How long will the Ka run?

[assassin7420]

Now, This isnt a thread where im asking questions about the ka as i know far to well of its habits of leaning out. So far me and some friends have a little bet going on.....

A guy out here is about to put a T3-T4 60AR *(at 8psi)* on a bone stock KA24 with Q45 injectors thats been beat on and from how the car looks at least 135k miles.

He plans on running it with no tune and or air-fuel gauge. I give it 3 good runs till the head gasket gives out. Whats your take?

[modulation]

?I'm confused.What do you mean by "no tune"?How's he going to tell the ECU it has larger injectors?If he doesn't it'll just flood the car and probably won't even idle or run.

Also you have to get very specific and hard to find year of Q45 injectors.

What state is this in too?8psi isn't that high.

[assassin7420]

?I'm confused.What do you mean by "no tune"?How's he going to tell the ECU it has larger injectors?If he doesn't it'll just flood the car and probably won't even idle or run.

Also you have to get very specific and hard to find year of Q45 injectors.

What state is this in too?8psi isn't that high.

Its out in GA, As for the the injectors i have no idea how he plans to run the car. 8psi is high on a stock ka with no tune (no stand-alone or piggyback just a stock KA ecu) that has been beat on its whole life.

[modulation]

Its out in GA, As for the the injectors i have no idea how he plans to run the car. 8psi is high on a stock ka with no tune (no stand-alone or piggyback just a stock KA ecu) that has been beat on its whole life.

Unless he uses a hacked MAF with his injectors his car ain't gonna run at all with different injectors.

[janda240sx]

I agree, unless he does some serious tuning it prolly won't even start. Not to threadjack but where in sav. are you located?

[assassin7420]

Unless he uses a hacked MAF with his injectors his car ain't gonna run at all with different injectors.

He will prob end up using stock KA injectors once he finds this out. He said he pulled on SR's back in tampa but i walked away like nothing. Well, I was side ways till 65mph but none the less. I was pulling as i was spinning.

I agree, unless he does some serious tuning it prolly won't even start. Not to threadjack but where in sav. are you located?

On the Islands, How far are you out of savannah?

[motoman399]

Its out in GA, As for the the injectors i have no idea how he plans to run the car. 8psi is high on a stock ka with no tune (no stand-alone or piggyback just a stock KA ecu) that has been beat on its whole life.

i had a 95 with 7psi and stock ecu and stock injectors and it ran fine i had a fmu and a fuel pump but thats about it.

[assassin7420]

i had a 95 with 7psi and stock ecu and stock injectors and it ran fine i had a fmu and a fuel pump but thats about it.

See, You used that key word "had". How long did it run "fine" for?

[DriftingisLame]

Stock injectors with a stock computer will run fine with low amounts of boost and an FMU. I've seen KA's, d series and b series turbo motors last years with a setup like that.

Have any of you put larger injectors in a car without a reflash, or a standalone? I have, on a couple of motors including my own. No its not a good idea for long term, yes mine was temporary, and not railed on much, once I compensated a little with the SAFC was more than enough to drive around for a while before my reflash.

The ECU's not as dumb as you think, and it will compensate a little for the added fuel. Its not a good idea, but everyone that says "probably wont even start" or "wont run" probably hasnt ever done it.

[modulation]

Stock injectors with a stock computer will run fine with low amounts of boost and an FMU. I've seen KA's, d series and b series turbo motors last years with a setup like that.

Dude with a FMU you are messing with engine management. He is saying 100% stock here, no piggy backing devices on the ecu, no hacked maf nothing.

Most EFI computers can handle low (LOW) amounts of boost.Some BMW computers can do up to ~8 PSI stock but I doubt the ka24de ecu can handle that. I would think less then 6 PSI. If you'd like to debate this more I'd be more then happy to start throwing up some math to prove my point. But god I hate math please don't make me do it.

Quote »Have any of you put larger injectors in a car without a reflash, or a standalone? [/quote]No I'd rather just buy a nistune like I did and do it the right way.

Quote » I have, on a couple of motors including my own. No its not a good idea for long term, yes mine was temporary, and not railed on much, once I compensated a little with the SAFC was more than enough to drive around for a while before my reflash.[/quote]No one said anything about a SAFC, you are messing with engine management there. We are talking about a stock ECU with a stock program and NO hacked MAF.

Quote »The ECU's not as dumb as you think, and it will compensate a little for the added fuel. Its not a good idea, but everyone that says "probably wont even start" or "wont run" probably hasnt ever done it.[/quote]?Yes when the ECU is in closed loop mode it will see the car is running a bit rich and will trim the injector pulse width to bring the car back within it's parameters. Under WOT our cars don't function on closed loop and will run too rich. Get a wideband o2 and you can see this.

You might get away with running a little larger injectors, but you aren't going to be able to run injectors >50cc's for that long without ****ing **** up.

http://eccs.hybridka.com/viewtopic.php?t=47

[DriftingisLame]

"Dude with a FMU you are messing with engine management. He is saying 100% stock here, no piggy backing devices on the ecu, no hacked maf nothing."

Okay, I'm sorry I assumed that since 99% of the rest of the world refers to a rising rate fuel pressure regulator as an FMU, that you would know what an FMU is, but I'll call it a RRFPR from now on. This has nothing to do with the computer, it is completely mechanical.

"Most EFI computers can handle low (LOW) amounts of boost.Some BMW computers can do up to ~8 PSI stock but I doubt the ka24de ecu can handle that. I would think less then 6 PSI. If you'd like to debate this more I'd be more then happy to start throwing up some math to prove my point. But god I hate math please don't make me do it."

Motoman399 said he had a KA with a FMU and a fuel pump, with stock injectors and and computer. I was elaborating on this and saying that his setup is safe. Assassin said "keyword had, how long did it last for?". I'll just explain what an FMU is... Rising rate fuel pressure regulators keep fuel pressure at whatever you set them to with the vacuum line off, in the case of a positive manifold pressure situation, when the vacuum signal turns into a boost signal, the FMU raises fuel pressure accordingly. You can buy them for 10 psi per 1 psi above atmospheric pressure, or whatever pressure you want really.

"No I'd rather just buy a nistune like I did and do it the right way."

I never told anyone to do it the wrong way, clearly you just dont understand that it will work without a reflash, or compensation with a maf interceptor or you wouldnt have made the comment earlier. All I was doing was disproving this. If you need transportation until the ECU is reflashed, or an aftermarket ECU is installed, drive the car with the injectors, as long as their not twice the size, the car will run and drive. I have a wideband, and I have 0% correction on my SAFC, my AFR is safe, between 14-15:1 at low throttle. This is with 440cc injectors where 270cc injectors are supposed to be on my RB20. At low throttle, low RPM, the cars o2 sensor will read the excessively rich mixture and compensate.

"No one said anything about a SAFC, you are messing with engine management there. We are talking about a stock ECU with a stock program and NO hacked MAF."

Sorry, I worded that wrong, my SAFC is at 0% correction at low throttle like I said. I have it corrected for High throttle, and thats it. The car would drive the same without the SAFC, just too rich if you try to go WOT. The car starts, runs, drives, gets 20mph+, WITHOUT an aftermarket computer, or maf interceptor!

"?Yes when the ECU is in closed loop mode it will see the car is running a bit rich and will trim the injector pulse width to bring the car back within it's parameters. Under WOT our cars don't function on closed loop and will run too rich. Get a wideband o2 and you can see this."

I have a wideband, and I know this. Under WOT the car is still in closed loop, I dont know why you think it switches back.. Open loop is only to make sure the right timing and fuel is run while the car is warming up, it has nothing to do with WOT. Under WOT instead of relying *mostly* on the TPS, and o2 sensor, it rely's on the MAF and TPS to control the AFR. If you read my post again, its basically just disproving people like yourself who say things like "Unless he uses a hacked MAF with his injectors his car ain't gonna run at all with different injectors" or "If he doesn't it'll just flood the car and probably won't even idle or run." Comments that come directly from lack of experience, complete guesses, since you've never done this stuff yourself.

"You might get away with running a little larger injectors, but you aren't going to be able to run injectors >50cc's for that long without ****ing **** up."

440cc - 270cc= 170cc... hmm weird..

I never told anyone its efficient, good for power, or good for cleaning carbon out of the combustion chamber to run larger injectors on the stock computer. All I'm saying is that I dont like when people claim things as truth when they've never attempted the things themselves, and obviously dont understand the system in the first place.

I'll use the KA for example, dont use anymore than a 370cc injector without reflashing the computer. If you do run 370cc's, you must have something to compensate for the larger injectors (SAFC, e-manage, whatever), or you'll make very bad power. For a KA setup of around 7 psi, a RRFPR on stock injectors is a good option, as long as you have a fuel pump that can keep up. And for efficiency, power, and longevity's sake, Tuning is beautiful, you can never tune too good. Dont be a cheap ***

Hope this helps someone.

-Max

[modulation]

Ok first are we talking about S13/OBDI or s14/OBDII?I'm talking about a S13/OBDI you must be talking about a S14 ecu right?If so then we should just stop arguing cause they are totally different, the S14 ecu might even have VE tables.

If you are talking about a Rb20 which is what you mentioned then what the hell man? Does an RB20 ECU work even remotely close to that of a S13 ECU?If so then please provide me a link and I'll shut the hell up.

Okay, I'm sorry I assumed that since 99% of the rest of the world refers to a rising rate fuel pressure regulator as an FMU, that you would know what an FMU is, but I'll call it a RRFPR from now on. This has nothing to do with the computer, it is completely mechanical.

I thought you we referring to a fuel management unit my bad.However a RRFPR still messes with the engine management even though it does so mechanically.

TP = (VQ x K Value / CAS Value) / Number of Cylinders If you change the fuel pressure you are changing the K value.The K value is normally a constant for the injectors you are using.However if you change your Fuel pressure you are changing the flow rate of the injectors, so you are messing with engine management.

Does that no make sense at all? I'm not being a d!ck I'm honestly wondering if I explained it well enough.

Motoman399 said he had a KA with a FMU and a fuel pump, with stock injectors and and computer. I was elaborating on this and saying that his setup is safe. Assassin said "keyword had, how long did it last for?".

Safe under WOT?

I never told anyone to do it the wrong way, clearly you just dont understand that it will work without a reflash, or compensation with a maf interceptor or you wouldnt have made the comment earlier. All I was doing was disproving this.

Dude you are really splitting hairs here. I said it won't run STOCK. Yeah it'll work with a FMU, yeah it'll work under low throttle at low loads.It won't work with a STOCK untouched setup at WOT. I guess I was wrong about it not idling right, but I'm still sticking with that statement if it's a S13.

Quote » If you need transportation until the ECU is reflashed, or an aftermarket ECU is installed, drive the car with the injectors, as long as their not twice the size, the car will run and drive. I have a wideband, and I have 0% correction on my SAFC, my AFR is safe, between 14-15:1 at low throttle. This is with 440cc injectors where 270cc injectors are supposed to be on my RB20. At low throttle, low RPM, the cars o2 sensor will read the excessively rich mixture and compensate. [/quote]How do you come up with twice the size?Also your RB20 is totally different then a Ka24de.

Quote »Sorry, I worded that wrong, my SAFC is at 0% correction at low throttle like I said. I have it corrected for High throttle, and thats it. The car would drive the same without the SAFC, just too rich if you try to go WOT. The car starts, runs, drives, gets 20mph+, WITHOUT an aftermarket computer, or maf interceptor!I have a wideband, and I know this. Under WOT the car is still in closed loop, I dont know why you think it switches back[/quote]Once again your RB20 isn't a Ka24de. All ECU's don't work the same.

Quote ».. Open loop is only to make sure the right timing and fuel is run while the car is warming up, it has nothing to do with WOT. Under WOT instead of relying *mostly* on the TPS, and o2 sensor, it rely's on the MAF and TPS to control the AFR. [/quote]Maybe a RB20 works this way, but not a S13 ka24de ecu.

[modulation]

"I have a wideband, and I know this. Under WOT the car is still in closed loop, I dont know why you think it switches back.. Open loop is only to make sure the right timing and fuel is run while the car is warming up, it has nothing to do with WOT. Under WOT instead of relying *mostly* on the TPS, and o2 sensor, it rely's on the MAF and TPS to control the AFR. If you read my post again, its basically just disproving people like yourself who say things like "Unless he uses a hacked MAF with his injectors his car ain't gonna run at all with different injectors" or "If he doesn't it'll just flood the car and probably won't even idle or run."

I think you are getting your open loop and closed loop mixed up.Why would the computer NOT listen to sensors if it's trying to "to make sure the right timing and fuel is run while the car is warming up?"

Open loop = no feedback being used, this is what is used under WOT. Most ECU's simply don't have enough speed to run at closed loop under WOT.

Closed loop = feedback being used such as o2 sensor to trim fuel/air ratios

http://www.autoshop101.com/forms/h58.pdf

I also checked and S13/S14/S15/ER34/Y33/Z32 all use a M7790 and the RB doesn't so it's going to work quite differently.

Quote » Comments that come directly from lack of experience, complete guesses, since you've never done this stuff yourself. [/quote]That was sort of a ****ed up thing to say. I thought we were having a mature debate here.But you are right I never have tried to swap injectors/mafs or turbo a car without modifying the engine management in some way. Sorry I don't half *** **** like you do.

[janda240sx]

On the Islands, How far are you out of savannah?

Well now that you guys have all that said and done, I'm stayin in statesboro right now but i head to Sav. every other weekend just about.

[DriftingisLame]

I'm talking about an OBD1 ecu. Yes the DOHC KA ECU is a 16 bit and the RB is an 8 bit, but they still work off of the same principles..

I dont know what you were talking about, but I was refering to someone's 7 psi KA-T being safe with a FMU and stock injectors, stock computer. YES it would be safe under WOT, think about it, the only time fuel pressure is adjusted is during boost situations, and it varies based on how much boost is present. I really dont know what you're getting to with your formula..

"Dude you are really splitting hairs here. I said it won't run STOCK. Yeah it'll work with a FMU, yeah it'll work under low throttle at low loads.It won't work with a STOCK untouched setup at WOT. I guess I was wrong about it not idling right, but I'm still sticking with that statement if it's a S13"

I dont even know what you're trying to say here. FMU's dont help idle.. Do you still not know what an FMU is? uhh, you know what, I really dont even know what this means, I'm not going to try to give an answer, because what you wrote isnt specific and sounds to me like it disproves itself...? I dont know, either way, I'm not going to touch that one..

"How do you come up with twice the size?Also your RB20 is totally different then a Ka24de."

I dont know the exact cutoff point where you can run injectors without tuning or not, twice was a guess based on how mine work... I dont know..? The rb20 is not as different as you think, I dont know why you think that one works on a different brand of electricity or what.. The principles that make the RB20 run are the same ones that make the KA run.

"Once again your RB20 isn't a Ka24de. All ECU's don't work the same."

You're right, the KA has a different rev limiter.... a 16 bit computer will work faster than an 8 bit, They still work the same.

"Most ECU's simply don't have enough speed to run at closed loop under WOT."

That is totally wrong, in this sense, all ecu's work the same. You're correct about what sensors are used when in open/closed loop, but under WOT, how would the ECU compensate for boost, if it was not relying on the MAP or MAFS signal? Why do you think you have to upgrade to a Z32 maf when you get into extreme power levels? The stock unit cannot read the amount of airflow under WOT...

"That was sort of a ****ed up thing to say"

What, that you havent put injectors in that the computer didnt recognize? And then you came on to a forum where people want accurate information and you made a claim that was not true?

"Sorry I don't half *** **** like you do."

Now that was what you'd call a ****ed up thing to say.. What did I half ***? If not for being able to drive me to work until my ECU was done, at least I found out so I could give people accurate information. I have my new prom in now that is set for these injectors and different timing.. Least I know the tiny piece of carbon I put on my piston isnt going to blow my motor since I half assed **** lol.

[motoman399]

See, You used that key word "had". How long did it run "fine" for?

it was like that for about a year and then someone ran a red light and totaled my car ran great. probably a low 14 high 13. was a fun car.

[modulation]

I'm talking about an OBD1 ecu. Yes the DOHC KA ECU is a 16 bit and the RB is an 8 bit, but they still work off of the same principles..

Principles yes but not the exact same. They will give different weights to different sensors and lots of other things. You can't assume all ECU's run the same that's just silly even with Nissans.

Quote »I dont know what you were talking about, but I was refering to someone's 7 psi KA-T being safe with a FMU and stock injectors, stock computer. YES it would be safe under WOT, think about it, the only time fuel pressure is adjusted is during boost situations, and it varies based on how much boost is present. I really dont know what you're getting to with your formula.. [/quote]Fuel pressure is never adjusted. Fuel pressure is constant.Only the amount of time the injector stays open for changes.

Quote »I dont even know what you're trying to say here. FMU's dont help idle.. Do you still not know what an FMU is? uhh, you know what, I really dont even know what this means, I'm not going to try to give an answer, because what you wrote isnt specific and sounds to me like it disproves itself...? I dont know, either way, I'm not going to touch that one..[/quote]When did I ever say FMU's have anything to do with Idle?If you put larger injectors in the engine without telling the ECU or tricking in in some way (such as a using a FMU) then the engine is going to run more rich then the ECU intended. There is no way around this.

Quote »I dont know the exact cutoff point where you can run injectors without tuning or not, twice was a guess based on how mine work... I dont know..? The rb20 is not as different as you think, I dont know why you think that one works on a different brand of electricity or what.. The principles that make the RB20 run are the same ones that make the KA run.[/quote]So you just made the cut off point up? I thought you had math or something to back it up.

Quote »You're right, the KA has a different rev limiter.... a 16 bit computer will work faster than an 8 bit, They still work the same.[/quote]Actually a 16 bit computer isn't necessarily faster then a 8 bit computer it can just access more memory. The ka24de and rb20 ecu don't work as close as you think they do because I know the s13 ecu and it doesn't work in the way that you describe it, the ECU doesn't use the TPS how you describe it at all.

Quote »"Most ECU's simply don't have enough speed to run at closed loop under WOT."That is totally wrong, in this sense, all ecu's work the same. [/quote]I've heard that from multiple sources multiple times.This being one of them:http://www.amazon.com/Modify-M...15825Only the newest ones do.

Quote » You're correct about what sensors are used when in open/closed loop, but under WOT, how would the ECU compensate for boost, if it was not relying on the MAP or MAFS signal?[/quote]The MAP/MAFS has nothing to do with open/closed loop. Closed loop deals with the injectors and the o2 sensor and fuel trim. The ECU doesn't compensate for boost. The MAF simply sees more air coming in, so the MAF voltage is higher and the ECU sees this and adjust TP accordingly.

Quote » Why do you think you have to upgrade to a Z32 maf when you get into extreme power levels? The stock unit cannot read the amount of airflow under WOT...[/quote]Uh I'll tell you why cause I've done it.A ka24de odb1 ecu looks at a VQ table which is a graph of the maf voltage reading and a corresponding value. This value is VQ in your favorite equation:TP = (VQ x K Value / CAS Value) / Number of Cylinders The MAF voltage is 0-5v. With a ka24de MAF 5v = 250hp with a Z32 5v=~500hp. So you can only get 250hp with a ka24de maf.

Why do you think we change MAF's and what the hell does it have to do with this debate?

Quote »What, that you havent put injectors in that the computer didnt recognize? [/quote]You're telling me the computer just "recognizes" the new injectors and changes it's k constant accordingly?

Quote »And then you came on to a forum where people want accurate information and you made a claim that was not true?[/quote]My claim was true. All you've said is if you add this or add that it'll run in this this specific condition for a little while but you don't know about anything but your RB. You've never taken a ka24de ecu and engine and put on larger injectors so maybe your Rb20 is the same maybe it isn't but you haven't proven anything I said was wrong have you?

Quote »Now that was what you'd call a ****ed up thing to say.. What did I half ***? If not for being able to drive me to work until my ECU was done, at least I found out so I could give people accurate information. I have my new prom in now that is set for these injectors and different timing.. Least I know the tiny piece of carbon I put on my piston isnt going to blow my motor since I half assed **** lol.[/quote]I was agreeing with you here. You said I've never done it before and you're right I've never half assed a turbo install or a injector upgrade so I wouldn't know if a RB20 would run with some half-asses setup, but I know a S13 obd1 managed ka24de wouldn't.

You seem to be knowledgeable in the practice, but your theory is lacking/confused.
Modified by modulation at 12:48 AM 2/26/2008

[assassin7420]

Well now that you guys have all that said and done, I'm stayin in statesboro right now but i head to Sav. every other weekend just about.

We have weekly meets on south side Savannah at Saturdays around 9:30-10:00 ish. You should try to come out once.

As for the 2 or 3 pople going back and fourth its a stock ODI1 S13 ECU. Not chiped hacked or anything.

[justjuiceit4]

?I'm confused.What do you mean by "no tune"?How's he going to tell the ECU it has larger injectors?If he doesn't it'll just flood the car and probably won't even idle or run.

Also you have to get very specific and hard to find year of Q45 injectors.

What state is this in too?8psi isn't that high.

Which year Q45 injectors work?

[modulation]

Which year Q45 injectors work?

94-96

Besides the fact that I pulled the wrong year, here is also a posting.zer...02188

They are all side feed injectors but the ones that I pulled are from a 90-93..

Mafs from Q45's of all those years work, but they aren't as good as the z32 maf.