need advice: turbo vs sr20

[shigitySxSe]

i have 1992 240 SX SE, and around 3 grand or so to spend towards it...im the only one in my town with a 240 and a little money to throw into it, and would be able to have any labor costs covered (by some friends and hook ups i have) who are willing to do it for free... just because of how much they love 240's and want to be be able to say theyve actually "done" the work on it. ANYWAY, i want some advice on what would be my best bet with my money, to turbo the ka or swap for a sr20? i have about 125,000 on the motor now, which is really clean...
what do you guys think?
:aw:

thanks alot

[daredevildoug]

if i had three thousand dollars to fix up my 240, id definately through in a blacktop motor. you have to much miles on you KA to turbo it out. Go with the sr20det.

[mistaanime]

heh juss get sr20..and wit wuts left over..get some mods for it...heh

[brokenben]

deng. hasnt this topic been beaten to death? search.

[SimpleS14]

Either route YOU go.....$3000 may not be alot.

[AadosX]

Dude I have 8 grand and even it's not enough. :(

[Anubis]

buy some nice clothes and some pleasurable company ;)

[mademan]

i would say buy some knowledge.. i'm the head of a financial consulting corporation and we are putting out a financial guide soon. It helps ordinary people learn how to create financial success. I suggest you invest your money and wait until you can get back the amount you put in, then use that money on your car.

[AadosX]

Heh, I've been doing that for a long time, where do you think I got this money from?

[brokenben]

Originally posted by anubis9228
buy some nice clothes and some pleasurable company ;)

haha.. lets see... $3000 ....thats about 3000 strippers in TJ eh?

[90sr]

Well think about it like this decent motor $2500 including shipping freight, depending on exhaust you want to run thatll easily be 5 or $600 maybe more, then you want to replace the gaskets with new ones as i recetnly just found out, hehe, order like 10 oil filters thatll be like 100 bucks you dont need a FMIC right away it comes with a side mount, you need a boost gauge, air/fuel gauge, oil pressure/temp gauge, and water temp, if the motor doesnt come with a fuel pump then you have to order the walboro 255, most likely to start, a turbo timer and that should have your motor started n running a good low 14 high 13, and thats probly almost $3500 bucks to start and your not even close to done yet.

[knghtryde]

PM me. I can probably tell you how to turbo that KA and rebuild it with $3000 and you will be pushing about 220rwhp or more depending on how knowledgeable the people that are going to do the work for you are on KA's. I can easily break it down.

[LonePhantom]

If you've got the option and the cash go the blacktop SR20DET. The only thing you'll really need to do in stock form is not over-rev too much (the hydraulic lifters don't like it too much - there's plenty of torque lower in the reve range anyway) and make sure you change oil regularly (maybe every 3000 miles or 5000kms). I use a 5W 50 synthetic based oil oil and it goes quite nicely. Also use a performance engine treatment on oil changes to help clean up the lifters, etc.

[SimpleS14]

Originally posted by knghtryde
PM me. I can probably tell you how to turbo that KA and rebuild it with $3000 and you will be pushing about 220rwhp or more depending on how knowledgeable the people that are going to do the work for you are on KA's. I can easily break it down.

why not type it here? :confused:

[knghtryde]

Fine....

Like I said, this will only work if you have someone who can put do work for you for free or if you know how to do the work yourself. It worked for me because me and my brother do all the work for areselves.

Okay... Here's the list...

Ross Forged Pistons and total seal rings set at 9:1--- $590.00
(Stock is 9.6:1, and you don't need to replace the rods or crank because they will hold)

Rebuild gasket kit from nissan to to do the rebuild --- $132.00

Custom Build turbo manifold for a T28 ball bearing from a S15 Silvia SR20DET $250 - $350

Silvia 370cc injectors from Ebay $100.00
(The KA24DE ECU can utalize these injectors perfectly since the ECU is set to run 345 ccs even though the car only came with 255cc injectors)

High pressure fuel pump from ebay $100.00

T28 turbo from an S15 Silvia rebuilt off Ebay $300.00

Stock Sidemount intercooler from an S13 180sx/Silvia will all piping intact including recirculator valve $100 - $250

Electronic Boost Controller and Boost Gauge $250 - $500

Misc. Parts and expenses $250.00

Aqua Mist system from Ebay $400.00

This comes to a grand total of $2972.00 that's less than your $3000.00 budget and since you will be using total seal rings and an Aqua Mist system you will be able to boost around 16 to 17psi safely.

The Aqua mist System will keep the chamber kewl, the Total seal rings will also help with holding the boost. With this Exact Set up built properly and tunned properly you should be looking at anything between 220 to 270 rwhp if done correctly.

This set up is for the KA24DE only. There are many alterations that would need to be done to do a KA24E set up.

THIS IS WHY I DIDN'T WANT TO POST IT IN HERE BECAUSE THIS IS ONE LONG ASS POST.

[knghtryde]

Oh, and if you can scroung up enough extra money to get a Steal Head Gasket and an S15 intercooler core which is larger and will bolt up to the S13 intercooler brackets.

You will be able to get around 260-300 rwhp for under $4000.00 out of your KA24DE. This would beat spending $4000.00 for an SR20DET and only getting around what 190rwhp....

[mbmbmb23]

Originally posted by shigitySxSe
i have 1992 240 SX SE, and around 3 grand or so to spend towards it...im the only one in my town with a 240 and a little money to throw into it, and would be able to have any labor costs covered (by some friends and hook ups i have) who are willing to do it for free... just because of how much they love 240's and want to be be able to say theyve actually "done" the work on it. ANYWAY, i want some advice on what would be my best bet with my money, to turbo the ka or swap for a sr20? i have about 125,000 on the motor now, which is really clean...
what do you guys think?
:aw:

thanks alot


You may even check into a CA18DET, they are (from what Ive seen) alot cheaper than an SR. They are probably harder to get parts for, but they are cheaper, more rare.....and can be built for high HP.

[mellojoe]

Originally posted by knghtryde
Fine....

Like I said, this will only work if you have someone who can put do work for you for free or if you know how to do the work yourself. It worked for me because me and my brother do all the work for areselves.

Okay... Here's the list...

Ross Forged Pistons and total seal rings set at 9:1--- $590.00
(Stock is 9.6:1, and you don't need to replace the rods or crank because they will hold)

Rebuild gasket kit from nissan to to do the rebuild --- $132.00

Custom Build turbo manifold for a T28 ball bearing from a S15 Silvia SR20DET $250 - $350

Silvia 370cc injectors from Ebay $100.00
(The KA24DE ECU can utalize these injectors perfectly since the ECU is set to run 345 ccs even though the car only came with 255cc injectors)

High pressure fuel pump from ebay $100.00

T28 turbo from an S15 Silvia rebuilt off Ebay $300.00

Stock Sidemount intercooler from an S13 180sx/Silvia will all piping intact including recirculator valve $100 - $250

Electronic Boost Controller and Boost Gauge $250 - $500

Misc. Parts and expenses $250.00

Aqua Mist system from Ebay $400.00

This comes to a grand total of $2972.00 that's less than your $3000.00 budget and since you will be using total seal rings and an Aqua Mist system you will be able to boost around 16 to 17psi safely.

The Aqua mist System will keep the chamber kewl, the Total seal rings will also help with holding the boost. With this Exact Set up built properly and tunned properly you should be looking at anything between 220 to 270 rwhp if done correctly.

This set up is for the KA24DE only. There are many alterations that would need to be done to do a KA24E set up.

THIS IS WHY I DIDN'T WANT TO POST IT IN HERE BECAUSE THIS IS ONE LONG ASS POST.

I like a lot of this. However...

I wouldn't go with a T28 turbo. Not on a 2.4L KA. I'd go something like a T-04. The exaust pulse on a 2.4L will spool the T-28 quickly, yes, but it will leave nothing to gain. A T04 turbo will take advantage of the full displacement of the KA. The stock KA has enough low-end grunt to make it through until the t-04 turbo kicks in (probably around 3400rpm) which is really where you want the turbo anyway. And you'll get much more out of the turbo.

Probably only need to boost 10psi and get 220whp.

If you are boosting 18psi on the KA, you should have a lot more hp on tap than just 220. I've seen KA-T's at 5psi at 205whp.

EDIT: and if you keep the boost down around 9-10psi, you wouldn't need that "Aquamist" setup. So, that will justify the price difference on the turbo.

... my $0.02.

[knghtryde]

You are right. That's why I said that it depends on tunning because I've seen a KA-T at 18 psi only push 240rwhp. It's all in doing it right. The setup I named using a T04 will give you close to 300+ power to the ground.

I myself perfer the T28 cause I love having the turbo on full spool from launch to finish. But that is just me.

But you are definately right.

My point was though, with less than what it would cost you to get an SR at 194rwhp you can have a 300rwhp KA-T fully rebuilt.

[mellojoe]

You are right. That's why I said that it depends on tunning because I've seen a KA-T at 18 psi only push 240rwhp. It's all in doing it right. The setup I named using a T04 will give you close to 300+ power to the ground.

I myself perfer the T28 cause I love having the turbo on full spool from launch to finish. But that is just me.

But you are definately right.

My point was though, with less than what it would cost you to get an SR at 194rwhp you can have a 300rwhp KA-T fully rebuilt.

Agreed.

With a budget of only $3,000, I would go this route. Either turbo, depending on your personal preference.

If I had a little more, say in the $5,000 range, I would swap the SR, though. Only because it has more potential down the road if you plan on spending more money during the life of the project.

But, if you want between 230whp and 280whp as a max goal, then turbo KA is a great way to go.

[SimpleS14]

Newbie question: When it comes to changing the pistons and headgasket....is that a time consuming, but easy task? or is it a PITA, time consuming and very easy to fuck shit up?

[old_s13]

Fine....
Silvia 370cc injectors from Ebay $100.00
(The KA24DE ECU can utalize these injectors perfectly since the ECU is set to run 345 ccs even though the car only came with 255cc injectors)
High pressure fuel pump from ebay $100.00
T28 turbo from an S15 Silvia rebuilt off Ebay $300.00
Aqua Mist system from Ebay $400.00


ebay is not a credible source especially not for pricing. 100 dollar injectors off of ebay huh? i have doubts about the above pricing AND the reliability.

- mike

[sykikchimp]

Fine....

Like I said, this will only work if you have someone who can put do work for you for free or if you know how to do the work yourself. It worked for me because me and my brother do all the work for areselves.

Okay... Here's the list...

Ross Forged Pistons and total seal rings set at 9:1--- $590.00
(Stock is 9.6:1, and you don't need to replace the rods or crank because they will hold)

If your compression and leak down look good, you don't need either of these. If not so good, you don't need total seal rings. Get Altima KA rings. They work perfect. I've actually heard of some people having issues with the Total seal rings.


Rebuild gasket kit from nissan to to do the rebuild --- $132.00

Custom Build turbo manifold for a T28 ball bearing from a S15 Silvia SR20DET $250 - $350

T25 is WAY too small for the KA.


Silvia 370cc injectors from Ebay $100.00
(The KA24DE ECU can utalize these injectors perfectly since the ECU is set to run 345 ccs even though the car only came with 255cc injectors)

First the stock injectors are 270cc not 255cc. The ECU cannot utilize the larger injectors with the stock MAF. You will need either flashed ECU, Hacked MAF, or some sort of piggy back ecu, or full on stand-alone.


High pressure fuel pump from ebay $100.00

T28 turbo from an S15 Silvia rebuilt off Ebay $300.00

Again.. T25 or T28 both too small for the KA


Stock Sidemount intercooler from an S13 180sx/Silvia will all piping intact including recirculator valve $100 - $250

I think there are plenty of front mounts from older cars that you could get. The SR piping will not work for the KA, so that will have to be custom anyway. Starion intercoolers are common. You can get good intercoolers on ebay these days too. Some Volvo's also have good usable intercoolers.


Electronic Boost Controller and Boost Gauge $250 - $500

Misc. Parts and expenses $250.00

Aqua Mist system from Ebay $400.00

Aqua mist is absolutly not necessary on a budget system. Neither is the intercooler for that matter, but if you've got 3000 to work with..


This comes to a grand total of $2972.00 that's less than your $3000.00 budget and since you will be using total seal rings and an Aqua Mist system you will be able to boost around 16 to 17psi safely.

The engine stock can handle around 15psi on a T3/T4.. 16-17 psi on a t25 or a t28 and your just blowing hot air with a turbo out of it's efficency range and making no where near the HP #'s your claiming.


If you want some better info, do a search on "Junkyard turbo" or "Budget turbo" Lots of good cheap turbo ideas.

[knghtryde]

I'm just going by what I've done to my car, and I have dyno sheets to prove this. Of and the Stock ECU can go past the 270ccs that you are claiming on an OBD1 system. On the OBD2 systems they can't. Also, the stock injector size on the 91-93 KA24DE is not 270cc it is 255cc the 270cc where only used on the 96-98 KA24DE as far as I know....

If you wanna varify this, call JWT and ask them what size Injectors are used on which KA's and what amounts the ECU can properly allow.

[sykikchimp]

:bs:
NO.. I own a 92' and have flow tested them myself a while back when I was diagnosing a power problem. They ARE 270cc stock injectors for every year. Even the 89-90 had 270cc injectors. They were top feed instead of side feed. please STOP talking out your ass.

IF you were to put larger injectors in your car, how would the ECU know that you did so? Magic? NO.. the ECU still thinks it's using 270's. SO, it keeps the same injector pulse width with the same quantity of metered air, but b/c you have a much larger injector, it flows FAR more fuel than the stock injector for the same pulse width (or the time the injectors is open for u) . Now your car is a rich pig, and you dump so much fuel you can't even get it to idle.

To the topic starter, I would recommend getting your KA checked out. If it's healthy, go for it. It'll produce more power for the same money an SR would cost. Just do your research.

[SimpleS14]

Newbie question: When it comes to changing the pistons and headgasket....is that a time consuming, but easy task? or is it a PITA, time consuming and very easy to fuck shit up?

:confused:

[knghtryde]

You marked me as posting miss information then you should do your research. Call up any honda tuner and ask them what the ECU is actually programmed to run. Nissan programmed the ECU to run at anywhere from 310ccs to 325cc, but they only equiped the car with 255cc. You keep saying that you flow tested your injectors at 270cc. I've flow tested the KA24E injectors and I'm only getting 255cc. Also, look it up, in every nissan manual, repair guide, even the dealer will tell you that the injector size on the KA24E is 255cc not 270cc. You have the balls to report me for miss information then stop giving it yourself.

Second, depending on what you want from your car is going to be what size turbo you wanna run. And finally wtf do you mean you need a large MAF to run larger injectors. the SR20DET 370cc injectors I installed on my late S13 did not run rich.

The set up was a T3 turbo, on a 91 KA24DE, 370cc injectors, silvia side mount intercooler with custom piping, high pressure fuel pump at 10psi.

I did not have any idle problems, and actually I didn't have any problems what's so ever. The engine ran at 750rpms at idle, and excelerated perfectly fine.

Do your research before you start speaking. I'm talking from experiance. I've already built a KA24DET.

Have you ever had an idle problem with larger injectors, if so go read a book and learn to work on your car a little better.

[Advan]

Wow, I'm so glad I joined this forum. There's nothing than reading about tech parts and what gives more hp. Soaking up information, that I'll use later on. I like this thread.

Also, I feel bad for ya Kouki. Someone will answer it. heh.

[sykikchimp]

Since you obviously don't believe me..

Do yourself a favor, and do a quick search on this forum for "255cc" Wouldn't you think that if that was the stock injector size it would be mentioned all over the place??

You know what you get? 3 returns.. ALL OF THEM FROM YOU.

Now do a search on 270cc injectors? How many returns? 41.. spread across almost every respected member on this forum.

Still don't believe? Go to Freshalloy, and do the same search. How many do you return for 270cc? 100+

Now, how many for 255cc? 0

And what is a "high pressure fuel pump at 10psi." ?? that makes no sense whatsoever...

[sykikchimp]

And finally wtf do you mean you need a large MAF to run larger injectors.

I said:
"First the stock injectors are 270cc not 255cc. The ECU cannot utilize the larger injectors with the stock MAF. You will need either flashed ECU, Hacked MAF, or some sort of piggy back ecu, or full on stand-alone."

I did not say you needed a "large MAF"..

btw - just to clarify, you say you are using the STOCK ecu, with 370cc injectors? with a T3? What kind of T3? how much boost?

[kandyflip445]

ROFLMFAO. Were your injectors clean when you flow tested them? Was there suffcient voltage? There are several things that could throw off your results.

Also, don't make it a hostile thread. If you don't agree with someone then tell them why (as you did), but leave the smart ass remarks out.

[knghtryde]

kandyflip445,

Your right. My bad.

[mellojoe]

IF you were to put larger injectors in your car, how would the ECU know that you did so? Magic? NO.. the ECU still thinks it's using 270's. SO, it keeps the same injector pulse width with the same quantity of metered air, but b/c you have a much larger injector, it flows FAR more fuel than the stock injector for the same pulse width (or the time the injectors is open for u) . Now your car is a rich pig, and you dump so much fuel you can't even get it to idle.

I think the point of putting in larger injectors is to get more fuel into the engine. If you add a turbo, you are adding a LOT of air, and you need to even it out with more fuel. Keeping the pulse width the same and going to a larger injector is what will balance the a/f mixture. So, you seem to both be right, just missing the point. The point is the you WANT to run it "pig rich", because adding the turbo will lean it out by adding all that air.



First things first, though. Take that KA and do a full tune-up: new plugs, fresh fluids, fresh gaskets, etc etc.

[CoasTek240]

get em!.... go for the jugular

[sykikchimp]

I think the point of putting in larger injectors is to get more fuel into the engine. If you add a turbo, you are adding a LOT of air, and you need to even it out with more fuel. Keeping the pulse width the same and going to a larger injector is what will balance the a/f mixture. So, you seem to both be right, just missing the point. The point is the you WANT to run it "pig rich", because adding the turbo will lean it out by adding all that air.


that's also incorrect. I know it's complex so I'll try to explain how it works for you.

The injector pulse width is dependent on the amount of metered air at the MAF. For a given mass of air, the MAF reads a specific voltage on a 0-5v curve. More air = Higher voltage on the curve. The ECU doesn't know how big the injectors are. The ECU simply looks at a chart that tells it to open the injectors for a given time (pulse width) for a Given MAF Voltage. It runs on the assumption that the fuel map has been tuned with the MAF and flow rate of the injectors to produce the appropriate A/F ratio.

Now, change the 270cc/min to 370cc/min, and add a turbo. The turbo spools and sucks air through the MAF. The MASS of the air will be greater due to the turbo creating positive manifold pressure, but the MAF see's this increase in air mass, and shows a coresponding increase in voltage. So the ECU now take the new larger voltage number, and produces the appropriate Injector pulse width for that MAF voltage by looking at it's base air/fuel map. Remember that this map was tuned based on 270cc/min flow injectors. Now the ECU is opening the larger injectors the same amount of time it would have the smaller ones.

cliff notes:
MAF reads AIR MASS and delivers specific voltage turbo or not.
AIR/FUEL map is basically a "MAF Voltage/injector open time" map
Bigger injectors open for same amount of time as smaller ones flow more fuel.

Understand?

[RedlineRacer]

You are right. That's why I said that it depends on tunning because I've seen a KA-T at 18 psi only push 240rwhp. It's all in doing it right. The setup I named using a T04 will give you close to 300+ power to the ground.

I myself perfer the T28 cause I love having the turbo on full spool from launch to finish. But that is just me.

But you are definately right.

My point was though, with less than what it would cost you to get an SR at 194rwhp you can have a 300rwhp KA-T fully rebuilt.
I don't know who you have been talking to with a KA-T. But if they are running 18psi and only making 240rwhp, then they need to fix something. There are plenty of people, even on this board that are running 8psi and putting down around 220rwhp. The reason why people upgrade the KA injectors is because the stock injectors are only good up to to 8psi. Do some research on the KA-T before you come in here looking like a fool.

[sykikchimp]

The reason why people upgrade the KA injectors is because the stock injectors are only good up to to 8psi.

thats with an RRFPR.

with absolutely no fuel management changes you can run ~4psi before you max out the stock injectors. And most guys that have gone the rrfpr route found the a/f to be too lean for safety at 8psi. 7psi is where most guys traditionally limit themselves with that setup.

I'm seriously not trying to sound like a know-it-all ass with these posts.. just making sure information is correct.

[RedlineRacer]

sykik, don't you run a KA-T, and run around 220rwhp?

[sykikchimp]

sykik, don't you run a KA-T, and run around 220rwhp?

no sir. you might be thinking of Jeff240sx. Another mod. ;)

[mellojoe]

that's also incorrect. I know it's complex so I'll try to explain how it works for you.

The injector pulse width is dependent on the amount of metered air at the MAF. For a given mass of air, the MAF reads a specific voltage on a 0-5v curve. More air = Higher voltage on the curve. The ECU doesn't know how big the injectors are. The ECU simply looks at a chart that tells it to open the injectors for a given time (pulse width) for a Given MAF Voltage. It runs on the assumption that the fuel map has been tuned with the MAF and flow rate of the injectors to produce the appropriate A/F ratio.

Now, change the 270cc/min to 370cc/min, and add a turbo. The turbo spools and sucks air through the MAF. The MASS of the air will be greater due to the turbo creating positive manifold pressure, but the MAF see's this increase in air mass, and shows a coresponding increase in voltage. So the ECU now take the new larger voltage number, and produces the appropriate Injector pulse width for that MAF voltage by looking at it's base air/fuel map. Remember that this map was tuned based on 270cc/min flow injectors. Now the ECU is opening the larger injectors the same amount of time it would have the smaller ones.

cliff notes:
MAF reads AIR MASS and delivers specific voltage turbo or not.
AIR/FUEL map is basically a "MAF Voltage/injector open time" map
Bigger injectors open for same amount of time as smaller ones flow more fuel.

Understand?

I guess I'm not understanding.

Adding a turbo forces more air in. The ECU reads the air through the MAS and tries to correct by increasing the pulse width to try to get more fuel into the mix. But, if you add too much air, the pulse width maxes out and the injector size limits you to how much fuel can go into the mix. So, increasing the injector size will allow more fuel for the same pulse width.

4psi is all the stock injectors can handle, right? That is the max pulse width and max fuel pressure. FPR simply increase the fuel pressure to squeeze more fuel out during the pulse width. So even with a RR FPR, you'll max out the a/f ratio at around 7psi. Now, moving up to 10psi means you are adding more air that cannot be compensated for by the amount of fuel from the stock injectors. Upgrading the stock injectors will allow more fuel to flow for the same pulse width and same pressure. Then just tune the boost to the amount of fuel you CAN fit in that window, and you are off and running.

[MrKaisan]

well im running a t3/t4 turbo setup on my ka24de with a 10-1 fmu and it works totally fine.. i went this route because if there ever was a spike in my boost my fmu would see this and give me more fuel. ohh if you do go the turbo route expect delays.
custom piping always takes longer than expected.

[Muzzy]

hey um knghtryde and everyone else......wouldnt it also be wise to get new valves, springs, block honed, new timing chains, guides, rod, crank bearings, and clutch???

yea all that stuff is pretty important when pushing that much on an old motor correct??

im not sure if i missed this...but wut about about a WG, BOV, ex manifold and custom piping???

[sykikchimp]

Melllojoe - that is all correct. The only problem is you have to adjust the fuel maps so the injectors open a shorter amount of time for a given mass of air..

ex (totally figurative):
Engine is flowing 300cfm
MAF shows 2v
ECU checks fuel map and shows it should open the injector for 2 seconds to get the proper air fuel mixture
So your 270cc/min injector just flowed 540cc into the combustion chamber (WHOA! :eek: )
Now you add 370cc injectors.
repeat process.. 300cfm = 2v
stock ecu reads 2v, and opens injector for 2 sec. Now you just flowed 740cc (Double WHOA! :aw: ) into the combustion chamber given the SAME quantity of air.

What you have to do is modify the fuel maps so that you only open the new injector long enough to flow the original 540cc for the given 300cfm so that your A/F is correct.

So with the new injectors you now only open them 1.46 sec for the 300cfm.

The bonus is that you are now at a much lower duty cycle on the injectors, and you can supply enough fuel at the appropriate a/f for much higher volumes of air.

this is all of course no where near correct quantities, but maybe it will illustrate the idea a bit better.

..questions?

[RedlineRacer]

no sir. you might be thinking of Jeff240sx. Another mod. ;)

Weren't you working on the hacked MAFS with 370 injectors on a NA KA? Maybe I am thinking of someone totally different. Anyway, have you heard the outcome of the hacked mafs on a NA KA? I thought about running this first before I put my turbo in. Just to get my air/fuel components working good then add boost. But, I am thinking when you start adding the boost, it will start leaning it alot more than I am expecting.

[sykikchimp]

I wasn't doing that, but you could certainly do that. Adding the turbo won't lean out your a/f's any. As long as your fuel system is working before the turbo, it will work fine after.

[shigitySxSe]

im gonna go back to my original post and add a question for you guys....
im thinkin about goin through with gettin an rb20, is there anything you guys dont like about them, or from anyone that has one, any regrets from puttin it in?
thanks

[WaKeMaN]

Sorry SykikChimp... just checking.

Wouldn't a 270cc/min injector that is open for 2 secs only flow 4.5cc?
and therefore a 370cc would flow 6.17cc?

Damn, 740cc's, that much fuel would overflow the whole cylinder! :)

[keepitmovin]

im gonna go back to my original post and add a question for you guys....
im thinkin about goin through with gettin an rb20, is there anything you guys dont like about them, or from anyone that has one, any regrets from puttin it in?
thanks

This is no longer your thread...haha

[Doriftomodachi]

You are right. That's why I said that it depends on tunning because I've seen a KA-T at 18 psi only push 240rwhp. It's all in doing it right. The setup I named using a T04 will give you close to 300+ power to the ground.

I myself perfer the T28 cause I love having the turbo on full spool from launch to finish. But that is just me.

But you are definately right.

My point was though, with less than what it would cost you to get an SR at 194rwhp you can have a 300rwhp KA-T fully rebuilt.

18 psi on a KA-T? Is that on stock internals? Not for $3000 I dont think :-/

[mellojoe]

Melllojoe - that is all correct. The only problem is you have to adjust the fuel maps so the injectors open a shorter amount of time for a given mass of air..

ex (totally figurative):
Engine is flowing 300cfm
MAF shows 2v
ECU checks fuel map and shows it should open the injector for 2 seconds to get the proper air fuel mixture
So your 270cc/min injector just flowed 540cc into the combustion chamber (WHOA! :eek: )
Now you add 370cc injectors.
repeat process.. 300cfm = 2v
stock ecu reads 2v, and opens injector for 2 sec. Now you just flowed 740cc (Double WHOA! :aw: ) into the combustion chamber given the SAME quantity of air.

What you have to do is modify the fuel maps so that you only open the new injector long enough to flow the original 540cc for the given 300cfm so that your A/F is correct.

So with the new injectors you now only open them 1.46 sec for the 300cfm.

The bonus is that you are now at a much lower duty cycle on the injectors, and you can supply enough fuel at the appropriate a/f for much higher volumes of air.

this is all of course no where near correct quantities, but maybe it will illustrate the idea a bit better.

..questions?

Yes, exactly. Thats what I thought. Thanks.

[mellojoe]

im gonna go back to my original post and add a question for you guys....
im thinkin about goin through with gettin an rb20, is there anything you guys dont like about them, or from anyone that has one, any regrets from puttin it in?
thanks

The RB is a nice motor, but I don't think its all that its cracked up to be. Its definately got that unique factor, but if I were doing a 2.0L swap, I'd want to go with the SR. Its a much easier fit.

The RB is an inline six, which is great, but its just not a GREAT i-6. Sure, you can say, "I've got a Skyline motor!" but I'd rather go with an RB25. Sure, its a little more expensive, but its got a better aftermarket support and tons more potential than that little 2.0L. But, the RB will probably be a smoother running engine (6cyl vs 4cyl).

It all depends on your tastes and your pocket book. THe RB may be cheaper to buy initially (due to the popularity of the SR), but it will cost more to fit and require more time to get it into the car.

[DuffMan]

This thread is like an episode of the twilight zone. I mean it's weird. We all make mistakes, and say stupid things sometimes, but wow. Just install 370 injectors and everything will ballance out? Wow. All those companies selling piggyback computers and standalones must be trying to screw us then right?

:tweak:

When you run under heavy load, the computer is basicly running entirely off the MAFS, and taking that reading and using a fuel map to determine injector duty cycle. No where in this calculation is it taking into account how much fuel is ACTUALLY coming out of the injectors. The fuel maps are programmed for stock injectors. No matter what injector you have, the duty cycle is the same for x amount of MAFS voltage at x RPM under heavy load (such as acceleration). Under light load, (crusing, idle) there is a correction based on the O2 sensor but not enough to compensate for vastly incorrect injector sizes such 370cc.

It really isn't complicated people. If you want bigger injectors, you either adjust the MAFS signal, or the fuel maps. Fuel maps can be done by a reprogram or standalone ecu. MAFS signal can be done by hacking the MAFS (search for details) or a piggyback such as a SAFC. Just expecting the bigger injectors and more air from the turbo to magicly ballance themselves out isn't going to happen. I have to assume that knghtryde is lying about his car, because if he did what he said he did, it would take an act of God to keep his engine from destroying itself on a daily basis.

Ok, now that I've ranted sufficiently I would like to say something else. On this whole KA vs. SR thing. Lots of people have come up with innovative and creative ways to turbo their KA without spending a lot of money. I think that this is great. Kudos to those who have done it. I'd just like to point out that creativity and innovation can be applied to an SR swap to make it cheaper too. I did my swap for a grand total of a whopping $1775 for the things I needed including shipping and tax. This wasnt any special hookup, just a regular incomplete motorset, and finding cheaper alternatives to buying all the other odds and ends you need.

I don't see why people say you need 5 bagillion dollars to do the swap the "right" way. Install the engine stock at first and add parts as you go a long. I can understand doing certain things first like a clutch, or a front mount, because its more convienent to do a clutch when the engines out of the car, and if you didnt get a stock sidemount, skip it and upgrade to FMIC. But I can also understand not doing those things because you dont want to spend that much right now. It's not the "wrong" way to do things. Everyone has their own preferances. If you need to ask which engine to install or what things to do before installing it, you really should research and find what works for you rather than posting a stupid question and getting a bunch of wack ideas like this thread contains.

[sykikchimp]

Sorry SykikChimp... just checking.

Wouldn't a 270cc/min injector that is open for 2 secs only flow 4.5cc?
and therefore a 370cc would flow 6.17cc?

Damn, 740cc's, that much fuel would overflow the whole cylinder! :)

well yeah.. doh.. It was really just for the sake of example.. I didn't notice the Minute second thing.. :duh:

[SE-R_Peter]

If you wanted to stay *cheap*, but get the most
bang for your buck, get yourself a used, relatively
*cheap* RWD SR20DET, with engine harness and
ECU.

Take that and add a Greddy e-manage with the
support tool and whichever harnesses you want.

Spend the money on a walbro 255 pump, and get
an adjustable fuel pressure regulator - the nismo
one works well, I hear.

A RWD DET shouldn't cost you more than $2000.

The greddy stuff shouldn't cost more than $500.

A Z32 MAF seems to be going for around $100
these days, try to find one out of a junkyard
yourself - you'll always save money that way.

Buy your motor from someone like Soko in Chicago,
I have a boy from the SE-R crew who's a killer tech,
and will go, pull the valve cover, and doublecheck
your not getting some crappy sludge beast if you
don't put the motor on a stand and change out the
main and rod bearings, before you install it in your
car, your just stupid - it's cheap insurance.

Make sure you get a copy of the S14 SR20DET FSM
floating around. It has plenty of stuff in it you can
adapt to just about any DET motor - Nissan doesn't
change stuff that much. Double check the sections
on bearing tolerances, rod and main cap torque and
sequence before you do the bearings with someone
who has an FSM for the exact engine you have.

Spend money on a GOOD, not SS Autochrome (CRAP!)
equal length turbo manifold. Talk to protech fabrications
if you can't find anything elsewhere.

Get it Swain coated. Get a GTI-R T28 and extrude hone/swain
coat it. Spend the time to build a 3" downpipe, buy a
good 3" turbo dump pipe. Spend a little more time or
money, if you don't have the time/knowledge and build
a custom 3" mandrel bent catback with a resonator, and
a good, straight through, ceramic packed muffler.

Buy a bar and plate IC off ebay - something good that
doesn't drop any pressure at 30+ psi, get a spearco,
maybe. Take 2.5" mandrel bent tubing, and whatever
straight pipe you need, and a bunch of high quality
stainless hose clamps, about 3' worth of purosil tubing,
and fab up your IC piping to mount that bastard in the
front. This setup, at something like 14 psi, *should*
net you 250 almost out of the box, and with proper tuning,
you should be able to up the boost and add more fuel.

Keeping everything cool is the key, but adding fuel helps
that cause a bit. Keeping more heat flowing out the
exhaust and not soaking up in your engine bay will do
more for lack of detonation than anything else except
a kickass IC. Having the exhaust at 3" on a DET, for
EVERY part of it you can, even the j-pipe off the turbo,
will do more for performance than most people realize.

Total seal rings are CRAP. Nobody who actually does
any performance engines ever says *anything* good
about total seal. Saturn guys - (yes, there are about
6 of them ;)) hate them. Toyota guys hate them, Nissan
guys - you guessed it, hate them. If your getting into
doing something with an SR20, check out SR20forums.com.

Matt Hunt, the guy who runs it, in the words of some
*very* knowledgable SE-R/SERCA guys, and me is:
'A helluva guy'. He is. People who wrote the book
on SR20DE(and T) performance, like Mike Kojima also
are active on the forums.

Check out se-r.net, sentra.net, and especially the
"Kojima's Garage" section on sentra.net.

These guys have been squeezing performance out
of SR20 motors longer than you've owned your car.

If you *really* want to go crazy, check out doing
a thermal barrier on the tops of the pistons, getting
some killer headwork, building something barely
streetable. The IC I recommend is overkill, e-manage
is overkill - oh yeah, figure on adding about 10 hours
of dyno time at a place that *knows* SR20DET's, and
e-manage *really* well. On SR20Forums, people are
starting to pass around their e-manage maps.

Probably quite relevant.

Any flames, or if you need the contact info of my chicago
currently Maxima drivin' homeboy, let me know at
[email protected] I just stopped by here to do a couple
searches on total-boost and a buddy of mine *was* going
to get a 240, but turned it down for a Saturn SC.

I'm having a really hard time being friends with him now. ;)

Peter

[shigitySxSe]

:rawk:
thanks man

[Natty]

Hrm, between an Sr20 and a turbo, I would just get the best of both worlds, an Sr20Det.