SCT/BB catless/Dyno Results

[Viper Beau]

I wanted to show you guys the install pics of my BB catless mids to a Magnaflow muffler in case anyone should go this route. Also had a couple of questions to follow below that I hope you guys can comment on:

Here are a couple of pics of the install done by SR Performance in Tampa. I was pleased with the work they did:

Nice clean SS to rusty stock headers


Had an extra bung welded in for a wideband O2 sensor



This is where the difficulty is. BB catless normally end vertical and the Magnaflow inlets are horizontal. They did a good job getting them lined up and solid as a rock.


Finally, no exhaust heat on the rear axle and melted brake lines. Maybe even some sweet burnouts.


Nice SS, for now anyway.

I had them do a series of 3 Dyno pulls to see what the mods actually did. My baseline pull with stock cats resulted in 426rwhp, very typical of our trucks from what I read. 2nd pull after the cat delete dropped 15rwhp Not exactly what I was expecting since most claim a 15rwhp increase with cat delete. I wanted to see if some of you guys could comment on what you think is the problem. My thoughts 1. maybe the ecu was having difficulty figuring things out after the cat delete:dontknow: , doubt it. 2. back pressure issue. I read somewhere that our motors needs some back pressure to run right. Not sure either way. A nitrous install will follow later on this year so not worried about it just yet.

Now for the good news:



I was able to get in on the SCT group buy that Stinker and Torrie lined up recently. I had Torrie upload just one peformance tune with rear cat O2 turn off. The other 2 tunes will wait for the nitrous install. Torrie's tune jumped the torque numbers quit a bit more than I expected at 493 ft lbs and the hp came back to 431rwhp. I have to say the tune saved the day and my bad mood from the cat delete results. Even the guy at the shop was impressed with the torque increase, around 80 ft lbs from the cat delete alone.

I will say that anyone wanting to do a catless midpipe setup should definitely follow it up with a tune. I didn't expect in to drop hp.

I have to give a shout out to Stinker and Torrie for setting up an awesome SCT deal and an awesome SCT tune. :rock: :rock: :rock:

 

[ZCx]

sweet:rock: :rock: :rock: :burnout: :burnout: :burnout:

 

[JTS VENOM PERFORMANCE]

dont make alot of sense really

most everyone gains hp when dropping the cats, but too , if you ever get a chance , catch torrie when he is doing dyno tuning, and see how different the tune is when done on a dyno and not mail order deal,

what does the air fuel say?

but trq numbers went out of the window tho that is tire ripping trq bro

and that stainless looks sweet!

 

[Fireracer27]

Biggest difference I could feel by the seat of my pants & sounds was when I put in a cross pipe. It pulls harder now.

I put the Magnaflows on and drove it for a couple of days, not that noticable.
Cut the 2 back cats off and welded in dumps. drove it around for a couple of days, again very little difference.
Installed the H pipe. Big difference, can really feel it on the big end and throughout all the gears.
It made mine a little more Quiet than I wanted and it killed the truck sounding like Steve McQueen's Mustang in Bullitt when I shifted. It still sounds that way, just not as loud.

 

[mauiSRT/10]

Biggest thing I noticed when I got my catless mids was how the throttle response was so much better. Yeah the truck seemed to pull harder but throttle repsonse was awesome.

patrick

 

[Viper Beau]

Tony,

I did basic dyno pulls, just hp and torque, no a/f. I will make a trip to see Torrie when I get the nitrous kit installed. I was ready until Trick Performance ran into a manufacturing issue with the P and V gauges. A piece that was being made was dropped from the manufacturing process and now they have to find a new manufacturer. Anyone have a Trick P and V gauge they want to sell?
My clutch will have to be before that anyway. Tony can you PM me price for a SPEC stage 3+? Probably need a new flywheel but nothing light weight. Should I go OEM or can you suggest an aftermarket one. Are you set up for cryogenics. I'd get some spider gears cryod from you if you can freeze them. I want to beat the crap out of the clutch with the nitrous and not have to worry about it.

 

[JTS VENOM PERFORMANCE]

yessir we can cryo the spiders, and get you a killer deal on the spec too

I will shoot you a pm later this evening buddy

 

[rottenronnie]

I've seen that here as well.
Going catless does "something" to the flow and requires a re-tune.

 

[Viper Beau]

RottenRonnie,

Thanks for the comment. I was hoping you would chime in as I have read several of your commments and posts in the past. Glad to know that I am not the only one having experienced this hp drop with a catless setup. Once I get over to Torrie's sometime in the near future, I'll have him mess with the tune to see if he can get the hp back up. Even with his tune, I am only getting 5hp increase over stock with cats. Something should be able to be done with that.
My question Ronnie is if a cam upgrade would help out with this in some way. If it is a backpressure issues, will a different cam set up help with that. Bear in mind, that at some point this year I will install my nitrous kit with a 150 shot. After reading some post by you, Stinker, and others I felt that a cam upgrade was not really necessary for a 150 shot, ie. cost vs. reward. Now that I have this catless hp drop I am not so sure. Perhaps a cam upgrade would help and I wanted to get your thoughts if you had time.
Thanks

 

[JTS VENOM PERFORMANCE]

ronnie is like the walmart of knowledge bro

get him to design you a custom cam set up and we can get it done,:elefant:

I will get back to ya on the other things , right now trying to finish up the bling and freaking grass cuttin LOL dang belt blew off the deere:toilet: :toilet: