For those who have done the explorer intake swap, what size drill bit did you use? Also what size tap? I hope to work on my intake this weekend. Thanks for the help...Ray.
Act is 3/8 NPT. Drill is 37/64 but may be hard to find. 9/16 will do the trick.
John
Centerpunch and pilot hole, for real. Mine's off center a little, and it annoys me whenever I think about it. Hope you're working with a 96 or 97 lower, the later ones don't have a flat boss where the ACT goes. Also, while you're drilling and tapping, you should consider opening the coolant port for the EGR cooler, it's there on the Explorer intake, but like the ACT, it's just a flat boss, so you're left with a return fitting on the coolant manifold, but no coolant feed. I don't recall the drill size, but I'm pretty sure the tap was 1/8 NPT.
+1 on center punching before drilling. Also drill a smaller pilot hole before drilling the 9/16" final hole.
I'm thinking of this swap - what is this "ACT", and is it required with the swap?
Air Charge Temp, and most definitely yes, you need it.
Ugg, why can't anything be a bolt-in for our cars?! I'm assuming we can use the stock ACT for our cars, correct?
Yes. You can use the stock ACT. All you're doing on the Explorer intake is making a place to put that sensor. It's really not hard to do. Don't overthink it. I used about four or five drill bits to make the hole. I started with the pilot hole then gradually moved up with the bits. Made it a smoother operation for me. Easy stuff. Use cutting fluid when you are cutting the threads (tapping) in the intake and make sure all of the metal shavings are cleaned out. It's actually like a 5 minute job.
Thanks for the info - I also found a youtube video that made it seem more manageable. On the youtube video, they also bored out a coolant hose line towards the back of the lower intake manifold, which connects to the throttle body. Did you also bore this hole out, or is it not necessary?
Also, overall, how would everyone rate the power/torque gain that you get with the explorer intake? I have a mild built motor (bored .040, F303 cam). I've read that with some of the aftermarket intakes you get a loss of low-end torque, and I'd rather not do the swap if that is the same with the explorer intake.
Thanks!
You won't lose torque. The intake is the bigfest restriction on these motors once you've done a h.o. swap. More so on the lower.
Some of the aftermarket intakes give up runner length and plenum volume for max horsepower, the GT40 doesn't. Even with all that's available, the GT40 is still one of the best "all around" intakes in terms of torque vs RPM. After all, Horsepower isn't real, it's the result of a calculation (which is why torque and HP are always equal at 5750rpm).
Is that for all explorer intakes, I haven't heard that one before.... Please share.
All of them. On the HO lower, the front nipple for the EGR cooler is in the coolant tubes that run down that side of the intake, but the feed fitting is in the intake toward the rear. On GT40 intakes, this is not drilled and tapped, but it is there as a flat spot.