[AndyZ87]

Took my 2016 2ss to the track yesterday and was expecting better numbers. Appreciate any input you guys have. Is this due to wheel spin? Here is a list of mods;
Edlebrock Eforce s/c
Dynatech longtubes
Dynatech highflow cats
TSP custom grind cam (with supporting mods)
LT4 fuel system
Race star 17inch drag pack. ET street in the back and skinnies up front.

The car puts down 643whp and 587wtq.

[grampa_ss]

No. Not due to wheelspin. You're at least 10mph and 1 full second short of where you should be. You need a new tuner...or datalog for him and let him make adjustments.

Trust me, I've been there. I had numbers almost identical to yours. Got a new tuner and solved all the issues. I had given my original tuner multiple chances, but in the end...I went elsewhere.

[AndyZ87]

I emailed him my slips. I’m sure he’ll get back to me in the morning. I’ll see what he says. Appreciate your input.

[steelheadrob]

Your 60' is part of the problem 3/10ths or so. I guessing you need to adjust your shift mph, to shift at higher rpms and stay in the higher boost. Hard to say for sure without seeing the logs.

[danhr]

Originally Posted by steelheadrob

Your 60' is part of the problem 3/10ths or so. I guessing you need to adjust your shift mph, to shift at higher rpms and stay in the higher boost. Hard to say for sure without seeing the logs.

You dont even need to see the logs to know it short shifted. OP obviously spun off the line, and when you spin off the line, it messes up all your shift points, as the computer tries to anticipate the next shift but its timing is thrown off by the wheel spin

[AndyZ87]

Sorry, forgot to add the car is an M6. So I’m shifting too early?

[wnta1ss]

Originally Posted by danhr

You dont even need to see the logs to know it short shifted. OP obviously spun off the line, and when you spin off the line, it messes up all your shift points, as the computer tries to anticipate the next shift but its timing is thrown off by the wheel spin

I agree with danhr, the auto shifts get screwed up by wheelspin. I recently experienced this running on an unprepped surface with my PS4S tires in fact. Not saying that the shift points in your tune are correct, in fact I expect that they will need work. What I am saying is, until the car is basically working, you won't really be able to nail down the tune.

My question is, why was it spinning with drag radials? Were you lined up correctly in the groove? Do you do a wet burnout or a dry burnout?

[AndyZ87]

It’s an 6spd. I was burning out just at the edge of the box. Partially wet/dry. I’m also thinking I may not have warmed up the tires long enough. A lot of people are mentioning shifting early. Maybe I need to take the rpms to just before redline?

[Booher]

I dont think ps4s are the greatest for hooking with drag racing. I have the same tires, and almost always spin at the line., burnout or not.

[grampa_ss]

Originally Posted by AndyZ87

It’s an 6spd. I was burning out just at the edge of the box. Partially wet/dry. I’m also thinking I may not have warmed up the tires long enough. A lot of people are mentioning shifting early. Maybe I need to take the rpms to just before redline?

Even if you spun a little....your trap speed is way low. I mean, you have 250 more RWHP than stock and you're only trapping 6 mph more. And only 4/10 quicker than stock. Your tuner has work to do.

[KingLT1]

No way that is making 643whp. It seems we are in a age where these dyno shops will get you a number but a car that doesn't live up to it. That car is trapping like a 460whp mild bolt-on NA car.

A legit 640whp in a full weight car is going to trap 130+ in all but the worst conditions. 1.8 60ft isn't terrible for a manual. Your tune likely needs a lot of work. I wouldn't even go back to that tuner....I would order HPtuners and have Rick Clarke remote tune it.

[Juiced1]

Your trap speed seems a bit low. Seems like a few factors might have held you up. Your 60ft didn't help out much and it was pretty warm the other day. You might have had some heat soak. If you want we'd be glad to look over your tune and we can get you on our dyno as well. When you shift does it every feel like it lags in a certain gear? Maybe at the beginning or end of a gear?

[wnta1ss]

Originally Posted by AndyZ87

Sorry, forgot to add the car is an M6. So I’m shifting too early?

Oops, disregard the comments about automatic shift timing, as they don't apply on your car.

As far as shifting early, I'm guessing that you'll want to shift somewhere around redline, or maybe even higher, depending on where your tuner set the rpm limiter. Do you have a dyno chart that shows the power curve?

[wnta1ss]

Originally Posted by Booher

I dont think ps4s are the greatest for hooking with drag racing. I have the same tires, and almost always spin at the line., burnout or not.

Agree, but I was just giving a real-world observation of the auto shifts getting messed up by spinning. My example was not launching on a dragstrip, rather, it was spinning in 2nd giving short-shift to 3rd. Unprepped surface and no burnout box.