Turbo ETA build

Discussion pertaining to positive pressure E28s.
LeiseyJr
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Re: Turbo ETA build

Post by LeiseyJr »

turbodan wrote: May 22, 2023 3:18 PM Updates if anyone is even still reading this.

I inquired about a BMW driveshaft, which is still available although I was told it is six weeks out from Germany. I decided to give driveline services and PTI another chance. They sent a return label for the first abomination of a driveshaft and started building another one for me. Driveshaft number two arrived on Saturday and I was appalled by what I received. The rear joint had one axis that was very stiff and did not feel smooth if you applied enough force to move it. I found some circlips smashed into their grooves with excessive force, others not seated at all that popped out with a screwdriver and one fully seated in its groove but able to spin freely because it wasn't retaining shit. One circlip was installed backwards, flat side in and rounded side against the groove.

I'm not sure if this was incompetence or spite, but this driveshaft was fucked up worse than the first one. At least the first one appeared to have been built properly and the joints felt right. I decided to get out the hammer, the drift, the file and some good snap ring pliers and get work. Couldn't install it like this, didn't want to turn around and try to return it again. At this point I'm expecting serious doubt from driveline services that I'm not a ham fisted dickhead blaming their driveshafts for some other problem. So I filed some circlips, made adjustments with some precision hammer and drift action and got the apparent issues sorted out. With little confidence, I installed the driveshaft and was pleasantly surprised to find that it runs smooth as glass.

There are a few other places that offer driveshafts for these cars. Driveline Services can build you one but they will be more expensive than these other shops if they do it in house. Their basic replacement shaft is sublet out to PTI, which does a really bad job at building driveshafts. Maybe the first one was a fluke and the second one was a middle finger, who knows. Maybe things like this only happen to me. At least the car is running strong. Hanging in there at 12/13 psi with no clutch or head gasket trouble. I don't think I need more boost at the moment, but I am looking forward to getting this other head built with dual valve springs and a proper camshaft to broaden the power curve and raise that rev limit up.
I saved up for a Driveshaft from BMW so far its been worth it, hopefully it stays together.
Punnzzells
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Re: Turbo ETA build

Post by Punnzzells »

Great thread!
turbodan
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Re: Turbo ETA build

Post by turbodan »

I spent some time with my attention elsewhere for the last few weeks, found a nice 2002 Yamaha FZ1 with very low miles that needed some work. The price was excellent and I've been looking for a first gen FZ1 for about two years. Seen here on a recent trip into the Jemez Mountains:

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That bike is now sorted out and I'm picking back up where I left off with the cars. A kind and beautiful soul in Florida hooked me up with an entire M20B27 with a fresh top end, wiring harness, Megasquirt ECU and a whole bunch of other fine fixin's. Cost about $400 to ship it but even with that on top of the purchase price, this is a great deal. The plan is to dunk this motor into the 85 524td I picked up a few months ago and go a little bigger on the turbo. The largest turbine I can find in the internally gated T25 variety is a GT2971R, mating a 56.5mm, 90 trim turbine to a 53mm compressor. It's actually a very good fit on both sides. In terms of flow, the turbine is only about 10% smaller than the GT3582R I ended up with on the original build. Won't be spooling at <2000 RPM but that's okay, I like a large turbine for a lot of other reasons. The compressor is very efficient on a 2.7i and is capable of making more boost than I have any desire to run through this thing.

Still need to pull the motor out of the 524td, swap in the manual trans stuff and wire in the M20 harness. I will probably put a cam in this new motor since I don't know what's in it and I don't like variables.

Is there a market for turbo e28's? I will end up trying to sell one of these, would be nice to get some money back out of this build and I don't have room for two of these things.
turbodan
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Re: Turbo ETA build

Post by turbodan »

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More victims of inappropriate engine oil usage. Insufficient viscosity and zddp. This motor looks new inside. Can't have more than 20k miles since the head was rebuilt. When it comes to oil, it does not take long to trash a valvetrain with the wrong stuff.

It's got to be 20w50 folks, with lots of zinc they way oil used to be.
tschultz
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Re: Turbo ETA build

Post by tschultz »

Which 528e is this, the one from this thread or the 'new' one? That's worse than any I have seen in person!
turbodan
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Re: Turbo ETA build

Post by turbodan »

That valvetrain is out of the complete engine I just sourced for the next build. I'm wondering if they rebuilt the head with new valves and a new cam but they reused the old rockers. They are remarkably ugly.

For now there is still just one build in progress. On that front I am putting together a proper cylinder head for the super eta with a suitable cam and dual valve springs. I need to order a clutch but I'm trying to sell a bike and recharge the powersports budget before I pull the trigger on that. When I really get started on the 524td engine swap and turbo build I may start another thread so it is easier to follow.
Punnzzells
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Re: Turbo ETA build

Post by Punnzzells »

With all of these turbo builds, any plans on selling kits?
turbodan
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Re: Turbo ETA build

Post by turbodan »

Would have to cost quite a bit, even if I did I doubt the market would be very big. The process gives a great appreciation for the kit that TCD used to offer. There is so much to it, so many things to make and little problems to solve. Of course it's a high stakes situation too, once the kit is installed it is up to the owner to be responsible and not blow their shit sky high.

I do plan on selling one of these cars though, complete, worked out and tuned. Probably the first one featured in this thread. That's up in the air though, it's not quite done yet and the other one is nowhere near it.
Punnzzells
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Re: Turbo ETA build

Post by Punnzzells »

Its a great read and thread.....even for a newbie.
austin8753
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Re: Turbo ETA build

Post by austin8753 »

wow, good on you for sticking with the project, even with all the headache you've had to deal with. i've used tons of driveshafts from Powertrain Industries over the years, with great results. bummer to hear the quality is going downhill... sure takes away my interest in playing with old BMWs, with the quality of everything suffering, in today's world.
turbodan
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Re: Turbo ETA build

Post by turbodan »

I dropped a cylinder head off at the machine shop today. Bought on ebay as a good used head, came in with the usual wiped out cam/rockers and a decent gouge in the mating surface, precisely where the metal rings of the head gasket seal around the combustion chamber of cylinder number 6. I think it should be alright with a slight resurfacing.

It will be going together with a Catcams turbo conversion cam. More lift and duration on the intake side, wider lobe center on the exhaust side. I ran this exact cam before on the original build but ended up going back to the B25 cam for reasons I cannot remember. I think the power felt flatter through the midrange with this cam, which is actually a good thing at high boost. Spreads the BMEP out a bit and helps avoid excessive cylinder pressure in the typical det zone between 4000 and 5000 RPM. In any case, it's going in. When that head is done I'll pull the original super eta head off that's in the car now and slap on the new one with that cam and B25 valve springs.

For now I turned the boost back down to where the clutch can hold it. I don't need to run 1 bar right now, I can turn it down until I feel like buying a clutch that can handle it. I think I'm finally mature enough to be okay with that, at 37 years old. I may leave this one be with the small turbo and low boost, it's still plenty fast and fun to drive. Will be even better with a proper cam and a broad powerband.
Nebraska_e28
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Re: Turbo ETA build

Post by Nebraska_e28 »

Sounds like a good plan! Awaiting results.
turbodan
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Re: Turbo ETA build

Post by turbodan »

The head is built and installed. Waiting on a sintered intermediate shaft pulley to replace the shitty stamped steel original. I may order another set of head bolts, I was going through the torque process when I realized I wasn't really paying attention to the sequence like I should. May or may not have missed an angle torque at some point. No way to know, though after the fact I realized I should have marked all of the bolts after the initial 22 ft-lbs to keep track of each step. There are two angle torque steps so a little paint mark on the bolt head at 12 o clock before those steps would make it perfectly clear where each was in the process. Would be another $25 for a set of bolts, and if I pay attention this time I would have peace of mind.

That's the downside of working all day without a lunch break. The mind wanders. It is getting close though.
turbodan
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Re: Turbo ETA build

Post by turbodan »

The missing piece has arrived:

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I had forgotten to order the improved intermediate shaft pulley. This 2.7 still had the stamped steel pulley, not even the reinforced version but the early single sheet design. Cant be raising the rev limit with that in there.

Looks the same from here, though I cleaned the valve cover and timing covers. No external signs of the improvements:

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It runs good. Going back to tuning, the effect the cam has on the tables is dramatic. I did spool it up one time on the test drive and I was very surprised how it pulled for only 140kpa. That's minimum boost, around 8 psi. Very stout, and the broader torque curve is quite evident.

I rearranged the ignition map to fit the expected VE curve so that should be about right. I winged it on the fuel table and then I ended up pulling a bunch more out in the sub 3500 rpm range. The daily driver zone was super rich. Makes sense, that was where the eta cam was efficient.

In conclusion, don't even bother boosting the eta cam. Even un-tuned this thing runs so much better. Sounds pissed revving out under boost too. The exhaust note is markedly different. It is a total transformation.
turbodan
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Re: Turbo ETA build

Post by turbodan »

Also wanted to note that the valve cover can be removed and it looks like the spark plugs can even be serviced without removing the turbo with the US spec 524td manifold. The key is the riser between the manifold and turbine, that extra two inches sets it up in a very good spot.

I always hated that about the old setup with the european non-AGR manifold. It doesn't protrude out far enough to provide clearance even with a spacer between the manifold and turbine.
turbodan
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Re: Turbo ETA build

Post by turbodan »

This evening I had the opportunity to square off with a WRX, found out after the fact that it was a 2017. We opened it up from 40 mph and I gave him the jump. We started out pretty even but by the top of second gear I was reeling him in. Same story in third, again pulling on this WRX on the top end. If we had more room I would have officially walked by this guy, but no need really. The gap was closing and I was a little faster.

He said it was stock so it's a good benchmark. Google says these things dyno about 225 at the wheels and run a high 13 second 1/4. This squares up perfectly with the boost level I'm running and my past experience. The car really feels healthy, this is a good power level for an e28 and compromises nothing on longevity or reliability. More power than an e28 M5 with better mileage and less maintenance, with quite a bit more in reserve if desired.

That said, I will be pulling the engine out quite soon. It had always been prone to fouling the plugs on #4 and #5, and the oil consumption has been excessive. I was hoping this was valve seals and perhaps the new head would help alleviate this. Upon pulling the head I was disheartened to see significant scoring inside the suspect cylinders. Always optimistic, I put the head on anyway just to see what happens. The increased rev limit has resulted in a disproportionate increase in oil consumption and the same old plugs are coming out black and oily. If I'm lucky, this is the last surprise this e28 has in store for me.

The new plan of action is to dunk in the engine that was originally intended for the 524, it's sitting here with a brand new valvetrain essentially ready to go. I'll either get another block and swap this super ETA stuff into it with fresh rings or just slap the fresh head on a complete B25 bottom end. I need the car sorted by the end of the month, this will be my daily again for at least a little while.
Nebraska_e28
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Re: Turbo ETA build

Post by Nebraska_e28 »

Funny I was just about to ask if there have been any unsuspecting victims. :rofl:
turbodan
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Re: Turbo ETA build

Post by turbodan »

And there you have it. :banana:
Nebraska_e28
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Re: Turbo ETA build

Post by Nebraska_e28 »

Current highway mpg?
turbodan
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Re: Turbo ETA build

Post by turbodan »

Odometer is inop but I did make a run out to Estancia yesterday, a little over 140 miles round trip. Starting with a full tank, I returned home with 3/4 showing on the gauge. My estimate is that this is high 20's. I have seen 27 before with the last car on a similar trip and this one may be doing even better since I've been really working to get the fuel map to 14.7 under cruising. The M20 with a tall final drive ratio is a sure thing for good MPG.

I got tired of this pile of front end stuff on my floor so I reinstalled the valance, bumper trim and grilles. Looks nice again, weathered and old but nice. The valance only required minor trimming in the middle section to fit and it clears the intake plumbing easily.

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I hate to see those oil drops but the rear main has yet to be addressed. I've been having a hell of a time getting the front of the motor sealed up too. The head I just took off had a new cam seal and carrier o-ring as well as new rocker shaft cutout plugs and a new valve cover gasket. It was still leaking. This new head with all new seals and gaskets is leaking even worse. I used to be able to get these to seal up without silicone but I'll tell you what, next one is going to be absolutely glued together.
turbodan
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Re: Turbo ETA build

Post by turbodan »

Revisiting fuel maps since the new cam went in. Here we have the stock B27, then the B27 with the B25 intake:

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And now the catcams turbo cam with the B25 intake:

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Similar VE at 5800 RPM as the B25 intake with the B27 cam at 5000 RPM. The breadth of that torque curve is evident and the top end pull is excellent. Low-mid power isn't bad either, it's certainly sleepier than it was with the B27 cam but dipping into the throttle even partially still starts making boost without delay.

I don't know why I took this cam out of the last build. I have no complaints about the power delivery.
turbodan
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Re: Turbo ETA build

Post by turbodan »

Spent about four hours pulling the motor today. Not a record time by any stretch. Pretty filthy too with the rear main leak. That shit went everywhere.

I may get the other motor in tomorrow if I'm feeling spunky. The prospect of fixing oil leaks and resolving the oil consumption is enticing. I certainly hope this other motor is good, I never took the head off so it's a bit of a gamble. The plugs that came out looked good so I feel pretty confident.
turbodan
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Re: Turbo ETA build

Post by turbodan »

What a day. Got the motor and trans back in. I used a spare clutch I had on the parts pile from around 2009, a very low mile stock M20 unit. Looked great, far better than the crispy critter I took out. I had ordered a clutch from "gripforce" and they sent me about half of what I ordered, then upon my inquiry they informed me that the disc was on backorder and would not be here any time soon. Waste of time and a disappointment but at least I had the spare unit to get going in the meantime.

The new motor does run but it's not quite happy. It doesn't make as much vacuum as the turbo cam in the motor I just pulled or the original cam used to. Idle quality is not great even though this tune worked very well with the various configurations on the old motor. This motor was a gamble and I'm a little worried about it.

Above idle it smooths out well, which is the point I discovered the other issue. This very nice looking clutch I put in slips badly at the same boost level the crispy critter was holding. Clutch pedal effort is also significantly less than it used to be so I'm wondering if the pressure plate has somehow gone soft. Exact same part number as what came out, should have been the same part just in better condition.

I will be pulling the trans again to put in a proper clutch from someplace that actually has one in stock. I'll try to get the engine to run better with some tuning, though this cam is in between the turbo cam I just put in the other motor and the stock eta cam. If everything with the motor were good to go it would just need some tuning on the fuel map but I fear it may have some valve sealing issues indicated by the poor idle vacuum. If the bottom end seems good and it's not using oil perhaps I'll pull the head and swap it out with the other one with the turbo cam.

I never used to have these sorts of problems. I used to build motors from a bare block and leave nothing to chance. Something to be said for that. This shit is wearing me out.
turbodan
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Re: Turbo ETA build

Post by turbodan »

The original block:

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Cylinder number 4, the worst of the bunch. No surprise it was burning oil.

All six showed signs of foreign object damage. Something went through this motor at some point in its 30 plus years.

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The new motor is running better with some big changes in the tune. Vacuum is still not great but it doesn't seem to be using any oil so I'm thinking it might be good for now. The clutch is slipping less after getting, let's say, burnished somewhat. I'm probably still going to be back in there before long.

The oil leaks are fixed with the exception of the oil level sensor. This never leaked before and was installed with a new oring. Now it's dripping.
mitch5
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Re: Turbo ETA build

Post by mitch5 »

turbodan wrote: Aug 25, 2023 2:51 PM The original block:

Image

Cylinder number 4, the worst of the bunch. No surprise it was burning oil.

All six showed signs of foreign object damage. Something went through this motor at some point in its 30 plus years.

Image

The new motor is running better with some big changes in the tune. Vacuum is still not great but it doesn't seem to be using any oil so I'm thinking it might be good for now. The clutch is slipping less after getting, let's say, burnished somewhat. I'm probably still going to be back in there before long.

The oil leaks are fixed with the exception of the oil level sensor. This never leaked before and was installed with a new oring. Now it's dripping.
What kind of FOD would cause that damage to the piston top? If that was the piston, how did the head look? That looks like my time I semi melted a piston due to low injector flow
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