Installing TVS, S-hook not flush. Problem?

[TheFleshRocket]

We are installing a TVS on my '04 Cobra. Step 1 and 2 of the VMP instructions are for installing the S-hook, which is supposed to be flush after being tapped down. Mine is not. I used black RTV first, noticed the not-flushness, then pulled the S-hook and installed it dry, which was no better. So I reinstalled it with blue loctite.

Here's what it looks like. Is this a problem?

 

[Soap]

If it were me I would take it off and grind the extra material off. But in all honesty you can just use some extra RTV to seal the intercooler to the bottom of the blower.

--Joe

 

[04oxfordvert]

take it out and down to a machine shop and have it milled.

 

[TheFleshRocket]

I forgot to contact VMP until late this afternoon. They asked me to send pics, and said they may need to send out a new s-hook. (I bought this blower new from VMP.) No way I'm modding it myself if they're gonna make it right.

 

[MG0h3]

Good call. I would never try and modify a brand new piece


Sent from my iPhone using svtperformance.com

 

[04oxfordvert]

that is awesome customer service right there!

 

[TheFleshRocket]

A new s-hook is en route and the old one is on its way back.

 

[MalcolmV8]

I never install those. It reduces the surface area of the intercooler used under WOT. To me they are a marketing gimmick.

 

[Soap]

I never install those. It reduces the surface area of the intercooler used under WOT. To me they are a marketing gimmick.

Funny you say that. I didn't put it on my car for similar thinking.

--Joe

 

[lowflyn]

Mine was the same way. Installed just like that. No ill side effects since February. Vmp did send a new s hook, it's somewhere in the garage.

Sent from my XT1045 using Tapatalk

 

[TheFleshRocket]

I never install those. It reduces the surface area of the intercooler used under WOT. To me they are a marketing gimmick.

Interesting. Have you done any testing to confirm that the S-hook results in higher IAT2s under load?

 

[MalcolmV8]

Interesting. Have you done any testing to confirm that the S-hook results in higher IAT2s under load?

No. I didn't see the point in all that work of tearing everything apart and re-doing it all. In the end I'd be testing the theory of blocking off part of my intercooler and reducing surface area to see if it results in less performance of the intercooler. I think we all know the answer to that one already.

 

[TheFleshRocket]

I asked VMP support:
"I have a related question—a couple of people on SVT Performance have said that they specifically leave out the S-hooks when installing TVSes, because the S-hook partially obstructs access to the intercooler which would probably result in higher IAT2s when in boost. Does installing the S-hook negatively affect IAT2? Is there any benefit to omitting the S-hook? "

Their reply:
"The S hook was not in our original blower design, but was incorporated in the Gen2 update. The s hook recirculated air through the bypass a second time, which actually brings down temps. You can use the blower without it, and there is no noticeable power loss at WOT."

I was initially under the impression that, under non-boost conditions, intake air that went though the supercharger bypass also bypassed the intercooler. And that the S-hook forced bypass air to actually go through the intercooler before entering the question. But now that I think about it more, I assume that all air that enters the combustion chambers has to go past the intercooler, so I must be incorrect.

But I don't really follow the VMP tech's explanation either--do you guys understand how the S-hook would cause intake air to go through the bypass a second time, and why that would help IAT2s?

 

[MalcolmV8]

It forces air through the intercooler when not in boost. Normally out of boost air goes straight into the motor.
If attempting to cool IAT2 temps when idling and driving out of boost is important to you then install it.

The downside? It cuts off part of the surface area of your intercooler used in WOT. So WOT cooling has a smaller effective surface area of the intercooler to use.

IAT2 temps really only matter when in boost at WOT. That is why I never install them.

 

[TheFleshRocket]

Shouldn't IAT2s when not in boost be pretty close to ambient temperature, assuming that the vehicle is moving fast enough to get fresh air under the hood?

 

[MalcolmV8]

Shouldn't IAT2s when not in boost be pretty close to ambient temperature, assuming that the vehicle is moving fast enough to get fresh air under the hood?

It should be. Our cars report very hot IAT2 in normal cruise due to sensor location and heat soak.

 

[TheFleshRocket]

Okay, so I'm trying to wrap my head around air flow through the supercharger and engine, and how the S-hook and boost bypass affect those things.

Here's my understanding of things, which is probably at least somewhat wrong.

The supercharger bolts directly to the intercooler, which ought to mean that any air that passes through the supercharger or the boost bypass will go through the intercooler before going into the engine.

The boost bypass is the little throttle looking thing near the back of the super charger, visible only from beneath when the supercharger is not installed.

Under light, no-boost throttle, the boost bypass valve is (partially) open, which means that air goes down through the intercooler instead of past the supercharger rotors.

Under boost, the boost bypass valve closes, which means that all intake air goes past the rotors and is compressed.

If all of those assumptions are correct, how does the S-hook work, and affect IAT2s? If any of those assumptions are incorrect, which ones and why?

 

[MalcolmV8]

No incorrect. When you take your blower apart and see how everything goes together maybe it'll make more sense to you. The boost bypass valve does not feed air through the intercooler.

 

[TheFleshRocket]

Could you elaborate a bit on the path the air takes? The blower's already off at home..

 

[KLLR SNK]

^^ The intercooler bolts to the supercharger. The supercharger bolts to the intake.