TRWright

Other than the obvious of no overboost protection or factory boost gauge, what can I expect to happen if I disconnect the vacuum line going into the KLR?

Milkcow060

Could anyone chime in here? im curious...

theedge

Why would you remove it?

The MAP value could factor into the knock detection, but I dont know for sure.

Milkcow060

i dont think i would....i just found this old post and it got me wondering. I dont really know how the klr works and thought someone would know.
Dennis

wolfenstein

i know the timing runs through the klr

Rock

BRB!

mark944turbo

There will be no effect besides a non working boost gauge.

boerge

Car will go into Limp mode as it will see no boost pressure when it expect to see boost,and thus limiting boost to 0.2 bar.
Just had a plugged line to the KLR, and thats what it did.

Regards B.O

mark944turbo

Really? Reliable sources have said that the KLR does not use manifold pressure for anything. I will have to try it out.

Brian Morris

I'll second that the car will go into limp mode - been there, done that. It's just a safety check to make sure the boost system is working properly. AFAIK the KLR *doesn't* use the boost pressure to control boost - that is it's not in closed/feedback loop.

--Brian Morris
89 951

GreyDog

I would guess the DME/KLR will go into lim-home/safe mode if it can't detect a signal w/in range at a given rpm if expects to see it.

Cory9584

I had mine disconnected for a long time and didnt notice any difference.

xsboost90

could you use a boost controller to bleed off pressure to the klr to regulate the overboost protection down or would that just blow your engine up?

Oddjob

Unfortunately that will not work. The overboost protection in not in the KLR, its in the DME, and mapped on the DME chip.

The DME is measuring air flow through the AFM, and if that air flow exceeds a preset limit, the DME determines that the car is running too much boost (or that there is an intake leak), and it triggers the overboost protection and cuts the fuel. Its not a function of the manifold pressure line running to the KLR.

If you swap the factory DME chip with an aftermarket chip, and leave the KLR chip stock (e.g. Vitesse chips), you can run as much boost as you want w/o tripping the overboost protection.