Hey guys. The Solo 2 season is coming to an end, and ahead of it is a winter where my car is going to sit in the garage, lonely and unused. S my dad and I figured that we might as well make a few tweaks here and there while we are not driving it. Actually, some BIG tweaks .

Next year I will put the build up on my site, http://www.crxkswap.com, but as stage 2 of our build goes on I decided that I will again post updates along the way here at htuner.

My father and I decided that we are going to build the car to make it more competitive in the SSM class of SCCA solo 2. First things first, we are going to race tires instead of competing on street tires. And we are going to put on some seriously fat rubber, wide enough we are going to have to do some serious mods to the fenders.



Hoosier A6's, 275 front 225 rear

Next, we decided that our second gear needs to be longer. Right now we hit redline at around 55 MPH. It would be highly advantageous to get a bit more speed out of second so we dont have to shift. To acheive this we are going to install a lower final drive ratio, dropping from 4.7 to about 4.052, which would give us a jump to around 65 mph at the top of 2nd gear.

This creates the issue of slower acceleration. The solution? Some more power. We don't want to spend a fortune, and still want decent reliability. To keep things cheap(ish), we have decided on forced induction. Neither my dad or I are fans of turbocharging, since a turbo creates lots of heat in the engine bay, and we are not a fan of the lag a turbocharger generally makes. So Supercharging it is.
We have both been fascinated with the newer rotrex technology, so we have decided on a rotrex kit from kraftworks. That should give us more than enough power to move us along with a lower final drive. As an added bonus, the rotrex unit sits low and will not interfere with hood clearance. To compliment all the extra power we are going to need a larger set of injectors, a new fuel pump, and an oil cooler. We will also have to do some alterations to the engine bay to clear the rotrex unit. Then we will have to plumb the whole thing and fit an intercooler, and a bigger radiator to handle all the extra heat.

To my knowledge nobody has put a rotrex'd k20 in an CRX, or any EF for that matter. We are going to have alot of work cut out for us, but I believe the end product will be well worth it. Parts have started to be ordered, and in a few weeks the lovely New England fall weather starts coming to an end and the car will be back up on jack stands, ready for some more work. I look forward to the challenges I will have ahead of me while tearing back into our car, and will be posting updates along the way.

Keep sharing your progress. Especially if you decide to Rotrex your engine.

Seen some decent peak numbers with very linear power delivery.

Rotrex is definately happening Ben, I already ordered it
That is part of the reason we decided on it, the power curve seems very ideal for our application. I can't wait to see what kind of numbers our k20 will put down.

What size blower did you go with?

From the dyno plots I have seen most cars make 300+hp and 200+tq. I hope the carb eo KraftWerks kit will make those numbers for the '06+ Si.

Simple bolt-ons that you probably already have (i/h/e/cams) help make even more power.

Another picture but in a 92-95 hatch.

yes, it seems that stock k20a2's and k20a's are getting up to numbers around 320(i/h/e) with the c30 unit. I will also be using a c30, and my hopes are to also be in that range. I don't plan on putting a new cam on the engine.

Damn this is going to be NASTY


Edit:

What do you plan to do to counter act all that extra weight up front? K's already sit mostly in front of the axles and now you are slapping a blower on?

a lot of RR/AX guys I know griped about just a stock K in a rex/4g, but with even more any suspension changes planned?

I have changed over from my Tein's to a ground control setup with custom spring rates, and I must say that for autoX the ground controls are countless times better than the teins.
As for counteracting all the extra weight, I am not sure what will be done. To me the extra weight of the k up front is not a huge issue. One nice thing about the rotrex is that the supercharger itself is only 11 or so pounds. Yes you have to add in plumbing and the weight of the intercooler, but I don't think that it will be enough additional weight to make a seriously noticeable difference from where it is now. I will probably just race it as is next year, and if I do find the extra weight up front a problem I will have to think of something to help remedy the problem.

Sway bars.

Been able to put in any more time on this build recently?

Yes, I have been able to make a good amount of progress on the build so far. I test fitted the S/C, and made all the measurements I need for all of the plumbing and cooling. I modified the front crossmember in order to clear the s/c. As I speak my transmission is in the basement receiving the new final drive. I already dropped the fuel tank and installed the new fuel pump. I will post pictures of the crossmember and clearance when I upload all my camera pictures. Next on the to do list is install the new injectors and send out the motor mounts to receive stiffer urethane. I will try and update more ofter, its just been tough with school and the whole college application process that I am going through to find the spare time.

Are you still running an OEM X member?

If your class allows I'd look into something else personally FR (full race)'s X member for your car.

I ran a full race cross member all of last season. SSM doesn't actually allow it, so I am switching back to the OEM piece, but a modded one to clear the rotrex supercharger. There should be a writeup on the crossmember soon on http://www.crxkswap.com

UPDATES! When I was finished the transmission I decided to check on the clutch. Guess what!? My fidanza 3.2 clutch was worn ALL the way down. It is fortunate that it was checked when it was, because it would have not been long before no clutch material would be left. This is disappointing because the clutch has seen less than 7000 miles. The fidanza flywheel also showed signs of the bolts starting to back out. Verdict: Fidanza= .
A clutchmasters fx400 clutch and pressure plate went in, and the fidanza flywheel was pulled in favor of the stock ITR unit that I just got resurfaced. The fx400 is a much less streetable clutch, so my dad and I figured the heavier rotating mass of the ITR flywheel will make it a bit more reasonable on the streets (And we won't have to worry about this one trying to back its way out.)
The rest of the car is coming along nicely. The engine in back in with its new stiffer mounts and a little bit more clearance between the subframe and headers than before(The headers had been just barely hitting up against the subframe upon examination). The rotrex is in its final mounting position and my bell intercooler started getting built today. The wheel and tire fitment issue is currently being addressed, and I am looking around for fender flares(anyone know of any nice ones?).


On another note, CHECK OUT MY CAR IN HONDA TUNING MAGAZINE! (feb-mar issue).
After over half a year of waiting, they finally fit my car into an issue.

Lastly, my site is finally seeing some updates in case you want to follow the build in more detail.

I think J's racing made some fender flares for the rex and a few small groups of fabricators made carbon fiber and kevlar knockoff of them. It was years ago when I saw them though.

Maybe you could get a set of flared fenders for the front like the ones used to clear drag slicks. Someone way back also had a one piece fiberglass front end with holes cut in it for the head lights. If I recall correctly it looked pretty clean.

I had emailed J's a while ago, but the fender flares they make are not wide enough. Yasu from PPI couldn't find exactly how wide they were, but said they were "slightly less than an inch". In order to clear my setup I am going to need almost 1.25 inches.

Grab some universals for a true badass look and trim as needed.

Just an idea.

Who says a full size radiator AND intercooler wont fit in a CRX??

Were you able to find fender flares?

No luck with fender flares, but we are cooking up a solution. Wheel fitment at this point is on the bottom of the priority list, we are busy finalizing the intercooler and radiator plumbing, as well as doing other various things that need to be done so we can get this thing fired up.

I'm excited to see dyno numbers if you decide to tune on one.

Have you made any mods to the engine?