jesseenglish

Basically this is an override switch for the ATI procharger. If A/F ratios are higher than a preprogrammed level, and the pressure switch detects boost then it will trigger the relay which opens the ATI bypass valve, thus venting boost.

The valet switch is a magnetic reed switch which will be hidden behind the dash. If someone is borrowing your car then you just don't tell him where to swipe the magnet and then all boost will be vented.

There will be 2 LED's, one is for the safety switch activated by the Wideband O2 setup. The other is a blinking LED, indicating you're venting boost normally through the valet setup.

Parts of this were borrowed from the user need4speed on 350zfrenzy. Thanks for the idea. I've now made it my own with some different hardware. Will those who know what they're talking about please tear this thing apart and tell me if you see any theoretical problems. I've already installed the wideband O2, GM 2bar MAP sensor and a couple other things.

This is ultimately where I want to go with it.

Any additional ideas would be cool too.

elektrik_juggernaut

I'm not completely understanding your diagram.....i understand all of the standard electronics symbols, but the hoses coming off of the bypass valve are confusing me.....are they connected where they appear to cross over each other in front of the intake manifold?......also, did you tee-into that hose and add the check valves?

91na

Sounds absolutely awesome, I can really critique it because I, regretfully, am not very good at that stuff... but the concept seems pretty simple.

I have a feeling many more people would want to do something like this if you got yours to work

Good Luck!

jesseenglish

If you're talking about right next to the intake manifold, yes they are all connected together. Remember this is mostly theory. I haven't even found a pressure switch that will work yet. If you're not familiar with a vacuum switch, with a voltage applied to it, it will route the vacuum out of the reservoir and into the bypass valve. The check valves are necessary so when it goes on boost, it won't close the bypass valve when I'm trying to open it with the vacuum switch.

daddy Z

If all the boost is vented it is going to be very noisy. I had a hose that popped off and it sounded like I was using a leaf blower to drive around in.

I am not trying to be funny but wouldn't it be cheeper to buy a pair of sissors and just cut the small blower cog belt (cost of belt is like $30) and then replace it once your fixed the problem ?

jesseenglish

There is no problem with my Z this is an failsafe switch. It only takes a split second to blow your engine from running lean and I'm not constantly monitoring my A/F ratios while I'm driving. I generally like to keep my eyes on the road.

Let's say your DFMU explodes, fuel pump goes bad, fuel injector goes out, fuse to aux power blows, etc and you don't know about it. You're going to be running very lean. This will catch any lean conditions and vent boost immediately instead of after your engine blows up. Right now there is nothing to stop your engine from going.

The Valet switch is just for times when you don't want to have boost. Like you go to the dealer to get your oil changed, or you're going to the detailer to get your car detailed. I personally don't want those schmucks that work there to joyride in my boosted Z.

jesseenglish

My failsafe bypass will only take effect if you are on boost AND you're running lean. The reason I did this is because there are many times your engine runs lean, such as decelerating.

If Ravaz or MaxHax would've done something like this they never would've blown their engines by running lean and for $20 worth of extra parts, most of which I can pick up at a junkyard, it's worth it.

Dr Bonz

iTrader: (1)

Jesse: As I have said before, if you build it I will buy it! It sounds great. Keep me posted!

daddy Z

$20 now that is a different story. I am in too.

jesseenglish

$20 is assuming you already have a wideband 02 sensor and a gauge that can trigger a relay at a given A/F ratio. I actually already got everything I needed, most of it came out of a 1983 Pontiac Sunbird Turbo Total cost $6.56

I personally think that a Wideband O2 should be required equipment for an aftermarket FI car, but that's just me.

zland

I think that if you can produce something like this that would insure there would be no lean conditions while running the ATI SC thus no engine damage, it would do a lot toward many people purchasing that product. ATI should be contacting you and this should be part of their kit IMHO.

jesseenglish

Well, I'm gonna build one for myself, but I'm no manufacturer. Mine is gonna probably have a lot of wires and hoses running everywhere You should see the inside of my car right now, it looks like an electronics store exploded inside my car.

Once I've proven it works, I'll put it in an aluminum enclosure and make it look purdy, but it still isn't going to look like a finished manufactured product.

jesseenglish

This is a pic of my FMU, GM 2 bar MAP sensor and a little 12v - 5volt DC-DC supply I built. Not pretty, but it allows me to log boost levels to my laptop.

jesseenglish

Oops, let's try again

Juztin

iTrader: (9)

Dude I need to drive down the 40ish minutes to you sometime to scope out your frankenstein setup . Plus I have yet to still ride in a FI Z

L8te!
--Justin

Ag Z

Jess

Check this place out for a Hobbs pressure switch http://www.mcmaster.com/ Also they have some great check valves and parts for DIY'ers

Also you might want to check out his WB O2 setup. http://www.innovatemotorsports.com/

etx

napa sells a boost switch for $15, I use one on my other car.

jesseenglish

I've decided to not use a pressure switch, I'm going to use the MAP sensor that I've already installed, to log boost, as a trigger. Plus most of those pressure switches don't activate until it hits at least .5PSI which is not accurate enough for me.