Cat, etc.

  Ciro Design supplied the 100 cell race catalytic converter and Yawsport welded it directly behind the race header which gives plenty of clearance everywhere.  This mounting position loses the OE catback flange location so when SMOG time comes I will need to swap the entire exhaust to legally pass inspection.

During the shop visit we noticed the rear swaybar is making contact with both lower control arms.  Moving the swaybar mounting brackets up is an easy adjustment but it may not be enough.  Longer endlinks may help too so I will keep an eye on this problem.

Edit: Some quick searching and I think that I have the rear swaybar mounted upsidedown - Oops.

Okay, the first two pictures below show the new correct installation of the Hotchkis Competition swaybar.  Gained about a half inch more clearance to the LCA, but now the right side swaybar arm hits the exhaust when the swaybar mounting brackets are placed in their maximum 'up' position.  New poly bushings and new brackets are also installed at this time and there is enough wiggle room to make it work without interference, but the ultimate test will come at the next autox.

Thinking more about the catback exhaust and potential future swaybar changes and upgrades, it would be easy to save weight and avoid swaybar clearance issues altogether by using a custom muffler located where the resonator sits with a dump at the rear wheel. It would be a very tight fit, but a custom 6"x8"x24" muffler should keep the sound levels reasonable, especially if a Burns stage 2 muffler is used.  I think two Vibrant Ultra Quiet resonators would fit back-to-back but may not have enough total volume. Magnaflow sells a 6" round chambered muffler that is cheap enough to try.  Underbody exit and exhaust gasses entering the passenger compartment is a major concern.  Would also want to keep the sound quality good with minimal drone or raspyness. Stuff to think about.

EM2

  The front swaybar interference with the OBX race header does not seem to cause a problem or make any noise during normal street operation, but just looking at the bar mount bushings you can see that the bar is jammed to the right at least an inch due to full constant contact at the right top corner of the header.  The base Honda Civic EM2 front swaybar is a direct fit into the RSX chassis and is reported to clear most all race headers due to the lager main hoop section.  This civic swaybar measures 15.9mm and the 02-04 RSX-S bar measures 23mm; both swaybars are hollow and the weight difference is less than two pounds.

Front swaybar elimination or a minimal front bar will help put the power down better, but will also allow more roll and lean thus reducing active camber - transitions should be slower too.  From what I have seen all of the aftermarket RSX front bars are nearly the same size or larger than stock and will most likely have race header clearance issues as well, so the EM2 swaybar should meet my needs - low cost, decent fit, moderate stiffness.  Eventually I can see removing the front bar altogether and spring rate can be increased to help combat chassis roll.  Other possible options include modifying or replacing the header or making a custom under-the-header swaybar.

One step forward, two steps back.  Due to the design, the long tube race header needs to be dropped to remove or install the swaybar.  Careful not to damage the [new] primary O2 sensor, the header removal is simple and the new swaybar slips in with just 2mm clearance at the header.  I was expecting more room, but it is a much better fit than the OEM bar.  The EM2 bar has enough room on the arms to accept another endlink hole so I drilled it before the install and I mounted the Hotchkis adjustable endlinks to the newer stiffer holes.

Power is Everything - Part 1

I purchased a used OBX header and AEM intake about three months ago.  I have been waiting to install them until I got the car in a better state with fresh mounts, preventative maintenance, etc., and I also wanted to abuse the car a little in stock trim to feel it out and find any potential weak spots.  No problems found so I bought a new Yonaka catback exhaust and got to work.

The AEM Dual Chamber intake is basically just a filter on a tube, but AEM says it gains 18hp over stock.  http://www.aemintakes.com/  Not allowed per ST* rules to trim the fender liner or radiator shrouding to fit a true cold air or ram air intake so this was an easy off the shelf choice. Got is used at half price and the install was easy so I actually stuck it on the day before the last autox.  Stock intake weighs 10.2 lbs.  AEM weighs 3.8 lbs. This thing makes a loud intense growl on vtec so the perceived power increase is there.

The OBX V2 header is a Comptech long tube replica and I snagged it locally used for under $200. With so many header options for this vehicle, I just chose the one that is reported to make decent power, fit well, and is reasonably priced.  No braided flex hose or slip joints on this header, however the collector flange includes an oem style donut gasket with spring bolts which should help reduce any stress or cracking.   Aside from a known front swaybar interference issue and a damaged O2 sensor, the install was a simple nut and bolt procedure.  There is no provision for a catalytic converter.

   

The Yonaka catback exhaust was purchased mainly because of the canister size and volume and my need and desire to keep the car relatively quiet.  It is an Apexi WSII clone 2.5" OD and reported to be barely louder than stock and at just over $200 I could not resist. Quality is very good and includes all hardware and gaskets.  Fit is excellent.  Sound is mellow at low revs and mildly aggressive without being obnoxious at vtec. No drone.  Plans are to install a race cat in the mid-pipe; probably at the S-bend or immediately following the header collector.  The main muffler is shorter than the stock muffler which should allow some clearance for a future upgraded speedway style ASR swaybar.

Combined, the complete OEM exhaust weighs 57.4 lbs.  The OBX and Yonaka together weigh 41.5 lbs.  Midrange horsepower feels stronger between 3500-5000 rpm.

Hondata just released version 4 of their popular and powerful Kpro ecu.   This is next on my shopping list after some of the other suspension items are dealt with.

Event 1

First STF autox with a decent setup and the car works well and the initial results are promising.  Still have the B-Street MX5 16x7 wheels and 225 ZII tires on the car, but I did adjust the rear swaybar to full stiff.  Balance is still pushy, but the increased caster/camber and spring rate make the car come alive.

More pictures from LateApexPhoto.com

  After this first autox event I realize the front strut travel and caster may be less than I anticipated, even with the newest set of camber plates and a moderate ride height.  Some of this may be spring rate and swaybar choice, but either way I see the immediate need for another variation of top strut mounts / camber plates to increase bump and caster before other major setup changes should be made. Swaybars, ride height, rake, and alignment will all need tweaking after the basic spring balance is achieved, but for now I consider this first event a success.

November San Diego Autox Results

      


With the holiday season upon us the next autox event is not until mid-January or later.  This gives me plenty of time to make some changes and add more power.