Skunk 2 IM User's - IAC/Prop valve contact Solution

[Eyal 951]

I'm not sure if this is common knowledge or not, but I thought it might help a couple people. Good for the archives if nothing else. Running the skunk 2 intake manifold, you will soon hear a vibration noise coming through the firwall. The IAC sits only a few mm away from the brake prop valve in the EG chassis.
Investigating further quickly showed that the lower mounting bolt was what was actually hitting, so I decided to order a lower profile bolt. I ordered an allen "Socket Screw Cap" from McMasterCar. (actually, I ordered 10, it only comes in packs of ten) It was 4.90 for a pack of 10 grade 10.9 black oxide bolts, plus 4 bucks to ship (their close to me though)

The www.mcmaster.com item number is: 91239A444

So far, it has solved the contact, which makes me happy.

I had to jack on the engine (tranny case is best) to raise it slighty to be able to pull the bottom bolt out since the prop valve holds it in. You may have to remove the top mounting bolt first, then the bottom one so you have some wiggle room.
I have 9 extra bolts, but I'm not sure I have the time to ship em out to people with school and all. Let me know if this is helpful to anyone!

http://www.mcmaster.com/library/20050823/91239A444L.GIF

:TU:

[horny_devil]

hmmm nice work thats an idea that i didnt think of, im gonna try a engine damper and see if that helps a bit

[Eyal 951]

I tried the engine damper first too, it helped slighty, but still made plenty of contact. After the bolt switch, it hasn;t contacted ONCE. Problem solved on my car.

[horny_devil]

hmmm sounds like an idea to try if its still knocking after the engine damper

[Eyal 951]

Post about your results.

[DOHCDX]

i'm not sure what your problem is, cause the skunk2 IM was about 1/4" from hitting anything in my old z6 EH. stock mounts with ES inserts on all torque mounts. the engine doesn't move, so the manifold never hits

do you have stock mounts? if so, i bet that's the problem.

[vtecduck]

I've never had a problem with mine hitting, torque damper helps out a lot I guess :lol:

[Eyal 951]

Well, its a commonly reported issue. I do have stock mounts, I didn;t want all the extra vibration with the inserts. They wouldn't do enough for me that it would make it worth it.
I do have a torque damper as well, it didn't solve the problem, but the bolt did, so to anyone that DOES have this issue, this will help.
It may be worse for me since I have a 4040 prop valve, it does seem to sit a tiny tiny bit further out.

Also, my CX had a IAC that had the lower bolt in a different location then the Si IAC. Those with the other kind of IAC probably don't have any issue. I geuss there is another solution, source the other type of IAC. (They both bolt up to the S2 manifold)

[DOHCDX]

the vibration differences aren't that much with a d-series. now with a b18 or h22, yeah

[Eyal 951]

the vibration differences aren't that much with a d-series. now with a b18 or h22, yeah

Didn't know that. I'm basing off my experience with a friends GSR. I do have cam, so there is already vibration and such at idle as it is. I'll be fine, especially since I just bought an LSD.