We’re getting the band back together.
Built originally for the 2011 running of the One Lap of America, this CRX made four appearances total, racking up class wins and impressive overall finishes, with a high point of fourth overall in 2014.
Since then, the car has achieved an SCCA Solo Nat…
Super cool to see-my favorite project cars are the ones that go through multiple iterations with a single owner over time.
170mph in a CRX must be exciting.
Somewhere along the route of last year's One Lap of America run, co-driver Tom Suddard suggested that it would be fun to bring back the One Lap CRX for the 2024 running of the event.
Andy: "Uhhh...are you sure? Race car with a license plate?"
Tom: "Yeah, I'm game. I want that experience!"
Well who am I to deny that sort of request? Thus was hatched a plan to un-mothball this legendary steed. Follow along as we try to add back some street manners and reliability to what has become a "fast when it isn't broken" trailer queen.
Rather than the typical installment-based project car set of threads, it seemed more appropriate to follow the action as it happens. To index our journey for reference, we’ll have some thread links to key parts that can be found off the project car page.. There will be lots of balls in the air at once, and I'm sure a few dead-ends or mishaps.
We'll also put up some memories here from past events, but if you want a really deep dive, visit OneLapCRX.com, a Facebook page, and scroll back to the very beginning to enjoy the original build and various rebuilds as we ran the car in various venues.
Here's what the car looked like this past weekend at COTA...this is our NASA TT4 config. Hoosiers, small aero, stock internals TSX K24A2.
"Make it run, then make it fast"
That's always been our mantra and has served us well for various projects. "Perfect is the enemy of good" keeps so many car builds from ever getting out of the garage.
Last summer the car was not running. For NASA TT4 we were running a stock-internals TSX K24A2 that had been tuned to a flat horsepower curve. But that motor -- dubbed "old reliable" -- had been in and out of the car many times over the years as other, more potent powerplants found the limits of physics and offered up their internals to the God of Speed. Eventually, the mounting bosses in the aluminum block got boogered up to where they suddenly just let go.
Andy Hollis is doing a build thread!?
sleepyhead the buffalo said:Andy Hollis is doing a build thread!?
Technically, it's a rebuild. :)
That repair job would be tricky and we had an event we wanted to try and make last Fall....the GRM Ultimate Track Car Challenge and SCCA Time Trials Nationals. We did have a built motor sitting in the corner that was our spare. That was a "big block" K25...bored out and sleeved to add displacement. 12.5:1 compression, cams, ported head and all the trimmings needed for 300hp. It could run on either E85 or pump premium, which would also make it a good choice for One Lap. So everything was lining up nicely. Until it wasn't...
It started pushing water out on track...not overheating, just over-pressurizing the cooling system. And it only did this when pressed hard -- easy street driving would just merrily chug along, no problem. Likely a pinhole in the head gasket, as the overbore narrows the gasket material sealing the water jacket.
So the first step was to see if we could band-aid the situation long enough to get through track sessions. We added a swirl pot to the cooling system, along with a modern pressurized coolant reservoir. A trip to the Pick n' Pull netted a tank from a Mazda CX9 along with some hoses. The swirl pot itself came from OBP Motorsport and a T-fitting from Amazon was added to the lower line. One side benefit of this setup is it's ease of filling/bleeding. It pretty much bleeds itself.
So that motor was going to have to come back out for a head gasket, which meant we gave up on UTCC/TT Nats and ran our back-up car instead. Yes, we have two white CRX's...the B car has an old-school JDM B18C Type R swap.
In advance of those events, we had also planned to up our aero game. Those parts arrived and it was time to get the car running again to get them fitted and tested.
To repair "old reliable", we pulled the front timing cover and chain, and then used TimeSerts to repair two of the three mounting holes. Getting these perfectly centered and straight was accomplished by machining a pair of guides that could be bolted into the one remaining hole to use for drilling and tapping the TimeSert holes.
It came out great and is now stronger than ever.
The shake-down was this past weekend at COTA where the car did it's thing...crushing souls of seemingly faster high-end sports cars. Our NASA TT4 record at COTA is a 2:28. The car will do 2:25 with the built motor.
So now the real work begins and we have a couple of balls in the air at once...aero being one of them.
Originally the car had a dumpster-recovery APR GT200 wing that we repaired and put to good use for quite some time. Paired with an Alumalite splitter it worked pretty well and survived One Lap, including 150mph at Daytona. Deets on that fab work here: https://www.facebook.com/media/set/?set=a.922915627739682&type=3
Eventually, that wing gave way to a Nine Lives Racing wing that made more downforce with less drag, as seen in the COTA shots above.
Still, our splitter was just not great...and with a FWD car, front downforce is everything. It was time to up our game with something professionally built and custom designed. Enter Ryan Neff of Zebulon.
Ryan does bespoke, high quality all-carbon aero devices at a fairly reasonable price. We traded dimensional data and goals for a couple of weeks, he ran some numbers and eventually we settled on a design. It will meet NASA's side extension limits for TT3 but is way into the decreasing returns curve on size vs downforce.
Here's the underside, where all the action occurs...
And here's where we are today...fitting. Lots of challenges here.
In reply to Andy Hollis :
Can you tell us more about the hollow splined rear sway bar setup?
Does it just give you greater ability to fine-tune the suspension setup, or are there other advantages as well?
CrustyRedXpress said:In reply to Andy Hollis :
Can you tell us more about the hollow splined rear sway bar setup?
Does it just give you greater ability to fine-tune the suspension setup, or are there other advantages as well?
It started as a way to save weight and have more adjustability. I have center sections in a variety of thicknesses/stiffness. Originally done for my old STS Civic autocross car as shown here: https://www.facebook.com/notes/381841909838692/
Recently, with no bodywork rules restrictions in play, I went for a more solid frame mounting like so (note: the end link has been replaced with a more robust coupling).
Andy Hollis said:It started as a way to save weight and have more adjustability. I have center sections in a variety of thicknesses/stiffness. Originally done for my old STS Civic autocross car as shown here: https://www.facebook.com/notes/381841909838692/
Recently, with no bodywork rules restrictions in play, I went for a more solid frame mounting like so (note: the end link has been replaced with a more robust coupling).
That's amazing, thanks!
In the shop today developing a tire plan.
They say you can't fit 17's on an EF chassis Honda. Challenge accepted.
That was at full compression, which we tested by removing the spring. The bump stop setup is already fitted to just barely avoid contact between the upper control arm and the shock tower.
Note the o-ring on the damper shaft. That serves as a telltale on compression use .
One Lap rules require a 200tw tire or better, and must be purchased through Tire Rack to avoid one-off ringers. Further, the official OLOA Tire Policy lists the participating tire manufacturers for each year. And finally, you only get one set to last you the whole week. That's 3500 highway miles, plus about 40 laps of track use. Replacement/spares only allowed for verifiable road hazard damage...which does not include camber wear.
With its old school wheel well sizing, traditionally a 23" tall tire is the limit for this chassis w/o significant modifications. But the availability of suitable tires in that OD is limited.
Most competitors choose a tire from the Max Performance Summer category, which gives a good balance of both dry and wet performance. The latter is important since you always have to do the wet skid pad, and Spring weather typically includes rain other times during the week. Conti ECS02 and Michelin PS4S are popular choices. Neither of which comes in a 23" tall tire.
So that leaves Super 200's. The only ones that have acceptable wet performance (at least when new) are the Bridgestone RE71RS, which has become the new OLOA tire of choice and the Yokoaham A052. The former has only a 205/50-15 in 23" tall, and its a skinny 205. They do offer a 23.8" tall 225/50-15 which is a possibility.
Yokohama has a very uniquely sized A052...215/40-17...23.7" tall and wider even than the RE71RS 225. Plus, we have some 17x9" wheels already on hand to test with. A052 also comes in a shorter 205/40-17 and its a wide 205. Plus, there's the 205/50-15 and 225/50-15. We are going to try out pairs of each of these on the front.
The picture above is a well worn 215/40-17 on a 17x9 ET45 wheel. Pretty much fits. Might need some minor persuasion, though. We shall see.
PS: Endoscopes are the new schnizzle for checking tire clearance in tight confines.
much excite
Andy Hollis said:Replacement/spares only allowed for verifiable road hazard damage...which does not include camber wear.
I'm pretty sure I could design and build a road hazard generator for you.
In to see the new engine management. :)
A fast Ef Honda. Be still my heart.
What's going on here?
Measuring the dash binnacle area, eh?
How did the swirl pot and new reservoir work?
My K20 DC2 is slightly pushing coolant, I'm thinking tiny HG leak as well. Only runs hot on track when ambient temps are around 95+ here in UT. Which is usually only a problem in July-August. Trying delay rebuilding at the moment and was thinking of doing the same. I can't get it to overheat on the street or push coolant, can run with a/c all day. So still only at the extreme conditions.
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