Anyone know what year IAC assembly I need to get my
TB to fit atop the waterneck? I have an 85, and my TB is a 52mm holley. Thanks, John

 

Ttt

 

Does USR provide any guidance or instruction?

Because the USR is a modified HSR, I have to imagine you're seeing reduced clearance under the TB. As such, I'd figure you need a different waterneck than stock. IIRC, the MR waternecks (as sold by TPiS) are a great option.

I also have to ask if you are using your OEM IAC housing or if you're modified or bought an aftermarket. AFAIK, the SAME IAC housing was used on ALL TPIs and even continued until ~1993 with the LTs. I'm pretty sure that means you'll be FORCED to use a factory IAC. But... If you haven't hacked it up to remove the coolant B.S., look for my thread in the C4parts for sale section called "Do your TB bypass the right way!". I sold one that I'd modified as I'm suggesting. At the end of that thread, someone posted a link to the TPiS version which you can also buy -- if you're not into fabrication.

FYI,,,One of the problems with your issue is we can't see where contact/interference is occurring.

Since the OEM waterneck sits pretty tight to the base, I'm not sure if you can find one that's lower. OTOH, I believe the MR version does point in a different direction.

Sometimes the use of a modified, aftermarket part requires some creativity or fabrication. But you kinda think the USM guys would have provided some thought/guidance on that issue.

Good luck! Hope you like how that beoch runs!

EDIT: You could do a search for USM HSR and see if you can find prior users of this intake. At the very miminum, I think BJankuski used one...but I also think he did some of his own welding before he was happy with the setup.

 

Since they charge almost double what other used to build and sell them for, maybe they should provide some technical support.

I think a shorter water neck is the answer. Opinion only.

 

Very little tech support form these cats. Almost no instructions at all, just basically a disclaimer page stating your obligation to check clearances. I have the TB bypass mod, so the coolant passages are of no use to me. The parts that are hitting are the end pintle portion of the assembly and the driver's side part of the coolant inlet. It is very close to fitting. They do give you a chrome low rise waterneck, but it ain't low enough. I've had to do too much other crap to get this thing even close to going on the car. Bolt holes had to be elongated, all holes had to have a tap ran through them, adaptors added for sensors, the felpro 1205 gasket had to be matched, now this, and I'm sure the tune ain't gonna be spot on. Don't know if it will be worth the hassle, as I'd be driving it now if I purchased the mini. Thanks for the help guys. I'll check your post Gregg, and prepare myself for the fabbing.

 

How much clearance do you need?

I cut mine off like you see in the pic and re-welded the spout back on.

see sig

 

Since you have the TB bypass mod, you probably don't need to look at a pic of mine.

I just looked at USM's website. Holy Crap! 2k for a USM HSR now?!?!?!
And, with no support? Considering what Brian had to say about their QC, I'd give a pass on that option. But, back to now....

Maybe you got yours for less or just wanted to snub the MR option...I get it. Do you still have the factory TB? I'm curious how much issue you'd have with it. Maybe other TB options/brands would work....

That's one of the downsides of aftermarket performance parts, no single manufacturer is willing, wants to, or should be required to figure out what other parts work with their's and visa-versa. That's where fabrication comes into play.

Is your interference severe? Can you post a pic? These kinds of posts are awfully hard to respond to.

P.S. On a setup like LD85 posted above, I'd wonder if you could use a belt-sander with 60-grit to remove half the thickness of the mounting flange for the water neck. Seems like that would give you 1/8" or more.

 

I took a sawz all, cut the neck off, ground it down with a sander, made it close to flat, then welded it. Worked great

But I agree, that looks like a pretty thick flange

 

would a "swivel" style water neck be of any help?