Kooks installed - comments and questions inside.

BLACK_CTSV · #1 (**permalink**) 02-18-07, 12:50 AM

First off - the Kooks and Magnaflow exhaust sound WICKED. Not much difference when starting/idling from just the Magnaflows, but when you are WOT - holy crap!

Needless to say, lots of pedestrian heads swivel to see what's going by. I can already see a reduction in MPG just for my listening enjoyment

I had a StealthV tune, and took a baseline before the swap. For a 'box tune', this was pretty damn spot-on as far as A/F goes. The tuner was quite impressed!

My question: Has anyone else seen the A/F go way lean just after a header install? It went from 11.5 to 13+ from just a header swap. Checked for leaks of any kind, and everything looks good. Also have a CEL, but haven't had a chance to troubleshoot yet - just wondering about the A/F. Anyone?

rand49er · #2 (**permalink**) 02-18-07, 08:25 AM

Yes, you will go leaner from a header install due to the reduced backpressure, but I believe that this occurs mainly/only at WOT conditions where the headers are most effective. I know this from my early days doing engine dyno work, but can't properly explain the reasons at present.

BLACK_CTSV · #3 (**permalink**) 02-18-07, 04:41 PM

Yep, sorry - WOT only. Those stock manifolds look pretty restrictive, but I'm surprised it made that much of a difference. I'm about to go check to see what code[s] is/are being thrown...

Seattle CTS-V · #4 (**permalink**) 02-18-07, 05:53 PM

Rick (StealthV) told me I would need a retune if I added headers...just send it back to him (if you can live w/o his tune for a week).

dqw1 · #5 (**permalink**) 02-18-07, 07:11 PM

I'm looking at headers next and I also have the magnaflow exhaust. Any issues with the fit? Also, how long should it take a shop to install the Kooks?

BLACK_CTSV · #6 (**permalink**) 02-18-07, 09:52 PM

Quote:

Originally Posted by dqw1

I'm looking at headers next and I also have the magnaflow exhaust. Any issues with the fit? Also, how long should it take a shop to install the Kooks?

The Kooks did not mate up to the Magnaflow - didn't fit. Had to drive it to the muffler shop and have them make some modifications. Sounded mean with open headers

It's a tight fit, but not too bad.

BLACK_CTSV · #7 (**permalink**) 02-18-07, 09:55 PM

Quote:

Originally Posted by Seattle CTS-V

Rick (StealthV) told me I would need a retune if I added headers...just send it back to him (if you can live w/o his tune for a week).

I have a local guy that will finish tuning it - we didn't have enough time to sort it out on Friday. He's got a great reputation in this area, so I'm sure he'll figure it all out.

I tried to pull codes this afternoon, but apparently the scanner I have will only work on Fords [It's a tuner for my F-150]. So, I won't know what the CEL is until I take it back to the tuner, or my code reader shows up that I bought off of Ebay. Either way - it should get sorted out this week.

GT04CTS-V · #8 (**permalink**) 02-18-07, 10:02 PM

I'm interested in seeing what HP/TQ difference the headers made verses the stock manifolds on a blown car. Additionally, did the max boost decrease?? It used to max out at 7 PSI. What cats did you use??

Thanks,

GT

BLACK_CTSV · #9 (**permalink**) 02-18-07, 11:29 PM

Quote:

Originally Posted by GT04CTS-V

I'm interested in seeing what HP/TQ difference the headers made verses the stock manifolds on a blown car. Additionally, did the max boost decrease?? It used to max out at 7 PSI. What cats did you use??

Thanks,

GT

Gary - boost stayed at 7 - from about 2000 RPM and up. I used the cats that came with the Kooks - don't know what kind they are. I'll post up the results when I get the tune straightened out. It baselined at 416rwhp with the old manifolds [Mustang dyno].

TrazzNJ · #10 (**permalink**) 02-19-07, 02:50 PM

Any Droaning at highway speeds with the Magnaflow system??

BLACK_CTSV · #11 (**permalink**) 02-19-07, 06:10 PM

Quote:

Originally Posted by TrazzNJ

Any Droaning at highway speeds with the Magnaflow system??

Some - not too bad, though. It's very tolerable in the cabin with the windows closed. You can actually hear the radio or have a conversation. Small amount of drone at certain RPM levels, but not as bad as other cars/systems I've owned.

CTS-BV · #12 (**permalink**) 02-19-07, 10:01 PM

That's great news. Please post your dyno graphs when the local guy get's done with it.

CTS-BV

LS1Mike · #13 (**permalink**) 02-19-07, 10:10 PM

Did you get it all worked out yet?

BLACK_CTSV · #14 (**permalink**) 02-19-07, 10:30 PM

Quote:

Originally Posted by LS1Mike

Did you get it all worked out yet?

Going to see Tom tomorrow @ 10:30 am. I'll post after it's fixed [hopefully]

CTS-BV · #15 (**permalink**) 02-19-07, 10:38 PM

Quote:

Originally Posted by BLACK_CTSV

The Kooks did not mate up to the Magnaflow - didn't fit. Had to drive it to the muffler shop and have them make some modifications. Sounded mean with open headers

It's a tight fit, but not too bad.

See, now that makes me mad. I wish I could get a straight answer on this issue. When I talk to Tbyrne Motorsports, they assure me that the Kooks Headers fit just fine with their CATS and mate up to, especially, the Magnaflow exhaust. So what gives??!!

I'm planning to add Kooks headers to my Magnaflow exhaust and I really want to do this in my own garage. I can't be bending or welding up pieces to make it fit.

BTW, that was pretty dangerous driving around with open headers.

CTS-BV