d2801

[c5mtl]

guys table d2801 ...what do you think??? allow lockup during upshifts or not....trans builders say dont do it

car is 99 a4 3800vig ,rpm level 5, 317 heads,a&a blower cam,a&a s trim 10psi,3.42,tsp headers,hi flow cats,borla cat back,550rwhp

[joecar]

Hi c5mtl,

welcome to the forum.

Your trans builder is correct.

Don't allow lockup during WOT unless you have a TC built for WOT lockup (double or triple plate TCC) otherwise it will slip and the friction surface will burn and be damaged (and I am told you may break the cushioning springs on the TCC plate).

During WOT upshifts you want the TCC to be unlocked for another reason: as the new gear engages the TC hydraulically slips... when it does this, it is hydraulically multiplying engine torque... the slip prevents your engine rpm from dropping too low out of the torque band... your 3800 would allow your engine rpm to still be within range of peak torque... this "rpm extension" allows the engine to pull with more torque than if the TCC was locked and pulled the rpm down a significant distance from peak torque... the slipping TC (not TCC) is multiplying engine torque into the trans so the trans is pulling the vehicle hard... these 2 benefits give an auto trans car an advantage amounting to 2 tenths.

Of course, with your blower your torque curve would be big and wide...

Make sure you have a trans fluid cooler.

[c5mtl]

thanks...i do have a big cooler with a fan and rarely see temps over 175 on the street and at the track i never see over 205 .....and i do have a triple disc converter...concerning the tcc upshift table....for the converter to be locked durring upshift i'm guessing it got to be locked to start with...if i'm not command it to lock in the lockup@speed tables it wont be locked during shifts meaning no harm done...correct???


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Hi c5mtl,

welcome to the forum.

Your trans builder is correct.

Don't allow lockup during WOT unless you have a TC built for WOT lockup (double or triple plate TCC) otherwise it will slip and the friction surface will burn and be damaged (and I am told you may break the cushioning springs on the TCC plate).

During WOT upshifts you want the TCC to be unlocked for another reason: as the new gear engages the TC hydraulically slips... when it does this, it is hydraulically multiplying engine torque... the slip prevents your engine rpm from dropping too low out of the torque band... your 3800 would allow your engine rpm to still be within range of peak torque... this "rpm extension" allows the engine to pull with more torque than if the TCC was locked and pulled the rpm down a significant distance from peak torque... the slipping TC (not TCC) is multiplying engine torque into the trans so the trans is pulling the vehicle hard... these 2 benefits give an auto trans car an advantage amounting to 2 tenths.

Of course, with your blower your torque curve would be big and wide...

Make sure you have a trans fluid cooler.

[joecar]

I think with the TCC unlocked you can keep your engine rpm higher as each new gear engages... the TC is really good at multiplying torque whenever it hydraulically slips at the start of each new gear.

Also, you want to shift at the highest engine rpm that your engine allows (valvetrain, bottom end).

My $0.02... :)

[c5mtl]

the only advantage i see is locking the converter would be in top of 2nd to get some more rpm under full boost....after the shift into 3rd the supercharges tends to fall from 9 or 10 psi down to 6 or 7 psi....until the motor builds rpm again....as for my bottom end it stock except some dual springs on the heads and hardend pushrods...what do you think is to much rpm (would be a track setting only)

[joecar]

Dual springs allow for increased seat/open pressures, and along with the hardened PR's, that would allow you to redline higher... I don't know how high... you will have to research this... hmmm, by what you said you see the advantage of keeping the rev's higher.