Big turbo kits

[wheela]

Still patiently waiting on delivery of the EFR 8374 turbo, still no ETA...

[wheela]

Turbo has shipped!!

[wheela]

It's arrived!

[wheela]

Not a big update, but felt like posting some pics. Found some time to get the empty block, head, and valve cover up on an engine stand to install the kit and start working out inlet plumbing and water pump location.

[wheela]

Not a big update, but felt like bumping the thread Slowly getting the mock-up ready; added a cheap ebay water pump & T-stat, and my old stock air duct that I kept when I replaced mine. Also picked up the Full-Race inconel T4 turbo stud kit and matching inconel turbo gasket.

[AllanJR]

Originally Posted by wheela

Not a big update, but felt like bumping the thread Slowly getting the mock-up ready; added a cheap ebay water pump & T-stat, and my old stock air duct that I kept when I replaced mine. Also picked up the Full-Race inconel T4 turbo stud kit and matching inconel turbo gasket.

I just found this thread wish you the best of luck might pull the trigger after all is said and done

[wheela]

Originally Posted by AllanJR

I just found this thread wish you the best of luck might pull the trigger after all is said and done

Thanks! Progress is slow, but still moving forward. I bolted up an old stock turbo just to make sure I've got the air duct positioned properly. I've also ordered up parts to do some bench testing to confirm/quantify how well the boost solenoid I'm planning on using will work. I'd be further ahead, but had some unplanned life events come up that are taking my attention this spring.

[wheela]

So one of the challenges I knew I'd have to face is controlling the external wastegate. It's held closed by a spring and opened by boost pressure (modulated by a solenoid valve), which is the opposite of the oem wastegate that is held open by a spring and closed with vacuum from a pump (modulated by a pressure converter solenoid). The problem is our stock pressure converter runs on a 250Hz duty cycle frequency from the DME, and is designed for vacuum (it doesn't work with boost). All the solenoid valves that work with boost run on 32Hz duty cycle frequency, and don't work properly with the 250Hz signal from our DME. So people either have to use an external boost controller to control the wastegate, or just run spring pressure on the external wastegate. Neither of these approaches appeal to me.

[wheela]

Hardparker tried testing a Pierburg 7.01024.02.0 boost solenoid for conventional pressure-based wastegates in this thread, and seemed to have some success:

https://f30.bimmerpost.com/forums/sh....php?t=1656323

That thread is actually what convinced me to go with this externally gated kit - it seemed I could use that same solenoid to control my wastegate directly from the DME with no additional controllers required.

[wheela]

But before putting that on my car, I wanted to do some bench testing of my own to be confident in the valve's performance. So I bought a cheap adjustable duty cycle generator from Amazon, and set up a bench testing in my garage. This would allow me to test out that solenoid at 250Hz to see how it would perform.

[wheela]

I finally got around to testing this boost solenoid at a higher duty cycle frequency.

But first, I tried a baseline test at the 32Hz duty cycle frequency (what the valve was designed for). With about 23 psi supply pressure, It worked as expected. From 100% to 81% WGDC, the wastegate was fully closed with no boost pressure hitting the wastegate. Reducing from 81% WGDC gradually sent more pressure to the wastegate. By 30% WGDC, pressure in the wastegate had reached about 14psi, at which point the gate started to open (it had a 14psi spring, so it was nice to see the results align&#128077. Continuing to reduce WGDC gradually opened the gate further until at 13% WGDC the gate was fully open, with full boost pressure (about 23psi) holding open the gate. This would allow for a good range of wastegate positions, and varying boost force on the gate by varying duty cycle.

Testing at high frequency:
At duty cycle frequencies above around 100Hz, the valve fell on its face. It essentially turned into an on/off switch. There was no gradual transition or pressure control to the wastegate, beyond all or nothing. At high duty cycles, the gate was closed, with no pressure sent to the gate. As duty cycle decreased, pressure sent to the gate was relatively unchanged, until some point, the valve transitioned and sent all pressure to the gate, and it would fully open. And then increasing WGDC back up, there was a lot of hysteresis, as you needed a higher WGDC% to get the gate to transition back to closed than was needed for it to open.

I did not like how this valve performs under the high duty cycle frequency range our DME runs in, and was not comfortable moving forward with this valve. Here are some videos from the testing, and pictures of the set up.

https://youtube.com/shorts/x5bgBrRCbXo?feature=shared

https://youtube.com/shorts/S2hvP8GF9w8?feature=shared

[wheela]

In looking for a solenoid that would work, I've been reading about the stock pressure converter and how it works. Attached is some information about them. In summary, they have a diaphragm with vacuum on one side, and vent to atmosphere on the other. Vacuum level is controlled by balancing the pressure differential on the diaphragm against the magnetic force from the solenoid (which increases with duty cycle).

So I've been thinking if these work by the magnetic field pulling the diaphragm away from the vacuum from the vacuum supply, it should work just as well if the vacuum supply was vented to atmosphere, and the vent was instead connected to boost pressure - at least up to around 14psi (because the pressure differential across the diapgram would be the same magnitude, and in the same direction as its intended use condition). And obviously, it's designed to work on out stock 250Hz duty cycle frequency😃

However, our stock pressure converter doesn't have a port on its vent, it has a built in filter to keep crap from getting pulled in when vacuum is released. So I perused for a Pierburg pressure converter that had a barb connection on the vent, and the same style electrical connector. I found Pierburg valve 7.21903.70.0.

[wheela]

I tested this valve by connecting the boost supply to the valve's vent, and venting the valve's vac port. And it works!!!😎 This will allow external wastegate control by the DME with no external boost controllers required!!

Usable duty cycle range is about 15% to 100%. It's pressure output is quite linear between 15% and 100% duty cycle. At 100% duty cycle, it reduces boost pressure by around 13.5 psi or so. Should be plenty to work with either the 10 psi or 12 psi wastegate springs I'm considering using.

I still have some details to work out - since it's only rated for vacuum (worst case pressure differential across the diaphram of about 14.7 psi) I don't know how much over-pressure it will handle in my configuration. So I'll incorporate either some kind of regulator upstream of it, or a relief valve after an orifice in the boost line venting back to the intake to keep boost pressure hitting the valve below a 14-15 psi.

Attached are some videos of it in action, as well as pressure output vs. duty cycle graphs I made at various boost (supply) pressures from my air compressor.

https://youtube.com/shorts/wrlMIbDpVW0?feature=shared

https://youtube.com/shorts/a-38I7Qniy0?feature=shared

[e84_kellan]

I was wondering if a bigger bottom mount was possible and coming across this really gives much needed insight. I was going to pull the trigger on a used kit near me but glad I read through this to see it wouldn’t work. I still plan on a top mount in the future.

[wheela]

Originally Posted by e84_kellan

I was wondering if a bigger bottom mount was possible and coming across this really gives much needed insight. I was going to pull the trigger on a used kit near me but glad I read through this to see it wouldn’t work. I still plan on a top mount in the future.

I'm curious why you're thinking bottom mount won't work? Did you check out speedtech's site? I haven't encountered anything yet to suggest any differences on fitment on e84 X1 than e90 335 x-drive with 6hp auto; Speedtech, Big Boost, and 4n Motorsport all make bottom mount kits for that application.

My case is more challenging because of my own particular personal preferences regarding turbo selection and control strategy that I wasn't willing to compromise, but those are challenges I'm choosing to take on vs. any issues inherent to bottom mount kits.

That said, a top mount would be sweet! I hope you keep us updated with what direction you go!

[wheela]

Here's some updated fitment picks. Some comments - the shiny aluminum intake that clearly doesn't align is a full 3" inlet for stock turbos from Midnight Motorsports (they make the inlet for the Shuenk n55+ turboupgrade). I only bought this for the connection to the stock air duct pipe. It will get trimmed more for use as a barb connection to silicone inlet piping, but I've left it cut long for now while I work out what those connections will be/how long to trim it for final fitment.

So far fitment seems okay, except the water pump outlet will be touching my turbo inlet. TBD if I'll need to tweak water pump mounting depending what I do for the turbo inlet. This fitment is with the standard Speedtech water pump repositioning, so I haven't had to deviate from that yet

[wheela]

Wastegate will just clear the air duct

[e84_kellan]

Originally Posted by wheela

I'm curious why you're thinking bottom mount won't work? Did you check out speedtech's site? I haven't encountered anything yet to suggest any differences on fitment on e84 X1 than e90 335 x-drive with 6hp auto; Speedtech, Big Boost, and 4n Motorsport all make bottom mount kits for that application.

My case is more challenging because of my own particular personal preferences regarding turbo selection and control strategy that I wasn't willing to compromise, but those are challenges I'm choosing to take on vs. any issues inherent to bottom mount kits.

That said, a top mount would be sweet! I hope you keep us updated with what direction you go!

I remember seeing somewhere on the Facebook group that the subframe was different to the 335ix and that is what threw me off. It will be a while before I get everything for the top mount but will definitely keep y’all updated

[wheela]

Originally Posted by e84_kellan

I remember seeing somewhere on the Facebook group that the subframe was different to the 335ix and that is what threw me off. It will be a while before I get everything for the top mount but will definitely keep y’all updated

The subframe of e84 is a different part number than the 335ix subframe, but take a look at both of them on the first page of this thread. I can't say for sure why they're different p/n's, but they appear identical, at least in regards to potential turbo fitment. The only differences in front suspension components between X1 and 335ix appears to be the wheel carriers (how they get the extra ground clearance for X1), and the drive shafts, as they mate with the wheel carriers in a way that makes production easier. If I had to guess at the differences in subframes, I'm guessing the suspension mounting points on the e84 subframe may be positioned lower to help facilitate the X1's higher ground clearance.

I haven't seen any build threads, and I'm not on Facebook, or Instagram, but I do know there is atleast 1 e84 with a Big Boost bottom mount kit running around.

Looking forward to your top mount, definately have not seen one on an X1 There's another member on here that's also I believe interested in a top mount for his X1.

[wheela]

Nice to see some interest in modding X1's, this thread has been pretty silent the last couple years!!

[wheela]

I trimmed the midnight inlet down and rolled a bead on to make in into a silicone tube connector. I was able to cobble together a silicone inlet prototype, but I'd need to get a new elbow and re-trim for better fitment.

Honestly, I'm not sure I like this inlet, I'm worried it may collapse under vacuum since I'll be sucking through the full stock air ducting.

[wheela]

So my plan B, may actually turn out better than plan A. I got a 3D scanner so I can get an accurate digital model of all these components. Then I'll design my own inlet in CAD and get it 3D printed from an appropriate material.