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