Need advice/feedback from SC with automatic transmission

I hope to get some feedback on tunes/driveability of those of you that have put a supercharger on your mustang with an automatic transmission.

I have a '15 auto GT with the 3.55 axle. A few months ago I had Livernois Motorsports put their LMS675 kit on. This is the PD 2300 Magnuson supercharger making 564 rwhp/519 rwtq on my car with their dyno tune 93 octane.

Since this was put on I have had driveability issues. The shift is very firm even at a fairly slow normal driving speed. Upshifts occur quickly into 3rd and often if you don't just baby it while mildly accelerating, it downshifts, hits the traction control because the tires brake loose. Sometimes it will sort of cut out when it comes to shifting.

I took it back to LMS and explained the issues. They were very nice about my complaints and kept the car for two weeks to figure it out. Apparently it had a "glitch" in the tune where it would hit the rev limiter randomly at any RPM.

The fellow, Andy, who drives the cars to determine driveability tested it extensively, driving it 120 miles. I agreed to this. He said it shifts at 7,050 RPM and the rev limiter is set to 7,300 RPM. Makes sense.

Still has a flatish spot about 1,500 RPM, weird.

I just do not like the way the car drives. Yes, it has torque, but kinda finicky. I've had 2 other SC cars which were sticks and they were fun, predictable and got significantly better gas mileage.

Are all PD SC cars with automatic transmissions like this? Should I look elsewhere for a tune? If, so, who do you recommend?

My automatic running a whipple with their tune feels like bone stock until I get into the boost - then the power comes on strong. Part-throttle drive-ability is OEM level quality. Shifting is smooth as silk up and down.

You should try one of the bigger names like Jon Lund or Ken Bjonne @ Palm Beach Dyno. They have a lot of experience with these cars and many very happy customers.

Tony

^^ agreed

Whipple tune w Auto is better than OEM.

So this is either a tune issue or the Magnuson SC is not an appropriate application? It seems as though the transmission shift points should be tunable separate from the sc tune, is that correct?
I appreciate all your input.

Tune issue.

GreenS550 said:

So this is either a tune issue or the Magnuson SC is not an appropriate application? It seems as though the transmission shift points should be tunable separate from the sc tune, is that correct?
I appreciate all your input.

Click to expand...

It’s a tune issue. That supercharger is widely used on gm cars without issues.
Trans is a whole other animal when it comes to the tuning.

I put a call in to Livernois Motorsports about this issue. Trying one more time to see if they can get it right. On a cold start up the idle is "OK", not stock. But on first acceleration, the car sometimes bucks, kinda like a backfire and runs poorly for a while.
I am disappointed in LMS on this issue. They did gears and sprocket at the same time.

I had a similar situation. I have the same SC as you and finally decided to dump the Livernois tuning. I went with Lund and it's been perfect. I got tired of chasing Livernois around, and they just couldn't fix it. Granted, the guy that was there then is gone now. Not trying to bash on Livernois. I know they are a great company and all, but for me it was better to just give up and have Lund do it. On the Livernois tune, I also had some detonation issues with their tuning at low RPMs. None of this is happening with the Lund tune. It's expensive though and you would be required to get a BAP for Lund to tune your car. Mine is auto with 3.55 gears too. Call me if I can help at all.
Garrett
(480) 798-2906