ZZP Dual Pass

Robinjo

Goblin Guru
I'm considering doing the ZZP Dual Pass upgrade since the engine is out of the car awaiting a frame. It seems like a pretty easy time to do this. Anyone already done it and is it worth the cost/trouble?
Is the Option B worth doing? I think If I do this, I'd just get a reservoir off Rock Auto and plumb it out myself.
 

r3drckt

Goblin Guru
I didn’t tap the intake for the option B and I have my engine assembled and waiting for installation. Hoping I don’t have to tap it and not need the Option B, but we’ll see.

the dual pass will be needed though and now is the best time to do it before you add fluids. You can probably do it all without removing the intake manifold itself since you don’t need to dig down to the side of it like you would if the engine was in the cobalt.
 

Rttoys

Goblin Guru
Yep. Do it. Much easier out of the car. Get a second reservoir, order a second bracket for the pass side and plumb it yourself.
 

devianteng

Well-Known Member
Dual pass is a definite. Option B is a "should do" upgrade, but you can definitely get by without doing it if it's just a stock street car that you want to cruise around in.
 

Robinjo

Goblin Guru
Just curious, what are the benefits of the Option B? Just that it's easier to bleed the system out?
I understand the benefits of the Dual Pass setup.
 

Tinkles

Well-Known Member
Just curious, what are the benefits of the Option B? Just that it's easier to bleed the system out?
I understand the benefits of the Dual Pass setup.
Option B just keeps additional coolant in reserve so the system stays full. The extra coolant doesn't actually add more usable volume to the system. I highly recommend a flow through style coolant reservoir(I run a heat exchanger tank off a Mustang Cobra in my supercharged Cavalier) instead of the Option B. That way you will still be able to keep air bubbles out of the system and you will actually be adding more effective volume to the system.
 
Last edited:

95Blitz

Well-Known Member
Option B just keeps additional coolant in reserve so the system stays full. The extra coolant doesn't actually add more usable volume to the system. I highly recommend a flow through style coolant reservoir(I run a heat exchanger tank off a Mustang Cobra in my supercharged Cavalier) instead of the Option B. That way you will still be able to keep air bubbles out of the system and you will actually be adding for effective volume to the system.
I like that idea.
 

Waterdriver

Goblin Guru
Option B just keeps additional coolant in reserve so the system stays full. The extra coolant doesn't actually add more usable volume to the system. I highly recommend a flow through style coolant reservoir(I run a heat exchanger tank off a Mustang Cobra in my supercharged Cavalier) instead of the Option B. That way you will still be able to keep air bubbles out of the system and you will actually be adding more effective volume to the system.
Wondering in what way the tank you have is different from the Option B tank? I have the Option B tank with the bleed hose dumping into the top of it, the bottom of the tank feeding back into the heatexchanger coolant system. Same as yours?
Or do you have it connected up differently?
 

Tinkles

Well-Known Member
My tank has a 3/4" inlet at the top of the tank and a 3/4" outlet at the bottom of the tank and it is plumbed directly into the heat exchanger circuit.
 

Robinjo

Goblin Guru
Ok, just bought a lower intake manifold with the dual pass already installed because why not keep my stock unit as a backup. Seems safe since these cores are not easy to find. Are the 3/4" T connectors from Autozone/Advanced Auto for heater hosing acceptable to use?
 

Ross

Goblin Guru
I would think that is good. The intercooler water should never get as hot as the engine coolant that would flow thru a heater hose. With the stock supercharger making 12 PSI boost, my intercooler water barely gets warm.
 

Tinkles

Well-Known Member
Ok, just bought a lower intake manifold with the dual pass already installed because why not keep my stock unit as a backup. Seems safe since these cores are not easy to find. Are the 3/4" T connectors from Autozone/Advanced Auto for heater hosing acceptable to use?
Yes.
 

Robinjo

Goblin Guru
I guess since I'm going to take the intake manifold off for the Dual Pass unit I should do the phenolic spacer. I can now see how these build can spiral out of control.
I need my frame to hurry up so I have something else to do with my free time than surf the internet for 'upgrades'!
 
Last edited:

Wes

Well-Known Member
I guess since I'm going to take the intake manifold off for the Dual Pass unit I should do the phenolic spacer. I can now see how these build can spiral out of control.
I need my frame to hurry up so I have something else to do with my free time than surf the internet for 'upgrades'!
I got the spacer. I like the idea of keeping the manifold isolated from the block but it's not like it's a noticeable upgrade or anything. In my past life I did blow a S/C motor due to heat soak, still stings lol.
 

Ghostknife

Goblin Guru
I got the spacer. I like the idea of keeping the manifold isolated from the block but it's not like it's a noticeable upgrade or anything. In my past life I did blow a S/C motor due to heat soak, still stings lol.
Glad you said this, I just put everything back together from doing the dual pass and didn't want to take everything back apart haha
 
Top