Honda / Acura K20a K24a Engine Forum banner

1 - 20 of 472 Posts

·
Registered
Joined
·
533 Posts
Discussion Starter #1 (Edited by Moderator)
Rob's a busy guy like most of us, but he made time to send me an e-mail today asking what address to send the intake port info to, so that's a good start. Step by step, right? Everything worth while takes time.
So far the only thing we've found that can hurt the 8.5 or 9.0 HP-wise is a crappy header, which makes sense because the intake and exhaust work in concert with one another in a big way on a N/A engine.
Both 4 into 1 and 4-2-1 can work equally as well.
 

·
Registered
Joined
·
341 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

the intake and exhaust work in concert with one another in a big way on a N/A engine.
Both 4 into 1 and 4-2-1 can work equally as well.
Its amazing how little people realize these 2 very important facts about exhaust/intake design.
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Update:
$1,239.67 Received via Paypal.
Blazed,
We've used 78mm and 90mm T/B's primarily.
The 9.0 I delivered yesterday is the first one using a DBW T/B. Something the customer modified himself, a 76mm Tundra T/B. This will be a continuation on the 2,381cc engine testing done back in Oct, 2010. Its been sleeved now so its a little bigger too, 2,464cc. Its even in a different car ('07 Si) and owned by a different guy, but its basically the same engine. Same stock valve head, stage 4 cams, Crower Equipment rods. Different header, gone is the POS Skunk2 monstrosity, replaced by one Grudynski's guy built for it. I couldn't see much of the header, but its got 1 3/4" primaries and looks like 4 snakes who swallowed fat Rats for lunch. We'll see how that works out next week when it goes back on the dyno.
Rob,
I can drill and tap the T/B flange with any bolt pattern, or even multiple bolt patterns if you want. Just need the info from you.
You know, for all the shit talked about that header, that custom header picked up 3 whp over the skunk2 AFTER TUNING. 1 whp pre tuning. also lost power under 6k

Can you explain that? I know the person you're talking about, as i've said before. This wasn't on his 2.5L motor, it was his k20, but it still stands.
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

What 'custom header' are you talking about?
Custom, as in the one made by Hytech? It's a 4-1 am i correct?

Anyways, i'm just really curious how the header is so terrible. It doesn't seem to be all that terrible. Hell switching from the trash header i had on my car to the skunk2 i picked up 12 whp.
 

·
Registered
Joined
·
81 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

What 'custom header' are you talking about?
I won't use the S2 IM's on any of my builds as I have very little faith in any of the power claims, but calling it "junk" is a stretch. I've seen and had mixed results with the IM's (I actually had a K20 customer gain power switching to a ported RBC from a S2 IM), so it's really a bag of mixed nuts.

NOw as far as RH goes -- S2, by far, has the best OTS race header for the 8th gen Civics, at least as far as K20 builds go so far (I haven't personally seen any realistic data comparing the S2 MP vs custom RH's on K20/K24's).

On a K20, the "custom" race header you saw on the car in question picked up almost nothing over the S2 MP. Bold blue is the "custom" header, the other graph is the S2 MP.

 

·
Registered
Joined
·
533 Posts
Discussion Starter #7
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

w00t692,
Yep, he told me the Grudynski header was a 4 into 1 and I could see it has John's anti reversion setup and 1 3/4" primaries, consequently I'm not expecting to see much in the way of serious HP from it. It may be just as bad as the skunk2 header that was on the engine when we tested it 3 years ago.
We tested the skunk header against my standard dyno header and here's the chart.
 

Attachments

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

w00t692,
Yep, he told me the Grudynski header was a 4 into 1 and I could see it has John's anti reversion setup and 1 3/4" primaries, consequently I'm not expecting to see much in the way of serious HP from it. It may be just as bad as the skunk2 header that was on the engine when we tested it 3 years ago.
We tested the skunk header against my standard dyno header and here's the chart.
Thanks. That's all i wanted to see. I wouldn't expect to see gains like that on a k20 from a different header, but a larger engine i would.
 

·
Registered
Joined
·
533 Posts
Discussion Starter #10
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

You might be surprised on that. It all depends on how wrong one header is and how right the other one is.
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

You might be surprised on that. It all depends on how wrong one header is and how right the other one is.
How does the toda header look to you?



The sizes are:
1.77" primaries (16.5" long)
1.96" secondaries
2.16" inch collector after the secondaries
2.36" to the exhaust
 

·
Premium Member
Joined
·
764 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

How does the toda header look to you?



The sizes are:
1.77" primaries (16.5" long)
1.96" secondaries
2.16" inch collector after the secondaries
2.36" to the exhaust
Yeah, I'd be curious to hear what Joe thinks of this one, as well. If I correctly remember his previous header comments, the Toda would be in the right ballpark: shortish primaries around 1.75, secondaries around 2, and it has an interesting neck on the collector. Perhaps the main criticism would be the rest of the collector and the exit size?

Back in the day, this was the OTS header, but the price was a little too high for me back then... so I have my sorry-ass DCRH :whiner:
 

·
Registered
Joined
·
269 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Yeah, I'd be curious to hear what Joe thinks of this one, as well. If I correctly remember his previous header comments, the Toda would be in the right ballpark: shortish primaries around 1.75, secondaries around 2, and it has an interesting neck on the collector. Perhaps the main criticism would be the rest of the collector and the exit size?

Back in the day, this was the OTS header, but the price was a little too high for me back then... so I have my sorry-ass DCRH :whiner:
So would I as I have it on my k24 but I cut it at were it has 2 to 1 and made it 3inch to suit exhaust
 

·
Premium Member
Joined
·
956 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Good design with horrible collectors.That style of collector is usually not grounded smooth on the inside. Even if it was, the convergence angle stinks. The end of the Y section points too much into the side of the tube instead of the middle. This 12 deg SPD collector is ideal http://www.spdexhaust.com/MC_B.html#.

The merge sections of the header need to have the lowest pressure loss as possible, and this header doesn't show it. Looks like a good low end mid range candidate, but higher end it will fall short to a header with better collectors
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Good design with horrible collectors.That style of collector is usually not grounded smooth on the inside. Even if it was, the convergence angle stinks. The end of the Y section points too much into the side of the tube instead of the middle. This 12 deg SPD collector is ideal http://www.spdexhaust.com/MC_B.html#.

The merge sections of the header need to have the lowest pressure loss as possible, and this header doesn't show it. Looks like a good low end mid range candidate, but higher end it will fall short to a header with better collectors
Would you say it would perform well if you simply cut the piping and put custom collectors in place?

Because it seems like that's what you're saying heh.

From reading their site, you want the longest transition possible, then if you want a broad powerband you want more choke (minor diamter) at the end of the collector and if you want a more narrow high end powerband you choke it less. Not sure what to do with the divergent angle afterwards but this is obviously only if you're doing the final collector.

I'm sure it's more complicated than that, but that's what i got from "designing" my collector lol
 

·
Registered
Joined
·
533 Posts
Discussion Starter #16
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Its pretty common for metric tube manufacturers to use 5mm steps in their sizing. It may be convenient for them but it sure doesn't help when you're trying to build a header. The 1/8" increments (roughly 3mm) we have in the US works in our favor here.
The K-series is happiest with these tube sizes:
1 7/8" Primary (48mm)
2 1/8" Secondary (54mm)
2.35" Venturi (60mm)
3" Tertiary (76mm)
That Toda header has about the right length primaries but they're too small. The secondaries are WAY, WAY too long, and the collectors are WAY too short. Its also completely welded together, so as all of those pieces of tubing expand and contract in different directions as the EGT changes its attempting to tear itself apart. This is the reason using slip joint collectors is a better method.
Toda makes a pretty nice K-series flywheel, but nothing else they've made for this engine has impressed me in the slightest.
On this header, for instance, I can tell just from the picture that the primary tubes are substantially different in length. NOT the right way to design a high performance header.
I buy 15 degree collector tubes from SPD and make the collectors myself.
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Thanks, i was genuinely curious. Any reason to use 15 degree instead of 12? Space and fitment?
 

·
Registered
Joined
·
533 Posts
Discussion Starter #18
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

w00t692,
Personally I haven't found any advantage in 12 degree collector tubes. They may work better in some cases, but the K-series is the only engine I'm working on.
 

·
Registered
Joined
·
1,080 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

See the weird thing about the skunk2 is that it's got very long primaries and very short secondaries whereas almost all other headers ots for the civic si have the opposite (shorter primaries and longer secondaries).

This is why i'm confused. If its' supposed to have short primaries and short secondaries why the hell does it work so well if it's nearly exactly the opposite.

Also the cylinder pairings for the megapower are different than most. They pair 1 and 2 and 3 and 4 together.
 

·
Registered
Joined
·
145 Posts
Re: Joe McCarthy 9.0 Manifold Testing . . possibly?

Since we're talking about headers in this thread i'm curious what Joe thinks of the prayoonto header SickSilver is running. It obviously performs, but are the primaries, secondaries, and collector used ideal for the k series motor?
 
1 - 20 of 472 Posts
Top