Just to make sure I'm parsing that correctly: You changed only the cat to shave off three-tenths, and it wasn't the partially plugged original before the swap?

Thanks in advance for indulging my curiosity.

 

^ thats correct sort of lol

Before the oem cat started to affect ets lets say I was running 15.0 on avg.
As oem cat started plugging my last time at the track it had slowed to 15.15
Fresh h/f cat, ran 14.68 which was .32 faster than the avg prior to plugging or .47 faster than last time out.

Hope that makes sense

Edit, btw, dont expect the same gains with a 5.2 they seldom respond like a 5.9 does but there is still potential gains to be had
FYI, Ive taken my Indy down the 1/4m well over 1000x

 

Perfect sense. I wasn't expecting so dramatic an improvement, so now I'm even more eager to get the cat and Gibson cat-back on there. Woohoo!

Thanks for clarifying things, RM_Indy!

 

Do you have to get etested?
If no, straight pipe it for even more gains.

After the h/f swap I found out I had debris in my chambered catback so I yanked it(1.5yrs old ughh)
Magnaflow 3" glasspack added with 3" side exit ahead of the axle. Went with it cause its straight through (combined sound = wicked)
20k miles or so later h/f #1 collapsed.
While driving all of a sudden it sounded like a jet so I let off then nailed it.
Shot the debris right out the side exit(hit car driving beside me).
Upon returning to the track again I gained a further .15 (avg prior to ets slowing again)
Cat deleted altogether I bet I would of seen .6 better et over oem cat before it started to fail.
This is at low race wt so dont expect quite as dramatic a result

BTW, the cat collapsed & shot out the side exit 5days after passing an etest.(wasnt sure if it would pass)

Moral of the story?
Cats suck hp big time & dont drive beside an Indy with loud exhaust lmao

 

Yep. Otherwise I'd pitch the cat because it's a fire hazard and just something else to go wrong.

Oh heck no. My truck's getting heavier as time goes on rather than lighter. But the only significant weight adder from here on out will be the Buckstop Outback bumper and winch inside it.

The reduced quarter time you report, though, is probably in the neighborhood of 20RWHP or a tad better, wouldn't ya think?

I don't drive beside anything with a loud exhaust except when I absolutely have to. Same for bonehead bass thumpers whose hearing will be worse than mine when they're my age. If I wanted that much noise in the cab I'd have kept the second wife around.

I'm a bit concerned now about the new cat. I really don't want to have to fool around with it for another 100k once it's on.

 

Indy,

I don't have to get e-tested where I am. would taking the cat out entirely kill towing?

BTW, I have 3 cats because i bought the truck in Cali. I live in Arkansas now, so I don't need any smog tests anymore.

--dan

 

URU
59k miles fried 3 cats(2h/f), 1/2 way through the 4th when I yanked my exh.
As hp goes up, cat lifespan goes down.
Running 1/4m passes with cold motor, pushing 5400rpm shifts (5.9-6k rpm now))
As well as driving back roads doing testing n practise I drop cats 10x faster than normal so no worries

Yes, probably close to 20rwhp gained

CPT, with 3 cats Im thinking youve taken a HUGE hp/trq hit.
Dropping all those cats plus the fact you have some decent mods, think it would be a win/win senario.

 

A little OT,
Anyone besides pacesetter make a Y pipe to replace the factory Y in a 2001 fed emmissions?
I had heard the pacesetter Y pipe isn't very good. My cat is a magnaflow 3" si/so.

Wondering myself how much I might be losing to that stock Y with my current configuration.

 

Gotta get you a "Hurt Me Baby" sticker for your accelerator pedal.

Not bad at all.

Thanks for the insight!

 

i have the cat that can never mess up