I have been wondering if anyone has deleted the cats from the stock headers? If so we're you happy with the results? I'd assume there would be a relatively close power gain to aftermarket options.

I'd like to delete both sets of cats then use the rr racing tuner to delete the cel. Seems like it would be a cost effective way to get some solid hp gains.

 

if 5-9 hp is 'solid' in comparison to the 35 or so you get from headers then sure... solid gains...

 

It is pretty common to knock out the cats. You get about 90% of the gains from spending a fortune on headers. If is wasn't for a cracked manifold I would have definitely went that route. Ping83 has cat delete and JoeZ exhaust. I have Sikky and JoeZ. There is not a big difference between the two when we went out and "tested" over a lunch last week. Knock out the cats and buy a tune and you will be faster than headers and no tune, not to mention money ahead.

Also, look into the PPE plug and play O2 conditioners. No soldering wires off the ECU harness is a plus for a few more bucks.

 

I think the primary cat delete would yield more than "5-9 hp". But correct me if I am wrong. Perhaps OP is referring to the return on the amount of time/money spent on this mod for the power it produces.

 

dcguy and I have nearly identical mods with him being the exception with gutted cats at dyno day and he wasn't making much more than myself. thus the 5-9hp

 

Thanks for the confirmation

 

It's a debatable topic OP here with the forum members. One thing is for certain you will gain more power and tq with headers and not to mention you won't get the scavenging affect with the stock manifolds. There is a reason why Lexus changed the manifold design on the Blue top (RCF,GSF) 2UR-GSE.

Not knocking the gutting primaries route, it's cheap and you will gain power, just for some people the headers are an investment in their F platform and some choose to go that route.

 

^^^^They changed it, but not by a helluva lot. Big change was opening up the exit.

Lou

 

Is there a tutorial on how to gut the cat?

 

There you go, so by opening the exit like i did basically brings it up to the newer models. Though it looks like primaries are slightly larger as well.

 

Your right not by a lot lol....... for some reason I thought they changed it more than that

Your correct! Basically what your tuner did that was a cool mod to do and pretty innovative!

 

Noticed some gains on the higher end, pulled a little harder, but the lower end seemed not to pick up as much.. Got about 30% increase in sound, but headers are the way to go if you have them in budget.

 

Woooooooo!!

 

Try the search function to locate instructions for gutting cats.

 

I regret gutting the stock cats on my factory headers. My eyes literally water up when I'm standing behind my car and your clothes will smell like you just got back from the track. Did I notice a bump in power? Yes, but it was not worth the negatives.