The car lives ... again. Money shots first
I got a new whirley boi on the car: SoS TVS supercharger. Same same but different.
I’ve been jonesing for this thing since it came out. It looked like it had the flattest torque curve and the coldest air temps in the land, and I wanted as many v8 vibes my v6 is willing to put down. The car was quick before, honestly it had enough power, but the hedonic treadmill is real, I guess.
It’s larger than the CTSC it replaces (1.9 liters vs 1.6), is intercooled, and has a larger throttle body (75mm vs 68mm). After the first few drives, it produces about a half psi more boost than before, and air temps never break 120F in boost. My goal is a super consistent, weather independent 400-415 whp and just shy of 300 wtq.
First impressions
It took a couple passes to get the fueling in the ballpark. I'm pretty surprised how different its fuel needs are vs the CTSC. Overall it needed less fuel in vacuum (but not everywhere), and more in boost, but things were only off by max 5% in either direction.
It feels a lot more torquey everywhere, even in vacuum, which I didn't expect. Like going up small hills at 2500rpm require less throttle. Full throttle feels quicker, and the RPM charts are a tiny bit steeper. There is this stretch of road I usually do my 1-2-3 WOT test pull, but now it feels just a little too sketchy.
There is a super steep, straight, long hill by my place, which keeps the speeds under control, so that is now the new test pull area. Here's 2nd gear and a little into 3rd. 9.1 psi, no fade on a not-crazy-tight belt (90 lbs hot)
Then the air temps. With the CTSC, it was a challenge to keep air temps down below 150F, even with the water / meth injection. It is just the nature of the non-intercooled setup. The new thing is air-to-water intercooled, and it works super well. I did a lot of stopping and starting in my last tuning pass, a recipe for heat in the CTSC, and after several hours of running the car, air temps never really broke 120 in boost. Here's that same pull with the temp chart at the bottom: max 120F, even without any water injection:
Issues
It is, of course, not without issues. The biggest issue is that now the front bank runs leaner than the rear. This is the opposite of the last setup where the rear ran a little leaner. I don't know why yet. I would probably just leave it be, but there is new, even weirder behavior.
Sometimes the front bank will go
super lean, like 3 points leaner than the rear. It happens consistently at 4k-5k rpm with light throttle in vacuum, check it out:
I'm not sure what it is yet. I do feel hesitation when this happens, and with the o2 correction turned on it'll paper over it by adding like 15% fuel which solves the hesitation
This feels not normal enough that it could be a bad part, crimp, or ground. My plan is to recrimp a bunch of the terminals on the coil harness, replace all the front coils, replace the front plugs, move a known-questionable ground, and go back to the short, hard injector plug adapters instead of the wired ones.
It's possible none of that will change anything, though. If you have ideas, plz comment
There are other smaller issues
- It feels a lot jerkier transitioning from vacuum to boost than the CTSC. There's a pretty big power surge, like it jumps from 0 to 2psi of boost immediately. My guess is that it is from the bypass valve suddenly closing, probably just the nature of it
- The new throttle body is much less polished than the OEM one. It kind of sticks off 0, and the throttle plate blade doesnt engage to the TPS with much surface area. Sounds minor, but it caused a bunch of drama trying to get it to work at all, and junked one TPS already. The internal ears ripped off because of the lack of proper engagement surface area
- One of the giant 12AN fittings on the intercooler water tank leaks a tiny bit. Not sure if it was my install or the fitting itself. It is tight AF, but still leaks a little out the fitting. Need to replace that soon
Install
Install itself was a saga with missing or incorrect parts at several steps. Then there were a whole bunch of other changes I had to make to get everything to fit there (move WMI tank, pump etc.). Probably up next is a bit of detail about all that
