2016 Nebraska

  Loaded up with all the crap I would need for 10 days away from home, I drove the STF car to Lincoln for the SCCA Pro Solo Finale and Solo Nationals.  New 225/45-15 Kumho tires were mounted and scrubbed in at a local autox the prior week.  Having to abort my last driving trip to Nationals in my 99 STR Miata due to a mechanical breakdown, I was a bit nervous about the long distance journey but good old Honda reliability motored me effortlessly to my destination.  Combined fuel mileage averaged about 32 mpg on the 3188 mile trip.

 A late-summer failure of the ABS module left me without anti-lock and I expected brake bias or other problems but to my surprise the brake feel and feedback was excellent; much easier to drive at the limit - no more ice mode or kickback.  I bought a replacement module and had time to replace it before Nationals but decided to let it be.  Once I do replace the module, I will disable the ABS for autox which is easy as disconnecting the harness or pulling the fuse.

Pro Solo Finale:  Nothing to see here; I drove fine and the courses were fast, flowing, and fun, but I finished fourth in class.  The RSX was working well but I never quite put together a perfect run or I coned away my fastest times.  All dry runs.  Finished second in the STF overall Pro Solo year-end points.

And as a reminder, here is the setup I used for both the Pro and Nationals.

Springs:  750F 1300R
Swaybar:  06/08
Tires: 225/45-15 Kumho V720, 32psiF, 36 psiR
Rake:  1/4" reverse

Solo Nationals:   I was pleasantly surprised to land in first place after day one on the East course, but second and third were right behind me on the same tenth.  The East course had elements that I was more familiar with and suited my car setup and driving style whereas the West course was sweeper intensive with two pinchy corner exits. I was more comfortable and confident on the East and it shows in my times.  The West drove faster than it walked and my car was working better than I imagined, but I was fourth fastest on day two for an overall third place finish.  All dry runs.

Below is the East video - other videos can be found on my YouTube page.




BTW, the car is still for sale.

Update June 2016

  No luck finding a buyer yet for the Acura so I have continued to autox it locally with a few minor setup changes.

Playing around with front springs I went up from 650 to 750.  I don't think the strut valving is happy and the ride is not pleasant on rough roads, but for a front heavy autox vehicle I think this is the right direction.

  Big handling improvements came when I lowered the rear of the car.  I am now at a reverse rake (again), or approximately 1/4" lower than the front when measured at the pinchweld.  All told, I came down 6 turns at the shock; one full turn lower than my previous low.

  I have been toying with ride height since late last year when the 1300 springs were originally installed.  At first the balance was good but with varying grip surfaces and multiple tire choices I kept upping the rear height little by little trying to get more oversteer.  Didn't work, so I researched my notes and dumped the rear back down and the car came alive again.

 Not really sure why the lower rear creates oversteer but there are several potential contributing factors including roll center and roll axis, bushing bind, dynamic bushing changes, RUCA interference, bumpstops, and alignment.  The static alignment actually leans toward understeer at the lowest height with more camber and slight toe in.  All the other factors may have an effect, good or bad, but ultimately we think that it is simply because there is less weigh jacking to the front wheels.  Tripod action was easily lifting the rear wheel 4 inches or more and now is reduced to almost nothing.

Next is to tweak the rear alignment and play with staggered tires.

Also - with help from a 4" grinder, I removed some material from the front brake calipers to eliminate any interference with the 15" Rotas.

As for the RUCA interference, we decided to leave it alone and see what happens.  They should self clearance on their own or I may just grind down the top edge of the jam nut or adjust the center link next time I have the rear apart.  Offset bushings can fix this too.

For Sale

Time to sell the RSX.

$6500

2002 Acura RSX Type-S
181114 miles
K20A2 engine with 6-Speed manual transmission
Desert Silver (beige) exterior color with tan leather interior.
Bilstein struts / ASN shocks / custom caster plates / Swift helpers
Hyperco & Eibach springs
Hotchkis rear swaybar / JBR mounts
SPC rear UCA
New front bushings/ball joints.  New motor mounts.
OBX 4-2-1 header, Ciro Design cat, Yonaka exhaust
Hondata Kpro V4 ECU
AEM V2 intake
Odyssey PC680 battery / Password JDM bracket
Momo Start seat / BuddyClub rails
Rota Slipstream 15x7.5

$6500

1 : 2

Originally the car was setup with 10K front springs and 12K rear.  Used in combination with staggered 225/195 Hankook tires, the car actually worked quite well but exhibited a lot of body roll.  With the newer RE71R tires and a 'square' setup, the car decided not to turn as well anymore.

Next we tried 650F and 900R.  This was supposed to combat front roll and also add rotation.  Actually made it worse.  Lots of front push, even with the FSB removed.  Realigned the rear with less camber, positive rake, and toe-out but results were still about the same.

Went back to the 10K (560) front springs and left the 900 in the rear.  Not working as expected; still pushy even with the goofy rear alignment and stiff RSB.  This is the combination I used at 2015 SCCA Solo Nationals.

Finally decided to go with a 1:2 ratio with the 650 front and 1300 rear.  The new rear springs are 2.5" ID Hyperco so modified upper spring mounts and new lower perches and helpers replace the old 70mm ID stuff. Yawsport valves the Bilstein ASN shocks and also makes custom attachment points for the swaybar endlinks on the LCA. With a slight reverse rake and soft swaybar setting the car performed excellent at our year-end autox on Qualcomm's low grip surface.





My original idea to go with big rear bar/soft springs changed when I could find no easy or economical way to get the speedway bar routed around the exhaust and LCAs without custom fabrication.  Fortunately the large spring/moderate swaybar setup is initially working well and seems to be more linear and predictable at the limit.

Rear UCA to frame clearance and LCA to swaybar clearance are both close but modeling clay reveals no interference.  Plenty of room at the LCA/swaybar with the swaybar mounting brackets pushed up almost as high as they can go and with the end links extended to near maximum- almost 5 inches.  The UCA/frame clearance is about 1/8" left and 1/4" right.  Some adjustment of the main center link and jam nut could gain another 1/4" clearance if needed.  The current rear ride height is the lowest to date with no plans to go lower


Conclusion:  Start with at least a 1:2 spring rate bias and try to eliminate any bushing deflection or dynamic toe by replacing all the rear control arm and knuckle bushings.  The ultra stiff rear springs will greatly reduce unwanted suspension movement and make the handling more predictable.  My rear bushings are still the original OEM and probably a major contributing factor as to why the mild to moderate spring changes did not produce the desired results.

5102 Aksarben

   Late update, but 2015 SCCA Solo Nationals turned out about as I expected - fierce competition resulting in a distant second place finish.  No complaints though; drying conditions and cone trouble forced a mildly conservative final run each day and the pushy car setup kept me far away from the top spot.

After some good results from the Kumho V720 tires locally and at the Pro Solo Finale, I chose too run the Kumho at Nationals also.  The V720 gives immediate response and super quick turn-in.  Puts down power very well too.

Fastrack was released last week and the RSX Type-S will not be moved to STX and will remain in STF.   Time to open up the checkbook and start thinking about spending money again.

California emissions check (SMOG) was required for registration renewal which meant that I had to replace the complete exhaust and intake to legally pass the visual test. Easier than it looks and I'm good for another two years.  Yay.

First on the to do list is to lengthen the integral strut steering arms, as my OE spec Bilsteins are designed for a Civic and thus the steering arms are about 1/4" too short.  Yawsport has their welder do his magic and cut and space the arms 8mm to meet the correct dimensions.  While the struts were out I re-installed the 650# front springs and replaced some of the spring thrust washers.  Front swaybar was removed and front ride height is lowered 1/4".

Second is to keep an eye on the rear upper control arms.  These aftermarket arms allow for camber adjustment, but at reduced ride height the inner most part of the arm can come in contact with the body/subframe.  If the threads are long enough, it looks like I can thread the center outward and pick up a little space.  May need custom offset arms or a different brand?  Modeling clay comes in handy for checking clearances such as this.

At the first local autox after Nats I play around with the rear swaybar and discover that it is only set about half-stiff.  It is also bound up in the brackets and will not move by hand.  I thought the bar was maxxed out for Lincoln but I may have  adjusted it for wet weather conditions.  Whoops.  And the binding is due to poor lubrication and overly tight bushings.  Placing small spacers between the brackets and subframe eases up the bushings and allows easier rotation with the help of proper grease.

 While doing the strut mods listed above, I was driving the car for a week with stock front springs and I could really feel the softness of the rear suspension, as it should be with a motion ratio around .59.  My co-driver helps me find some 18K (1008lbs) Tein springs.  I am wanting at least 1200-1300lb, but these Teins are the correct 70mm ID and priced well at $40.

A broken wheel stud keeps me out of the car the the most recent local autox.  Bummer.  I have extended ARP studs but the front replacement requires hub removal and bearing replacement which is something I would need to have a shop fix.  $$$   Maybe later.  So I replaced it with a stock length stud.

Next up ?  Keep competing locally and increase real roll stiffness.  Saving weight and getting cold intake air to the engine are also on my radar.  More front camber and travel too. Rear suspension bushings.  All of this on the cheap, of course.

Zero Time

  Three days remaining until I leave for SCCA Solo Nationals in Lincoln, Nebraska and the suspension is not working as well as I like.  I have gone back to the softer 10K front springs and the rear is still equipped with the 16K springs while the Hotchkis swaybar is maxxed out beyond it's design capabilities. Professional alignment at Lutz Tire with zero toe all around and less rear camber (-2.70).   Ride height is also raised about 3/8" all around to help give more front strut travel. At the most recent El Toro autox, this setup seemed nervous at the limit- probably due to toe- but still would not sweep well or rotate.

   In a last ditch effort to get more rotation and/or lift-off oversteer, I raised the rear ride height about 1/2 inch for our last local autox before Nationals.  That seemed to do the trick - the car turns better than it did and now rotates off throttle, but still feels awkward.  Not as smooth or predictable as I would like, but that is probably due to the toe which should have increased out as the rear ride height was raised.





  Now, I know what you are thinking;  stop screwing with the rear and focus on getting the front to actually turn better instead.  Valid point and I am (slowly) working on that too, but some of the front understeer you may notice in the videos is because the rear will not come around so I turn the steering wheel more which makes it worse.  My main reason for recently going to the stiffer springs on all four corners was to allow a lower ride height to reduce the COG and minimize camber loss and body roll which should help the front grip.  Of course I know I need more front camber but that is another issue.

   Unfortunately, the spring changes I made six weeks ago to actually make the font bite better and help the rear rotate did not produce the results I expected and I panicked.  Spiraling out of control, the car setup has been different for each of the last 5+ autox events, usually on different brand tires too.

   So be it. I will take what I have to Lincoln and drink beer and have fun.

Again this year Rick from Ciro Design arranged a transporter for the journey to Lincoln.

New and Somewhat Improved

  I do not like making car setup changes this close to Solo Nationals, but with trying to get the 225 BFG Rival S to work better on my car I needed a stiffer and/or looser setup.  And regardless of tire make, the front suspension was too soft anyway and needed more roll stiffness for faster transitions.  Up on spring rate 90# front, 225# rear (650F, 900R).  After calculating the motion ratios this should give slightly more rear spring bias to help rotation.

At this first autox test event I had some unexpected ignition cutout problems that prevented good solid runs, but we were able to get an OK feel for the car's balance.  With the rear swaybar set full soft and flat rake the car is quite pushy.  So we disconnected the front bar and tried a couple more runs and it felt better but still far from ideal.  The BFG tires are so vague and delayed that most of the initial understeer and slow transitions are probably due to the tires as the Kumho and RE71 respond alot quicker.  Rear spring installation required unbolting the front LCA mount which can alter the alignment.  Toe plates reveal 7/32 rear toe in; this could explain some of the pushyness but it is not far off from what I had set originally.  Next event July 26 and the rear swaybar settings will be much more aggressive and return rake to 1/4" lower in the front.  Professional alignment TBD.

First impressions with the new setup;  slight improvement transitionally and the front strut travel is greatly reduced to the point where I can lower the front more without fear of totally mashing the bumpstops.  However, power down was not as good with the BFGs spinning more than ever, especially on their first run (warm 75* day). The rake and bar settings should help this situation and I already noticed a power down improvement after disconnecting the front swaybar.  Car corners much flatter now too so I may need to revisit camber and tire pressures.  ABS seems to want to kick in sooner and/or more often.

Downsides?  Yes, the ride on the street is worse and I don't think I could tolerate any more spring rate increase for this daily driver.  And with the ability to lower the car more, exhaust clearance becomes more of a problem.  Lower ride height also causes more bump steer.

FSB:  It is still on the car with one side disconnected.  One more event will determine if it stays or goes entirely.  Small, but effective enough to make minor setup changes.  Hope to rework it for more ground clearance and multiple adjustment settings.  With an LSD this swaybar could be more of a benefit.

The cutout problems I experienced at this test event first showed up during the Shootout rounds at the Utah Match Tour, possibly forcing me to lose in the third round.  I assumed it was fuel starve or something similar because it only happens during hard cornering.  Turns out the problem is related to my additional oil pressure sending unit and the configurations in the Kpro software.  Oil slosh and incorrectly scaled values were causing the advanced protection to cut ignition.  Lets just say that the V4 Hondata Kpro software still uses most of the V3 embeded help files so I was not aware of all the features and how they may react.

Speaking of the Utah Match Tour, I enjoyed the format and had fun despite the brutally hot temperatures and 4000+ ft. elevation.  I had cone troubles but still was outpaced by the well driven Honda Fit on RE71R tires. I purposely chose to run the Kumho tires based on their feedback and early performance versus the BFG.  Downshifting to first at the hairpin was key to a fast time but my transmission does not agree.





Five weeks to go before Nationals and I need to make the car turn easier and then also decide which tire is better/faster/easier to drive with the revised setup.  The Bridgestone is my primary tire choice at the moment because it puts down power best, sets quicker, and communicates very well.