Topic: Twincharged Solstice = Turbocharger + Supercharger

[Steelmesh]

I'll bump this myself.

I got my twin charged setup running, and will say that you will need to massively upsize the pulley.. I initially stepped up to a 3.1" pulley from the 2.8" I was running SC only and even with a 5psi gate, keeping boost below 25psi seemed impossible. It was a torque monster, with loads of boost even at 2000rpm, which will not be good for engine longevity.

I'm now running a 3.6" pulley and still 5psi gate and boost is more acceptable, but still around the 20-25psi range. Quite surprised how much boost is multiplied.
It's still a work in progress, but it does feel good on the road. I'm happy enough for now leaving this as a base to work from. It was suggested to use a 3.8" pulley, but I think the 3.6" is fine for me.

I agree for a series setup you need to reduce the supercharger speed, pressure ratio is wicked.  Not implying you're arguing here, just mentioning that I will be trying to target the spirit of the powertrain, SC boosts the low end, TC takes over up top: that is why I'd try to use an aggressive pulley because it will be bypassed properly to let the turbo take over on it's wastegate.  That's speculation related to what I got going on, so I'm open to whatever works and thanks for the tips on your experience here.

I've been running GT260 and brought some more timing in and it's starting to open up.  Planning to add the bypass here soon it will be a project not only mechanical work but controls side and bypass strategy. Looking at using a Ecotec 1.4T throttle body (since I have a spare and they're easy to find). 

Dash marks showing bypass path around the supercharger as you've seen before: https://hips.hearstapps.com/hmg-prod/images/lancia-delta-s4-7-1653585726.jpg

[stevieturbo]

If you're intending to bypass the blower or decouple the drive, then yes I'm sure you'll get away with a smaller pulley.

My first tries with the 3.1 and a simple turbo blowing through the M62, would result in close to 30psi even down at 2500rpm.

It might sound like a good idea, some engines/setups might even be happy to take it, but it wasn't what I wanted for this build.
Initially I had 9-10psi spring, and nothing I could do would see boost at a workable level ( had boost cuts in place  for obvious safety reasons ). Changing to a 5psi spring helped, but still too much with the 3.1 pulley.

With the 3.6" pulley and 5psi gate, it's now a fairly decent setup. It does still spike occasionally to 25psi mid range, but in general I can see high teens in boost easily enough which is perfectly safe. As long as I stay below 28psi or so for the most part I'll run with that

Although the EFR7163 is very responsive too ( obviously assisted by the blower too though )

I didn't bother with a bypass, as my overall goal was just to turbocharge it. But as the blower was already in place, it was easier to run both than to rip the SC off so wanted to try it just for a laugh, even if it has obvious deficiencies.

TBH it's working quite well now. Eventually I'll probably bin the SC, but it's a bit of fun for now.
If and when I do, it will certainly give a good comparison as to how much the blower really is assisting the turbo at lower rpm.

First short sprint is this saturday, so will see how that goes. Although weather suggests it's likely to rain

[Steelmesh]

Stevie nice work there that is awesome.  I have no idea what that VXR engine is!  Does that have the same intake bolt pattern as GM or did you adapt the SC to fit? Same here, 28 psi is about the max boost I'll go with my engine build.  I'm creeping near 90C IATs when the weather was warm, however I added a second fan dedicated to the air-water IC heat exchanger and has helped a lot as I was relying on the engine fan, push-pull now moves a lot more air.  However, looking back at my 444 whp dyno pull, it still had some mad high IAT tempsl. I think it wants more timing, however not sure about this new ECU knock retard strategy so wanted to look into setting up a secondary monitoring system before I find the knock limits. I played with tunernerd basic, my buddy got the full system for his car and said it was working, he's got about 20 years more tuning experience than me. This car is on the wastegate right away, right now it's dumping to atmosphere so it's so loud I don't want to rely on my ears.

I just put in ~35 hours this long weekend purging my garage and scrapped a truck load of my horde of parts, junk and lost projects (+$110, so far); making room for the Solstice to get inside.  I found my spare LUV 1.4T throttle body in the pile of stuff (I knew I had it somewhere!), going to look at using that to make the SC bypass.  I got some big plans for next summer with the car to start racing it finally.  I've been running my daily driver at autocross for some years now, learning all about suspension tuning trying to make a turd go fast and so far has been a bountiful experience tinkering, lots of effing around and finding out, finally got some turn plates to do alignments.

[Sly Bob]

 

[ennonne]

https://en.wikipedia.org/wiki/VXR

[stevieturbo]

Stevie nice work there that is awesome.  I have no idea what that VXR engine is!  Does that have the same intake bolt pattern as GM or did you adapt the SC to fit? Same here, 28 psi is about the max boost I'll go with my engine build.  I'm creeping near 90C IATs when the weather was warm, however I added a second fan dedicated to the air-water IC heat exchanger and has helped a lot as I was relying on the engine fan, push-pull now moves a lot more air.  However, looking back at my 444 whp dyno pull, it still had some mad high IAT tempsl. I think it wants more timing, however not sure about this new ECU knock retard strategy so wanted to look into setting up a secondary monitoring system before I find the knock limits. I played with tunernerd basic, my buddy got the full system for his car and said it was working, he's got about 20 years more tuning experience than me. This car is on the wastegate right away, right now it's dumping to atmosphere so it's so loud I don't want to rely on my ears.

I just put in ~35 hours this long weekend purging my garage and scrapped a truck load of my horde of parts, junk and lost projects (+$110, so far); making room for the Solstice to get inside.  I found my spare LUV 1.4T throttle body in the pile of stuff (I knew I had it somewhere!), going to look at using that to make the SC bypass.  I got some big plans for next summer with the car to start racing it finally.  I've been running my daily driver at autocross for some years now, learning all about suspension tuning trying to make a turd go fast and so far has been a bountiful experience tinkering, lots of effing around and finding out, finally got some turn plates to do alignments.

It's not a VXR engine, I just stuck that badge on as it's a sporty model badge from the Vauxhall range. The engine itself is just the B207, LSJ, whatever GM/Ecotec/Saab etc etc etc, albeit with the Z22SE 2.2 crankshaft. So it is a 2.2 ( Z22SE still the same Ecotec family, probably the earliest version of it )

I now have boost control ok, it was just a solenoid issue for the most part. 5psi spring and the 3.6" pulley and I can run from around 15psi upwards which is perfectly fine. A little less before the turbo spools up, but it spools very fast with the blower in place.
All in all it does work great.

That said, I've now pulled the supercharger off it to run turbo only. Ultimately I know it will make more power this way, but I also want to see just how responsive this turbo really is on it's own. Still waiting on a few pieces before it's ready to drive again though
If it is very responsive, I may leave it just turbo'd. If not, then I'll throw the blower back on and run it with both next year.

My IAT's were hot with the SC only and the 2.8" pulley, although I was always using water injection, injecting before the rotors to help with this. No meth, a small amount of water only.
Although on taking things apart I've also discovered the water was flowing through the laminovas the wrong way. I had never really touched this side of things, so were as I bought the car. Also they were leaking a little coolant into the intake. I doubt it affected much once driving, but after sitting for a few days, the first boost or two always seen a plume of smoke out the exhaust as the coolant ran through the engine. I've new seals etc all done there ready for if I do refit the blower setup.

[stevieturbo]

On the alignment topic....this recently popped up. I guess in theory it should work, but reality ? Who knows.

Gyraline.

Seems more geared towards I-Phone. I tried their app with my Android stuff, but the test seemed to fail so the gyro's inside my phones may not be good enough. But it's quite novel, and cheap.

[Steelmesh]

Merry Christmas update. Proof of concept to control the 1.4T LUV throttle body is a success for the SC bypass system I'm looking at.  No h-bridge, I'm just driving the open side of the motor with PWM through a FET, very simple with a few lines of code. I will add closed loop control, just need the TPS feedback. Will head to the upull junkyard and grab a TB connector pigtail to bench test that system. Will probably setup a durability test and run it for days to see what breaks.  This isn't a large volume bypass at 2", the trade off is it can snake through the mayhem without fundamentally reconfiguring the existing setup piping, plumbing, wiring harness that are packed into this area.  Where I'm the master fabricator working on their own junk and can get away with doing things half butt as I often do just to see what happens.

Showing a 0-5V pot analog input signal to partially open the butterfly, notice it's only drawing 1.3As current, where if you just put 12V DC to the motor it will draw almost 5A.


Here is the a benefit of going to Stand Alone engine control. The EMU black ECU has functions for 2D mapping and output, where I can send out a variable PWM signal in this case to a microcontroller that will translate that into the variable bypass opening based on RPM vs. MAP (as one option). The frequency of this output is max 255 Hz and does not sound great for the TB motor, where for example I found 8kHz is pretty good with the EMU dbw config for the main LE5 TB, where I can get 7.8kHz out of the Arduino.

[stevieturbo]

And is there any reason you're not using an H-Bridge ? Typically from, what understand ecu's do not simply hold the blade at any given position, but are actually always driven open/closed small amounts to maintain a "fixed" position. This is to prevent cooking the motor
Although I haven't actually scoped the output to test this, but was told this many years ago when DBW was just first starting to appear and be used and people were having problems just driving them straight and trying to hold positions.
I think ecumaster offer dedicated DBW controllers that you can just offer them a straight PWM signal though ?

For a bypass, I always thought a simple mechanical boost referenced valve would be fine. Whether even a wastegate, or the likes of Turbosmarts straight gate. Albeit they're very pricey and less controllable than a DBW unit. Simply when boost pre-blower is at a certain level, it opens.

Some stats I found for the OEM Saab DBW unit state it runs at around 600Hz. Although my ecu has always driven DBW units at 3800Hz, and I've never had any problems. I was using a 70mm Hitachi blade with the twin setup, but now with turbo only just using the 54mm Saab unit.

And onto that change....The basic twin setup was superb to drive, felt like it made decent power, but super responsive everywhere. It was great.

But I had to test turbo only too to see what difference it would be. And it is quite the change

It's now all soggy at low rpm, as any turbo always is. It does build boost well, and in higher gears is making boost from say 3000rpm, however it isn't really until about 37-3800rpm where things come on strong.
At approximately similar boost the twin setup ran a 100-200k of around 7.3s or so which felt decent. First few tries yesterday with boost starting around 12psi ramping to 21psi, that same range is around 6.1-6.3s
That is quite a difference, a lot more than I had expected, and clearly still lots more potential.

So clearly my twin setup was much less efficient ( but very easy to do ), your bypass will be very worthwhile. I just don't know that I can be bothered to take that route.
Ultimately I'll be using it mostly for racing, I'll rarely ever be below 3-3500rpm. Just need to wait a few months until there is any chance to use it properly again.
Need to change the gearbox and fit the LSD first though, and a better clutch. Current clutch ( unknown ) is holding, but I'm sure it is just ready to slip soon.

[stevieturbo]

Even 600Hz does seem on the low side though, but this is the info. The B207 uses this blade, which is also identical to the Z22SE 54mm blade, but the Saab version has a nice bead to aid with securing a hose onto it as it's obviously boosted.
Although again, I never had either on a running engine to test what the OEM ecu was actually doing.

As for 2" not being large.....the discharge on my turbo, and I presume yours is only 2".
Also why I used the standard 54mm blade. The 70 is far too large, and throttle resolution will definitely suffer. But 70mm suits the blower inlet and is fine when sucking through it. Massive overkill if blowing through it

[ Guests cannot view attachments ]

[stevieturbo]

I guess another option to consider for a bypass.

I've seen two videos where people created a box with a flap, looks overly large and cumbersome. Maptun did it from what little can be seen in the video with their twin charged Ecotec, and this diesel place. Although the diesel blew the blower into the turbo, rather than the other way round.
At least I assume that's what the large box type structure is on the Maptun. Doesn't look like a cooler. But I was never able to find out much info on their setup.

not sure why YT links are not appearing, videos TJ7_T0dU4P0 and TuoHcry12pY





But given we do not really need a huge orifice for this, surely a simple mechanical swing type one way valve would work, and would be entirely self regulating in terms of the transition, although it would not totally bypass the blower, but the vast majority of air would.

eg, something like this ? Looks like a simple off the shelf valve with decent flow ability.

https://johnsonvalves.co.uk/Data/080028-JV080028-Check-Non-Return-Valve.pdf

[Sol Asylum]

I guess another option to consider for a bypass.

I've seen two videos where people created a box with a flap, looks overly large and cumbersome. Maptun did it from what little can be seen in the video with their twin charged Ecotec, and this diesel place. Although the diesel blew the blower into the turbo, rather than the other way round.
At least I assume that's what the large box type structure is on the Maptun. Doesn't look like a cooler. But I was never able to find out much info on their setup.

not sure why YT links are not appearing, videos TJ7_T0dU4P0 and TuoHcry12pY

https://www.youtube.com/watch?v=TJ7_T0dU4P0

https://www.youtube.com/watch?v=TuoHcry12pY

But given we do not really need a huge orifice for this, surely a simple mechanical swing type one way valve would work, and would be entirely self regulating in terms of the transition, although it would not totally bypass the blower, but the vast majority of air would.

eg, something like this ? Looks like a simple off the shelf valve with decent flow ability.

https://johnsonvalves.co.uk/Data/080028-JV080028-Check-Non-Return-Valve.pdf

Have to add the url code for the links to show, there's a button under the font row that looks like a globe.  Hit the quote button for my post and you can see what I did. 

[Steelmesh]

And is there any reason you're not using an H-Bridge ? Typically from, what understand ecu's do not simply hold the blade at any given position, but are actually always driven open/closed small amounts to maintain a "fixed" position. This is to prevent cooking the motor
Although I haven't actually scoped the output to test this, but was told this many years ago when DBW was just first starting to appear and be used and people were having problems just driving them straight and trying to hold positions.
I think ecumaster offer dedicated DBW controllers that you can just offer them a straight PWM signal though ?

For a bypass, I always thought a simple mechanical boost referenced valve would be fine. Whether even a wastegate, or the likes of Turbosmarts straight gate. Albeit they're very pricey and less controllable than a DBW unit. Simply when boost pre-blower is at a certain level, it opens.

Some stats I found for the OEM Saab DBW unit state it runs at around 600Hz. Although my ecu has always driven DBW units at 3800Hz, and I've never had any problems. I was using a 70mm Hitachi blade with the twin setup, but now with turbo only just using the 54mm Saab unit.

Yes I am afraid of it burning up the motor, was hoping the lower operational duty cycle would make it survive, why I was thinking of doing a durability test on the bench. My logic is it'll only open at WOT, not holding it open at some position like when cruising.  The power draw is quite low if you don't slam it open with 12V so I was thinking it would be beneficial to PWM the one direction.  I understand the basics of an H-bridge, to reverse a DC motor and have made a electro-mechanical one with relays for another project (modded powerwheels with reverse).  As for holding position of a throttle blade with an H-bridge, I don't have a clue what the controls strategy looks like and a little time researching so far I haven't found it. As you mentioned, probably need to scope it and see what it's doing to maybe replicate that. 

Ecumaster does have an external DBW controller module and haven't contacted them on how to operate it with the EMU Black ecu and if it would work for my application (since I'm already using all the I/O for the primary LE5 DBW), however what turns me off right now is it's priced ~$100 USD in the UK, however shipping is $100 to the US.  I doubt Ecumaster USA pays $100 per unit to ship here, so being a cheap SOB I'm trying to go down the DIY path. https://ecumasterusa.com/products/ecumaster-drive-by-wire-throttle-control-module

Part of this adventure is to challenge myself and continue learning, failure is indeed an option, and look where it's got me now 

For my the DBW cal of the 2.4 LE5 TB, 8kHz sounded the least annoying to my ears and why I ended up there.  Hindsight I guess laziness or ignorance caused me to not scope the factory E67 frequency.

[Steelmesh]

I think I found the path for the bypass, got some bits and currently mocking it up before cutting and welding begins.  Will use silicone hoses to hardmount the bypass TB to the frame, my engine is using poly mounts so it doesn't move much. Also make servicing around it easier without it being fully hard piped.

Here is the easy side, mocked up in Fusion:


Made some tweaks, printing another one now:


When it looks good, I'll print a template to fit around the AL tube to cut/grind with and get a good fit up.  Going to be a little more challenging to get the intake side setup where I got to put a hole in the LSF intake manifold, fab life: install, remove, install, remove, install, remove, install, repeat until done...

[stevieturbo]

DBW, you just give it a PWM signal, it takes care of the actual control of the blade motor

https://rrrshop.co.uk/products/ecumaster-dbw-module?srsltid=AfmBOop2n-E6n_J1n9fns2j2Jti7DjkwHGHfDYdoW9F14O7xO_Y7R2fU

https://www.speedingparts.co.uk/p/engine-management/engine-control/ecu-master/modules-accessories/ecu-master-dbw-module.html?gad_source=1&gclid=Cj0KCQiAyc67BhDSARIsAM95QzuXBjLfS6tKkeyQXlQMFYFE4SOQjgoeBwK37yzNgY77yzGzp7iNjtEaAn3IEALw_wcB



For DBW, it is best to limit control duties so you're never driving it 100% in either direction, and even for say fully open or closed, where possible, avoid trying to drive the blade against that hard stop. It will be easier on it if you have it sitting at say 99% as opposed to driving it hard trying for 101% it can never achieve.
Erring on the side of caution too for reliability

[Steelmesh]

Those suppliers are estimating $100+ dollars to ship to my address in the US.  Then the price here from local suppliers is $235 USD or 187 pounds sterling shipped.

[Sol Asylum]

Keep in mind you might get hit with a customs fee and if it's UPS they will charge you a brokerage fee even if there isn't a customs fee.  Royal mail/USPS tends to be the best rates for international shipping.

I sent an engine rebuild kit to Kelu in Romania for around $100, that was around 20 lbs of parts, using the post office.  He didn't even have a customs fee which surprised both of us.

If you know someone in the UK they might be able to ship it to you for a lot less.

[stevieturbo]

It costs a fortune to ship either way unfortunately, it's difficult to get sensible rates. ( I'm in the UK )

And the customs duty is a f'ing nightmare. I've been robbed in duty more than the actual item and postage cost !!! And you have virtually no way to dispute it, because they force you to pay a fee to dispute the bloody thing

We get hit with 20% VAT in anything imported, that's on the goods and postage cost !! And if paperwork isn't filled in right, they estimate the postage cost, which the values they use are mental, about 5x what it actually cost. Which is how I got robbed a couple of times. And they hold your goods to ransom until you pay so you just can't win. No amount of arguing or showing them the invoices they had already seen would make them change their mind, the courier just blames HMRC and they're impossible to contact.
And then on top of that is the actual import duty, which usually around 5% for car parts.

I buy, well used to buy a load of stuff from the US, less so now though. With dollar-pound not being so great now, most stuff just not affordable unless there's no other option.

That said, buying regular parts from Rockauto is often cheaper and quicker than local sources, which is crazy too.

[Steelmesh]

Bypass circuit outlet at the intake, mockup. I chose this spot because it doesn't require major relocation of existing parts:




Once I was happy with the design of the mockup tube, I created a shell around that piece to fit over the aluminum pipe (2" 90? in my case) and use as a template to cut out the profile:




Got it tacked onto the intake manifold and test fitted:




Repeated the same for inlet side of the bypass circuit, see video here: https://www.youtube.com/shorts/E6hCdWBbUl8




Layout showing the 135?, 45? and 90? silicone hose layout, love it when a plan comes together:

[stevieturbo]

Maybe of some interest, this guy cut up his intake manifold to modify it for an external charge cooler ( A2A in his case ), but retaining the LSJ intake manifold, for the most part

https://z22se.co.uk/threads/dewismotorsports-astra-coupe.25659/page-35