I’m picking up the car tomorrow afternoon at 5, which is closing time for the shop. The tuner (and shop owner) asked me to come at that time so that he could have sufficient time to spend with me, given what I’ve been through with this car (his words), including a test drive. He mentioned is that boosted Mopars (at least the 5.7 Hemi) have a problem with ’partial throttle boost detonation,’ in that the PCM doesn’t recognize that the car is in boost while below full throttle, and runs lean with resulting detonation. It can be somewhat mitigated through tuning, but still requires a different approach to driving the car in boost. The test drive is going to include him literally showing me how to avoid this problem. Oddly enough, National Speed never even mentioned such a thing.
Anyway, I’ll follow up once I’ve driven the car for a couple of days.
So I’ve had my Charger for a couple of weeks since it was tuned and the upgraded transmission valve body installed. It runs really, really well. The shifts are firm, as the tuner told me to expect, and quick. That took a bit of getting used to, but now it seems normal.
The acceleration is amazing. Between the added displacement (~397 cubic inches vs the stock 345) due to stroking, headers, and cam, even though the cam isn’t optimal for this engine, it is much quicker than it was with the supercharger alone. Plus the long-tube headers coupled with the stock exhaust give it a nice subtle rumbly sound. Noticeable, but not at all obnoxious.
I’ve talked with the folks at National Speed, including telling them that I took it to another shop (and why I did), and that it runs better as a result. They pointed out that some things are no longer covered under their warranty since it’s been tuned by the other shop, but they say they will cover the oil leak and interior damage caused by the tow truck driver. We’ll see. I still don’t want them working on this car any more. I’ve already decided I’d take the car to another shop to fix the leak, if it becomes a problem. So far it’s not.
They (NS) questioned the other tuner’s work, and appear to be trying to create doubt in my mind as to what he did. He (the other tuner) has been very patient in explaining why he did what he did, and it makes sense to me; which reinforces my belief that I made the right choice in taking it to him.
Anyway, I have my car back. Last night I drained the break in oil and put in fresh synthetic oil and a new filter. I’m ready to put all that drama with the build and enjoy what is now a beast of a car. Not quite as powerful as a Hellcat, but not too far off, either. And it’s an AWD.