Hey guys this is my first post to the board. I have a problem with my torque converter. i just installed a vigilante torque converter 2800 in my 94 z28 with lt1 and 4l60e trans. I was running 13.4s before the change but after i changed to the vigilante my car is running 13.9's i have no idea what the hell happened. Thats the only thing that i change that would effect the way the car would run. Have any of you ever heard of this or have had it happen to you?
I think the car should have run a high 12 with the converter change?

Thanks

Tom

Mods:

K&n cold air intake,1Le high flow bellow,flowmaster exhaust,CAt delete Pipe, edelbrock headers and y pipe,electric water pump,accel wires, BBk throttle body, Granatelli MAF, Be cool aluminum radiator,B&M trans cooler,aluminum drive shaft, Miller racing torque arm, LCAs Panhard rod, LCA relocation brackets, sub frame connectors,kyb adjustable shocks, Bigger sway bars front 34 mm 26 mm rear, Ford 9 inch rear with 3:70 gears and locker,shift kit, vigilante converter.

new converter 60 foot
60 foot 1.87
1/4 mile 13.9 @98 mph "Something is wrong with the car big time"

 

What were your 60' before the converter swap?

Who did the swap? Was the distributor cap removed during the operation?

What were the track conditions for the runs before & after the swap?

 

My 60 foot time before the swap were 2.0 with slicks, no tire spin.
after the swap they were 1.8 no tire spin

I did the swap , and no i didnt remove the distributor cap the lt1s have a optispark distriubtor there is no cap on them.

The track conditions were

stock converter 70 degress 13.4 @102
vigilante 95 degree 13.9 @98
" " 68 degrees 13.9 @99
" " 72 degrees 13.9 @99

 

Your 60' shows an improvement from the converter swap but you mph is lower showing less hp. That could be from any number of things including weather conditions.

I'll calculate converter slip but I need some info.

Tire diameter (height)
Finish line rpm
Finish line mph - 99.xx
Gear ratio in the diff.

Typical converter slip should be less than 10%

 

Hi
tire height 26 inchs
finish line rpm 5038
13.918@96.69 mph
3:70 gears

tho most current run of 13.9 was done with 54 percent humidity and it was 70 degrees out side at englishtown newjersey.

thanks
Tom

 

Assuming tire growth is a maximum of 26.5 that would put your converter slip at exactly 10%. At 26" with no tire growth, converter slip is 8.2%. Both estimates are within limits so the converter swap shouldn't be the cause for lost performance.

Temperature and humidity are only part of the weather equation. The humidity percentage usually means nothing unless you know the dew point. There's more water in the air giving lower performance at 54% humidity and 70* than there is at 54% and 60*. The most important factor is the barometric pressure. If the pressure was really low compared to your best run then I'd say that the cause of the decreased performance. Unless you do swap testing under identical conditions you won't have a proper comparrison of the results.

I use dyno correction formulas in my laptop to calculate my runs. My quickest pass isn't my best pass. I ran slower but at a higher density altitude which corrected to a quicker corrected pass. Without knowing the correction, I'd assume my quickest pass was my best.

It's possible that without your converter swap you could have run even slower but the converter swap made better results than what you should have had.