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Discussion Starter #1
Just wondering if any member has tried to gut the stock cats and what if any the results were , Imo this seems to be the biggest restriction in the exhaust system and with the aftermarket down pipes priced at over 1200 bucks that is not a option for my budget ….
 

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I don't recommend it. But you'd have to disable the rear O2 sensors otherwise you will get an error code. It will also make your exhaust smell horrible.
 

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Just wondering if any member has tried to gut the stock cats and what if any the results were , Imo this seems to be the biggest restriction in the exhaust system and with the aftermarket down pipes priced at over 1200 bucks that is not a option for my budget ….
Based on testing by Matt @ ult. Performance, Between his catted and catless downpipes for FFS the gains were minimal. The biggest gains were from increasing pipe diameter and smoothing out the bends

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I would assume that if you took the time to take them off and gut them with a good tune you could improve power, I'm not sure how restrictive the stock dump piping is but it definitely would make some difference gutting them.
 

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My biggest concern would be the noise , when I am at the track and launch the car it seems to have a slight lag on first stab of the throttle then goes like hell , I guess my thought was if I remove the cats it would help the turbos respond faster which is what i'm looking for , I am more then happy with the power the car makes just looking for some improvement ...
 

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The 2.7 is fairly gutless below 4000 RPM. It is nowhere as torquey as the 3.5L EcoBoost. The 3.5 makes like 100 ft-lb more torque at 2700-3000 RPM than the 2.7, so you get that off-the-line grunt.
 

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Discussion Starter #7
I guess that's what i'm looking for more grunt and the only idea I thought of was to remove the stock cats to alter the spool of the stock turbos
 

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My biggest concern would be the noise , when I am at the track and launch the car it seems to have a slight lag on first stab of the throttle then goes like hell , I guess my thought was if I remove the cats it would help the turbos respond faster which is what i'm looking for , I am more then happy with the power the car makes just looking for some improvement ...
Based on my own experiences there seems to be some torque limiting safety nannies that intervene when you go 100% WOT from a stand still that cant be disabled. My guess is Ford engineers wanted to protect the transmission/ PTU from premature failure

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Based on my own experiences there seems to be some torque limiting safety nannies that intervene when you go 100% WOT from a stand still that cant be disabled. My guess is Ford engineers wanted to protect the transmission/ PTU from premature failure

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That is what I thought at first, but looking at my datalogs, my throttle plate is wide open during a launch (it's not closing) and wastegate duty cycle is 0% so it's not trying to vent anything anywhere. I looked at the VE model/torque tables and sure enough the 2.7 engine doesn't produce nearly as much torque launching as the 3.5 no matter how you cut it. My SHO had 2.77 final drive, and the Perf Package gives you 3.16 like the Police Interceptors. The Fusion Sport comes with 3.16s, probably to try and make up for the lack of low end torque.
 

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That is what I thought at first, but looking at my datalogs, my throttle plate is wide open during a launch (it's not closing) and wastegate duty cycle is 0% so it's not trying to vent anything anywhere. I looked at the VE model/torque tables and sure enough the 2.7 engine doesn't produce nearly as much torque launching as the 3.5 no matter how you cut it. My SHO had 2.77 final drive, and the Perf Package gives you 3.16 like the Police Interceptors. The Fusion Sport comes with 3.16s, probably to try and make up for the lack of low end torque.
Theres something we are missing, and the reason I suspect it is hidden safety nannies is because when I launch by rolling into throttle without just flooring the gas pedal I seem to get much better response and torque. The best 0-60 times i have recoded is using this method - this is the only way I can get all 4 tires to break loose

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When I am at the track and launch the car it seems to have a slight lag on first stab of the throttle then goes like hell , I guess my thought was if I remove the cats it would help the turbos respond faster which is what i'm looking for , I am more then happy with the power the car makes just looking for some improvement ...
Proper tuning will fix this...
 

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Top is the Fusion Sport when launching at the track, bottom is the SHO. Both are tuned. This is basically coming right off powerbraking and then going WOT. The SHO's throttle plate is actually cycling after launch while the Fusion Sport's throttle plate seems to be wide open with nothing restricting it. The torque of the SHO climbs rapidly shortly after, so it is about 100 ft-lb more torque coming off the line than the Fusion Sport. The factory VE tables reflect this drastic difference as well, so it's not being limited by anything I could detect (fuel, spark, throttle plate, boost, etc...)

26397
 

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Top is the Fusion Sport when launching at the track, bottom is the SHO. Both are tuned. This is basically coming right off powerbraking and then going WOT. The SHO's throttle plate is actually cycling after launch while the Fusion Sport's throttle plate seems to be wide open with nothing restricting it. The torque of the SHO climbs rapidly shortly after, so it is about 100 ft-lb more torque coming off the line than the Fusion Sport. The factory VE tables reflect this drastic difference as well, so it's not being limited by anything I could detect (fuel, spark, throttle plate, boost, etc...)

View attachment 26397
I guess we shouldnt be too surprised given the SHO has almost 1 whole liter of displacement advantage over the FFS

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I guess we shouldnt be too surprised given the SHO has almost 1 whole liter of displacement advantage over the FFS

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To put things in perspective, looking at both VE models the Explorer's N/A 3.5 V6 makes slightly more torque when launching than the Fusion's twin-turbo 2.7 V6. Of course the 2.7 starts to build up a lot more steam than the N/A 3.5 past 3000 RPM, but off the line I'm not that impressed with the 2.7 as it feels like "turbo lag" but I'm more convinced that it is the nature of the engine itself.
 

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Discussion Starter #15
Does any member know what the turbo psi is when brake boosting , i wonder if my methanol starting point might be low at 10 psi ?
 

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I don't recommend it. But you'd have to disable the rear O2 sensors otherwise you will get an error code. It will also make your exhaust smell horrible.
Could use these.........

 

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Top is the Fusion Sport when launching at the track, bottom is the SHO. Both are tuned. This is basically coming right off powerbraking and then going WOT. The SHO's throttle plate is actually cycling after launch while the Fusion Sport's throttle plate seems to be wide open with nothing restricting it. The torque of the SHO climbs rapidly shortly after, so it is about 100 ft-lb more torque coming off the line than the Fusion Sport. The factory VE tables reflect this drastic difference as well, so it's not being limited by anything I could detect (fuel, spark, throttle plate, boost, etc...)

View attachment 26397
I thought ecoboosts build boost faster by closing throttle very briefly to "pre-build" boost.
May not be able to do that when going WOT right off idle, from 0 MPH. Rolling in, ever
so slightly, might give the programming the time it needs to do that pre-boost.
 

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Weird thing is my Fusion Sport doesn't seem to want to build boost powerbraking but on the SHO it was able to build some boost while powerbraking. Once the Fusion Sport starts moving boost catches up very quickly.
 

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metro - can you log the awd system (or TCU) during the launch? Might be a combination of the motor output as you've highlighted, in addition to the tq converter or awd? Maybe the car while being brake boosted is anticipating wheel spin so it preloads the awd or adds slip?

Purely ancedotal - but my car feels similar even with the 3.0, in that a rolling start generally feels stronger below 3500-4000 than a WOT launch w/ brakeboosting.
 

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Funny story (long time ago) related to gutting a cat converter...had an ‘86 Bronco II, 3.8 V6, 5 speed manual; gutted the cat; if I ran the RPMs high thru 1st and 2nd gear, then threw it in 3rd with no throttle, about a second later it would fire a pop and flame out the side ‘firing’ tailpipe...scared the mess out me the first time; everyone else the 2nd and multiple times after that...🤣
 
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