Inktake manifold vacuum line nipple threading?

[Nordicskier]

Trying to plug the unused brake booster vacuum nipple on the intake manifold. Could someone confirm the threading on the intake vacuum port nipples, is it 1/8" BSPT?

[Bob_n_Cincy]

Trying to plug the unused brake booster vacuum nipple on the intake manifold. Could someone confirm the threading on the intake vacuum port nipples, is it 1/8" BSPT?

I think it might be a 10mm diameter by 1mm pitch. Try a M10 fine thread bolt to see if it fits.
Bob

edit: This is not correct
Bob

[NevaLift2Shift]

Trying to plug the unused brake booster vacuum nipple on the intake manifold. Could someone confirm the threading on the intake vacuum port nipples, is it 1/8" BSPT?

Let me check when I get home tonight, because I think I have an extra plug for it. I'll let you know and would send you the extra plug I have, if you want it.

[RPGs818SNA]

Trying to plug the unused brake booster vacuum nipple on the intake manifold. Could someone confirm the threading on the intake vacuum port nipples, is it 1/8" BSPT?

Just took mine out and it measures as 1/8" BSPT or ISO. I measured 0.187 ID, 28 TPI, 0.3806 OD. Please let me know where you find a plug that size.

[Sgt.Gator]

Just took mine out and it measures as 1/8" BSPT or ISO. I measured 0.187 ID, 28 TPI, 0.3806 OD. Please let me know where you find a plug that size.

https://fastfittings.com/collections/steel-bspt-hydraulic-adapters/products/steel-bspt-plug?variant=8943918809177

[RPGs818SNA]

Thanks for the link, Sgt. Gator!

[Nordicskier]

Thanks for the checking and the information. I ordered my plug from Belmetric, trying to have all parts on hand for a refresh of the boost control system and any little things that can be cleaned up along the way. I'm going to install a hybrid MAF system, moving the intake air temperature sensor to after the intercooler, leaving the flow measuring in the OEM location before the turbo, then retuning the ECU for this hybrid set up. The goal being to limit boost and mitigate pre-detonation in the event the intake air is too hot.

[Bob_n_Cincy]

Thanks for the checking and the information. I ordered my plug from Belmetric, trying to have all parts on hand for a refresh of the boost control system and any little things that can be cleaned up along the way. I'm going to install a hybrid MAF system, moving the intake air temperature sensor to after the intercooler, leaving the flow measuring in the OEM location before the turbo, then retuning the ECU for this hybrid set up. The goal being to limit boost and mitigate pre-detonation in the event the intake air is too hot.

NordicSkier,
Moving the IAT sensor is very easy for me. I have a tapped hole in my AWIC. Are there any consequences if I make this change and don't get retuned?
Bob

[Sgt.Gator]

NordicSkier,
Moving the IAT sensor is very easy for me. I have a tapped hole in my AWIC. Are there any consequences if I make this change and don't get retuned?
Bob

I don't think you'll need a retune. It's just a more accurate IAT reading. I had this on my LGT race car. It works really well but if you pop off a boost tube your engine will die in 1/2 lap just like it will on a MAF+IAT oem sensor. With a pure speed density tune the engine will keep running with whatever boost is still getting thru or even as a pure NA engine.
You can imagine how I know this, more than once! :cool:

iWire makes the wiring easy if you don't want to mess with DIY: https://www.iwireservices.com/product-page/hybrid-maf-adapter-for-subaru

[NevaLift2Shift]

NordicSkier,
Moving the IAT sensor is very easy for me. I have a tapped hole in my AWIC. Are there any consequences if I make this change and don't get retuned?
Bob

I would strongly recommend retuning if you are moving your IAT, especially if you are replacing the factory IAT sensor in the MAF. An aftermarket IAT is going to be scaled differently and the ECU is tuned to compensate for the IAT was originally placed.

Both MAF and MAP (Speed density) requires the IAT for calculation of air density. If you move your IAT and the reading would be different, you need to retune. Even moving pre intercooler to post intercool (where it should be), a tune would be strongly advised.

I just got my '03 running on a speed density tune and a reflashed factory ECU. I installed a GM IAT right before the throttle body on my AWIC, rescaled the IAT and retuned it. I would be glad to help anyone with that.