Well **** me in the goat ass....
07-08-2006, 11:08 AM
#16
Originally posted by LA_phantom_240
...yeah i guess it IS rebuildable, BUT the only problem i have with that is i dont have the necessary equipment at my disposal anymore... My garage is messy as hell and full of stuff, so i cant do it there. THAT and ive been looking at prices for different stuff to rebuild my motor for high CR and its looking to be about as expensive (if not more than) as the cost of a decent CA18.
...yeah i guess it IS rebuildable, BUT the only problem i have with that is i dont have the necessary equipment at my disposal anymore... My garage is messy as hell and full of stuff, so i cant do it there. THAT and ive been looking at prices for different stuff to rebuild my motor for high CR and its looking to be about as expensive (if not more than) as the cost of a decent CA18.
By the time you install a CA, get all the parts you want to run boost, and go through a years supply of fuel you would of spent more, and had gotten less gas mileage at WOT, then if you were to run a high compression 2.4 litre setup that produces more energy output on NO boost, and conserves fuel much better on a much better regulated fuel output (smaller pulse width and CC injection).
It takes about 9psi on stock turbo to have a CA18det make 200Crank HP, While it takes a 2.4 litre 10.5:1 CR set up to achieve the same power output on less fuel. This is also running both engines on 91Octane pump gas.
I also wouldn't go with an RB20det just because it's an old engine, and I have heard nothing but complaints about it's transmission and the power you can actually make on boost. It's gear ratio's are horrible for the high reving that the RB20 makes, and makes no where near the amount of power that an RB25det NEO can produce, with it's gear ratio and stronger transmission. supplementing parts for an RB20det is just one big fU^&ing headache.
KA parts are becoming abundantly cheaper as well since Brian Crower sells performance cams that are better than Jim Wolfe for $250.00. Since the KA is a USDM parts are also easier to find. If you want to stretch the power band on a KA use some adjustable cam sprockets for $150... The list goes on with the KA and the parts and affordability are out there.
Last edited by BigVinnie; 07-08-2006 at 11:20 AM.
07-08-2006, 12:54 PM
#18
Originally posted by Badazz_240
Where do I get the timing chain kit mentioned above?
my guides are dead and what a day it would be if this happened to me....
Where do I get the timing chain kit mentioned above?
my guides are dead and what a day it would be if this happened to me....
http://www.bmaparts.com/epcvsoapimc....entid=bmaparts
07-10-2006, 01:55 PM
#21
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Join Date: Apr 2005
Location: Slidell, LA
Posts: 2,550
Originally posted by BigVinnie
Down the road you spend more money on a CA18det anyways. When you run boost you need controller and blow off valve, as well as a good intercooler to suffice for boost. Also increasing the boost will also use more fuel since the inlet boost charge becomes hotter and less dense, more fuel is needed to control A/F ratio. Although the energy potential increases as boost does, air is crammed into a small cylinder space making it hotter on compression, so in order to control the energy output more fuel is needed to cool the cylinder charge to prevent knock. CA18det's are known to be engines that run hot, or overheat when boosted. From what I understand a CA18det uses a 8bit mother board, and doesn't tune well to A/F ratio's as does OBD1 and OBD2 16bit ecu's. CA's are truely outdated, and parts are becoming much more scarce to come by.
By the time you install a CA, get all the parts you want to run boost, and go through a years supply of fuel you would of spent more, and had gotten less gas mileage at WOT, then if you were to run a high compression 2.4 litre setup that produces more energy output on NO boost, and conserves fuel much better on a much better regulated fuel output (smaller pulse width and CC injection).
It takes about 9psi on stock turbo to have a CA18det make 200Crank HP, While it takes a 2.4 litre 10.5:1 CR set up to achieve the same power output on less fuel. This is also running both engines on 91Octane pump gas.
I also wouldn't go with an RB20det just because it's an old engine, and I have heard nothing but complaints about it's transmission and the power you can actually make on boost. It's gear ratio's are horrible for the high reving that the RB20 makes, and makes no where near the amount of power that an RB25det NEO can produce, with it's gear ratio and stronger transmission. supplementing parts for an RB20det is just one big fU^&ing headache.
KA parts are becoming abundantly cheaper as well since Brian Crower sells performance cams that are better than Jim Wolfe for $250.00. Since the KA is a USDM parts are also easier to find. If you want to stretch the power band on a KA use some adjustable cam sprockets for $150... The list goes on with the KA and the parts and affordability are out there.
Down the road you spend more money on a CA18det anyways. When you run boost you need controller and blow off valve, as well as a good intercooler to suffice for boost. Also increasing the boost will also use more fuel since the inlet boost charge becomes hotter and less dense, more fuel is needed to control A/F ratio. Although the energy potential increases as boost does, air is crammed into a small cylinder space making it hotter on compression, so in order to control the energy output more fuel is needed to cool the cylinder charge to prevent knock. CA18det's are known to be engines that run hot, or overheat when boosted. From what I understand a CA18det uses a 8bit mother board, and doesn't tune well to A/F ratio's as does OBD1 and OBD2 16bit ecu's. CA's are truely outdated, and parts are becoming much more scarce to come by.
By the time you install a CA, get all the parts you want to run boost, and go through a years supply of fuel you would of spent more, and had gotten less gas mileage at WOT, then if you were to run a high compression 2.4 litre setup that produces more energy output on NO boost, and conserves fuel much better on a much better regulated fuel output (smaller pulse width and CC injection).
It takes about 9psi on stock turbo to have a CA18det make 200Crank HP, While it takes a 2.4 litre 10.5:1 CR set up to achieve the same power output on less fuel. This is also running both engines on 91Octane pump gas.
I also wouldn't go with an RB20det just because it's an old engine, and I have heard nothing but complaints about it's transmission and the power you can actually make on boost. It's gear ratio's are horrible for the high reving that the RB20 makes, and makes no where near the amount of power that an RB25det NEO can produce, with it's gear ratio and stronger transmission. supplementing parts for an RB20det is just one big fU^&ing headache.
KA parts are becoming abundantly cheaper as well since Brian Crower sells performance cams that are better than Jim Wolfe for $250.00. Since the KA is a USDM parts are also easier to find. If you want to stretch the power band on a KA use some adjustable cam sprockets for $150... The list goes on with the KA and the parts and affordability are out there.
07-10-2006, 09:51 PM
#22
Originally posted by LA_phantom_240
...well i thought about it, and 200hp NA is much better than 200hp FI, BUT i started sourcing and pricing parts to build a high CR KA, and there's no way in hell im spending that much to rebuild my motor for high compression. Found some pistons, 10.7:1 CR form Arias for 479 + shipping, PDM Racing ka24de cams $620 a set. Also wanted to have my crank knife edged and balanced, wanted to do port and polish job myself, wanted to get a header, and good valve springs. THEN i would upgrade ECU. Now just to build the motor for high CR and get it to running condition would still be well over 600 dollars.
...well i thought about it, and 200hp NA is much better than 200hp FI, BUT i started sourcing and pricing parts to build a high CR KA, and there's no way in hell im spending that much to rebuild my motor for high compression. Found some pistons, 10.7:1 CR form Arias for 479 + shipping, PDM Racing ka24de cams $620 a set. Also wanted to have my crank knife edged and balanced, wanted to do port and polish job myself, wanted to get a header, and good valve springs. THEN i would upgrade ECU. Now just to build the motor for high CR and get it to running condition would still be well over 600 dollars.
Arias pistons $400
Brian Crower cams (better than PDM are $250).
Ported TB $150
SAFC used $150
I would call that done for well over 200WHP
07-11-2006, 07:15 AM
#23
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Join Date: Apr 2005
Location: Slidell, LA
Posts: 2,550
....200hp with no header? Seems like exhaust is a very important part of making power. Also, there are a lot of other costs that need to be added in, like my front cover, which my chain so gracefully destroyed. A new timing chain and guides, Oils, possibly a headgasket, studs (if i replace the hg)
Also, please explain how the SAFC works, nobody has been able to tell me. Is it like a piggyback? It says it modifies the airflow meter's signal to change the amount of fuel injected. So.... wtf. Im lost. Why would i need that anyways? Is it really going to suck in that much more air? Also, wouldnt i need a wideband o2 sensor to monitor the A/F ratio so i dont royally bone my motor with the SAFC?
Also, what would i have to do to get my ka to rev higher without screwing it up, i know that i would need better valve springs, but is the KA's crank up to the task to rev to, lets say, 7500RPM?
Also, please explain how the SAFC works, nobody has been able to tell me. Is it like a piggyback? It says it modifies the airflow meter's signal to change the amount of fuel injected. So.... wtf. Im lost. Why would i need that anyways? Is it really going to suck in that much more air? Also, wouldnt i need a wideband o2 sensor to monitor the A/F ratio so i dont royally bone my motor with the SAFC?
Also, what would i have to do to get my ka to rev higher without screwing it up, i know that i would need better valve springs, but is the KA's crank up to the task to rev to, lets say, 7500RPM?
Last edited by LA_phantom_240; 07-11-2006 at 07:27 AM.
07-11-2006, 04:22 PM
#24
Originally posted by LA_phantom_240
....
Also, please explain how the SAFC works, nobody has been able to tell me. Is it like a piggyback? It says it modifies the airflow meter's signal to change the amount of fuel injected. So.... wtf. Im lost. Why would i need that anyways? Is it really going to suck in that much more air? Also, wouldnt i need a wideband o2 sensor to monitor the A/F ratio so i dont royally bone my motor with the SAFC?
Also, what would i have to do to get my ka to rev higher without screwing it up, i know that i would need better valve springs, but is the KA's crank up to the task to rev to, lets say, 7500RPM?
....
Also, please explain how the SAFC works, nobody has been able to tell me. Is it like a piggyback? It says it modifies the airflow meter's signal to change the amount of fuel injected. So.... wtf. Im lost. Why would i need that anyways? Is it really going to suck in that much more air? Also, wouldnt i need a wideband o2 sensor to monitor the A/F ratio so i dont royally bone my motor with the SAFC?
Also, what would i have to do to get my ka to rev higher without screwing it up, i know that i would need better valve springs, but is the KA's crank up to the task to rev to, lets say, 7500RPM?
First off rev isn't anything you should care about it's more about peak HP and where it is made in the power band.
Secondly an SAFC lies to the ecu. By cheating the ecu to claim that more or less air has travelled through the maf and to the engine depending on the position of throttle and opening. Air determines how much fuel will or will not be used to the amount of air that was given to part of it's throttle.
This means although the ecu is meant to function on one particular way to it's programming (MAP), you can trick the ecu to move from one part of it's map sooner than later by lieng about it's air percentage. So when the fuel map changes you are also changing the ignition timing depending on it's laocation in RPM and how much fuel you have decided to deliver.
Mostly in the case of an NA engine you would want to increase leaness in the ratio this overall increases the engines VE.
07-11-2006, 07:02 PM
#25
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Thread Starter
Join Date: Apr 2005
Location: Slidell, LA
Posts: 2,550
I understand about revs not being a huge concern, the only reason i would want to do that is to stretch out the gears a little more. But i have another question i thought of at work. Why would i need to trick the ECU? Im not increasing the bore or stroke, but would going from 9:1 (IIRC) to 10.7:1 make that much difference in the A/F ratio? And if you want to make it more lean, and by increasing the compression you need more fuel, then wouldnt the stock fuel map be sufficient to make it more lean? Also, running leaner means hotter internal combustion temperatures, right? With that in mind, that would put much more strain on the motor's internals heat-wise? I wouldnt wanna melt a piston or 4...
Also "This overall increases the engines VE"
Whats VE?
Also "This overall increases the engines VE"
Whats VE?
07-11-2006, 09:08 PM
#30
Originally posted by LA_phantom_240
I understand about revs not being a huge concern, the only reason i would want to do that is to stretch out the gears a little more. But i have another question i thought of at work. Why would i need to trick the ECU? Im not increasing the bore or stroke, but would going from 9:1 (IIRC) to 10.7:1 make that much difference in the A/F ratio? And if you want to make it more lean, and by increasing the compression you need more fuel, then wouldnt the stock fuel map be sufficient to make it more lean? Also, running leaner means hotter internal combustion temperatures, right? With that in mind, that would put much more strain on the motor's internals heat-wise? I wouldnt wanna melt a piston or 4...
Also "This overall increases the engines VE"
Whats VE?
I understand about revs not being a huge concern, the only reason i would want to do that is to stretch out the gears a little more. But i have another question i thought of at work. Why would i need to trick the ECU? Im not increasing the bore or stroke, but would going from 9:1 (IIRC) to 10.7:1 make that much difference in the A/F ratio? And if you want to make it more lean, and by increasing the compression you need more fuel, then wouldnt the stock fuel map be sufficient to make it more lean? Also, running leaner means hotter internal combustion temperatures, right? With that in mind, that would put much more strain on the motor's internals heat-wise? I wouldnt wanna melt a piston or 4...
Also "This overall increases the engines VE"
Whats VE?
http://en.wikipedia.org/wiki/Volumetric_efficiency
Yes Badazz 240 hit it on the button, it's called volumetric efficiency.
O.K tomorrow I am hitting up my 1/4mile against my friends 1999 Prelude H22a with a 10.0:1 CR ratio. His engine only needs to run stoich (14.7.1) maybe a little leaner in order to produce a power output of 200HP to the flywheel or the equivlant of 172HP to the front wheels.
I am running my 240sx with a 9.5:1 CR which means in order for me to compete I am going to have to adjust the A/F ratio through the SAFC and run it leaner than stoich at about an (11.2:1) with my 9.5:1 compression in order to match the energy potential his engine can make stoich. So I am only given so much litre's and in those litres I can configure a ratio that will best suit my engines VE, usually using less fuel charge in order to produce a greater air charge. Increasing the air charge is going to produce the majority of the power I will need but it becomes dangerous as it increases the EGT (Exhaust Gas Temprature), this will make my engine more suseptable to knock and ping although increasing it's energy output to the equivelant of the 200HP that I would need at the crank, most of the power that is made in changing this ratio will take place mostly after 4000RPM when overlap between the intake and exhaust valves occur allowing for a stronger vacuum of air charge to be used at my engines disposal.
So I am defenitely going to need a higher than normal octane I will probably get 98Octane to prevent early ignition.
Now since the SAFC shrinks pulse width by saying there is less air than what there really is, at that RPM the ecu ignition timing will advance further, only increasing my scavaging. Scavaging, and valve overlap have to both work in conjunction with each other. The advanced ignition timing only further increases the scavaging effect, which will further increase inlet air through the valve overlap, this in all works to increase volumetric effeciency by FORCING more air than normal into the combustion chamber (basically making a stronger vacuum or air pump than at stock specs or tune).
That is why tricking the ecu is important to increasing power an SAFC is just cheap.
In your case using the stock injectors you will want to slightly increase fuel to the ratio in order to make up the additional air that a 10.5:1CR engine consumes, the engine would now make enough streetable power that you would want to run your ratio closer to stoich, than ultra lean. Just the reverse situation that I am doing using a lower CR engine.
Last edited by BigVinnie; 07-11-2006 at 09:21 PM.