Can I lose central locking but keep locking diff???

[skinthespin]

Hi,

I am building a CQ track car and have stripped the doors down, removing locks etc.

I have removed the interior and under the rear seat is the ABS ECU and the rear diff control unit. I have no ABS on the car so the ECU is redundant but there appears to be wires from it to the diff control unit and also vacuum pipes from the central locking reservoir to the diff control unit too.

Do I have to retain the abs ecu and all the central locking nonsense to keep the locking diff?

Thanks in advance

Simon

[S2central.net]

I would need to look at diagrams to remind but I think the diff lock module tells the ABS to shutoff when diff lock is engaged.

The diff lock module merely controls a valve that directs vacuum to an actuator rod for the diff lock.

If diff lock sees vehicle speed higher than 25kph it disables the lock. The usual work around for that is to wire in a cut out switch for the blue/white VSS wire going into diff lock module.

You will need to keep the vacuum reservoir under rear seat area for the diff lock to operate.

I am toying with a Torsen rear diff for mine (from D1Q).

I can understand a locked centre diff - like the Rally URs had - but locked rear is surely mud / snow / donut territory.

[johne]

[QUOTE

Do I have to retain the abs ecu and all the central locking nonsense to keep the locking diff?
[/QUOTE]

The diff control unit is not connected to the central locking unit, the vacuum pipe you see goes to the vacuum reservoir.

The connection(s) to the abs ecu are outputs from the diff control unit so if there's no abs there doesn't need to be any connection from the diff unit to the abs.

So, the abs and central locking can go.

In reality the diff locking control unit is just a solenoid switching the vacuum feed to the diff actuator with a speed control input.

You could just replace the diff control unit with a 12 volt vacuum solenoid off eBay for less than £10 and an on/off switch of your choice to actuate the solenoid and hence lock/unlock the diff. The one thing you do need is a vacuum supply retained from before.

John

[UrS4boy]

E83 = ABS connection

[skinthespin]

Thanks for the help, all understood now. Forgotten that the diff disengages at 25 kph so doesn't seem worth the hassle on a track car, only driven the car once 8 years ago....long story.....running a standalone engine ECU so think its best just to junk the lot!!

Thanks again for the help

[UrS4boy]

..running a standalone engine ECU so think its best just to junk the lot!! Thanks again for the help

Please don't "Junk" the lot. Offer the bits to forum members here. Some of those bits break and need replacement. They are NLA so reusing them on somebody elses car is helping the UrS/S2 community.

For example, I have a local UrS club member looking for a good used actuator to replace one on his 95 UrS6.