Cat guts removal
- Thread starter Don W.
- Start date
killerrudy
New member
Re: Cat guts removal
I thought that the saying went, "Whats the best way to skin a cat?"
I thought that the saying went, "Whats the best way to skin a cat?"
Don W.
Stab it and steer it
Re: Cat guts removal
Well that was easy. Most of the cat fell out when I took it out. Now when I punch it it misses. I think the motor is finally breathing correctly and I've got real cyl pressure so I'm blowing the spark out. I was gonna pull the plugs anyway so this will be good.
Well that was easy. Most of the cat fell out when I took it out. Now when I punch it it misses. I think the motor is finally breathing correctly and I've got real cyl pressure so I'm blowing the spark out. I was gonna pull the plugs anyway so this will be good.
Osmosis
New member
Re: Cat guts removal
Don,
Sorry, I may be a bit late. Instead of gutting the cat, U can got to autozone/shucks..what ever and get a 12 inch pipe with a flange on each end, cut the cat off and put the new pipe in place of the cat. This way, if you ever need a cat...say emmissions, you can strap it on and your good....that's what I did. I actually put a Y with a electronic dump. I kept my cat just incase my county started emmissions testing
Don,
Sorry, I may be a bit late. Instead of gutting the cat, U can got to autozone/shucks..what ever and get a 12 inch pipe with a flange on each end, cut the cat off and put the new pipe in place of the cat. This way, if you ever need a cat...say emmissions, you can strap it on and your good....that's what I did. I actually put a Y with a electronic dump. I kept my cat just incase my county started emmissions testing
Don W.
Stab it and steer it
Re: Cat guts removal
Nope. Turbo is a 60-1 compressor side on a stock but clipped turbine side, runs a nice even 20# at WOT. Whats happened though is motor is now missing at WOT. I narrowed the plug gap to .026 and it got worse?? Gonna go back to a wider gap and see what happens.
Nope. Turbo is a 60-1 compressor side on a stock but clipped turbine side, runs a nice even 20# at WOT. Whats happened though is motor is now missing at WOT. I narrowed the plug gap to .026 and it got worse?? Gonna go back to a wider gap and see what happens.
WyoSyclone
Active member
Re: Cat guts removal
I'll be anxious to see what you find on this one, Don.... I'm sitting here scratching my head.
Are your AFR's the same?? Maybe the scavenging is better and one injector is a little weak?? :dunno:
I'll be anxious to see what you find on this one, Don.... I'm sitting here scratching my head.
Are your AFR's the same?? Maybe the scavenging is better and one injector is a little weak?? :dunno:
Ty_Guy
Banned
Re: Cat guts removal
I think your best bet is to run a straight through pipe when u don't want to run a cat.
I have a cat that i swap out when I'm done doing an emissions test.
So i just do a quick unbolt of the cat then stick the straight through pipe in it's place.
Both have a three bolt flange on either side, nobody ever looks under the truck so.....
Just measure the pipes the same length then u can easily swap them as needed.
Thought I would share what has worked for me.
I think your best bet is to run a straight through pipe when u don't want to run a cat.
I have a cat that i swap out when I'm done doing an emissions test.
So i just do a quick unbolt of the cat then stick the straight through pipe in it's place.
Both have a three bolt flange on either side, nobody ever looks under the truck so.....
Just measure the pipes the same length then u can easily swap them as needed.
Thought I would share what has worked for me.
Don W.
Stab it and steer it
Re: Cat guts removal
My AFR goes to 10.0 and just sits there when I'm under boost. Don't know if that, by itself is good or bad. Close to what it supposed to be but it doesn't vary at all.
Anyway, when I pulled the plugs I found 2 cracked insulators. No way to know if I did it taking them out or putting them in. Anyway, put the1 hotter plug in #6, replace the 2 cracked ones, and gaped them all to a slightly loose .035. So they are prolly actually .036. Anyway went out to my "test" road and the truck is pulling better than it ever has. DM's 1/4 calculator says I did the 1/4 in under 12. We'll see about that on Wed..
Getting a fair amount of difference between what my boost gauge says and what DM says. 2-3 pounds, which seems like a lot to me.
My AFR goes to 10.0 and just sits there when I'm under boost. Don't know if that, by itself is good or bad. Close to what it supposed to be but it doesn't vary at all.
Anyway, when I pulled the plugs I found 2 cracked insulators. No way to know if I did it taking them out or putting them in. Anyway, put the1 hotter plug in #6, replace the 2 cracked ones, and gaped them all to a slightly loose .035. So they are prolly actually .036. Anyway went out to my "test" road and the truck is pulling better than it ever has. DM's 1/4 calculator says I did the 1/4 in under 12. We'll see about that on Wed..
Getting a fair amount of difference between what my boost gauge says and what DM says. 2-3 pounds, which seems like a lot to me.
WyoSyclone
Active member
Re: Cat guts removal
10.0 seems pretty rich, but it's just a matter of what your truck likes. Could try taking it a tad leaner if your KR doesn't increase... maybe pick up a few tenths.
Isn't that weird about the plug gap.... amazing how these trucks all respond differently to the same mod/adjustment. Wonder if the possible rich condition is quenching the spark a bit at the tighter gap?
2 to 3 lbs diff seems like quite a bit. Maybe check for a bit of a loose/bad ground on your boost gauge?
I sure like reading your threads/post, Don. Seems I always rethink something, or learn something a bit new from them
10.0 seems pretty rich, but it's just a matter of what your truck likes. Could try taking it a tad leaner if your KR doesn't increase... maybe pick up a few tenths.
Isn't that weird about the plug gap.... amazing how these trucks all respond differently to the same mod/adjustment. Wonder if the possible rich condition is quenching the spark a bit at the tighter gap?
2 to 3 lbs diff seems like quite a bit. Maybe check for a bit of a loose/bad ground on your boost gauge?
I sure like reading your threads/post, Don. Seems I always rethink something, or learn something a bit new from them
Don W.
Stab it and steer it
Re: Cat guts removal
Thanks.
FYI The boost gauge is mechanical. Ya, I thought it was rich also. Thinking I might lower fuel pressure a bit and see what happens.
10.0 seems pretty rich, but it's just a matter of what your truck likes. Could try taking it a tad leaner if your KR doesn't increase... maybe pick up a few tenths.
Isn't that weird about the plug gap.... amazing how these trucks all respond differently to the same mod/adjustment. Wonder if the possible rich condition is quenching the spark a bit at the tighter gap?
2 to 3 lbs diff seems like quite a bit. Maybe check for a bit of a loose/bad ground on your boost gauge?
I sure like reading your threads/post, Don. Seems I always rethink something, or learn something a bit new from them
Thanks.
FYI The boost gauge is mechanical. Ya, I thought it was rich also. Thinking I might lower fuel pressure a bit and see what happens.
It's just a six
Super Member
Re: Cat guts removal
I would think your Sy would run w/more top end pull if you had a larger turbine wheel.,& larger turbine housing,,:2cents: It's still a 8 CM turbine housing?
I run .035 gap w/an MSD 6A box, no spark blow out,but I also do not use a lot of meth or a lot of boost.
Goodluck @ the track!!:tup:
On the boost gauge,it could not be reading correctly. Might want to compare it to a know good pressure gage ,or send it out for calibration if they can?????
I would think your Sy would run w/more top end pull if you had a larger turbine wheel.,& larger turbine housing,,:2cents: It's still a 8 CM turbine housing?
I run .035 gap w/an MSD 6A box, no spark blow out,but I also do not use a lot of meth or a lot of boost.
Goodluck @ the track!!:tup:
On the boost gauge,it could not be reading correctly. Might want to compare it to a know good pressure gage ,or send it out for calibration if they can?????
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Don W.
Stab it and steer it
Re: Cat guts removal
MSD here also. I'd prolly change the turbine housing if I could find one. I was thinking of how I might check the gauge and other than replacing the thing haven't come up with anything.
MSD here also. I'd prolly change the turbine housing if I could find one. I was thinking of how I might check the gauge and other than replacing the thing haven't come up with anything.
WyoSyclone
Active member
Re: Cat guts removal
DUH, yes of course it is I've been fighting all the gauges in my Sy reading low, and found they all kind of corrected themselves when I went through and cleaned all the grounds... my mind was still in that mode.
I would almost think that you could rig up a small test rig with an air tank and a wide sweep tire (0 to 30psi) gauge, with the boost gauge tee'd in. Of course it wouldn't be 'calibrated', but it could at least show you if you were within a 1/2lb, or so, of the tire gauge.
What chip are you running? edit... I see RPM... maybe call Mike.
DUH, yes of course it is
I've been fighting all the gauges in my Sy reading low, and found they all kind of corrected themselves when I went through and cleaned all the grounds... my mind was still in that mode.I would almost think that you could rig up a small test rig with an air tank and a wide sweep tire (0 to 30psi) gauge, with the boost gauge tee'd in. Of course it wouldn't be 'calibrated', but it could at least show you if you were within a 1/2lb, or so, of the tire gauge.
What chip are you running? edit... I see RPM... maybe call Mike.
Don W.
Stab it and steer it
Re: Cat guts removal
Geez, that's worse than road kill...
Cat ripped and gutted. You asked.
Geez, that's worse than road kill...
Nitrous
New member
Re: Cat guts removal
I know alot of guys like to remove or gut a cat for stricly race vehicles but you can keep your truck emmisions legal with a Random Technology Metal Matrix cat and keep the HP numbers where they need to be. I dynoed my 97 GMC LS6 without the cats and then installed a set of Random Tech Metal Matrix cats and there was no change in HP or torque and I didn't have to smell unburnt gas anymore. I know Dave over at Random if anyone's interested in a group purchase. They're pricey but worth it when you want to keep CFM's flowing. Here's the Sy/Ty part number 192-25009 but you can go universal with this one if you like 141-30000- 3" inlet/outlet. There's also 151-40000- 4" inlet/outlet. Just thought I'd add this to the thread.
I know alot of guys like to remove or gut a cat for stricly race vehicles but you can keep your truck emmisions legal with a Random Technology Metal Matrix cat and keep the HP numbers where they need to be. I dynoed my 97 GMC LS6 without the cats and then installed a set of Random Tech Metal Matrix cats and there was no change in HP or torque and I didn't have to smell unburnt gas anymore. I know Dave over at Random if anyone's interested in a group purchase. They're pricey but worth it when you want to keep CFM's flowing. Here's the Sy/Ty part number 192-25009 but you can go universal with this one if you like 141-30000- 3" inlet/outlet. There's also 151-40000- 4" inlet/outlet. Just thought I'd add this to the thread.