I've just gotten my twin turbo setup done on my 82 trans am, using .60/.63 T3's from a SVO/turbocoupe. (dont worry, ill be posting pics of the whole build later, just want to get it running well first). The stock wastegates on those are at 9-10psi.

The problem is, after a few 10psi blasts, the rubber connector to the throttle body blows off. There just isnt enough friction (and no bead) on the throttle body. The connection is a quite tightly fitting rubber plumbing connector (3" i believe). Im just using cheapo worm-gear hose clams ( i know, i know). Will stepping up to a t-bolt clamp or similar and tightening it down more solve this? Im planning on picking some up after work today and trying them out. Or is there any other solution that might work better?

 

Are you running a BOV? I know I had problems with hoses coming apart, but it was usually when I let off the throttle and the pressure would spike in the IC plumbing (never came off at the TB though). With the BOV, things stayed together quite well (I usually run 6psi, but I have experimented with 10psi with no problems). However, my stock TB on my 89 IROC has two small lips on it, so maybe that is what kept this connection from coming apart (even with just the worm clamps). I now connect to the TB with 4" Hose Techniques turbo hose and T-bolt clamps, just to make it look a little more professional.

Can't wait to see your turbo system. I am especially interested in your DIS coil-packs. I wish I knew enough electronics to do something like that myself!

 

I've got a 1g DSM blowoff valve right before the throttle body. Its a stock tpi throttle body, just on a stealth ram. Now that you mention it though, the connector has never blown off from boost alone, it comes off (i believe) when i let off the gas after getting up to 10psi. Ive been driving it only on my residential road, so it has been WOT, brakes, WOT, brakes etc. Its very possible that the BOV is too small; it came stock on what, a 2.0L? If the t-bolt clamp doesnt solve this, i will toss another BOV on there (i dont really want to spend big bucks on an HKS or other decent one). Do you think a pressure spike enough to blow apart tubes would be damaging the turbos?

 

Seriously doubt it. There are many factory turbo systems with no BOV (GNs, SVO T-birbs, etc) that have no turbo failures even after many miles of abuse.

I would be curious what the max pressure is in the IC piping during compressor surge. I never measured it, but I would imagine 20+ psi is very possible.

 

You need a BOV like this

 

Strap the charge pipe to the TB.... BTDT. BW

 

why mount the blowoff so far away from the tb elbow? couldnt you just mount it like 1" off of it instead of the big u bend?

just wondering......

 

Its is just like that for packaging reasons. When assembled, the PS pump and radiator hose go right in that area. Plus, I wanted the BOV to be easily visible.

 

As was mentioned, a good BOV should help.

Also, you can spray hair spray on your TB before sliding the connector over it. Adds a bit of lubrication putting it on. And makes it stick when trying to seperate.

Also, you can flare the ends of your pipes to keep them together.

Lastly, you can put a birdge from one side of a connection to another. For instance, you could build a bar that bolts to your TB behind one of the bolts holding the TB to the plenum, bend it and make it go towards the tubing across the connection, and then attach it to the tubing somehow.

This is how mine was done:

 

Whats your take on mounting the TB direct on the manifold, vs using that 90d elbow you have and facing it forward?

Mine is mounted in the center with a 1.25" spacer:

<img src="http://members.cisdi.com/~anesthes/projects/singleplane/complete1.jpg">

-- Joe

 

Every bend adds a bit of resistance, and if there is no place for the tubing to go (i.e. shoot off forwards) it will not want to separate. I'd put a 45 deg bend after the blower, turn the hat 45 deg, and get rid of the 90.

Not that I can talk (I wanted to keep most of my existing IC tubing).

 

I retooled guidos for the tube blowing apart reason...I dont use the braces like he did or the connectors>>> But the way we routed the IC tubes the only way my tubes will seperate is If either my crossover tube snaps allowing the turbo to move, the silicone connectors rupture, or the intercooler breaks the front subframe and blows itself out of the drivers side 1/4 panel... When all assembled I can do chin ups on the tubing and it wont seperate.. basically when routing the tubing keep the number of bends to a minimum and keep the angles under 90....Usually you see blowoff because you see long straights into 90 degree angles...the straights pivot at the silicone and the 90 blows out...

I wish I had some good pics of what I did to explain what I mean... when I get the engine back in Ill try to get some usable pics....

 

if you have a way to weld alum, you could just try to weld a bead, or even just a couple spots on the top and bottom edge of the throttle body.

then your current method should work.

 

That hat only goes on one way.. I need to find a replacement hat.. I should prolly see what Vortech supplies with their kits for Vortec trucks. (thats kinda funny)

It's a vortec TB off a 98+ van + stock vortec hat. THe angle is actually worse than it looks, it aims a little more twords the passanger side rather than straight forward.

-- Joe