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Can you upgrade your cams on the stock ECU map?

Stevearcade

Stevearcade

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Cams! Talk ta me :lol:

But seriously, this thinking is out of my depth a bit here as I consider Cams as more than a simple mod like air intake. But from reading the brief for these Skunk2 Stage 1 Cams, it sounds as simple as replacing the stock cams with these and feel the difference.

But I'm not convinced. Is it really that simple?! Would the ECU map not need adjusting to reflect the changes in cam angles etc? Or is there another catch/sting in the tail that I'm not aware of :unsure: .
 
A couple of things about the K24 engine first.
It comprises of two systems. The VTC part (Variable Valve Timing Control), and the LC part (Lift Control).


In this first picture of the engine in my car, you can see the inlet camshaft on the right and the exhaust camshaft on the left
i.e. the picture is taken from the driver's side of the car
The large sprocket on the inlet camshaft, allows the angle of the camshaft to be dynamically changed relative to the sprocket
i.e. the phase of the camshaft can be altered relative to the timing chain
This is the VTC part.

DSCF0185_zps2d19f896.jpg


In this second picture, the inlet camshaft is at the bottom and the exhaust camshaft is at the top (the timing chain can just be seen on the left). If you look along the inlet camshaft to the 3rd cylinder from the left, you can see the high-lift cam in the middle of the lower-lift cams. When the LC is engaged, this cam will open both valves and the other two cams become redundant. The exhaust is the same (can be seen on the 4th cylinder from the left)


DSCF0181_zpsd2a4685e.jpg



Here is a picture of the Skunk2 camshafts (these are for the K20A2), exhaust at the top and inlet at the bottom


680799-zoom_zps5bb898e5.jpg




So if you bought the camshafts for the K24A3 engine in your car, you would simply swap them with the ones in the middle picture.


Now to answer your question "would a remap be required", IMO the answer is "it is not required, but a remap to bring in the LC sooner would be more useful".

So if you didn't change the cams and had a remap, then one of the main improvements is to bring in the LC sooner. I'm not sure if the VVT would also be changed in a remap, Fahad would tell you. But AFAIK, there isn't much else you can change with a remap on a K24 engine. Put another way, a remap of an ECU on a conventional non-VTC, non-LC, or non-boost-pressure engine would give hardly any improvement (if at all).

The thing to bear in mind is that the ECU on the K24 controls (not in any particular order)
1. VTC
2. LC
3. EI (Electronic Ignition) timing
4. AFR ... Air-Fuel Ratio ... controlled by the EFI part (Electronic Fuel Injection)

To all intents, you can consider these as separate systems, as if the engine had mechanical VTC and LC with limited electronic input, with a separate EI, and a standard EFI. At a guess, I would think that early Honda VTEC engines fit this description.

If you go back to an engine without VTC or LC, that has EI and a carb, then changing the camshafts on their own will alter the torque curve and hence the power delivery, without changing anything else, provided that the carb could still run at the correct AFR in the new range of air flows. Normally, one would expect to change the camshafts and the carb at least ...and this is why you may be thinking that a remap would be required. But an EFI system is like having separate carbs that self-tune to keep the AFR constant over a wider range of air-flows.

So what would be the difference with these camshafts. I would think that its mainly the lobe shapes (durations) and phases angles that are slightly different, but as they mention, you would really need their inlet manifold and throttle body as well. And then a remap to bring it all together.

Why did Honda not fit camshafts like this in the first place. Because the camshaft, manifolds, and engine map are a compromise that they make to
1. keep the engine quiet
2. keep emissions down
3. keep the mpg up
4. give flexible range of torque - driveability
5. provide a bit of power at the top end
6. keep service intervals down
7. keep reliability up
 
Steve if you want the car to go faster stick a TXS v6 lump in there lol
 
:lol: Sorry Brian, you're a bit vague, do you think you could elaborate? ;)

Well, I just stumbled upon these cams surfing the web last night and from reading the description thought it sounded too simple for what a K series cams actually do. I get the whole VTC and VTEC stuff and I'm ***uming these cams are engineered to still work with these systems. I just find it hard to believe they'll give an improved torque band without having to adjust the fuelling (ECU map) as well. Or worse, throwing check engine lights due to different things than expected happening?


I mean, if they are as simple as plug and play, I could well be interested, but I worry there's a sting in the tail here. I'm thinking also maybe valve springs might want upgrading too :unsure: .

And the linked cams are specific for the K24A3, Skunk2 make a range and the picture you've lifted off the site is actually a pair of Stage 2 cams for the K20. The whole "picture is an example and may not represent your specific product" ;) .
 
Stevearcade said:
I just find it hard to believe they'll give an improved torque band without having to adjust the fuelling (ECU map) as well.
Click to expand...
What do you mean by "adjust the fuelling (ECU map)" ?

Put it the other way around, if you went to Fahad and said "don't change the VTC or LC, just adjust the fuelling" what do you think he would say ?

The point is that the fuelling self-adjusts to keep the AFR constant. There is no point running rich, it won't give you more power. At high powers some engines do run rich, but this is to help keep the valves cool. On some engines they do run slightly lean to help improve mpg. But generally, the AFR is constant at stochiometry. Also you have fitted a CAI and not had a remap, and you claim that it gives better power. ***uming it does, why ? And if it does, then fitting a different camshaft with different cam profiles, will also alter the engine breathing.

An EFI system is only an improvement over a carburettor. There are two problems with the latter:
1. A single carburettor on a 4 cylinder engine will usually give a slightly rich mixture to the middle two cylinders and a slightly lean mixture to the end two cylinders. That's why they fit twin carbs to a 4 cylinder engine, but then it is difficult to adjust. Better still is to fit individual carbs to each cylinder, but again you have to adjust the carbs. A multi-point EFI overcomes this problem, because once the injectors are calibrated, the AFR to each cylinder is more even. Remember that mechanical and electronic FI systems were introduced to SI engines in the 1960's, without O2 sensors. The benefit of the FI system was same as multiple carbs, but required less maintenance.
2. A Venturi has limited range of air-flow over which it can deliver constant AFR. That's why they had twin-venturi (aka twin-choke) carbs. An EFI system can cope with a much wider range of air-flow, as long as the device that measures the air-flow is calibrated for and can cope with that range of air-flow.

So let's go back to basics. Take a 4-cylinder Ford Cortina engine, change the camshafts, and you will get an improvement. Same if you just changed the inlet manifold and/or ported it. To get complete increase in power on such an engine, you would change the camshafts, the inlet manfold etc, the exhaust manifold, and fit twin carbs. But you could change any of those and get a change, but note that fitting twin carbs gives a change because of reasons stated in 2 above.

So why is the K24 engine any different ? How would it "know" that you had changed the camshafts, apart from the fact that the MAF would show different air-flows at different engine speeds and loads (and it wouldn't actually "know" that so to speak).

And yes, the pricture is of the Skunk 2 camshafts for the K20 engine, I said it was, but what mystique is there in a photograph of two camshafts. It simply shows that there are 2 camshafts to change, the 2 that are in the pictures of my own engine.
 
:huh: So what are you saying Brian? I should be able to change the cams and see improvements, as simple as the blurb on the Skunk2 website makes it out to be?

Oh, and fuelling I meant timing and ratios. It's these that I'd have thought a different in cam angle/depth could affect and therefore need the map adjusted accordingly?
 
Yes I am certain there would be a change, depends what you mean by "improvement". They say that it would "improve low end torque" and this implies a shorter profile, possibly a staggered profile on the two "low-lift" cams. Out of interest, it might be worth emailing them and asking them the difference between stock profile and their profile. If they know what they're doing (I'm sure they do) then they will at least give the info in start and end degrees on each cam.

Not sure what you mean by "timing" on fuelling. TBO I haven't worked on EI or EFI since the 80's, and back then things were a tad simpler (no CAT, so no Lambda sensor). An EFI system has a "map" that represents points on curves (the computer interpolates between the points). Depending on throttle position, air-flow, and rpm, the computer looks up and interpolates the amount of fuel to deliver (the injector duration). On non-FSI engines, the injector sits in the manifold close to the inlet port, and I don't think the start of the injector firing is as critical as you imply. As for ratios, as said, it calculates based on air-flow etc, so no change there.

All that you would be doing by changing a camshaft, is alter the way the engine breathes. As I say, the reason why the stock profile is chosen, is based on
1. keep the engine quiet
2. keep emissions down
3. keep the mpg up
4. give flexible range of torque - driveability
5. provide a bit of power at the top end
6. keep service intervals down
7. keep reliability up

A change in cam profiles will alter one or several of the above. Regarding 4 and 5, I think that the profiles in the stock K24A3 engine have been chosen to deliver better Volumetric Efficiency (more torque) at higher engine speeds, and I think these other camshafts may move that to lower engine speeds, possibly a wider band by staggering the valves as a guess (if you look at the pics of the cams in our engie, both cams look the same, they don't look staggered).

edit: but for big gains in power, one would require: different inlet manifold, different camshafts, different exhaust, and then a rempa on a dyno to bring it all together (the latter would be like fitting multiple carbs and then tuning them).
 
I got ya. So no it wouldn't need a remap, but actually should be considered as part of a bigger overall upgrade of inlet, springs, cams and exhaust in which case the remap would really be worthwhile too to retune the engine to suit the new parts.

So it's not really as simple as they make it sound on the website blurb. Maybe put that down the bottom of my "maybe, one day" list :lol: .
 
Well it does say "Tuner Series Stage 1", and "Larger gains can be had by coupling these cams with the Skunk2 Intake Manifold and Throttle Body" which is presumably Stage 2.
After that a remap and/or a sports exhaust.
But if I was going to throw any money at modding, I'd simply throw it in the direction of a Subaru :lol:

Still worth sending them an email asking for the data on stock cams and their cams. I'll do that if you're not inclined ;)
 
I think you may need a remap for this, afterall your changing the balance and ratio of the engine so the ecu has to compemsate for that.
 
I was thinking of contacting them, and I went to the main Skunk2 website, which is better.
Camshafts for many Honda engines but not really the K24 engine, though they refer to some K24 derivatives in relation to the K20.

e.g.

A screen-shot from that link ....

0017-1_zpsc5181c12.jpg


Therein is the data on the camshafts. All we need now is the data on the stock camshafts ...blood out of a stone methinks :lol:

If I was going to do something like this, as I said, I'd rather get a Subaru. But if I stayed with Honda, I'd either stick a different engine in my current car, or get a different Honda altogether and mod that. IMO the K24 is a weird lump that's a bit off the beaten track.
 
Those are stage 2 though. And generally stage 2 modifications require supporting mods. I was thinking the stage 1 cams which in theory should give some performance gains within the limits of the other parts remaining stock. I dunno, either way, it looks like there's more to this than Skunk2 would have you believe. Never mind :rolleyes: .
 
I think the use of "stage" in modding has different semantics, depending on who is using the word. I don't think there is an absolute definition of the word "stage" in engine modding. I suspect "stage" can mean either the degree of difficulty, or the relative step in a sequence to an ultimate goal, or the dependence on previous mods, or some other defnition.

Look at the level higher up in the menu from the previous link that I posted, click here. Note that all these camshafts are for Honda engines, some are listed as Stage1, some as Stage2, and some as Stage3. If you then examine the description, it comes down to what is in the "Required" and "Recommended" parts of the description. But there doesn't seem to be a coherent use of the word "stage" relative to "required". Overall, it seems to depend on the spec of the camshaft as to whether any other mods (including remap) are required.

But if an experienced manufacturer of camshafts says that other mods are not required, then why doubt them ? (Note that the link in your original post did not list Skunk2 part-numbers, and furthermore they are in Malaysia :eek: so we cannot verify their claims on the Skunk2 website )

I firmly believe that if Skunk2 had a camshaft for K24A3 listed as not requiring a remap, then it will be a straight swap without requiring a remap, because the ECU will adapt to the relatively non-aggressive cam profiles. Sadly there is no camshaft listed on the Skunk2 website for K24A3, though there are several suitable for some K24 derivatives, and at least one that does not require a remap.
 
Ooh err, reading through some of the specs on the camshafts, I noticed this one

Acura K20A2, Acura K24A2 Stage 1.
"Required: Tuner Series Valve Springs, ***anium Retainers, header, aftermarket ECU."
So even at Stage 1, this camshaft requires an aftermarket ECU (remap therefore implied).


RPM Range: 1,500 - 8,200 rpm
HP Gains: 12 - 15 hp
Torque Gains: 15 - 18 lb-ft
*iVTEC settings: small lobe, 35° advance; big lobe, 40° initial taper to 30° advance. VTEC crossover: 5,500 - 6,500 rpm.

On this particular camshaft it's interesting to note that the low-lift primary and secondary lobes are indeed staggered.

Exhuast
K20A2-Tuner-1-Exhaust-Specs.jpg


Inlet
K20A2-Tuner-1-Intake-Specs.jpg



In complete contrast, in descriptions of the camshafts for B and H series Stage 1, nothing at all is listed as Required.

I might email them, or get on Skype and call them in the USA, to clarify their terminologies !!
 
better stop reading this or i might get carried away :p

i think performance gains from this sorta work is marginal and it works out like

initial cost (cams, labour, ecu map etc) $$$$$$$$$

actual hp gain $$


just my 2c.
 
unless you do all the work yourself, either way the bhp gains are marginal.

don't see it working for me, i would just sell up and buy a different motor tbh.

in once sense it can be likened to upgrading an old laptop/desktop, sure you can put on a new cpu, memory and hell get a solid state hard drive, but at the end of the day you might need a new motherboard also, might as well buy a whole new machine.
 
^ yeah, that's how I'm looking at this one. Too much ***ociated work with other parts of the engine.
 
Stevearcade said:
^ yeah, that's how I'm looking at this one.
Click to expand...
Steve, careful putting yourself in the same boat as Eric :eek:

Stevearcade said:
Too much ***ociated work with other parts of the engine.
Click to expand...
how so ?
what is the "mystique" that makes camshafts for a Honda "K" engine any different from any other engine ?
or are you saying that changing camshafts on an engine in any car has "Too much ***ociated work with other parts of the engine" ?
 
I swapped the cam shaft out of my mk2 Golf for a more aggressive one, it was nice and easy! Just had to make sure you torqued the retaining bolts down in sequence and you were good to go once the valve cover was back on and you were sure you had the timing belt aligned correctly on the new sprocket. The 8v lump in my Golf uses hydraulic cam followers though so is a doddle to strip down and rebuild. The Honda engines look slightly more scary inside :lol:
 
Josh2109 said:
I swapped the cam shaft out of my mk2 Golf for a more aggressive one, it was nice and easy! Just had to make sure you torqued the retaining bolts down in sequence and you were good to go once the valve cover was back on and you were sure you had the timing belt aligned correctly on the new sprocket. The 8v lump in my Golf uses hydraulic cam followers though so is a doddle to strip down and rebuild. The Honda engines look slightly more scary inside :lol:
Click to expand...
QED B)
 
Well, it's just the suggestion of uprated springs and other things. Ok, you might not need them, but it's the kind of job that probably warrants is and so it just seems like too much work unless I was making a track car monster. In which case, I'd be putting in stage 3 cams anyway :lol: . But I can just about afford to fuel my car and give it the occasional treat like lowering springs, so perhaps cams are out of the question.

Stop tempting me Brian :lol: .
 
:lol: Well, you get it done and let us know how it is ;)
 
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