Let's talk about K-swaps

K24 vs K20... Opinions??

I am assuming more torque with the K24, and higher revs with the K20. 

This should be a very lightweight build- I’m leaning toward the K20. But torque is fun too!!

In reply to SVreX :

This thread has me looking for an old thread on speed-talk where these engines were discussed.

The gist of the K-series part of that discussion was that there is no reason to use a K20, the K24 is not bottom end limited.  Drag racers are turning 99mm stroke K24s up into the five digits range and making 400-450hp naturally aspirated on methanol.  (By recollection, have not found thread yet)

This is the general feeling on practically ANY engine... there's no disadvantage to having more stroke, the bottom end is never the limit for making power, it's the ability for the valvetrain to hold together.

SVreX said:

In reply to Knurled. :

What’s “Earth Dreams”?

That's Honda's super green marketing speak for... whatever they did with the K series to make it more fuel efficient.  Like Mazda's Skyactiv. 

Most/all of them are direct injected.

K series motors are rev limited by the oil pumps mainly. 

On the 02-06 rsx type S (k20a2 and k20z1) this is about 8600rpm if you want it to last. I have my own limiter set to 8450rpm as the momentum from accelerating into the limiter pushes it to 8600rpm.

On 06-011 Civic si (k20z3) this is slightly lower as the oil pumps also have a balance shaft assembly built into them. A fellow local autox-er has one of these with his limiter at 8600rpm and done two seasons without issue yet.

The 04-08 TSX (K24A2) some say keep the rpm below 7800, some say 8200. Personally I like err on the side of caution. Some drag racers spin them to 9k+, but they don't last a long time.

It used to be that grinding down S2000 oil pumps to fit K series was the way to go to reliably raise the rev limit, now people are porting the K20A2 rsx type S pumps. The pump isn't a direct swap on engines other than K20As, the chain, guides, and windage tray are different. See here https://afhkparts.com/shop/k20-rsx-type-s-oil-pump-kit/

I'm not sure of the safe rev limit of the lesser k20 and k24s. 

For a challenge build, one of the major hurdles will be a cost effective management setup. Both kpro and ktuner are not cheap. 

I would also think buying a complete donor car will be the most cost effective way to get all the bits and pieces needed without nickel and diming yourself over budget. There's so many people swapping these engines that every little part needed has value. U-pull junkyard pricing will be better than local classifieds, and the good parts at the yard will go quickly. 

What's your horse power goal? Boost or NA?

In reply to Run_Away :

I am not a Challenge rules lawyer, but I thought software counted as a tool and tools aren't part of the budget.  If you pay somebody else to do it, then it is.

Anyway, I found the thread, and it wasn't 99mm stroke, it was 108mm stroke and over 11,000rpm.  Yikes.

Knurled. said:

In reply to Run_Away :

I am not a Challenge rules lawyer, but I thought software counted as a tool and tools aren't part of the budget.  If you pay somebody else to do it, then it is.

 

i think they are talking about the actual kpro/hondata chips that need to be done to the ECU because the stock ecu has to be sent to hondata to be modded to work with ktuner.

https://www.hybrid-racing.com/products/hondata-k-pro-c that alone is $700 and requires a core ecu

I’m a bit skeptical on these. call me a downer, but what about the known ring issues on these engines? That’s why I didn’t get an Accord with one. I rarely see mention that.

And then there’s the fact that Hollis’s went boom in a longitudinal situation. I’m like, a bit more luke than most.

Yes, both tuning solutions require ECU hardware modification. I have an old kpro V2 (they're on V4 now) and there's a physical Hondata daughterboard inside the ECU.

In reply to Run_Away :

Yes, I intend to buy a complete donor car. 

I’d rather not do boost this time. 

HP?  Fun. That’s how much power I want. Fun. 

MrJoshua said:

SVreX said:

In reply to Knurled. :

What’s “Earth Dreams”?

Sounds like a recipe for the worlds most simple turbo manifold to me.

Earth Dreams motors are Direct injected. 

The K24Z3 and K24Z7 are NOT earth dreams motors. They're more power limited because of their single outlet head design, but the Z3 is what the new lower cost K swap kit is aimed at, because the motors are cheaper than the K24a2 by a good bit and for power to weight TT and W2W they fit the bill perfect and they change the packaging requirements such that the stock miata subframe can be retained. 

Also, here's a little compression and piston speed calculator for those who are interested. 

https://www.zealautowerks.com/kseries.html

I am highly skeptical a legit K swap can be done in challenge budget, the affordable motors need "expensive" equipment to run them as Run_Away pointed out. 

That said.. Having bought 8th gen civic Si in challenge budget myself.. Nothing is impossible... 

The advantage my car had/has is the fact that it uses a outside tool for tuning and you don't have to actually physically install something on the car for the tuning to work. 

I think it can be done on a challenge budget, but you'll be building it to say you did it. There are a lot cheaper ways to obtain 200-220whp....

I didn't know the Hondata Flashpro setup was software only, if you could get a complete 8th gen Civic Si (06-11) donor and are good enough with wiring that you could run it on the stock ECU that might be a pretty solid choice. I'm not sure how much stuff you can turn off with Flashpro  - if it's enough to be able to run it like a standalone, or if you'll be swapping BCMs and CAN controlled fuse boxes to make it work.  The other benefit to 06-11 Civic Si is it's the only north american K-series trans to come with an LSD,  and it also has one of the best intake manifolds. 8th gen Civic Si are drive by wire and use a MAF sensor, while the RSX based mangement solutions (Kpro and Ktuner) are speed density and conventional cable actuated throttle body.

What's the cheapest Megasquirt unit that has the capability of PWM based VVT? Map switching is also a big plus so you can have tables for the low cam and high cam profiles (if using a "real VTEC" head).

In reply to Run_Away :

My point about not making a 2k challenge K swap is, you'd probably consume the entire budget on the swap if you could do it, Your point on power is also valid unless the chassis is very light. 

The chassis is very light. 

I expect to consume nearly the entire budget (and recoup) on the drivetrain. 

Yes, it will look like I built it just to say I did it. Isn’t that why MOST  Challenge cars are built?  

This is a 3 year project. My reasons for doing it will not be explained in the first year. After 3, it will make sense. 

If the only thing I accomplish is proving the naysayers wrong, it will be worth it. 

...and if I fail to accomplish it, no one will day I didn’t try. 

poopshovel again said:

Tunes and basic breathing mods are really helpful.   My K24A2 with only I/H/E and tune is putting 205whp and 185 WTq, with a stock redline.  

That's berkeleying badass, Chris.

Hell yes it is.  The car rocks now, keeps up with C5 vettes on track now.  

Some of you may have seen me win the Q45, then pass it on. 

I decided I want to focus on this K-swap instead.

I’m counting on you guys to hold me accountable and help make this happen!! 

In reply to Sonic :

What'd you do for hubs and axles? Any pictures of the swap or a build? I've been working through trying to do a cheap eg/ef hatch w/ a k20 swap.

I've been recently contemplating doing this exact thing (though not challenge focused)!

https://grassrootsmotorsports.com/forum/grm/buyingparting-a-newer-car-for-cheap-project-entrance-cr-vbeige-hondasetc/160600/page1/

3 year plan should make this much more viable. Pricing will drop as the donor cars get older...maybe they will even be an open source tuning option? I did my K-swap in mid 2013 and Ktuner didn't even exist at the time. Pricing on engines/swap parts has also fallen drastically in the last 6 years.

I'd love to see it done. I spent all last night discussing how to cost effectively Kswap a 1g Neon with a buddy....who knows, if the right car comes along we'll be competing beside you!

In reply to Run_Away :

I may have mis-spoke. 

3 year plan is for the CAR. Not the engine swap. 

I want the engine in in the first year. The car will be something very different after 3 years. 

In reply to Run_Away :

I believe you need MS3 for true VVT control. I want to say they made a standalone VVT box for a while (https://www.diyautotune.com/product/vvtuner-valve-timing-control-unit-assembled/)

If the K isn't going to work, may I suggest a 2ZZ-GE from a matrix/vibe/celica? Seems like you had a XRS Matrix in the past.

This is not intended to poo poo the K, just brainstorming.

When faced with this dilemma for a challenge car, a $500 Altima with a 5 speed was my answer. I am not suggesting that it was a good answer.

In reply to wheelsmithy :

I really like the 2ZZ. But I’m not ready to cut up my Vibe. 

Posting to bookmark for future research. 

This thread has some great info, I am doing a k-Swap on an old Triumph, basically following the Miata recipe but in a Triumph Spitfire chassis. Carry on with more details, I am using K-Power's adapter for the Miata 5 speed and their intake, clutch and many other components. Definitely not on a Challenge budget