Cat Delete with Whipple? Yes, no, why?

[desant89]

Well I ordered Pypes headers with Cat delete so I can have that done when my Whipple kit comes in. However, the more I read, I see a lot of people using high flow cats or keeping the stockers. Just second guessing now as to whether or not I made the wrong decision. Can anyone let me know why or why they did not keep them? I see a lot more that did keep them or go to hi-flow which concerns me. Thanks!

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[TheHydro]

I've been wondering if I should install mak cat deletes to go with my Whipple as well. Not looking to make max hp but wonder if the better efficiency would be worth it.

 

[Higgs Boson]

I always recommend deleting cats with blowers, turbos, and nitrous. The extra heat can kill them easily, the restriction is more pronounced at higher power levels, and the only way to attempt to keep them cool is by dumping tons of fuel and killing power with Cat OverTemp protection.

The only reason to keep cats with FI is if you can't pass emissions test without them.

 

[desant89]

I always recommend deleting cats with blowers, turbos, and nitrous. The extra heat can kill them easily, the restriction is more pronounced at higher power levels, and the only way to attempt to keep them cool is by dumping tons of fuel and killing power with Cat OverTemp protection.

The only reason to keep cats with FI is if you can't pass emissions test without them.

I like this reasoning. I did not want it too loud so what my plan was is to use catless headers. I also bought Flowmaster axle back as I prefer that sound. I was going to leave the resonated mid section for now to see how loud it is. I just do not want it to be too loud to start at night or in the morning as I live in a relatively quiet area. I guess if need be later, I can add an H pipe in place of resonator to keep the deeper tone as opposed to an X pipe. Any thoughts on leaving the resonator in place? Is that going to kill the performance?

 

[Superman15]

Just keep in mind that if you are running the Whipple tune... they do not tune for headers. You would need an outside tuner. If you do not have the Whipple tune then completely ignore what I said Personally I need to pass emissions, so if I was to go with headers I would go Kooks Green cat headers. Tooooo many issues with CEL's without cats. I know ppl use foulers and have success with them. But it is by NO MEANS a sure thing that it will work.

 

[desant89]

Just keep in mind that if you are running the Whipple tune... they do not tune for headers. You would need an outside tuner. If you do not have the Whipple tune then completely ignore what I said Personally I need to pass emissions, so if I was to go with headers I would go Kooks Green cat headers. Tooooo many issues with CEL's without cats. I know ppl use foulers and have success with them. But it is by NO MEANS a sure thing that it will work.

That CEL does not get cancelled out in a custom tune? I will not be using the Whipple tune. Ken will be tuning mine.

 

[Superman15]

That CEL does not get cancelled out in a custom tune? I will not be using the Whipple tune. Ken will be tuning mine.

Ken can tune out the CEL... but it's gona show up when you go for emissions. It may just show up as a "not ready" code. So it depends on your state laws for emissions.

 

[GigaHz]

NJ has a 4 year new car inspection cycle. One good thing about living there. Here in Pa it is every year.

 

[desant89]

NJ has a 4 year new car inspection cycle. One good thing about living there. Here in Pa it is every year.

Yeah, I will go get inspection prior to anything being done which will last for 4 years. I am not sure what I will do after that, but will figure something out.

 

[LethalPerformance]

Ditch the cats and don't look back. Stockers and even high flow cats not only hold you back from making more power but they won't last long under boost.

 

[desant89]

Ditch the cats and don't look back. Stockers and even high flow cats not only hold you back from making more power but they won't last long under boost.

How bad will it hurt me keeping resonator?

 

[LethalPerformance]

How bad will it hurt me keeping resonator?

The resonator really doesn't affect performance. At least at the stock power level when we did initial testing with our resonator delete. It's the cats which are the big restriction.

 

[Superman15]

Personally, I am not a huge fan of the low end torque loss you get without cats. But I do A LOT of local city driving, and I like my low end torque. If I was purely looking for power gains, or taking the car to the track, then I would go with headers.

 

[Higgs Boson]

Personally, I am not a huge fan of the low end torque loss you get without cats. But I do A LOT of local city driving, and I like my low end torque. If I was purely looking for power gains, or taking the car to the track, then I would go with headers.

I've only noticed torque gains by removing cats. Do you have any data showing torque losses? Please don't say backpressure.

 

[Superman15]

I've only noticed torque gains by removing cats. Do you have any data showing torque losses? Please don't say backpressure.

Its the butt dyno feel. I know the gains are good up top, but yes.. the back pressure is the dumb shit I am talking about Still has the better torque feel down low. I'm sure folks may disagree.. but in every car I have ever driven without cats.. the low end torque is not the same. If I was ever spending time up around the 7,000 RPM range, I'd buy headers for sure. But the only time mine has ever seen 7k RPM is on the dyno lol

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