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'92 plenum hose question

D

DaWoodster

Guest
Looking at a '92 ZR-1; There is a hose/nipple at the front driver's side of the intake plenum, that does a quick 90deg back to a smaller fitting between the first and second pair of intake runners. My guess is this is to feed a coolant jacket for the throttle body, but I'm not sure.

This particular car has the hose and connectors removed and has the large hole welded closed. Two questions:

- Am I correct in assuming it's a coolant line?
- Any guesses on why they would weld the hole and not plug it?

I have attached a picture to hopefully make this clearer.

My thanks in advance for any help.
 
U

USA ZR1

Guest
Looks like the coolant passage for the throttle body has been bypassed. Mine is done the same way. It keeps hot coolant from heating up the incoming airflow.
 
F

FrogindaBlender

Guest
Was this the white zr1 in escondido? I was over looking at it in my hunt for a zr1. I think that is a egr pipe. If it is that car. I bailed on the car because it looked really tired. Watch out for the dealer. They had a nice black one 90 they offering @23.9k and told me it was a misprint and would not let go of it for under 24.2k. Two weeks later the ad still show 23.9k. Thanks distictive auto. I bought a red/red 91 for the same 23.9k with 16k miles.
 
S

secondchance

Guest
Actually, EGR is on the passenger side. I think Clint is right. Looks like coolant bypass for the throttle body.
 
F

FrogindaBlender

Guest
I saw that car too. I just did not know, but it was one of the factors why I did not buy it. Looks like Wood is getting it. I smell DRAG RACE!
 

JT ZR-Won

Well-known member
Joined
Dec 6, 2000
Messages
1,291
Location
Bradenton, FL
Corvette
'90 ZR-1 #3010
That is the coolant bypass. However I have never seen one welded closed. No need to weld when a .50 cent cap does the trick.....plus, pretty tough to return it to stock form.

I bypassed my coolant as well so it wouldn't heat the plenum up as much but didn't weld anythng

Jay
 
9

91vettezr1

Guest
D

DaWoodster

Guest
Thanks, all for your help and input. As per my last post, I did buy the car, so I now am the proud owner of a coolant challenged throttle body.

Functionally, all seems fine, runs strong/well. But, man, that is one ugly weld, making for one ugly plenum. I will address it as time/$ allows.

I did find a new plenum, and yes, they do fetch a pretty penny.

"91", a special thanks for taking the time to post the pictures.

PS: Already have 2ea 911's and naive kid in a 300zx "enlightened". They didn't see my welded plenum, but they did see that ZR-1 emblem, the back one :)
 

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