Honda / Acura K20a K24a Engine Forum banner

1 - 20 of 930 Posts

·
Banned
Joined
·
764 Posts
Discussion Starter #1
Post your questions here, to be answered.

Thanks,
Daniel

Edit: Here's some questions that are frequently asked, and their answers:

Q:
I have XXXX swap going into a XXX, what ecu should I use with kpro, what ecu should I use.
A:
GST2RSX-S said:
Any of these ECUs will work best for K-Pro, and be reasonably priced:
2002-2004 RSX Base 5 speed (PND -A0 ECU)
2002-2004 RSX Type S 6 speed (PRB-A0 - ECU)
2002-2004 CRV 5 speed (PPA-A0 ECU)
2002-2005 Civic Si (PNF ECU)

The 6-Speed ECUs will allow you to easily find 6th gear. It's what I call, "6th gear for dummies." There's nothing wrong with the 5-speed ECUs, and they go for about $100 less. So, look for a 5-speed and look for a 6th speed, if you're willing to pay $100 more for "6th gear for dummies" feature, then go for it.

If you can't afford K-Pro, and need an ECU that will work right up without K-Pro, look for either of these ECUs:
2002-2005 Japanese DC5 Integra Type R (PRC-O ECU)
2003-2005 Japanese Civic Type R (PRD-O ECU)
note: These are more expensive than the US ECUs. PRC-J isn't the same, it requires K-Pro

If you're never going to run the factory wideband with K-Pro, and only an aftermarket, go with this one (if you can find it):
2002-2006 Civic Type R (European) (PRA ECU)
Note: Hard to find, pricing may vary a lot, and it's nothing special, it's bottom of the totem pole.
 

·
Banned
Joined
·
764 Posts
Discussion Starter #2
Here's the First question:
abuck said:
My question is:
After the k-pro installed, are they gonna be a difference between the two ecu (k20aR kpro and k20a2) ? In other word
is it better to make kpro on a k20aR or a k20a2 or it's exaclty the same thing after the kpro installed ?

thanks

Jonathan.
There are advantages and disadvantages to both ECU's. As a general statement Type-R ECU's (PRD & PRC) are good for swaps where you don't have the money to go K-pro, and Type-S ECU's (PRB) are goog for when you do go K-pro. First of all Type-R ECU's can run on any car with one small jumper wire for the fuel pump, and then the car will run, simple as that. I've seen them go for up $350 because of this. The PRB ECU can't be made to work that simply, it's extremely complicated and you have to modify the car's wiring instead. So, that's what makes the Type-R ECU better in that respect. You also have to remember that a Type-R ECU has a speed limiter at about 112mph, although it is removed once the ECU is K-pro'd. So, once K-Pro'd they're both about the same thing. "About," but not quite. The Type-R ECUs can't use the nitrous feature on K-pro because they have less electronics to manipulate by the CPU on the ECU, which is the same reason why you can make them work so easily on any car. And lastly, which you already know, the Type-R ECUs don't have the immobilizer, which is nice to get to function for you since I hear of many Car->motor thefts going on in California.

So, basically, the Type-S ECU has much more going on, has more electronics on it, and goes for about $200-$300 from what I've seen, while the Type-R ECUs have less troublesome electronics, yet does less, and goes for up to $350 from what I've seen.
 

·
Registered
Joined
·
1,420 Posts
A lot of people think they can just use a calibration for their setup that is already given with kpro.

For every setup, there is a different tune. If the k-pro tells you it is for a Toda Camed and Toda Race Header w/ high flowing exhaust, you cannot use IPS Cams and DC Sports Race Header (there is an IPS tune w/ dc sports race header). But if you had a different race header (i.e. ssr, buddy club, custom), you would need to tune your cam angles and a/f for that particular setup.

Also, cams play a big role in ignition timing, as well as the engines compression ratio. Another example would be if you have a higher compression motor, but you are running the CAI calibration on your motor. This might actually harm your engine because the higher the compression, the less ignition timing you can run (depending on the octane fuel you use)

I hope this helps those who are not k-pro guru's
 

·
Banned
Joined
·
764 Posts
Discussion Starter #4
Awesome thanks for the help. We now have two very knowlegeable guys in here.

Another I ran into the other day, similar to what you're talking about. I had a customer ask me if I could put the CAI calibration to start off with so that he ran the least amount of risk, and that he was in a hurry so that will do. I told him that might not be the most optimal to start with depending on his mods. He told me he had a CAI and a DC Sports race header, "so that's fine, just give me that," he said. I said, OK... Then he drove off, and in about 20 min he came back and says, "what gives my car won't go over 3K RPM?" I told him I had a feeling he'd get some kind of result as he did. The problem was that he was running way to lean and he was getting fuel cut, baaaaddddd!!! He figured that since it had been tuned to a CAI then it had the least amount of tuning done and that it would be safe. In actuality, sure it has the least amount of timing advance put in, but it also has the least amount of fuel put in. Remember, it was tuned for just a CAI and stock exhaust. If you have a small amount of air flow, then you'll need a small amount of fuel to get the optimal AF ratio. So, in regards to fuel, if you tune a car with a small amount of air flow, and you switch to a large amount of air flow (relatively, like a Race Header), then you'll be causing trouble to the AF ratio by going lean. If you do the opposite, and you go from a large amount of air flow to a small amount, the opposite will happen, and you'll go very rich. Rich is safe, lean is not. So, in regards to fuel, it's dangerous to go from small pipe to large pipe (or air flow).

Although, in regards to timing, it's actually the opposite. If you go from timing advance tuned at using large air flow to small air flow then you run the risk of causing a lot of knocking for being too far advanced, but if you go from small air flow to large air flow then you're OK. I can go into this more some other time

It's all about having things set just right. This isn't even about making the most power, it's about running safely.

Anyway, to make a long story short, I gave him a calibration that would better fit his mods rather than what he thought would work for him. It's just an interesting scenerio and theory I had to test out, and mention. Fact is, if you don't listen to your tuner, you're not going to get good results, much less safe results. Oh and by the way, there was no damage done to the customers car since lean at 3K RPM is nothing to really worry about, it's when you go lean way up top at 7-8K RPM. Funny though, isn't it.
 

·
Registered
Joined
·
1,420 Posts
GST2RSX-S said:
Awesome thanks for the help. We now have two very knowlegeable guys in here.

Another I ran into the other day, similar to what you're talking about. I had a customer ask me if I could put the CAI calibration to start off with so that he ran the least amount of risk, and that he was in a hurry so that will do. I told him that might not be the most optimal to start with depending on his mods. He told me he had a CAI and a DC Sports race header, "so that's fine, just give me that," he said. I said, OK... Then he drove off, and in about 20 min he came back and says, "what gives my car won't go over 3K RPM?" I told him I had a feeling he'd get some kind of result as he did. The problem was that he was running way to lean and he was getting fuel cut, baaaaddddd!!! He figured that since it had been tuned to a CAI then it had the least amount of tuning done and that it would be safe. In actuality, sure it has the least amount of timing advance put in, but it also has the least amount of fuel put in. Remember, it was tuned for just a CAI and stock exhaust. If you have a small amount of air flow, then you'll need a small amount of fuel to get the optimal AF ratio. So, in regards to fuel, if you tune a car with a small amount of air flow, and you switch to a large amount of air flow (relatively, like a Race Header), then you'll be causing trouble to the AF ratio by going lean. If you do the opposite, and you go from a large amount of air flow to a small amount, the opposite will happen, and you'll go very rich. Rich is safe, lean is not. So, in regards to fuel, it's dangerous to go from small pipe to large pipe (or air flow).

Although, in regards to timing, it's actually the opposite. If you go from timing advance tuned at using large air flow to small air flow then you run the risk of causing a lot of knocking for being too far advanced, but if you go from small air flow to large air flow then you're OK. I can go into this more some other time

It's all about having things set just right. This isn't even about making the most power, it's about running safely.

Anyway, to make a long story short, I gave him a calibration that would better fit his mods rather than what he thought would work for him. It's just an interesting scenerio and theory I had to test out, and mention. Fact is, if you don't listen to your tuner, you're not going to get good results, much less safe results. Oh and by the way, there was no damage done to the customers car since lean at 3K RPM is nothing to really worry about, it's when you go lean way up top at 7-8K RPM. Funny though, isn't it.
Ya, you have to like the lean-cut feature in k-pro (as long as your primary o2 works). I would like to know however when Hondata will make k-pro work with aftermarket wideband o2 sensors. I think once they do this, things will become a lot more easier for street tuners and the regular enthusiast
 

·
Banned
Joined
·
764 Posts
Discussion Starter #6
From what I've heard it's not a Hondata K-pro issue it's the ECU that has the problem. The Stock ECU and stock Wideband O2 communicate by current changes, wereas aftermarket wideband O2s operate by voltage changes. I'm no O2 sensor expert, and I may have it backwards between which O2 uses what, but regardless that's my understanding of where the problem lies. I don't think that there is a solution for that problem, unless the ECU has some MAJOR changes done to it, making it not worth the cost or effort. That's my take on it.
 

·
Registered
Joined
·
1,420 Posts
It would be nice if we contacted the oem sensor maker (delco?) and have them tell us what is a direct replacement o2 sensor instead of purchasing o2 sensors directly from honda or junk yards (most of the time, they go for 75-125)
 

·
Banned
Joined
·
764 Posts
Discussion Starter #8
Actually, it's already been figured out. If you do a search on ClubRSX, they have experimented with quite a few different ones and have found which aftermarket replacement O2s work and which ones don't. I think the reason more people want to use aftermarket widebands is so that they can just use anyone they happen to have available that has any range they desire, and then go and use it on any car they want, having one for all. The way it is now, we have to use either the one that's made by Honda, or one that works the same way Honda's does and has the same range of AF reading. From what I've seen it won't go any lower than 11.5 (rich) or any higher than maybe 16 (lean). The problem is the 11.5 rich is not rich enough for some Turbo systems, they want to go richer at times, and it just doesn't allow it. So, that's the problem... but thats when you use your own wideband connected to another system. You can't go and datalog on the road with something not attached, but what else can you do. It's a problem, not worth the cost of the fix likely. Again, that's my take on that.
 

·
Banned
Joined
·
764 Posts
Discussion Starter #9
Here's another question (editted to protect identity):
K100 Guy said:
...i've got a prc ecu that has a k100 on it and i've got two k20a2 vehicles...on a egk20a2 and another a rsx-s i was wondering i would be able to key the prc ecu so that i could run it on the rsx as well as my egK-power...if so i would like to [Edit: change from a K-100 to K-pro]...reason for that is if i wanted to slap the hondata to my rsx on the weekdays and put it back in my egk20a2 on the weekends...my wife drives the rsx often so that's the reason for not wanting to upgrade that ecu instead...if the prc ecu isnt keyable to work with the rsx-s ...can i [Edit: have someone take the PRC ECU and PRB ECU and] switch over the chip into the prb ecu...
Ok, so far I'm understanding that you have two ECUs, one is a PRB ECU in an RSX that is stock, and another that is a PRC ECU in a EG that has a K100 in it. To answer your questions there a little bit you need to know. First off, the PRC doesn't have the immobilizer function as the PRB does. Next thing, once an ECU is modified to K-100/K-pro, it can't be switched back to stock.

More details, part 1: The PRC will work on any car regardless what it is keyed to, and all it needs is a internal jumper put in place so that the fuel pump signal comes out on both pins for both a USDM vehicle and a JDM vehicle. That's it, it will work on both cars with that simple change, or any car for that matter. So, there is no need for a "rekey" since there is no "key" matching system on it to begin with.

More details, part 2: Now, in order to K-100/K-pro an ECU, what is taking place is the Hondata system is allowing for a backdoor to be opened to be able to reprogram an already programmable ECU. It's not like the old B-series systems where they had chips that could be programmed and changed out. The K-series ECUs can be programmed with a click of a button once the system is accessed by connecting to it through a OBDII connector (prior to K-pro). Additionally, both K-100 and K-pro are circuit boards, not chips, that are made to be removed from the ECU with modifications to the ECU to hold the boards. In other words, there are connectors installed on a stock ECU to plug in the boards, among various other modifications to the ECU (that create the backdoor). Once K-pro is in your system, the backdoor that is opened allows for K-pro to program it with a click of a button. If you leave the backdoor open, the ECU will not run, so it needs to be closed, that's the function of K-100. So, K-100 only shuts that backdoor, while K-pro reprograms and shuts the backdoor.

K-Pro ECU = K-pro board + modified ECU
K-100 ECU = K-100 board + modified ECU
K-Pro board = Circuit board that works in conjunction with a modified ECU to 1) be able to program the ECU through a USB and 2) allow the ECU to run (once the ECU has been programmed through the back door created).
K-100 board = Circuit board that works in conjunction with a modified ECU to allow the ECU to run (once the ECU has been programmed through the back door created).
K-pro = term used to refer to either K-pro ECU or the K-Pro board
K-100 = term used to refer to either K-100 ECU or the K-100 board
 

·
Registered
Joined
·
302 Posts
I am currently running a stock k20a w/intake and DTR 421 header, 2.5" exhaust with cat, stock PRC ecu. No CEL's.

Due to the higher flow of the exhaust you are saying that I might be running lean? I will eventually get KPRO but would like to run this setup for a while, and not have to change anything.
 

·
Banned
Joined
·
764 Posts
Discussion Starter #11
If it was a setup without a cat then yes, most likely. Although, with a cat you are restricting it quite a bit. Therefore, you may be just fine. That's quite a nice setup you have, by the way. It's about the amount of air flow, not just the piping. You'd have one heck of a car if you didn't have a cat. As it is, you're not making the most use of your large piping powerwise, but when you need to have a cat you gotta do what you gotta do. Do you live where they have tail pipe sniffers for emmissions checks? If you don't then you'd be just fine without the cat, once you go K-pro, and the gain would be signigificant. You might see upwards of 25whp, maybe more!

Your cat is what's saving you from going lean, but restricting you from power, which is a good temporary fix until you get K-pro (if you're not worried about a tail pipe sniffer test).

A cat therefore does two things: 1) Reduces air flow so that you can not worry about running lean, and 2) keeps you from having to worry about getting into trouble when the tail pipe sniffer (emmisions) test comes around.
 

·
Registered
Joined
·
302 Posts
I don't like the shitty smell without a cat so thats why its on there, and I always thought that you don't loose too much power from a high flow cat.
 

·
Banned
Joined
·
764 Posts
Discussion Starter #13
A high flow cat is still a cat, it's just one that has the minimum requirements for reducing emmissions. The words "high flow" is just a marketing term, it should be called a minimally restricted cat. Although, it still gives restriction. Our engines are very sensitive to air flow restrictions, hence the amount of power that can be gained once all restrictions and large piping is achieved. If it was an 8cyl, then I wouldn't worry about it. I also haven't noticed a bad smell from such a small 4cyl 2.0L motor.

It's really up to you to decide, and see the facts for yourself. If you dyno your car with a cat, and then dyno it without, you'll be able to decide what you'd rather have.

It doesn't matter much right now with a stock ECU. Either way you won't be gaining much without the cat with a stock ECU, and you're safe from running lean. Once you get K-pro it will be quite a bit of difference. So, when you have the money for K-pro, you can decide at that point.

In that respect, there isn't much power to be gained, if you're not tuned. Once you can tune it, then you want to get rid of the cat, or at least come to that decision.

Good luck.
 

·
Registered
Joined
·
38 Posts
One question, can a Kpro PRB ECU work in a JDM RSX-R Car ? Disable the oil pressure switch will work with JDM car?
 

·
Banned
Joined
·
764 Posts
Discussion Starter #15
That's exactly correct, you have to disable the VTEC oil pressure switch on Kmanager. You'll also have to disable the immobilizer and physically put a jumper wire in/on the ECU for the fuel pump, as the JDM cars use a different pin output for the fuel pump.

(I assume you know that a RSX-R actually doesn't exist in Japan, and it's actually called a Honda Integra Type-R (DC5 chassis, not DC2))
 

·
Registered
Joined
·
420 Posts
Is it true that a 5-speed ECU wont work with a 6-speed tranny??

Also if i car has an inmobilizer do i just disable it with K-Pro or is there a way to keep it?
 

·
Banned
Joined
·
764 Posts
Discussion Starter #18
civicmexicano said:
Is it true that a 5-speed ECU wont work with a 6-speed tranny??

Also if i car has an inmobilizer do i just disable it with K-Pro or is there a way to keep it?
No, a 5-speed ECU will work fine with a 6-speed tranny, the ECU just won't engage reverse lockout. It's kind of annoying not being able to smoothly go from 5th to 6th like that, but not that big of a deal. My reverse lockout wasn't engaging when I first put in my swap, so I had first hand experience with that.

The immobilizer is nice to have, so if you can figure out a way to get the circuitry to work on your car, I'd keep it on. I've heard of a lot of thefts in California already from cars that get swaps and don't have the immobilizer functioning. All you need is the an Acura/Honda key (like Accord) that has the immobilizer crystal inside, the immobilizer circular device that goes around the iginition (where the key goes to start the car), and a way to wire it into the car. I don't know exactly, but that's what's required on an RSX/Accord.

The ECU is what cuts the car from running when the immobilizer codes don't match up from the key to immobilizer to the ECU, so when you turn it off in K-pro it's the ECU that ignores everything else and just runs. So, disable it if you don't have all the components working together, or keep it on if you do.
 

·
Banned
Joined
·
764 Posts
Discussion Starter #20
1 - 20 of 930 Posts
Top