[steelheadrob]

I am wanting to change the A8 shift points to improve my 1/4 miles times. I am wonder from those that have already experimented, what are the best shift point rpms and whether I am looking at the correct table in HP Tuners.

Here is what I am currently seeing in the hp tuners log:

1-2 shift 26mph 4,600 rpms, rpms build to 5,900 before they drop
2-3 shift 50mph 5,500 rpms, rpms build to 5,900 before they drop
3-4 shift 81mph 5,900 rpms, rmps build to 6,200 before they drop
4-5 shift 107mph 6,250 rpms, rpms build to 6,400 before they drop

The shift from 4-5 looks about where I would want it but the others look low. What rpms should I be targeting for the different shifts?

Here is the table in HP Tuners that appears to be driving the shift points.

Is this the correct table?

Thanks

[dmcmahan60]

I am curious about this also.

[danhr]

Shift points kind of depend on your setup.... like a key mod is intake manifold... if you get an MSD intake, you carry the power out longer, allowing you to extend your shifts.

But you are in the right table. I also like to go to the partial throttle table and make 80%+ match the WOT some and then interpolate.

I've experimented with out to 7000 rpms (I have to admit, the first time at 7000 rpms on factory valvesprings had my butt cheeks puckered a good bit), but 6400 for all the shifts is a good starting point

[Snowblind]

I copy my modified upshifts to the pattern A and pattern B tables as well. Try only going up 1 mph for each upshift gear, in my experience any more than 2mph in any gear triggers TM for some reason.

Alternatively you can modify the tire height in the Tire/Gear Wizard which also changes the shift mph speeds, it worked for me but it wasn't as easy to dial in.

[KonigWolf]

Shift points will depend on tire size, supporting mods, and how high you're willing to sping your motor.

These are the shift points I use for 275/35R20. They also work really good with 305/45R17 DR.

Also be aware that if you use my Higher shift points that you might hit the stock rev limiter.

[steelheadrob]

Thanks for all of the input. I am running the 305/45R17 DR, with the Whipple. My tuner sent me an updated file, they added 3 mph to the 1-2 shift, 7 mph to the 2-3 shift, 3 mph to the 3-4 shift and 1 mph to the 4-5 shift. Last weekend the local track is open for the season, so I will run the update tune file on Saturday and might make some adjustments on Sunday depending what the log files from Saturday look like.

[KingLT1]

My work shift mph looks like this.

30
56
86
108
147

Then I go over to the normal, a, b part throttle tables and match the last 2 cells for each gear to what the Wot mph table.

Then I have WOT shift rpm set as:
6400
6500
6500
6500
6400
6400

Then I bumped up the Rev limiter... engine dfco, cutoff

Set rpm cutoff to 6800. Then there is a cutoff based on ECT table right below and set the 6600 cells to 6800 as well. Set enable rpm 6799.

Your Whipple carries power well and it's going to reach MPH faster then a bolt-on setup so you may need more lead time MPH to make the shift by commanded RPM. So I wouldn't be surprised if you need the commanded shift MPH set lower then mine if you are shifting by the same RPM...I would think you want to shift at 66-6700rpm with the Whipple. It's one of those things you will have to tweak in yourself...every car is a little different.

[wnta1ss]

I agree that you should do WOT Pattern A and B the same as you do for Normal, both speed tables and rpm tables. Think that Pattern B is Sport Mode and Track Mode on the drive mode selector. So if your tuner did not make these tables identical, my suggestion is to fix that before you run.

The rpm limiter stuff that KingLT1 is mentioning could come into play if you are shifting near redline. I've seen it close the throttle because of that issue before so that's how I learned. I also agree with him that your powerband warrants more than 6400rpm if you can do it.

Good luck at the track on your quest for 10s!

[steelheadrob]

WOT & Partial Normal, A & B Tables were all updated. Fuel cutoff was increased to 6,750.

Getting ready to head to the track to see what difference the changes make.

[cmitchell17]

Does the TCM ignore everyone and shift the WOT 1-2 way early at about 5,500? I have a 2017 so I can't tune my TCM but I know its never shifted at WOT above 5500.

[KingLT1]

No...your TCM isn't ignoring anything. The stock setting has the shift mph set way low around 19mph to account for tire spin. Btw You can tune your TCM if you send it out and have it unlocked .

[wnta1ss]

steelheadrob, noticed that you ran in the 10s, congrats!

[cmitchell17]

Originally Posted by KingLT1

No...your TCM isn't ignoring anything. The stock setting has the shift mph set way low around 19mph to account for tire spin. Btw You can tune your TCM if you send it out and have it unlocked .

Ok thanks for the info. And yeah I'm trying to find time when I don't need my car to send it in. So you think they programmed the shift mph low on purpose since the tires could be spinning and it would hit the rev limiter before it could shift? I don't see how this would be a problem, but I haven't found any documentation on whether the shifts are only determined by the rpm and mph shift tables or whether the TCM works with the ECM to try to target torque (delivered wheel torque) by shifting up and down and locking and unlocking the TC. Also I believe the shift strategy for all the other TCMs and ECMs at WOT was that both speed and rpm have to be met for a WOT shift to occur?

[steelheadrob]

Originally Posted by wnta1ss

steelheadrob, noticed that you ran in the 10s, congrats!

Thanks. Trans tune from Kaizenspeed made a big difference. 11.04 to 10.75. Shift points moved from the 6,000 range to 6,400. Kept me in the higher boost. I think I can push it a little more to get into the 6,500 to 6,600 range.