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Discussion Starter · #1 ·
i thought would do a new build thread, i had one over on HT.com for my car from its street car state in 2001 through its track day, and all out honda challenge H4 race car stages.

The H4 class kind of died out in NorCal, and at that same time i started to look into wanting an Enduro car. H4 cars, in the enduro classing, just don't stack up very well to the much faster cars. So i looked into the H2 class which is faster and is better for an enduro car (more power and just tad more weight).

I did a bunch of research and was set on going with the B16a for H2. But i decided against it for many reasons, and went with the newly classed K20a3 (with the 5 speed tranny).

The rules are fairly limited, must use all factory parts (excluding valve springs and retainers), can't do any sort of fancy port job only "gasket matching". The things you can do are Intake, header, ECU, and Exhaust.

The transmission is pretty limited too. We are allowed to add any LSD we want, and can change the FD to anything we want.

I'll be running an R-crew header, K-pro ECU, and a custom exhaust. As of now the exhaust is 2.5 16g stainless with 2 Burns Stainless mufflers. I might be upgrading to 3inch depending on what the dyno says. The intake is up in the air as of now too, and will be decided on the dyno.

Here is the car last year with the D16z6

here is the old motor, it is a great motor ran and WON the 04 25 hours of thunderhill in the E2 class, and then ran 2 full seasons of sprint races. it made around 130whp and 110ft/tq. (it is FS BTW)

A few older pictures of the interior.



I pulled the old motor back in November/october. Since that time i had been deciding what motor to go with and trying to sell off all the D series stuff i had to help fund this swap. I finally found a motor, for a GREAT price.


It is a complete swap (minus ECU) out of an 03 honda civic SI.


I have read on here that i can use the axles it came with (EG with HASPORT MOUNTS) I hope this is true.

And now the process to install the motor has begun
transmission mount with the spot welds drilled out ready to be removed

bye bye D/B/H motors HELLO K

As mentioned just above I am using HASPORT mounts. They support Honda Challenge (they have sponsored the championship video for 3 years now THANKS GUYS), you never have to worry about fitment, the quality is top notch, and their customer service is great to deal with.

here is the passenger side mount just on sitting on the frame rail.

and here it is bolted down


After driving a K swaped honda with power steering i decided i HAD to have it. So i picked up a power steering rack, and sub frame from HAP. If you need any honda/acura part and are in the sacramento, CA area give them a call and ask for Bee. He is a very knowledge about honda/acura as he has been into them since the early 90s.

Here is the PS rack and subframe with the HASPORT rear bracket bolted up.

and in the car


That is about as far as i have got thus far. I am waiting for my KAAZ diff to come in from www.prima-racing.com so that i can put that in the transmission and then put the trans and the motor in all at once.

I have my fuel lines, ordered everything from http://www.xrp.com/ . After dealing with cheap fittings on my first try at an oil cooler setup i swore never to deal with cheap fittings again. XRPs stuff is super nice quality and they have great customer service.


Ill be installing "Jiffy Tite" quick disconnect for the ease of disconnecting.

Other improvements to the car in preparation for H2 include the P1 spec splitter kit. Kiwi is a great guy, and fellow Honda Challenge racer who makes very very nice products for road race cars.



I will be going with electrical power steering because i don't want to and it isn't exactly legal to cut up the hood in order for the pulley and PS line to fit. Plus it should make it easy to roll the car around the paddock and garage.

I'd like to use the EP3 shifter since i have the EP3 shifter cables, and it should be cheaper to just buy that rather then purchase RSX cables, shifter, and shift level.

Unless the EP3 and RSX shifter cables are interchangeable, but i doubt that is the case.

So the major things left to purchase are

1. K-pro ECU
2. Radiator
3. EP3 shifter (or if i can't mount it up all the RSX stuff)
4. custom clutch line
5. Clutch and fly wheel (going with exedy as they offer a great nasa discount)
6. charging harness

I'll keep this thread updated as time goes on.

thanks for looking!
 

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GL with the swap man. I'm just curious as to why you didn't go with a k20a2 or were you on a very low budget? Since it seems as though you could've went with that motor after reading what you posted.
 

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nice build man. Also curious on why the a3 tho?? None the less, nice chasis set up. I'm in the process of building an h1 car over here on the east coast, anyway you could set me up with that kiwi guy?? I'm having some issues with not enough downforce comin from the front. Pm me if you can help a brotha out.
 

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the A3 is probly the only motor classed for H2...

A2/Z motors and K24's are probly all only legal in H1
 

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yup. k20a3 is allowed in h2 limited prep. All other k motors are limited to h1 hybrid.

the A3 is probly the only motor classed for H2...

A2/Z motors and K24's are probly all only legal in H1
 

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I will be going with electrical power steering because i don't want to and it isn't exactly legal to cut up the hood in order for the pulley and PS line to fit. Plus it should make it easy to roll the car around the paddock and garage.
I'm pretty sure electric power steering is illegal in h2. The rules for h1 hybrid list "power steering system" as an unrestricted modification. However h2 *does not* give that same option in their list of allowed modifications in sec 10.2 .
 

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Discussion Starter · #11 ·
In road racing speed= $ cubed IE the faster you go the more money you spend. Going faster costs you more money in consumables. And it costs you more in the build up front.

Just looking at it from the motor stand point, it would be about $1500 dollar more to run a K20a/z. But then that would bump me up to H1 or my car would have to weight in around 2800 lbs (weight in road racing also = $$$). Making the switch to H1 would mean wider more expensive tires (an on going cost), new wider wheels, a bigger brake setup. And then i would be going through tires faster, brakes faster, wheels bearings, ect ect ect. THe expense just of the build was enough to keep me away for now.

The k20a3 in H2 runs against the B18a/b(2200lbs), B16a w/CTR cams(2250lbs), B18c1(2400lbs), B18c5 (2500lbs), H23a(2475lbs), H22a (2600lbs) and maybe a few other motors i am missing.

I went with the K20a3 because it has a good balance of HP and TQ, at a weight on the lower end of the spectrum. The only motors that will make more tq are the H23a, and H22a but that comes at a lot more weight.

If i can make 160whp and 140ft/tq i feel that the car will be ok in the power department at 2350lbs (if i wanted to run a 6speed i'd have to weigh 2400lbs). I would like to see the k20a3 at 2300lbs, and that maybe in the works as it is becoming more and more apparent that these motors don't make the power gains, and or aren't as underated as the K20a/z and K24a(tsx).

kommon_sense Good point, and this is were things get very very very weird. H2 follows the H3-h5 section, and all that mentions is that PS may be removed. But because of the nature of H2, a class full of hybrids, i am sure it is an oversight. Ill be sending in a rules request and seeing what happens.

I'll be getting the diff, charging harness and several other things early next week. Once i get the diff ill put that in and then wait for my next paycheck and get my clutch from Exedy.

Then its time to throw the motor in and setup the fuel lines, PS, and wiring.

THen it will again be a waiting game for money to come in for the KPRO.
 

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Discussion Starter · #13 ·
Sorry not pictures, but i did make some progress.

I pulled the transmision off of the motor, and got it most of the way apart. But i was dumbfounded when i saw that there was a ~1/2 allen wrench in the spot that is normally occupied by a 3/8 female ratch end.

I don't have any allen wrenchs that big so that stoped the progress. Ill update with some pictures tomarrow
 

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I don't have any allen wrenchs that big so that stoped the progress. Ill update with some pictures tomarrow
bah... thats when you take a bolt with the head the same size as the allen hole. double nut the bolt and voila... No buying freakish sized allen keys for a single use.
 

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Discussion Starter · #17 ·
Picking up the new Diff bearings and ring gear bolts today, a long with the charging harness.

FYI

The K20a3 Ring Gear bolts are not the same as other K trans. If you are dropping in a LSD like KAAZ, you need to order ring gear bolts from a RSX type S or 06+ civic SI Part Number 90017-PYZ-000.

I PROMISE to finally snap some pictures of the project.

I did some research on the clutch/fly wheel combo and am changing it up. I am a huge fan of the least amount of rotational mass when possible.
 

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Discussion Starter · #18 ·
ok so finally some updates!

Here is the trans completly dissembled. I have torn apart D and B series transmissions 10 to 15 times. The K series was a little different but nothing impossibly hard to figure out.


here are some pictures of the KAAZ diff, and the speedo gear it comes with (must change this out as the OE one just wont work).



Comparison picture of the two side by side KAAZ on the left OE a3 on the right

Here is the difference between the 03 a3 ring gear bolts, and the 06 civic SI ring gear bolts. (06 SI civic ring gear bolt on the left and a3 bolt on the right)
It is pretty easy to see the different and the a3 bolts just don't work.


here is a picture of the speed sensor and the different between the two gears, not only are the teeth different but they also sit in a different position once installed.


i tried to snap a picture of how you remove the gear, there is tiny c-clip that must be removed, having two sets of hands or a vice makes this much easier.

Here is the diff, and ring gear in the trans.


and here is the trans everything else installed.


oo look i can see straight through the axle hole in the diff = LSD :)


Unfortunately my honda bond went missing so i wasn't able to put the case back together, im getting some today and will take some more pictures as the case goes together.

I also spent some time "cleaning" up the motor. When you have a race car, there are A LOT of things that you don't need and add another possible failure point. So i went and removed everything that I don't need. Ill be getting plugs/plates, and zipping everything up as before the motor is fired up.
HVAC hole that will be plugged.

Removed all of the tubing for HVAC and emissions stuff

this will be plugged also. K-pro will be sending all of the engine vitals to AIM were they will be displayed on the dash and logged.

this sensor is not needed, and the hole will be be plugged.

the heater core bung will be plugged.

the fitting closest tot he camera will be used for the catch can system and the one closest to the injectors will be capped off.

Everything i pulled off of the motor

Here is the charging harness, all nice and new. It was $~80 from the dealer, and i needed all the plugs, it will be modified though as i am completly re-wiring the car.

Here is the old chassis harness.

and inside the car with all the wiring gone. The switch boards and wiring you see in there will be cleaned up and added to. I need 3 more relays and then i need to figure out wiring for the ignition, brake lights, and that is it really. I already have relays and switches for the AIM datalogger, Windshield wipers, and cooling fan. Still to be added are; Electric PS pump, fuel pump, and a defroster fan. If you look under/at where the dash would be you will see two tube coming down, the one on the right is were the OE HVAC system draws in new air, and the one in the middle is where the system distributes air to all the vents. I blocked off all of the openings except for the the "windsheild defrost" ones. I will be putting in an inline blower fan, and connect to two ports, flip the switch and ill have some what of a defroster system.


and here is a picture of the R-Crew header, just need to trim up my exhaust some that it meets in the same location (i already ran a slip fit setup so no need to weld/cut/add anything to the system, just need to take out maybe 6 or 8 inchs of tubing.
 

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Discussion Starter · #20 ·
I would also like to know the pin outs from Kpro to AIM and what is also require for other sensor to be output to the AIM. If it is possible.
You use an RS32 cable (i think) and have Hondata setup you're Kpro for it. Contact them for the info on what need to be done.


Then your AIM can see everything that K-pro sees.
 
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