Impact Wrench Recommendations
 

For those of you that have home shops with an impact wrench, what CFM and torque ratings do you recommend? I just bought a compressor with a 3.2CFM @ 90PSI rating for interior trim work, but am now tempted to get something that would be usable with an impact wrench for working on the car. It looks like that at 3CFM the tools provide ~200 ft/lbs of torque.

And, yes, I realize that I should be careful with an impact wrench. This would mostly be for taking things off or doing an initial tightening. A torque wrench would be used to bring things into final spec.

Look into electric impact wrenches if you don't really want to replace your compressor. I have a Kobalt electric and am very happy with it.

for smaller work the cordless dewalts work wonderfully. :p

I have a Makita impact driver that I can use for the smaller stuff. Also, I was looking at the pneumatic ones since the unit is smaller and you can get it into tighter spots without having to resort to an extension. I'll take a look at how big the other electrics are though.

The one downside to the Kobalt certainly is the size. It's a big gun. The Dewalt one that was at Lowe's is a good bit smaller (though about $50 more ).

when i was installing my suspension i got the best I could find at Home Depot (Husky) for my air compressor, and right off the bat, even after being oiled, it was leaking and couldn't move the suspension bolt holding the shock in place. I then returned it, went to sears, and got a nice Ingersoll Rand impact driver, and i never looked back. The thing is a beast. Be weary of the marketed numbers, the one at home depot was supposedly a 600ft lbs driver, that couldn't move a supposedly 90 ft-lbs bolt. My 550 ft-lbs IR impact has conquered everything i've thrown at it so far, and its quiet to boot.

I've become a big fan of McMaster Carr. They sell just about ANYTHING you could ever want with respect to tools, fittings, fasteners, bolts, taps, etc etc etc. Excellent quality too. Hell, they just saved my butt when I picked up a 1 1/16" crowfoot wrench this weekend. And I may be getting a 7/8"-14 tap to fix a fitting...good luck finding those at Home Depot, Sears, or Lowes :)

That sucks. Maybe yours was an unlucky random bad one... I bought a $100 Husky that has served me well... took off a few stubborn crank pulley bolts off a few Hondas that my big giant DeWalt electric impact could not take off.

But since you have an Ingersoll Rand, even nicer! :tup:

from looking at the electric impact wrenches, online, i can't seen to find how to change the torque setting. where is this setting located on the dewalt/kobalt

On my DeWalt, i didn't think there was one...

thats weird. How do you make sure you don't overtorque something?

You can use torque sticks or estimate the torque by a graph that's usually available in a manual. It shows time vs. applied torque. So you can just tap it for a second or so. It's far from accurate however.

Ideally though you'd use an impact wrench for removal and a torque wrench for tightening. With a torque wrench you can set it to the desired ft/lbs and just rotate until it clicks.

That said, most people just zap it with the impact wrench and call it a day.

yea, i have a torque wrench. I guess i could just use that for the final tightening

Harbor Freight had some electric Impact Gun on sale for ~$50
Rated at 240 ft/lb

FYI, I bought an electric DeWalt at Lowe's last week for 299. It comes with 2 18v batteries, but they are having a special where you get a 3rd battery for free. The batteries are 89 each, so its quite a deal.

not a big fan of electric guns..not enough torque imo...most shop guys i know prefer the IR's..

I've got an air one too, but the electric is awesome trackside for tire swaps.

The electric ones are obviously going to be larger than the pneumatic ones. However, what bolts require >150 ft/lbs of torque on the Z? Prior to purchasing my Makita (rated at 260 ft/lbs) I didn't find anything above that number in the manual. I did just check bolt specs for the CBE, suspension, wheels, and anything related to front-end work (front strut tower, end links, mass dampener, etc.).

You do know you need more torque to take something off vs putting it back on right?

taking off the strut would probably require quiet a bit of force

Agreed. I usually use the impact if there's a stubborn nut/bolt, but for the tightening, just a normal wrench and then tighten to spec with the appropriate torque wrench.

Fair enough. My comment was aimed at questioning the upper bound of how much torque you need for an impact wrench. If a bolt is rated at 150 ft/lbs, then having 2x that amount on the tool seams reasonable.

If an electric impact wrench won't cut it, that's why they make $20 breaker bars.