The One Lap CRX is back

Air dam built and in place.  Needs a bit of trimming in places to be perfect but this is good for now. 
 

Rear mounting brackets interface with the LCA cross bar.  Slide in place while the front bolts in. 
 

First time using double sided tape to hold the dam in place.  It's really strong in the direction of air flow.   Had to be absolutely certain of positioning because it sticks permanently at first contact. 
 

More details...end fences and titanium rub blocks.

Rolled outside for some beauty shots of the complete package.

One of my least favorite things...bodywork.  But at least this big has a performance purpose rather than just cosmetics.  
 

We originally built our hi-rise  hood to clear the tall K24 engine.  We then vented it for a trip to Daytona.  A few years later, when we switched to a different intake manifold, we had to undo that mod for clearance.  It's been like that for a decade.

But we recently changed intakes again which gave us more clearance.  At the same time,  our old patch undo work became undone.  Killing two birds with one stone, we put the vents back in.  
 

Cut outline and use heat gun to bend to desired curve.  We then used some leftover flat fiberglass strips as verticals and glued them in place with resin.

next, fiberglass the backside to add strength. 

Then a bit of Bondo, glazing putty, and plenty of sandpaper to get to "race car" level cosmetics.

Two coats of Rustoleum semi-gloss and we have a proper old school JDM style hood in Tom's least favorite color.

"perfect is the enemy of good enough"

Oh, and if you want to see how the original hood was built, have a look here: https://www.facebook.com/media/set/?set=a.193201697377749&type=3

The captions give the step-by-step.

Thanks for the pictures of the mounting and info on how the splitter is reinforced for them internally.  Looks great. 

Which double sided tape did you use for the garden edging... erm airdam?

apexanimal said:

Which double sided tape did you use for the garden edging... erm airdam?

 

It's in the photo on the previous page. Zoom in.

Scotch Extreme ...I got the big roll.

https://www.lowes.com/pd/Scotch-Mount-1-in-x-33-33-ft-Two-Sided-Tape/1002036724

So this just happened.  Tom says blondes have more fun...and photograph better.  
 

I'm getting a Billy Idol vibe from this...

Awhile back we did a bunch of tire size testing...I posted a couple shots earlier but no results.

That full test story is now online:

https://grassrootsmotorsports.com/articles/how-to-find-the-ideal-wheel-and-tire-size/

Do you run a muffler?  Do you like how it sounds?   I'm trying to plan ahead for a k24 swap exhaust. 

You're going to need a muffler.  I have two on my k24 car, resonated and chambered, and it is still really loud when on the big cam especially.  I have a 3" exhaust which doesn't help.   It's not an unpleasant sound, but not an Alfa V6 or flat plane V8, typical high rpm four cylinder. 

I was going to say, if you're already painting, might as well make the hood white. I've always loved reading about this car. I'm sure it's quite an ordeal doing One-Lap in it.

Lof8 - Andy said:

Do you run a muffler?  Do you like how it sounds?   I'm trying to plan ahead for a k24 swap exhaust. 

Yes, two of them.  Burns 17" in the tunnel and a Magnaflow oval at the back.  Both have been repacked with Bristol Core loose fill for even better damping. 3" exhaust.

Have a look at the pics here: https://www.facebook.com/media/set/?set=a.730236905775233&type=3

Harvey said:

 I've always loved reading about this car. I'm sure it's quite an ordeal doing One-Lap in it.

Tom has no idea what he's getting into...it's basically a race car with a license plate.

Here's a quick vid from the last time we ran it back in 2014...Michigan interstate.

With great downforce comes great down force ... on the springs.  To keep from constantly riding the bump stops, it's usually necessary to up the rates accordingly. 

This establishes a more constant "platform" for the aero to stay in it's optimal operating zone.  Ground effect is key to splitter performance, and with FWD aero, it;s all about the splitter.  Rear downforce is easy.

With our previous setup we ran ride frequencies around 2.1 in front and 2.2 in the rear (11k/7k springs, 1.5 motion ratio).  Very compliant over curbs, with big sway bars to handle roll control.

Eibach sent us a whole box of spring rates so we could dial in our aero without bottoming.  As a starting point, we turned it up to 11 to bracket the range of rates in our stash...16k in front, 10k rear.  Resulting ride frequency is now over 2.5.  Let's hope Tom's kidneys are in good shape. 

We also swapped in a helper spring setup to keep our shock body length constant as we adjusted ride height via perch position to compensate for the increased rates.  
 

Old Swift spring on the right is 6", Eibach full metric spring is 120mm length which is 4.75".  All are 60mm id.  Low rate helper and connector spacer on the left. 
 

To compensate for spring length difference and helper/spacer compressed height, we had to raise the perch 7 turns.  Empirically verified by just moving it up until there is zero pre-load on the installed combo.  
 

Then we moved the perch back down five turns to compensate for the higher spring rate and reset ride height to nominal as before.