VAK problem...

[Tunez]

Well first off let me say that this is not a bad thing for those of you chomping at the bit for conflicts. My car being a late 1998 had a few differences that the guys hadn't seen and we have been working together to make things right for all of us SHO owners instead of complaining.

On to the subject....

For reference when I say the VAK is activated, I mean that the accessories are shut down and when it is shut off, I mean it is back to normal with all accessories on.

In my car, it works like a charm and activates from off the line all the way up to 5200 rpms. Problem is that at 5200 RPMs when you need it most, it shuts off and all accessories come back on. I know that's what it is doing because when it is active at night, all the lights go slightyly dim because of the alternator not charging then and the alternator light comes on. When it does hit 5200 RPMs, the lights go back bright and the alternator light goes off.

I am sure it is nothing but some kind of adjustment to the vacuum sensing that needs to be done but I didn't want to tamper with it.

Maybe with some combined thoughts, we can get this things 100% right so we can all enjoy them for far less and a far better gain than the cumbersome pullies.

PS, it does seem to make a relativly nice difference ESPECIALLY at night when it is active.

 

[99V8SHO]

So this VAK that you speak of actually gives you more power than pullies? Why is that? Does the VAK shut down everything in side the car? I don't see how shutting the radio off will give you more power.... shrug

 

[wuzzzer]

99V8SHO:
So this VAK that you speak of actually gives you more power than pullies? Why is that? Does the VAK shut down everything in side the car? I don't see how shutting the radio off will give you more power.... shrug

99V8, the idea is that the VAK system doesn't give you more power, it just frees up power that is used when you have the radio on, lights on, etc. It's an inexpensive way to get back the parasitic loss of power from electrical components without having to physically remove them from the car.

 

[SHOZ123]

The VAK is vacuum triggered. If you can not keep the VAK active then you are having a problem keeping the vacuum level low. If you cannot keep it on when the pedal is to the metal then there are intake or exhaust issues.

What kind of intake and exhaust setup are you running?

<small>[ May 01, 2003, 01:10 PM: Message edited by: SHOZ123 ]</small>

 

[99V8SHO]

So when I decide that I want to get of the line quickly, like in a light to light battle, then I should shut off everything, lights, radio, climate control? I guess it makes sense...buthow much power does that really free up?

 

[Mike Kopstain]

I see this and I will watch it, but Bryan, as you know, I'm not a V8 guy, so I'll let Paul do all the question answering.

 

[SHOZ123]

99V8SHO:
So when I decide that I want to get of the line quickly, like in a light to light battle, then I should shut off everything, lights, radio, climate control? I guess it makes sense...buthow much power does that really free up?

If you shut everything off before a run then there is not near the effect. But one the GEN 3 the PS will be reduced and the motor is still drawing 25-30 amps.

The power freed up is proportional to the accessory load at the time.

 

[Tunez]

The exhaust is Flowmasters, no third cat, resonator removed, and the flex pipe is replaced by a true 2.5 inside diameter piece. As for the intake, it is a cold air intake that runs into the fender well. Not sure where any of that would cause a problem but maybe you can tell me.

Are you meaning that there is a loss of vacuum or too much?? Also does this mean that it will not work with the other mods??

99V8SHO, for reference, it doesn't "turn off" any of your accesories, it just stops the alternator from being the thing that is actually running them. They will just be running off of the battery while you are at full throttle.

The advantage with the VAK over UD Pullies is that the pullies will reduce your charge ALL of the time, thus giving you less power to run accessories when you need it most. The VAK only reduces that at full throttle and is back to normal as soon as you are not.

 

[SHOZ123]

You need to get a vacuum gauge and monitor you engine. If the VAK works at all it will work whenever the vacuum is low. If you cannot maintain under 3" of vacuum when the throttle is wide open there are breathing problems.

FWIW I can go from a standing start to the top end limiter with the VAK constantly engaged. The VAK is not affected by any other mod except one that pressurizes the intake.

 

[99V8SHO]

If pullies were installed, what accessories do they affect? Right now it is sounding like everybody is having trouble with the VAK. The pullies sound more reliable to me. BTW...how much do pullies and VAK cost?

 

[Tunez]

Nah, there aren't really any problems, just some differences with the late 98 and 99 SHO's. Where you would think that all Gen 3's would be the same, they are not.

The pullies will not turn anything off, they will only reduce the amount of charge that goes to the accessories. Translation: When you are sitting at a stop light, your AC will not be as cold, your stereo will not be as loud, and your lights will not be as bright. They would never be as bright as they would have with the stock pullies anyway but even worse at idle. BIG difference here, if the pullies break or have a failure, you have MAJOR problems. If the VAK stops or shuts down, your car defaults to normal.

VAK only affects things at full throttle and frees up closer to 85% of the power robbed when compared to about 30% by the pullies.

 

[SHOZ123]

Right now it is sounding like everybody is having trouble with the VAK.

You must be hearing a lot more than me. Install problems due to instruction conflicts are what I have heard. It is interesting that I include my home address, phone number and email address but have not be contacted by anyone but Tunez.

The group buy VAK was the most basic of units. It can be improved upon with a timer and with a better battery/power supply setup. Keeping the cost low was a major concern, probably not the best thing to do in retrospect.

Any new VAK will include the timer which will stop any rapid cycling of the switch. The vacuum setting on the switch is not adjustable.