97-98 MK VIII Shift Points

[fordknutt]

I've been reading posts about the shift points on the 97-98 MK VIII, & the more I read, the more questions I have. I own a '97 Mk VIII. When first purchased, it was stock w/3.07:1 gears. WOT shift point was 5900-6000 rpm. I have slightly modified with 2 1/2" true dual exhaust, partial J-Mod to transmission (only drilled the orifices on the separator plate), K&N air filter, & 3.55 traction lock w/correct speedometer gear installed. Car still shifts @ 5900-6000 rpm @ WOT. Verified I have the correct speedometer driven gear by checking w/GPS & is within 1 mph @ 70 mph. Maybe someone can help w/a few answers:
1. What is the correct shift point @ WOT?
2. The forum posts state the transmission shift points are determined by the VSS driven gear for
the speedometer, is that correct? If that is so, wouldn't it shift gears @ the same mph
regardless of throttle input?
3. If speedometer gear determines shift point, than if I installed the original that was with the
3.07:1 gears, than (in theory) the WOT shift point should be lower RPM, since the speedometer
would be reading a higher than correct mph???
4. Can the WOT shift point be lowered (5500 rpm) & still have an accurate speedometer?

Thank you for your time.

 

[chris2523]

97-98 mark viiis read the speedometer from the ABS system. NOT the speedo gear.
changing the gearing does NOT change the speedo.

also, WOT shifts points sound normal to me. they are not affected by the speedo gear either.

gear change will raise the WOT shift point because the engine rev's faster.
JMOD will lower the WOT shift point because the shift completes faster.
doing both means WOT stays about the same.

i don't know that the speedo gear and VSS is used for anything but the speed sensitive steering, and the lowering of the air suspension.

most of the computers shifting is determined by TPS, RPM, and calculated load.

the WOT shift points can be changed via a tune, but, why?

 

[robsMarkVIII]

At WOT shift point is by engine rpm. 5900 to 6000 is correct for a stock set up. This can be raised or lowered with an add on chip or a tune. Why would you want to lower your shift points? Your performance will decrease, the engine in our cars are rpm engines they don't make a lot of torque. If you are after more performance install a torque converter with a higher stall speed and get a tune that will raise your WOT shift points. Our engines can safely turn 6500 rpm and can go 7000 rpm properly set up. All WOT shifts are engine rpm open loop. Part throttle shifts are determined by engine load and vehicle speed closed loop. Where vehicle speed comes from doesn't matter. I hope this helps

 

[fordknutt]

Thank you. I wanted a lower shift point (5500 rpm) because my MK VIII starts feeling weak after 5500 rpm & appears to be flat by 6000 rpm. If I lift the throttle just a bit @ 5500 rpm, the car pulls harder & barks the tires (which it won't do @ 6000). I assume that it must be @ it's torque peak around 5500 rpm. I realize you can spin these engines, they are built for it, & the horsepower is in the upper band, but torque is what moves an object.

 

[opalescent 96]

On my 96 I believe the stock shift point is 5600. That's right at the horsepower peak for a gen one with the gen one intake manifold.

When I had Lonnie do my blue oval tune I asked him to make the shift point 6000. He advised me against it but I said do it and anyways he was right. It does go flat after 5600 and if I lift it is faster. I'd really like him to change it but he's so busy and I've bugged him already.

I know the gen 2 shifts a little later because of the slightly different power band of the manifold. I guess stock is 5900-6000.

Why don't you have it tuned at this point... You've done gears... you'll get more power it will pull harder etc. You can ask to make the shift point 5800 for instance and Lonnie's tune you can adjust the shift point up or down 3 mph, which isn't much but at least you can fine tune it a little

 

[chris2523]

I assume that it must be @ it's torque peak around 5500 rpm.

peak torque occurs around 4500 rpm.