Cats and tune

**karpetcm** · 11-24-2008, 10:07 PM

Im wondering, removing my cats and getting a tune would it be worth doing and would it give atleast 15rwhp. How much louder do you guys think my car will be by removing them, i have no worries on smog just curious on power and sound. Im not going to do headers for a while. The mods i have and want to have are SLP Lid, K&N filter, Smooth Bellow, TB Bypass, Exhuast cut out and Hooker muffler and 4.10's but not installed yet, thinking of deleting cats and tune.

**side2000** · 11-25-2008, 06:12 AM

you'll definately pick up some noticeable seat of the pants power w/ ORY and a tune. hell, you'd notice a substantial power gain from a tune w/o removin cats. . .it's worth doin. ORY is cheap upgrade, especially if you don't think you're gonna do anything else for a while, AND you want a tune.

**karpetcm** · 11-25-2008, 06:26 AM

Ya i figured trying to find a shop in southern cali that will keep my cats and give me a good deal removing them is another issue. They will remove them no problem and keep them but giving me a good deal is another issue i might as well just keep them and have them pull them off. Your right about the tune definitly gonna need it for the 02's and my 4.10's so within the next couple of months ill get those done.

**GatorSS** · 11-27-2008, 10:38 PM

A good tune is always worth it.

**lvbroham1** · 11-28-2008, 06:21 PM

Originally Posted by karpetcm

Ya i figured trying to find a shop in southern cali that will keep my cats and give me a good deal removing them is another issue. They will remove them no problem and keep them but giving me a good deal is another issue i might as well just keep them and have them pull them off. Your right about the tune definitly gonna need it for the 02's and my 4.10's so within the next couple of months ill get those done.

I thought running no cats in California isn't legal, or at least when they smog it they'll notice something's up?...

**Vexzer** · 11-28-2008, 07:35 PM

Only reason to reprogram the ECM after pulling the cats will be to disable the circuits and eliminate the DTC's caused by the secondary O2 sensors. The only reason the secondary O2's are there is to monitor the performance of the cats. While you're in there might as well disable the CAGS. You will gain no additional power by tuning until you change the cam or install a power adder. A tuner can make these recommendations to you over the counter and reprogram the PCM in the parking lot in about 20 minutes. There would be no need to run the car on a dyno unless you want a printout to bench race with. The printout will show that your car makes just as much power as another semi-stock SS.

**km346** · 11-28-2008, 08:49 PM

Originally Posted by Vexzer

You will gain no additional power by tuning until you change the cam or install a power adder.

This statement is completely untrue, there is plenty of power to be had with a good tune no matter what the modifications.

**side2000** · 11-29-2008, 08:40 AM

Originally Posted by km346

This statement is completely untrue, there is plenty of power to be had with a good tune no matter what the modifications.

on a completely stock car you can tune 20 extra horse easy.

**mark21742** · 11-29-2008, 09:17 AM

Originally Posted by side2000

on a completely stock car you can tune 20 extra horse easy.

+ you can see even more if you have an automatic if you disable torque managment and adjust shift points and pressure.
id recomend a tune to anyone.

dyno tune will let the tuner perfect your WOT......that can not be done in a parking lot.

**karpetcm** · 11-29-2008, 09:17 AM

Ive heard you can pull pretty good numbers on stock cars as well, i dont know about mail order tunes but even that should atleast get me 10-15rwhp atleast. I hope with the mods i have meaning No cats(soon), Hooker exhuast, SLP Lid, K&N, Smooth Bellow, TB bypass and exhuast cut out with the 4.10's(not yet installed). Im hoping with those mods i hope i can get about 320rwhp but who knows.

**mark21742** · 11-29-2008, 09:26 AM

Originally Posted by karpetcm

Ive heard you can pull pretty good numbers on stock cars as well, i dont know about mail order tunes but even that should atleast get me 10-15rwhp atleast. I hope with the mods i have meaning No cats(soon), Hooker exhuast, SLP Lid, K&N, Smooth Bellow, TB bypass and exhuast cut out with the 4.10's(not yet installed). Im hoping with those mods i hope i can get about 320rwhp but who knows.

you can run your car without a tune for awhile and not have any problems if your upgrading more anytime soon, a good tune isnt cheap.
mail order tunes are a good price and great for bolt ons like exhaust and headers and if you talk to the tuner they might beable to do bigger mods with mail order.

ive never used him but ive heard lots of good things about Frost on here from LSXtune.com

**karpetcm** · 11-29-2008, 09:33 AM

^^^ thats who i want to use for my tune so will see, i need to get these cats taken care of once i do that ill order the tune and in a couple of months ill go ahead and install my 4.10's i know my speedo will be off till i install the gears since im gonna have frost tune for the gears. Does anyone know a good rear end shop in southern california meaning glendale, pasadena, sunland, sun valley area that does a good job for a good price. I dont want to take it to Hoopers i know them well they charge 250.00 for the labor plus 20 for oil. Is there another shop thats good to take to for about the same price ?

**slpdablueZ28** · 11-30-2008, 02:55 PM

i gained 53 rwhp after a tune

**Vexzer** · 12-01-2008, 06:54 AM

Originally Posted by km346

This statement is completely untrue, there is plenty of power to be had with a good tune no matter what the modifications.

Well I guess I should have used phrases like "not much" and "You will gain [very little] additional power". I stand corrected. But my statements had to do with the value of the gains versus the cost. A tune can be expensive and my statement was mostly based on the need for tuning purely for power gains. There are settings that you can change to improve driveability and fun factor, and disabling features that would cause DTC's. Given the cost of a dyno tune, I am not sure it's worth the effort [cost] to tune for power on a relatively stock motor. What prices are you guy's finding around the country for dyno tuning? [I mean the price for real power tuning vs just power pulls like at a dyno-day.]

**Firebirdjones** · 12-01-2008, 07:20 AM

Originally Posted by Vexzer

Well I guess I should have used phrases like "not much" and "You will gain [very little] additional power". I stand corrected. But my statements had to do with the value of the gains versus the cost. A tune can be expensive and my statement was mostly based on the need for tuning purely for power gains. There are settings that you can change to improve driveability and fun factor, and disabling features that would cause DTC's. Given the cost of a dyno tune, I am not sure it's worth the effort [cost] to tune for power on a relatively stock motor. What prices are you guy's finding around the country for dyno tuning? [I mean the price for real power tuning vs just power pulls like at a dyno-day.]

I tuned my own car with HPtuner, simply using fuel trims and driving/logging on the street. On an otherwise bone stock convertable 02 SS I went from running 13.70's at 102 mph to 13.40's at 104 mph,,,,,so yea I'd say there is substantial gains to be had with even the most basic of tunes such as what I did. A good dyno tune or simply using a wideband would have pulled even more out of the car,,,as I later found out.

And for original posters information,,,I removed my cats on my otherwise stock car to experiment,,,the car ran the same,,,no gains at all. The exhaust tone wasn't even enough change to really notice, through a factory SLP CME setup. It wasn't until I later installed long tube headers and off road Y-pipe where the tone got slightly deeper,,,still nothing I would call loud at all though. It's still quite acceptable even with the top down.

With that said I wouldn't bother with removing the cats until you do a header install. For now a tune would do the trick.

**side2000** · 12-01-2008, 07:21 AM

shop by me does 500 bucks for life, as long as it's same motor/car and not every week. . . .i've seen well over twenty horse bein unlocked from a stock ls1. i guess it's up to the guy shovelin the money to decide if that's worth it. . . .i sure think it is.

**karpetcm** · 12-03-2008, 08:27 AM

Im suprised by removing the cats there are no gains, those cats are big and all the crap thats in there restricting exhuast flow, well i shouldnt say crap. I can see on the other hand that the stock cats and y have good flow for a stock manifolds or a regular bolt on car excluding headers. I think sticking with what i said above with the tune and gears i should be ok for a little while, hopefully. Maybe ill get nitrous down the road since ive done that on my 93Z. I think on my 01 ill go with 100 shot wet and do other supporting mods and i think that will cover me with plenty of power down the road.

OMGls1jz · 12-03-2008, 01:35 PM

i have a 00 ws6 and my brother's got a 99 z28 with bolt-ons. before i added my custom y-pipe with cutouts and a lid, my brother use to walk all over me. but after i bolted up my custom y-pipe and welded on my cutouts we are dead even. i welded my cutouts on to my y-pipe before it merges back to one pipe, removing my cats with a custom 3 inche y-pipe and cutouts i would say equaled LTs. i still havent got a tuned yet but i'm planning on it, i hope to make around 330-340 hp after a tune and i think its worth it.

**Vexzer** · 12-03-2008, 02:18 PM

Originally Posted by OMGls1jz

i welded my cutouts on to my y-pipe before it merges back to one pipe

What Balls! That's awesome, but kinda scares' em at the school zones 'eh?

Originally Posted by OMGls1jz

after i bolted up my custom y-pipe and welded on my cutouts we are dead even.

My Dyno printout proves a straight-up +20 HP by opening my single-exit cutout!

**side2000** · 12-03-2008, 05:11 PM

Originally Posted by karpetcm

Im suprised by removing the cats there are no gains, those cats are big and all the crap thats in there restricting exhuast flow, well i shouldnt say crap. I can see on the other hand that the stock cats and y have good flow for a stock manifolds or a regular bolt on car excluding headers. I think sticking with what i said above with the tune and gears i should be ok for a little while, hopefully. Maybe ill get nitrous down the road since ive done that on my 93Z. I think on my 01 ill go with 100 shot wet and do other supporting mods and i think that will cover me with plenty of power down the road.

you WILL untimately see more power w/o cats. but you need a tune. a tune w/ cats wont make as much power as a tune w/o cats. the cats are a restriction, just wont run good w/o tune cuz the computer wont know what to think. get the ORY and a tune you wont be disappointed.

---fact manifolds in ANY configuration is no comparison to LT's and a tune.