Author Topic: Twincharged Solstice = Turbocharger + Supercharger  (Read 311713 times)

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Offline Steelmesh

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Re: Twincharged Solstice = Turbocharger + Supercharger
« Reply #650 on: October 28, 2026, 11:50:19 AM »
The added complexity is paying off.  I did a lot of messing around and finding out about the charge pipe dump valve and got it figured out the day before the race.  No mechanical or electrical issues overall, the car ran pretty good.  It was a cool day however, air temps in the 40's in the AM and 50's in the day.  It was pretty slippery at this venue even on 200 tw tires.  The track was slower then, therefore it showed more room for improvement at lower torque demands, the bypass table needs some updates to help with this and not slam the valve shut at these areas.

I had a fair spinout on the first run this day.   Noticed something in the video footage, there is a pattern of tipping in the gas around a corner and then the car suddenly snap oversteering.  I can see the GFB boost controller in the video.  Within frames of the video, it's 11 psi → 18 psi → 25 psi really quick, when it hits that 25 psi the rear end gets loose. Then to confirm, I pulled up footage from last year, when the tune was even worse, that showed the same boost induced snap oversteer, where I'm coming around the corner bringing in pedel, then likely the SC bypass valve slams shut because I'm demanding torque, and pow it sends all the torque. 

That is a good problem I guess, and know that I can dial it back.

Shifting gears, I'd like to look into improving the suspension: looking at the Redshift coilovers, however need to know what spring rates to run.  I'm going to swap in some new springs working on that right now, 900 lb/in front and 1000 lb/in rear which estimates frequencies in the 2.2-2.5 Hz area.  To make life easier, I built to Hub Stands, so that was holding up this job.  I finished those recently and now going back through with a full coilover blueprint setup. 


Where I ended last night, springs removed, double checked shock travels and wheel travels.  Next got to install a wheel and double check the tire clearance when the shock is on the bumpstop.  Then I can install the new spring to set the droop.  It's a lot of work, why I'm doing it myself because I don't got that kind of money!




2006 Solstice #1458, Twincharged LE5/LEA, 5757+M62, Werks exh manifold, Tial bpv/wg, Cams, dual meth, 40 PSI lol without ring seal, Kappadapt clutch hose/flywheel bolts/trans mount, Aisin AR5, Stage 5 clutch
Turbo-only power 444whp/422wtrq

2013 Cruze Missile, tuned, 42 lb, ZZP SRI/FMIC/DP/MP/CB, Kappadapt trans mount

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Offline Steelmesh

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Re: Twincharged Solstice = Turbocharger + Supercharger
« Reply #651 on: Today at 12:20:09 PM »
Really liking these stands now, fully realized when it comes to dialing in the final settings for the coilover spring pre-load and ride height [if you have the target].  Don't have to raise and remove the wheels to tweak the settings, the reinstall the wheel and lower it. I intend to go back to the previous ride heights to keep the alignment where it was.






Found 200 lbs of stuff to put in the driver seat: punching bag, ar500 plates, kettle bell, concrete, and a onewheel.

2006 Solstice #1458, Twincharged LE5/LEA, 5757+M62, Werks exh manifold, Tial bpv/wg, Cams, dual meth, 40 PSI lol without ring seal, Kappadapt clutch hose/flywheel bolts/trans mount, Aisin AR5, Stage 5 clutch
Turbo-only power 444whp/422wtrq

2013 Cruze Missile, tuned, 42 lb, ZZP SRI/FMIC/DP/MP/CB, Kappadapt trans mount

Support Kappaperformance.com!!  Note: a couple huge corporations own and control several hundred of the top automotive enthusiast forums subsequently profiteering from these communities on the backs of volunteer moderators.