was the same with the NA K22 stroker.

 

On the Doctronic'd ECU? I let it pull IGT at -85 rpm by 5° and by -200 rpm by 10° BTDC - sort of S-shape IGT correction, quite effective and not too harsh to get it instable in normal conditions.

 

I have implemented that since the beginning. Same as on my Emerald ECU on the SC Rover K beforehand.

 

Ok, still wondering why 800-850 rpm idle causes weak torque to lift of. But anyway, 950 rpm is not far away, only for the TÜV, which don't like to see that on a warmed engine. Maybe you have a good friend at the TÜV doing AU for you?

 

I adjust idle down for the AU. The higher idle is only for convenience. Idle quality is the same. It is just the torque.

 

Understood 🆙. Anyway, with these cams the 2-Liter engine can idle smooth at 850 rpm. The TODA C, D, E and F have a bigger low speed lobe design, a kind of race spec design, an engine idles with these around 1000 rpm on a 2-Liter engine. All these cams have in common the same lift and ramp design of the high speed lobe, thence the characteristics of those are the same, just for different engine speed by different durations at high speed lobe.

For all non-AU guys. Here in Germany AU (= Abgasuntersuchung, German for emission inspection) is sort of MOT test, which has a duty interval of 2 years for legality.

 

intake: 3inch custom
70mm tb
RRC IM with extrude hone + 70mm port
410cc rdx
toda light weight pulleys
plm header
3 inch exhaust
KPRO
HP:216.1 TQ:159.8

 

Hi, would it be possible to get power output in range 270-300whp with this setup? Goal is NA high revs and response. It is for rx8 swap.

K24a3
S2000 intake/ext. manifold
3inch decat exhaust pipe
82mm dbw tb
Skunk2 tuner stage3 cams
50° vtc gear
12,5:1 CR pistons
410cc inject.

 

I’d give yourself more injector, esp because getting the higher parts of that number will require more octane than 93.

 

I think so. Please read through the all motor section.
I'd still would not rev a k24 build post 8k unless for very short periods of time on the street. Pistons speeds get very high and with it side forces. These will wear out pistons, liners and rings. Oil film is at its limits. Does not matter for a few 1/4 mile runs or squirts on the streets, but doing 100+ circuit track miles every other weekend will wear a k24 engine out in a short period of time reving it that high.

 

Just got my car dyno tuned, here's the setup:

k24a2 junkyard stock block, unknown condition/milage
PRB type S cylinder head with DC 3.2 cams and 50 deg vtc gear
RBC intake manifold with 74mm skunk2 TB and 3.5'' intake
Type S oil pump
skunk2 alpha header with 3'' exhaust
Oem decapped 550cc injectors with walbro 255 fuel pump
2006 civic Si LSD transmission

Really need more compression to take fully advantage of those cams tho but car is pulling strong and car is running really good. Will probably have a bottom end built next but this is fun for now

 

PRB type S cylinder head with DC 3.2 cams and 50 deg vtc gear
RBC intake manifold with 74mm skunk2 TB and 3.5'' intake

That's a nice setup. Thanks for sharing. VTEC is DC OG-typical quite late - torque graph looks like this is no must, but a feature - on the cost side, on the win side it carries torque high and wide into the 7 krpm. Was it redlined at 7900 rpm?

 

we did rev it out to 8200 but it won't make any more power

 

Thanks for your reply. I've tuned a few K24's with the DC OG 3.2, one setup was quite similar with an built longblock (11:1 CR), which made 188 wftlb@6500 rpm and 255 whp@7800 rpm. I wouldn't expect too much from an built block. Ignition timing was very conservative, due to the hot summer there (up to 44 °C), around 26-27° BTDC at the high speed cam.

Also consider the 3.2 cams are not recommended to run at 50° VTC, you may need to clay these if the valve relief depth is to low. We run, as customer didn't want to open the engine at max. 40° VTC, loosing about 12 wftlb of torque over a 1500 rpm range. Claying would open up some potential.

If the header is a good one and the atmospheric conditions are power-wise supportiveness, a 200 wftlb and 265 whp may be possible. The alternation of load is restrictive, you won't exceed that area with that alternation of load setup.

 

My tuner did mention to weld a 3'' collector on my header. Its only 2.5'' right now but the whole exhaust is 3'' so the collector is a bit of a restriction

 

Figured I'd share something with y'all. Not the perfect comparison, but as close as I could get.

These were both run on the same dyno, but different days. Both cars are junkyard K24A swapped into a Lotus Elise/Exige.

Similarities:
K24A with K20A2 oil pump
K20Z3 transmission
3" intake tube
RBC intake manifold
Danny Tran Racing long-tube Lotus header
BOE 2.5" Lotus exhaust
Haltech ECU and same tuner
Injector Dynamics ID1050XDS
Pump 91 octane from Arizona

Differences:
Throttle body:

• Red - RSX Type-S 62mm
• Blue - ZDX 70mm

Head:

• Red - Stock RBB
• Blue - 4Piston CNC'd RBB with +1 intake and exhaust valves

Cams:

• Red - Toda A3, VTC pinned to 40*
• Blue - 4Piston RR3, VTC pinned to 35*

I couldn't figure out how to turn off the lift trail in WinPep because I'm dumb

 

Thats a healthy difference up top but also alot more effort

 

Im sus that tb and stock k20 head would make same and wouldnt loose anywhere else.

 

I was curious how much of the gap the larger TB and RBC head would make up, maybe we will find out later this year. I'm very close to the power to weight cap for my class as-is, but being able to turn it down at the very peak and gain some area under the curve over 6k would be nice without spending a bunch of money.

 

Thanks for sharing the result @chibo.

...but being able to turn it down at the very peak and gain some area under the curve over 6k would be nice without spending a bunch of money.

Isn't it still a stock block?

4Piston CNC'd RBB with +1 intake and exhaust valves

Beside my comment and flowbench result on that head (s. (1) Flow bench results - 4Piston ProTSX vs Honda F20C1 | Honda / Acura K20a K24a Engine Forum), I am sure I mentioned that going +1 mm on exhaust side is a risk of a serious lower torque down low (depending on valve throat ratio more or less). Also you kill valueable down low with the fact of less VTC by valve to valve restrictions. On a stock block (not sure, but looks like according the torque curve) it is a disadvantage.

My recommendation would be a simple setup:

• 70 mm TB
• TODA A3 cams
• RBC stock head (no porting, no "special valve seat cut", just sealing valves and healthy condition)

This would give you a better torque everywhere, not the same peak power (maybe 256-263 whp), but for racing the better out of corner torque. When your chassis setup can stand this, the laptime would be easily to cut down more far as with the actual peaky setup, for 1/10 of the price.

 

Thanks for sharing the result @chibo.

Isn't it still a stock block?

Beside my comment and flowbench result on that head (s. (1) Flow bench results - 4Piston ProTSX vs Honda F20C1 | Honda / Acura K20a K24a Engine Forum), I am sure I mentioned that going +1 mm on exhaust side is a risk of a serious lower torque down low (depending on valve throat ratio more or less). Also you kill valueable down low with the fact of less VTC by valve to valve restrictions. On a stock block (not sure, but looks like according the torque curve) it is a disadvantage.

My recommendation would be a simple setup:

• 70 mm TB
• TODA A3 cams
• RBC stock head (no porting, no "special valve seat cut", just sealing valves and healthy condition)

This would give you a better torque everywhere, not the same peak power (maybe 256-263 whp), but for racing the better out of corner torque. When your chassis setup can stand this, the laptime would be easily to cut down more far as with the actual peaky setup, for 1/10 of the price.

It is a stock block, yeah. To add more to the story, the red line is my car and the blue line is my friend's car, the head is off one of the ill-fated 4p motors from a thread on this forum, he figured may as well try and reuse something instead of a complete waste of money.

I will find myself a RBC head to put in around May during our season summer break

 

K24 S2000
Stock JDM RBB-2 K24A (10.5:1 CR)
Stock head
50 degree VTC
06-08 TSX cams
K20 oil Pump
70mm throttle body
S2000 header
S2000 intake manifold
S2000 intake box with air duct
70mm test pipe + 3 inch exhaust


What should I get if I want to make more power without touching the bottom end? The car is 90% track but I do drive it on street every once in a while.

I'm thinking about getting the following:
RSP head
Toda A3 cams with Toda valve springs
Better intake manifold (KPower RWD RBC style or PracWorks RWD)

 

s2000 intake manifold is hot garbage , your on the right track with the KPower RWD RBC style or PracWorks RWD) idea

dont get toda cams , get DC or crower instead

 

Curious if the intake manifold and huge TB are hurting the low end torque. Im running a similar motor JDM RBB4 all stock internally with RBC gear and Type S pump. As you can see I make much more torque and earlier. I love it as it really helps pull me through and out of the turns on the track. I make less top end but I had to cap at 220 due to power to weight class rules.

Untitled by Victor M, on Flickr

 

I think All JDM K24s have 04-05 USDM TSX cams so could be the one of the factors

 

it may also be header style as well as mine is a 4-2-1 so that helps with torque as well

 

The stock k24a2 RBB intake manifold offers really high mid range torque. Honda literally optimized it for that mid range torque. Avoids many down and upshifts out of corners. No need to always exit the corner in 2nd gear at 6k just to make progress. 3rd at 4.5k will perfectly do it.

 

s2000 intake manifold is hot garbage , your on the right track with the KPower RWD RBC style or PracWorks RWD) idea

Would be nice if you can prove your claim. As @Lotus already shared a dyno sheet of a K24/K20 engine where the RRC outperformed the PracWorks by far everywhere on high speed cam, I am curious what data your claim is based of.

dont get toda cams , get DC or crower instead

I run simple TODA A3 cams on this well developed 2 Liter NA hill climb race engine, producing 311 hp and 211 ftlb of torque (s. below).

Also my customers are always in the top 3 in their race classes, using TODA cams. Members here run their TODA cams over 90.000 km without any significant wear. I think there is a reason why TODA cams are on these engines. I am not saying DC cams have not their purpose, but to win races you need a wide and high torque bandwidth to work with or more gears to compensate peaky torque curves to win. I put no DC cams in these engines, even if they give higher peak torque, their bandwidth is at around 600 to 1000 rpm smaller than that of a comparable TODA camshaft. The good on the DC cams is they are easy on the valvetrain, and durable. They have their purpose, that's why I see no reason to wipe one of these in that generosity from the table of interest.

At @beefystud, please explain further why you are claiming this.

 

Would be nice if you can prove your claim. As @Lotus already shared a dyno sheet of a K24/K20 engine where the RRC outperformed the PracWorks by far everywhere on high speed cam, I am curious what data your claim is based of.

RCC CANT FIT ON RWD SET UP AND THE S2000 INTAKE MANIFOLD IS TERRIBLE/DATED , I WONT ARGUE THAT THE RCC IS NOT BETTER THAN PRAC OR KPOWER, ITS WHAT I RUN

I run simple TODA A3 cams on this well developed 2 Liter NA hill climb race engine, producing 311 hp and 211 ftlb of torque (s. below).

View attachment 121565

Also my customers are always in the top 3 in their race classes, using TODA cams. Members here run their TODA cams over 90.000 km without any significant wear. I think there is a reason why TODA cams are on these engines. I am not saying DC cams have not their purpose, but to win races you need a wide and high torque bandwidth to work with or more gears to compensate peaky torque curves to win. I put no DC cams in these engines, even if they give higher peak torque, their bandwidth is at around 600 to 1000 rpm smaller than that of a comparable TODA camshaft. The good on the DC cams is they are easy on the valvetrain, and durable. They have their purpose, that's why I see no reason to wipe one of these in that generosity from the table of interest.

At @beefystud, please explain further why you are claiming this.

TO BE HONEST IM GOING OFF MY EXPERIENCE WITH THE F20C CAMS FROM TODA, THEY ADD ZERO POWER, I GUESS YOUR RESULTS PROVE THE TODA CAMS FOR K SERIES ARE MUCH BETTER SUITED

Mod Edit: corrected quotes, please use the mark and quote function next time (PC) or quote and shorten the quote and copy it when you need different phrases. Otherwise it is hard to understand what you state.

 

RCC CANT FIT ON RWD SET UP AND THE S2000 INTAKE MANIFOLD IS TERRIBLE/DATED , I WONT ARGUE THAT THE RCC IS NOT BETTER THAN PRAC OR KPOWER, ITS WHAT I RUN

Ok, understood it's about a RWD setup. There are also Hayward, Skunk2, ITB's and of course moded F20C IM's one can use beside the mentioned. I am sure there are more, but recommending a 1200 USD expensive one, which doesn't much as a RRC would add makes no sense to me. A S2 US IM can do that for half the price at least the same .

TO BE HONEST IM GOING OFF MY EXPERIENCE WITH THE F20C CAMS FROM TODA, THEY ADD ZERO POWER,

It's still a claim, can you prove it or give some background to it? Who did tune it?

 

Ok, understood it's about a RWD setup. There are also Hayward, Skunk2, ITB's and of course moded F20C IM's one can use beside the mentioned. I am sure there are more, but recommending a 1200 USD expensive one, which doesn't much as a RRC would add makes no sense to me. A S2 US IM can do that for half the price at least the same .

It's still a claim, can you prove it or give some background to it? Who did tune it?

id have to dig through s2ki.com to find the threads but have heard of alot of unhappy customers who tried using the toda f20c cams and never got any noticeable improvements in power

 

F20c and F22c have no VTC on the intake cam. Lacking variable cam timing makes adding power with cams much harder. Usually you have to dial in cam timing using adjustable cam gears or pulleys (verniers) with aftermarket cams to make them perform well.
I have done this during my Rover times. Without the correct settings, the torque curve plainly sucks.


VTC makes a HUGE difference as you don’t have to compromise optimized cam timing for one rpm band for an other.
We all know that even plainly changing an exhaust system with less back pressure requires retuning of the cam maps.

 

I have placed the order for toda a3 and will report back once I have the dyno with RSP head installed. Any recommendation for intake manifold? Looks like KMiata is the most common one for RWD applications

 

Skund2 Ultra street is a very solid performer and can be cleaned up internally as well. Worked for RWD and FWD as the intake section can be flipped.

 

HONDA K20 K24 CL9 FD2 TYPR R FN2 FG2 BILLET RWD INTAKE (optional 4 or 8 injector | CNC INNOVATIONS

HONDA K20 K24 CL9 FD2 TYPR R FN2 FG2 BILLET SIDEFEED RWD INTAKE MANIFOLD (optional 4 or 8 injectors) (optional 4 or 8 injectors) A SET IS INCLUDED : PLENUM & RUNNER FEUL RAIL & BRACKET FITTINGS (AN6, AN8 ,AN 10 AND HOSE FITTINGS) INCLUDED ADDITIONAL OPTIONAL BILLET FUEL RAIL AND INJECTOR PORTS...

www.cncinnovationsmy.com

This intake manifold looks pretty interesting to me although it might be too much for a stock bottom end. Looks like a pretty big plenum.

 

https://skunk2.com/induction/intake-manifolds/ultra-street-intake-manifolds/307-05-0605.html

HONDA K-SERIES INTAKE MANIFOLD DYNO FACE-OFF – Tegiwa Automotive Blog

www.tegiwaimports.com

The ultra race is not suitable for street driven engines as the runners are to short.

 

Yea the ultra street looks pretty good but I also noticed the KPower RWD IM claiming better performance than the ultra street. KPower RWD Cast Intake Manifold

• Comparable top end power with increased mid range torque compared to the Skunk2 Ultra Street

 

good to have options.
What I like about the Sk2 is the modularity. You can open and clean or port it, fit spacers, flip it around for RWD or FWD.

From KPower FB page 2020.
View attachment 121600

https://www.k20a.org/threads/official-dyno-chart-comparison-calibration-registry.34644/page-72

and same thread:

https://www.k20a.org/posts/3332093/