Who's stock cats are surviving a TVS/Whipple/KB?

nrmustang

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As the title says, who has kept their stock cats with an upgraded blower? Experiences?

The reason I ask, is i'm getting ready to install a ported Trinity TVS w/supporting mods, and am on the fence about keeping the cats on or going offroad. Now before you offroad supporters chime in, read on...

Reasons for sticking with the stock cats are as follows:

1. My tuner is 3.5 hours away, and says in order to have TWO tunes (one for cats , one for O/R), I'd have to bring both midpipes, and swap them out at the shop, and dyno each setup. More shop time=more money.
2. Not wanting to R&R the mid pipe every 2 years for California smog. And I only drive the car 5k a year - maybe, and just street driving.

If it was as easy as just writing two tunes without the shop & extra dyno time, it'd be a no-brainer. So I'm leaning more towards sticking with the stock cats. So for you guys that kept the stock cats, what say you?

Thanks
 
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Speedboosted

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Clogged cat is much more trouble than swapping them on/off every couple years. Blown motor or a an hour or so every two years of laying on your back changing the mid pipe? Sounds like an easy choice to me
 

nrmustang

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Clogged cat is much more trouble than swapping them on/off every couple years. Blown motor or a an hour or so every two years of laying on your back changing the mid pipe? Sounds like an easy choice to me

Thanks for your input. Are you running a swapped blower as I asked? And again, it's not as simple as swapping mid-pipes every two years. We're talking basically 2 dyno sessions to make that happen.
 

Booky

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I have been running a 2.3 TVS for almost 2 years (approx. 20K miles) and have no problems with the stock cats. My exhaust is all OEM except for Pype Bomb axle backs.

With a good tune you should not have any problems with just a simple TVS swap and supporting mods.
 

Black Sex

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I had my converters warrantied at roughly 3K mile IIRC. That was just before my TVS swap. After the swap I hollowed out those brand new converters
 

GT Premi

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I've been running my 2.9 Whipple and stock cats/exhaust coming up on 5 years now and 37K miles. As far as I know, my cats are perfectly fine. I installed some Corsa mufflers in the Spring of last year.
 

nrmustang

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Thanks for the input! I'm feeling much better about possibly going that route. Thanks guys, keep it coming! Also, power levels with stock cats would be nice. How much are you putting out? And how do you drive it? (90/10 street/strip for example)

Thanks again!
 

usmc_mustang

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Mine did not last. My car started detonating a few months after the TVS swap. Recently changed to an off road H and all is good now. Your boost will tell the tale...I ended up making 18.6 lbs on a 2013 TVS with a 2.6....higher than the norm for that set up, which led us to the cats. Seems to be hit or miss.
 
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GT Premi

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Thanks for the input! I'm feeling much better about possibly going that route. Thanks guys, keep it coming! Also, power levels with stock cats would be nice. How much are you putting out? And how do you drive it? (90/10 street/strip for example)

Thanks again!

Mine is all street driving. I prefer twisties over the 1/4. Zero drag strip duty for my car. I do hammer it on the on-ramps, though. I haven't had it back on a dyno since the VMP tune and Killer Chiller, so I'll just say it's 650+RWHP.
 

nxhappy

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I am running catless. Yes it's a PITA when you have to swap .....but it's worth it.

The system flows much better without the cats. With the stock cats, fuel is being dumped it order to cool them (cat protection). Because of this fuel dump, you lose power. With the H-pipe you should gain about 10-15 whp up top.
 

Speedboosted

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Thanks for your input. Are you running a swapped blower as I asked? And again, it's not as simple as swapping mid-pipes every two years. We're talking basically 2 dyno sessions to make that happen.

Yes, TVS on 17 pounds. Why can't your tuner just load both tunes to your handheld? Unless you're saying that it's two tunes initially, then I understand. But also why couldn't he just turn off over cat protection and the sensors?
 

nrmustang

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Yes, TVS on 17 pounds. Why can't your tuner just load both tunes to your handheld? Unless you're saying that it's two tunes initially, then I understand. But also why couldn't he just turn off over cat protection and the sensors?

That's exactly what I was wondering. And that's what I want. But in emailing my tuner back and forth, it doesn't sound like it's that easy.

I spoke to him yesterday, and he suggested dyno tuning with the O/R pipe on. And every two years swapping in the stock pipe, but staying out of boost until I can smog it. That's what I did with my Terminator he tuned, but I had a Magnaflow high flow cat-pipe. So keeping the rear 02's on was ok. So without him clearly telling me that he's going to keep the rear 02's on in the tune, I'm assuming that's what he's going to do. Otherwise, how would that tune pass smog?

So he's making me feel more comfortable about going O/R, but I still won't be able to actually run the stock mid pipe if I wanted to.

So this brings me to my next point. I have the Flowmaster Force II axle back system that I really do like. Nice and throaty, little to no drone. And after 12+ muscle cars and a muscle truck (Dakota R/T) :burnout: over the years, that's what I want. I bought a Lethal O/R H, and want to swap it out before the dyno tune, and drive it around for a while to see if i'll be ok with the sound/possible drone. I know i'll get a check engine light, but will it hurt the motor if I run it like that for a couple weeks?
 
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nxhappy

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Flows with the lethal H.....it's gonna be nascar loud LOL.....be prepared to buy some stock mufflers, if you don't already have them

ask me how I know :)
 

nrmustang

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Yeah, I know the American Thunder is too loud. I had a similar setup on my G8, and I felt like shooting myself in the head after a trip down the highway. But I've had the Force II on one of my Foxes with an O/R H and it had ZERO drone. But even though it says "Force II", they are different mufflers. My 5.0 had 3 chamber Delta Flows and this kit has 60 series. But I'm hoping for little to no drone.

What Flowmaster kit did you have?
 

SCGallo2

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Still running original cats, 33k miles, 680ish rwhp, 17-18psi boost, had 3 custom tunes on the car. Ran road course, auto-cross, 25 or so drag strip passes, and I drive it hard, 95% street/5% track... cats are holding up fine. Had the mid-pipe off over the winter to install a wideband O2 sensor and had the chance to inspect them. If you are worried about them collapsing and blowing your engine, install an Aeroforce Interceptor and monitor boost and AFR so you are aware if the boost spikes and it starts to go lean. My AFR is 11.0 at WOT and it seems to keep the cats cool enough.
 

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