Tips on tightening down v-clamp on downpipe and turbo?

GreatShamanGT · 11-18-2008, 12:34 PM

Hey guys,

Got a little dilemma. I need to get my car inspected, but I have an exhaust leak right now between the turbo and the downpipe. I think it's because my v-clamp isn't down tight enough. I've tried to muscle it in tightly, but it still doesn't seem to work. I'm afraid that I'll get boost creep while I'm boosting, so I want to fix it asap.

Can someone give me some tips on getting it completely clamped down?

proz07 · 11-18-2008, 11:45 PM

To get a v-band tightened down you need to tighten it a bit then tap around the clamp with a hammer to recenter the clamp you will feel it looser when you go to start tightening it again repeat to desired torque. i believe a v-band 2.5-5" is about 95inlb but i know i crank mine down more than that as they get wore out(the v expands). reason being for the recenter is your really only tightening one side of the clamp at a time. hope this helps you.

i also found this on rx7club that a guy was using this material as a gasket.

http://www.phelpsweb.thomasregister....5/phel3_12.htm
7club thread http://www.rx7club.com/showthread.php?t=467421

although the correct gasket for a v-band is a spiral wound metal crush gasket(1 time use only) but im not going to search for it you can if you want. we use them on aircraft v-bands that hold upwards of 150+ psi 600f

z

proz07 · 11-18-2008, 11:55 PM

i should also add you shouldnt need a gasket in that location as there is no real pressure to speak of in that location (post turbo) but if your flange is warped you may need one.

i have 2 v-band clamps NO GASKETS on my 4-in exhaust currently with no leakage although i made sure that one of the pipes slips into the other band flange by a minimum 1/4in to help in sealing.

z

cewrx7r1 · 11-19-2008, 12:06 AM

If alignment is off, then it might be imposible to tighten enough to seal properly.
When ever I dismantle and have to re-assemble fasteners like this, it is best to lubricate the lips of the pipes and inside the "V" of the clamp. This helps the parts to slip together under compression. Then go drive and burn the lubbricant off.

IR Performance · 11-29-2008, 10:57 AM

V bands almost always leak a little bit in my experiences. I normally have someone hold the dp from underneath the car while I compress the vband with a big pair of channel lock pliers, and then tighten the nut down. The lubricant helps me as well. If the flanges are warped you might have to have them faced by a machine shop. I have also seem different style vbands where the pipes are slightly tapered to fit into each other. I have yet to see anyone use those on an rx-7 however.

proz07 · 11-30-2008, 04:00 AM

hmmm well when i get back state side i may take some pictures how mine are as well as a type of gasket that will seal it with no leaks if done correctly.

z

11-18-2008, 12:34 PM	#1
GreatShamanGT Rotary Fan in Training Join Date: May 2008 Posts: 99 Rep Power: 17	Tips on tightening down v-clamp on downpipe and turbo? Hey guys, Got a little dilemma. I need to get my car inspected, but I have an exhaust leak right now between the turbo and the downpipe. I think it's because my v-clamp isn't down tight enough. I've tried to muscle it in tightly, but it still doesn't seem to work. I'm afraid that I'll get boost creep while I'm boosting, so I want to fix it asap. Can someone give me some tips on getting it completely clamped down?

11-29-2008, 10:57 AM	#5
IR Performance Rotary Fanatic Join Date: Feb 2008 Location: Metuchen, NJ Posts: 249 Rep Power: 18	V bands almost always leak a little bit in my experiences. I normally have someone hold the dp from underneath the car while I compress the vband with a big pair of channel lock pliers, and then tighten the nut down. The lubricant helps me as well. If the flanges are warped you might have to have them faced by a machine shop. I have also seem different style vbands where the pipes are slightly tapered to fit into each other. I have yet to see anyone use those on an rx-7 however. __________________ Providing rotary engine rebuilds, porting, turbo installs, parts installations, full maintenance, etc. We work on all cars. www.irperformance.com www.myspace.com/rotaryexperimentseven irperformance@live.com 732-662-1794

11-18-2008, 11:45 PM	#2
proz07 Needing a new tow rig. Join Date: Mar 2008 Location: AR Posts: 245 Rep Power: 18	To get a v-band tightened down you need to tighten it a bit then tap around the clamp with a hammer to recenter the clamp you will feel it looser when you go to start tightening it again repeat to desired torque. i believe a v-band 2.5-5" is about 95inlb but i know i crank mine down more than that as they get wore out(the v expands). reason being for the recenter is your really only tightening one side of the clamp at a time. hope this helps you. i also found this on rx7club that a guy was using this material as a gasket. http://www.phelpsweb.thomasregister....5/phel3_12.htm 7club thread http://www.rx7club.com/showthread.php?t=467421 although the correct gasket for a v-band is a spiral wound metal crush gasket(1 time use only) but im not going to search for it you can if you want. we use them on aircraft v-bands that hold upwards of 150+ psi 600f z

11-18-2008, 11:55 PM	#3
proz07 Needing a new tow rig. Join Date: Mar 2008 Location: AR Posts: 245 Rep Power: 18	i should also add you shouldnt need a gasket in that location as there is no real pressure to speak of in that location (post turbo) but if your flange is warped you may need one. i have 2 v-band clamps NO GASKETS on my 4-in exhaust currently with no leakage although i made sure that one of the pipes slips into the other band flange by a minimum 1/4in to help in sealing. z

11-19-2008, 12:06 AM	#4
cewrx7r1 The Judge Join Date: Feb 2008 Posts: 196 Rep Power: 18	If alignment is off, then it might be imposible to tighten enough to seal properly. When ever I dismantle and have to re-assemble fasteners like this, it is best to lubricate the lips of the pipes and inside the "V" of the clamp. This helps the parts to slip together under compression. Then go drive and burn the lubbricant off.

11-30-2008, 04:00 AM	#6
proz07 Needing a new tow rig. Join Date: Mar 2008 Location: AR Posts: 245 Rep Power: 18	hmmm well when i get back state side i may take some pictures how mine are as well as a type of gasket that will seal it with no leaks if done correctly. z