MSD whistle
 

Installed my ported MSD and 95mm TB. Thing f**** pulls hard. But it makes some whistling sound like a deflating balloon at low speeds light throttle? Wonder if it’s the GM CAI without that lame diverter plate now that the LT5 Tb is in. Idk. Help me please.

Check your gasket fitting and turn the gasket facing the other way. Tighten TB to 89 lbs.

I’ll give that a try. Better than removing the manifold. I figured those gaskets aren’t handed.

I also re-used the stock TB bolts. Didn’t back out the brass inserts. But now I’m afraid maybe punctured the manifold? Idk just spitballing.

You may have punctured the manifold because MSD gives you new bolts and washers to use that way you don't puncture it when installing the throttle body.

Yea I didn’t get them as I bought mine used. But the bottom bolts go all the way through. The top 2 are the 2 that are encased. But I imagine it would back out the brass fitting before puncturing. I’ll take a look. Nothing a little epoxy can’t fix

If the bolts go to far in just put some washers on to act like a spacer. RTV is your best friend after this.

I checked the hole depth with a micrometer and the stock bolts a just shy of the bolt hole depth of the msd. Just to be safe I bought some shorter M6 bolts. Checked the backside of the casting and found no signs of puncture. Car idles fine and pulls fine no codes. Starting to thin the 95mm Tb makes some noise stock? Maybe the blade screws are making this sound idk. Gonna put my ported sticker on and see what’s up. Maybe some RTV on the snout face? I followed the torque specs to a T so idk what it is. It’s just annoying.

I did notice that the brake line booster hose doesn’t seat all the way like it does on the stock unit. Brake pedal is firm so no issues there.

Did you use RTV on the snout face?

I have done my test fits and I am back to stock manifold because it’s going to get heads and cam soon. Once the that’s done then I am going to use RTV to sealer up mainly because of the porting. No more O ring gasket. Paper and RTV should be 100% fine. Back to stock manifold because I do want to base line my car because of current CAI, secondary cat delete, and 3 inch custom rear axle stainless steel with FM super 10’s mufflers then I can see the true gains of the mods with the LT2/95mm/cam/heads and NOS.

I wouldn't bother trying the GM plate, it was designed for the LT1 and would probably cause problems if installed on anything but factory stuff.

If you bought the MSD used, did you replace the gasket with a new one? The OEM gasket - which looks pretty similar to the MSD - is supposed to be replaced whenever you remove the throttle body. I would be that is your issue. Just get a new MSD gasket.

-Geoff

Hmmm well the paper gasket is gonna be solid for sure. I may try that and if this kills the whistle I’ll know the problem. If not I’m gonna have a f’n mental breakdown. Sounds like a micro bypass valve. Since my car has no turbo it’s not a cool noise

I have all new gaskets.. hmm

What makes it weird is that it idles totally fine. No codes nothing. I figure if it was a leak it would either idle rough or throw a code. It would be pulling air after the MAF