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trans table preferences

A

Anthony Smith

New member
What is everyones preference for downshift and upshift tables. I have been tweaking on this tune every summer for 3 years now and still havent gotten the trans tables to perform the way I would like them too. One of my biggest issues is my 1-2 upshift in drive. Anywhere WOT in first it spins then once it spins it instantly shifts into 2nd even if the car is actually only going 30mph. Then it lags because its way under speed for second. If it does it bad enough, at a low enough speed it will even try to downshift back to first again.
 


I bumped the shift point from 35 to 36 mph then it bumps the rev limiter like 3 or 4 times before it shifts and sometimes if it spins bad it still short shifts like mad. I've got my manual 1st point set way above the rev limit so I can pedal it in low 1 then bump it into 2nd when its good and ready but I get a flare on the 1-2 doing that. What I've considered doing is setting the 1-2 table over the rev limit to like 45mph from 50% throttle up to 90% so I can pedal it in first without a short shift then put it wot to get the shift
 
Mine bounces of the rev limiter once in awhile and my 1-2 shift is set at 46mph shift point is 5850 and limiter is set at 6200
 
DHP had an excell sheet that helps plan shift points. It would how you the rpm per gear and the mph. With this you can see that if you shifted at say 30mph that you will be at 2000 rpm in 2nd. Or if you down shift from 3rd you will be at 3500 rpm. I have used this for years to plan all my shifts so that I am always in a proper gear. Below 20% throttle it keeps shifts smooth and calm. Above it gets more aggressive. No point changing gears is the car is going to bog down, just hold that gear longer
 
Best solution when you have a lot of power is to only have a 2nd gear by disabling the shift solenoid fuse. Once turbo you can do this and still spin at will in 2nd gear at any speed even below 30 mph.
You get more line pressure and the shift to 3rd is crisp as well. No more wasted time of downshift and slip when shifting 1st to 2nd at full throttle.
Unfortunately with a M90 unless running a tiny pulley/IC and all you don't have the power to use 2nd gear efficiently at low speed.

I'm going to set mine up on a switch, when I want to play, it stays in 2nd. That wil be an excellent setup for road course racing/autocross. As I said, even low RPM I can blow the tires right off so no need to downshift. On an autocross course, I would most likely never shift once, always stay in gear. Much better for the input shaft and clutch pack.
 
If you wanted to do that why wouldn't you just set up your drive2 shift points so it was full manual into 2nd on the shifter. I have already set mine up for manual 1st control for launching and manual 3rd control for dynoing. I would never launch my car in 2nd gear anyway. I have since done what I was saying above and set my shift points from 1-2 in drive to 60mph from 50% TP to 87.5% so I can leave the shifter in drive and pedal the wheel spin from a dig without it shifting into second. Once its moving in first I just throttle it down the last 10% and it goes into 2nd.
 
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Anthony Smith said:
If you wanted to do that why wouldn't you just set up your drive2 shift points so it was full manual into 2nd on the shifter. I have already set mine up for manual 1st control for launching and manual 3rd control for dynoing. I would never launch my car in 2nd gear anyway
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I could certainly change that in the PCM but I like to have it switch back to normal drive in an instant. 2nd gear start are ok for racing or aggressive driving but not fun for running in traffic.
 
If you had the Drive2 shifter position settings setup for manual control of second gear the car would still take off and shift normal with the shifter in drive
 
You dont get overrun if you dont manually limit the valve body either which also makes the solenoid unplug a really stupid idea.
 
darkhorizon said:
You dont get overrun if you dont manually limit the valve body either which also makes the solenoid unplug a really stupid idea.
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Stupid idea or not, stock trans still alive and and well after 100 + runs at 11.0 power level and it was a high miles trans to start with.
I am certain the reason why it is still alive is my 2nd gear start.

My new daily driver turbo with trans in Drive will slip ****loads shifting to 2nd and bang into 2nd gear if I stay in the throttle. With manual shift and solenoid unplugged, I start in 2nd, roast the tires at will. Run 12.0 all day and no slip in 2nd unless I try to push for more power.

I think it's working, regarless of the theory behind your reasoning.
 


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