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High flow cat results (Sikky headers/JoeZ exhaust)

18375 Views 27 Replies 13 Participants Last post by  caymandiver75
I installed some Random Technology high flow metal matrix 100 cell cats (3" diameter, 9-5/8 in long and 2-1/2" inlet/outlet). I was expecting to lose around 5-7 hp, but to my surprise I actually lost ZERO and even gained in a few places! I decided to install these because I was getting complaints from the wife about exhaust smell in the garage, wanted to cut down on exhaust drone and pass my Virginia Safety inspection each year. Needless to say the smell has drastically been reduced, the drone is almost gone and I will pass my yearly safety inspection. This was a true WIN WIN WIN WIN scenario for me and I couldn't be happier with the results.

Special thanks goes out to
1. JE Import Performance for their outstanding workmanship

Video of my run is posted via facebook: http://www.facebook.com/video/video.php?v=933965992551

The graph below shows the before and after results. The thin lines are pre-cat install and the thick lines are after-cat install results. The graph is also a bit messed up in that the rpm sensor seems to be off by about 450rpms, but at least it's consistent for both runs.


Some O2 sensor extensions were used to allow room for the cats.




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Looks good James. Too bad the strips are closed for the year. I'd be interested to see if you can still cut an 11.9. We need to go asap once the gates open since I may have some new goodies on my F.
Looks good James. Too bad the strips are closed for the year. I'd be interested to see if you can still cut an 11.9. We need to go asap once the gates open since I may have some new goodies on my F.
Thanks man. I have no reason to believe my quarter mile times would change any though considering the power is the same. When I cut the 11.9 it was my one and only run for the day and I know I could have cut a better time with the temps cooling as it progressed into the evening. If I decide to go again in March when the tracks open I'll shoot you a message. My drag radials are on their last leg and I'll be lucky to get more than 2 more days out of them.
Nice work, so did the O2 extension prove to be effective and still necessary with the new Cats or did you just leave it on there?
Nice work, so did the O2 extension prove to be effective and still necessary with the new Cats or did you just leave it on there?
Thanks! The secondary O2's are doing nothing since the headers came with an O2 simulator that is wired into the ECU. Those extensions are there only for easier fitments of the O2 sensors. I have about 5000 miles on the car with the headers and to date no CEL. :D
10,000 plus miles and no cel for me.
10,000 plus miles and no cel for me.
Good to hear the headers are giving no problems. What do you estimate your 0-60 and 1/4 mile times are?
Good to hear the headers are giving no problems. What do you estimate your 0-60 and 1/4 mile times are?
Pending his upcoming mods his times would be the same as mine. We both have the same mods and dyno'd nearly identical on the same dyno. So sub 4 second 0-60 and high 11's are doable.
Around what RPM were you getting drone before the cats were installed?
Around what RPM were you getting drone before the cats were installed?
Engine under load in the 1500-2000rpm range. It's funny actually because according to my decibel meter the db's have not changed, but the frequencies that cause "drone" have all but been eliminated.
Engine under load in the 1500-2000rpm range. It's funny actually because according to my decibel meter the db's have not changed, but the frequencies that cause "drone" have all but been eliminated.
Was the drone that bad before cats though? I'm getting this exact setup but don't want it to drive me nuts. lol.
Was the drone that bad before cats though? I'm getting this exact setup but don't want it to drive me nuts. lol.
Drone wasn't the primary reason for me adding the high flow cats. I needed to pass my state inspection yearly which requires a visual check to see if cats are in place, the wife was complaining about exhaust smell in the garage and I had some rattles that I couldn't isolate. I would put it this way. If you drive around in manual mode most of the time the "drone" will not bother you because most likely the rpms would be kept above the drone range. If you like to drive around comfortably say with family members and the car is kept in standard auto, you will not be able to enjoy conversation with other people in the car.

See thread link below:

http://www.clublexus.com/forums/is-f/537869-sound-deadening-trunk.html
Awesome! Thanks for the info and that extremely helpful link... I'll be following your footsteps for sure.
This is great and I am having JE do this to my sikky/joe z set up they are installing next month to pass the vermont visual inspection
Thanks! The secondary O2's are doing nothing since the headers came with an O2 simulator that is wired into the ECU. Those extensions are there only for easier fitments of the O2 sensors. I have about 5000 miles on the car with the headers and to date no CEL. :D
What size slicks are you running and on what size rim? i have an extra set of factory wheels and id love to be able to fit a set of slicks on. Sorry i quoted the wrong post...
So happy to be a member of the header club
^^ Damn...

Now you guys got me thinking about installing a set on my ride..... :D


Joe Z
^^ Damn...

Now you guys got me thinking about installing a set on my ride..... :D


Joe Z
Joe,

I agree after seeing darbs put 420whp headers are next on my mod list. Looking forward to Elite's and PPE's final results.
hi caymandive, would you please tell me what your high flow cat's model number was ? The result seems impressive with cats on. :)
Is the header installation for the IS-F somewhat something that needs to be done by a shop, or can you knock it out with a lift and a couple of friend's help?
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