Having some issues getting it fitted where I want before installing the fogs, turns, and possibly new spoiler.



Oh yeah, I also bought some parts on Ebay and pieced together a coarse spline hub and Raid/Racemark I steering wheel (330mm) and Alpina horn button! The turn signal shut off was damaged, so I may just live with it or get one at some point. I won't install it until I get the front end of the car redone (control arms, shocks, springs). So it's patiently waiting hanging above my work bench.

[9mil]

I need that steering wheel!

[tschultz]

Yeah, I thought it was pretty cool, which is why I got the hub for it. Not putting it on until I get the suspension re-installed and everything replaced up front first

With the subframe out, conveniently my welder Frank could make it out today and finish cleaning up and re-welding the mount location. We were able to pull the plate that is hanging in the photo, out completely by hand. Pretty sure it scraping/shifting is what caused the noises I was hearing.







We cleaned up and prepped the area with a grinder and in the process saw the full extent of the cracking. I don't know how this happened, other than by somebody beating the crap out of the car. I guess it's possible the cracks were caused by the accident damage, and over 4-5 years of daily driving after the 'repairs'. Fortunately the bolt for the subframe was solidly in place. I think everything had just been shifting upward before the initial repair a couple months ago. Lately I still heard a small squeaking sound, which I think was that plate rubbing against where it had torn off.

Frank at work again. In the last test drive, he was really impressed with the performance of the car, saying he felt it 'hauled ass' after I described I wasn't happy with the Callaway turbo response.



Today he closed up the holes inside the wheel well. These were there from the initial welding work where his stick welding was too hot and cut through the rusted metal.



From the bottom, his weld beads show the extent of the cracking that wasn't visible originally:



The largest crack moved outward to the edge where the uni-body met the lip/skirt that runs the length of the car.



Now no more light is visible through the body. Before we could see a few locations-- such as the wheel well. I'm going to clean up the areas where he welded, pull off the burnt under-coating, and then re-coat it all before reassembly.



I won't have time tomorrow to do much unfortunately, but I plan to jump on it Sunday.

After this is all back together, I will have the following:
-T04E turbo replacewment
-Tclamps, and coupling replacement
-Intercooler piping sand and clear coat
-finish exhaust so that it doesn't sit so low(quick coupling method?)
-front shock/strut replacement
-front control arm replacement
-front alignment

Not sure how fast I will get to it-- funds are limited. some items may be in the next month or two, others may not be until 2016.7

[9mil]

Progress is progress and you are making it my friend! These little setbacks suck- but happen... Back to the fun stuff! Now ship me that steering wheel :-)

[tschultz]

I have another update. This weekend was my bachelor party for a wedding in December. With that said, it sort of explains my somewhat slow progress. But anyway, my brothers both signed themselves and me up for a lapping day at High Plains Raceway here in CO. I have been there about 4/5 times prior in my 535i. I have the same shocks/springs from that car on this car now, but the fronts haven't yet been swapped over.

It was good thing I got the subframe issue resolved a little over a week ago, because my brother planned to bring a new project e30, but he ran into issues literally the night before the event while driving it to my house where he was going to spend the night. We thought we fixed the problem, but his temp gauge heated up just a couple of miles from my house so he puleld over. As we were looking at it, all of the sudden a coolant pipe (plastic) blew right in front of us. The plastic barb had broken off. After some issues, we luckily had a trailer, unloaded the other car and the got the E30 loaded and back to my house.



I had my car ready to go, as I had sort of anticipated the issues and wanted to have a small backup plan. With confidence of driving the prior full week to work, I headed out in the Turbo, knowing that temps would be 50-65's. I had stole the wheels off the M5 and headed out.

At the track it almost didn't work out because I forgot to grab the standard lug bolts (the RA's use extended lugs) and was sitting SOL when I went to change my wheels and tires.



I decided I might as well check the air pressures and anticipated using those wheels and 'going easy', like that would be possible at the racetrack A nice camera makes it look like a fairly decent car!



A short video following my brother is the car my dad built, a 1600 with a 2.0 M10.

The car did very well, I ran probably a good 3 sessions, with the next 2 being cut short due to hose coupling issues. I still haven't yet upgraded from the originals on pg 1. I have pressure tested it, so I had been fairly confident. It was very easy to drive, the sway bars really helped and seemed to grip nicely. I really didn't push it in the corners, nor on the brakes. The sport seats worked great, and the sway bar mounts didn't break like I was worried about! I still flew by my friend jesse (Blue Owl) in his 535i on the straight where he was hitting 100 and I was at about 115mph.

The turbo was really laggy, like full throttle... count one....two...three... and you'd hear the spool and feel the power kick in. Very interesting as it made me break early and get on the gas ASAP in the turns. Really neat to drive this car and then hop in the 02 for a few laps and have a car with max corner speed, a car that really is meant to be thrown around a bit.

http://www.youtube.com/watch?v=LD33euK-8Us

I may have a few others in the next week or so.

Here's a few other photos which turned out pretty sweet. I taped the headlights as a tribute to the racing E24 heritage-- IMO it makes the car look that much more aggressive.





In the pit between sessions with some of the other BMW guys who showed up together:

[86GT635]

It looks like those sway bars help quite a bit. Nice run!

[9mil]

Looks fun- people ask if I am going to take mine to the track..... not sure how it would do, seems too flexible- but looks like it gets along pretty well. I think an autocross of a tight little track wouldn't be much fun. maybe ill try It when it gets done.

Keep the progress going! and congratulations!

[downforce22]

Some more photos.

[tschultz]

Thanks for sharing, they sure make the car look pretty reasonable!
How did the video inside the car turn out? Maybe you can hear the turbo spool?

Another short video showing the other cars I went out there with. The steep hill I could get on the gas early and really power up as compared to all of the other NA cars and fellow BMW's.
The VW was a 2.0 running 15psi. He accelerated so much better than me-- I was really wishing I had the TCD turbo on at that point. But I'd reel him in by getting on the gas earlier on a few corners.
The funny part was his turbo was slightly bigger than mine

https://www.youtube.com/watch?v=BV6z1PUlCEU

[tschultz]

An in-car video from Sunday. You can really tell how laggy the turbo is since you can hear the spool. That's the next item on the list-- now just gotta find the time to swap it!

https://www.youtube.com/watch?v=7lB7Ws88Uz0

[yodman]

What a read.

Love it so far. I never knew these existed, and I feel it's a super rare car. I like the direction you are going as it seems you are retaining the functionality of all the gadgets and original equipment. I hope to build a car this way someday.

Hopefully I'll be lucky enough to build an E24, although an E28 is not much different.

[tschultz]

Thanks Yodman,

next step is swapping the turbo and replacing my couplings and possibly intercooler. Not sure if I will get started in November or not. Getting married in December, so it may be difficult to get the time for the swap. I don't want to leave it half apart for more than a week.

[tschultz]

Some proper photos since I had some spare time today.

It looks quite a bit different since I purchased the car. Not great lighting, but I didn't have many high quality photos of the car so I figured I'd shoot them anyway.

[downforce22]

Need more progress!!

[tschultz]

Nice photo, thanks! That's the one I had been waiting for.

The shark is lurking-- waiting for me to get my butt in gear and continue making progress!