The ACD on my evo isn't working (I think the pump is bad) and I get the three lights on my dash after a minute of driving.
I recently started going to the local 1/4 mile track, but I can't seem to get lower than a 14.1. I'm sure I'm not the greatest driver, but that seems a little too slow.
My question is, when the ACD isn't working, would the open mode affect my quarter time?

Edit:
Evo VIII, mostly stock except for 3" TBE.

 

I believe its still a 50/50 lock. It doesn't enter an open state when the pump fails.

What are your mods?

 

Im not sure how the diff would behave with the 3 lights. Are you hitting solid boost? Wheel spin? Does the car feel like its pulling normally?

 

Are you tuned for the TBE? If not, your car could be misfiring like crazy and giving you the aforementioned time.

 

There are some very extensive threads on acd pump failures and in this one in particular someone mentions their 60' being drastically affected by a failed acd pump:
https://www.evolutionm.net/forums/ev...l-pay-you.html

Here is the exact post:
https://www.evolutionm.net/forums/9560396-post175.html

 

Feels normal, but I've only had the car since June, it came with a bad acd.
Not tuned, I didn't think about tuning before doing more mods....

 

I dont see how a failed pump will affect 1/4 times. It reverts to its standard setting of tarmac as a fail safe. It does not make the car front wheel drive. If you just have a exhaust installed and no tune and you say you are not the best driver, then those times are pretty normal i think. Spend some more time driving the car and get more mods and that time should improve. Also I would suggest fixing the problem anyway.

 

Lol you will not misfire because of an exhaust.... just a heads up..

 

So you are saying running a TBE untuned will not create knock/misfire which would then pull timing?

 

Its not going to "misfire" no. The extra load/boost created with an exhaust will not knock enough for concern. Even when I turned cars up to 23-24psi on stock tunes (full 3 inch on mine and an 05, third I wasn't tuning just seeing what was up with his car) have I ever encountered serious or even above average knock. The timing goes more negative on the rom yes but doesn't result in a misfire.

No need to battle, its just not going to "misfire" or blow your motor from having an exhaust is all I'm saying :-)

 

I agree, 50/50 is the normal steady state of the drivetrain... the pump allows the clutches to reduce the torque to the rear, very similar to Acura SH-awd system which reduces torque to one side, inadvertantly transferring torque to the other side.
The systems are made like this because its too much to depend on a pump to give pressure 100% of the time for traction, it would never happen and the warranty would be rediculous.