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Discussion Starter #1
I picked up a used on3 kit a few months ago. I'm trying to get everything installed but have run into a few problems. Does anyone know what size bolts(length) are used to mount the turbo to the t-4 flange. Of the 4 holes, two will be no problem and clear fine. The two towards the inside of the header/flange have very little clearance.

Is there a trick to getting the bolts through the mounting holes?
 

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Is there a trick to getting the bolts through the mounting holes?
Yep. Put the bolts in through the bottom and put the nuts on the top. I used stainless bolts and crimp style lock nuts on mine.
 

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Discussion Starter #3
Yep. Put the bolts in through the bottom and put the nuts on the top. I used stainless bolts and crimp style lock nuts on mine.
I'll have to get some pictures but I don't think a bolt has enough room to go in from the bottom on the two holes towards the center of the car.
 

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Discussion Starter #7
Ok, I took some pictures. The bolts are 7/16 and need to be 1.5 inches long. The problem, only a 1 inch long 7/16 bolt fits. Just wondering how other on3 users overcame this poor design?

The problem hole:






1.5 inch bolt:




Here is the 1 inch bolt in place, obviously not long enough:


A stud may work. The problem is going to be finding a grade 8, 7/16 stud that is 1.5 inches long.
 

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maybe insert that one through the hole from the top with the rest of the bolts out. I might have done that too, i forget
 

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Discussion Starter #11
From what I've read, on3 sends you a smaller bolt that fits right there, I know it's in the instructions so if you can find someone with those they can tell you what size it is.

Sent from AutoGuide.com Free App
opps....I just made it fit with a really big hammer. The collector now has a "slight" dimple in it. REALLY poor placement on on3's part. If the flange was 1/4 inch higher, it would not have been an issue.
 

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I'll be damned, right from the On3 instructions...

2. Bolting on the turbo after the header is already installed can be really hard and its ideal to bolt the turbo on the header before you install it. With your kit, you will have (3) 7/16” bolts with prevailing locking nuts and (1) 8mm bolt, prevailing locking nut and washers. Due to the confined area where the v band is on the outlet of the turbo, we use the single 8mm bolt in that hole. Use the (3) 7/16” bolts and hardware on the other 3 flange holes. In the package with your turbo, you will find a metal gasket for this mounting surface to be used. We DO NOT include gaskets for the headers as we have had very good luck just running a bead of high temp copper RTV instead of gaskets. If you wanted to run a gasket it would be up to you but we have always just used copper RTV. To keep underhood temps to a minimum, you may also consider a turbo blanket
 

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yep, sent. Although my 10 year old daughter could probably write a better set
 

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Discussion Starter #20
all you need to do is put the nut on the bottom and run a little shorter bolt through the top
Any bolt long enough to go through the turbo flange and the header flange will not go through the top due to part of the exhaust housing partially blocking the top of the hole. It causes the bolt to go in at an angle.
 
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