JWT ECU + 370 cc injectors + 10 psi + n00b questions...

[MarkEmark]

I forgive the multitude of questions I've been asking lately...what can I say, I'm a huge post whore!

I found a JWT ECU for $250--Actually, it's a KA ECU with an SR program. Now, it costs $100 to reprogram these ECU's, correct?

I figured for that price, I may as well try it; I could always sell it and get my money back.

Anyway, I'm asking you guys, especially orion (I emailed you like 4 days ago about this, maybe you're out of town), if it's worth it for me to get it. My car runs fine as it is, and makes decent power, but I can't help but imagine how much better it'd feel with an ECU actually PROGRAMMED to take boost and a lot more fuel; I think it'd deliver a lot better power all across the RPM range.

If I'm running 9-10 psi, are 370 cc injectors big enough to use? Or should I go up another step (What is the next step? 440 cc?) And you use just the ECU, bigger injectors, and stock FPR, correct? If 370 cc inejctors are NOT big enough, could I use a RRFPR along with it, such as a 2:1? As a side note---I have consistent access to 94 octane gas--does JWT distinguish between 91, 93, and 94 octane?

I've heard JWT tunes conservatively--how conservative are we talking? I know they run a bit rich, but is it so rich as to rob a significant amount of power (I've looked at your charts, Brian, but I'm wondering if it'd be similar with another 2 psi)?

Also they come with pre-programmed timing curves according to rpm, boost, or both? How much does the timing fluctuate between the RPM/boost range? If they do come pre-programmed with their own timing, what would actually adjusting the timing manually (ie, at distributor) do? Would it just advance or retard however much you manually adjusted it, with the effective timing being whatever was programmed at that point + or - what you did to the distributor? I haven't really screwed with my timing that much (except, of course, when I changed my upper timing chain ), and I don't want to be running into problems. What it's at right now seems to work fine, and as the old adage goes, "if it ain't broken, don't fix it."

Basically what I'm asking is if 370 cc injectors + the ECU would be sufficient fuel for 9-10 psi of boost. (Note that currently, my car drops from around 8/9 psi at 5k rpm to around 6 psi at 6k rpm, that is, it never sees a full 9-10 psi for more than 2.5k rpm, however, I may be upgrading the turbo to a .63 a/r turbine from the existing .48 a/r turbine, which would give it a full 9 psi till past 6k rpm).

Overall, is it worth the money? Basically, I want my engine just like orion's--248 RWHP at just 8 psi. WOW. Once I get a larger turbo and an ECU, I figure not much is different between our setups. (except the hacked MAF/ECU) I have all 180+ compression across the board.

I'll think of more questions to ask along with it, but this'll do for now

Thanks...marc :ylsuper

[AceInhole]

lol. i'm hurt you can't ask a fellow connectican :p

II found a JWT ECU for $250--Actually, it's a KA ECU with an SR program. Now, it costs $100 to reprogram these ECU's, correct?

that's correct... although not sure if that would count having to reprogram it completely. usually a retune means minor variable changes. IIRC they used to charge $150 for certain programs.

Quote »Anyway, I'm asking you guys, especially orion (I emailed you like 4 days ago about this, maybe you're out of town), if it's worth it for me to get it. My car runs fine as it is, and makes decent power, but I can't help but imagine how much better it'd feel with an ECU actually PROGRAMMED to take boost and a lot more fuel; I think it'd deliver a lot better power all across the RPM range.[/quote]Orion actually made more power with the stock ECU than he did with the JWT. The JWT becomes more useful going into higher boost (10 - 15ish and more).

Quote »If I'm running 9-10 psi, are 370 cc injectors big enough to use? Or should I go up another step (What is the next step? 440 cc?) And you use just the ECU, bigger injectors, and stock FPR, correct? If 370 cc inejctors are NOT big enough, could I use a RRFPR along with it, such as a 2:1? As a side note---I have consistent access to 94 octane gas--does JWT distinguish between 91, 93, and 94 octane?[/quote]370's should be good enough for 10psi.... although it's not going to be a sure thing for every setup. Mine really didn't start leaning out untill 12psi....As for the next step, you could always follow me and raise fuel pressure linearly by going to a 4bar fuel setup (stock is 3 bar). it effectively turns your 370cc injectors into 424cc injectors, which should supply enough fuel to get to 1bar.

Quote »I've heard JWT tunes conservatively--how conservative are we talking? I know they run a bit rich, but is it so rich as to rob a significant amount of power (I've looked at your charts, Brian, but I'm wondering if it'd be similar with another 2 psi)?[/quote]i recall brian saying the JWT retards timing down to like 15deg btdc. not very ideal for low boost. that's what really robs power.

Quote »If they do come pre-programmed with their own timing, what would actually adjusting the timing manually (ie, at distributor) do? Would it just advance or retard however much you manually adjusted it, with the effective timing being whatever was programmed at that point + or - what you did to the distributor? I haven't really screwed with my timing that much (except, of course, when I changed my upper timing chain ), and I don't want to be running into problems. What it's at right now seems to work fine, and as the old adage goes, "if it ain't broken, don't fix it."[/quote]adjusting timing at the distributor will effectively shift the entire timing map up or down.

Quote »Basically what I'm asking is if 370 cc injectors + the ECU would be sufficient fuel for 9-10 psi of boost. (Note that currently, my car drops from around 8/9 psi at 5k rpm to around 6 psi at 6k rpm, that is, it never sees a full 9-10 psi for more than 2.5k rpm, however, I may be upgrading the turbo to a .63 a/r turbine from the existing .48 a/r turbine, which would give it a full 9 psi till past 6k rpm). [/quote] it would work. personally i think the hacked maf or an S-AFC is sufficient. to prevent your boost drop-off, though, try tapping the boost line from the intake plenum or the intake piping closer to the throttle body if you haven't done so. if you did that already, and it's dropping off, you somehow have a smaller turbo than i do.

Quote »Overall, is it worth the money? Basically, I want my engine just like orion's--248 RWHP at just 8 psi. WOW. Once I get a larger turbo and an ECU, I figure not much is different between our setups. (except the hacked MAF/ECU) I have all 180+ compression across the board. [/quote]his JWT setup makes less than 240rwhp at 8psi. the extra 10rwhp or so is the difference between the hacked MAF and the JWT.My setup made 220 with a small turbo and a good leak in the exhaust manifold. IMO it'd be closer to 230 with the manifold fixed (or with a better manifold). [actually my actual power output was 234rwhp, but SAE factored down cause the cold weather :P). The only thing Orion has on me other than a non- leaking manifold is the ASP pulleys.

hit me up on AIM @ A7r sometime if you wanna talk KAt's.

[MarkEmark]

Sorry Ace, I forgot about you

How do you like this bloody snow? We have about 14" It was fun digging out the cars this morning (not mine of course, she's garaged )

Hmm...I guess I'd have to call JWT though...god knows they don't respond to my emails--How is there customer service, anyway? I don't want to be dealing with people who dont answer customer concerns, especially if I'm playing around with something as major as an ECU.

I know orion made more power with his stock ECU, but I think that was in part due to the fact that his timing was substantially more advanced with his stock ECU than the JWT one. So does JWT just keep the timing constant at 15 deg. btdc? Ie, it's not RPM or boost related? Also, I'm not as "ballsy" I guess, as orion--I'd rather leave my MAF in tact and go the sure-footed way by using JWT and an ECU tuned for boost.

I don't need enough fuel to get to one bar; 10 psi will probably be my max. What ratio does a 4 bar FPR raise fuel pressure in accordance with boost? I know a lot of the FMU's out there are like 7:1 or 10:1, is the 4bar more conservative?

So if JWT DOES retard their timing to 15 deg btdc, and mine is running perfectly at the timing it's at right now, couldnt I just adjust the distributor to the timing it's at right now after I get the ECU installed and decide I'm not happy with how "retarded" hehe their timing is?

I have my manual boost controller all tapped right near the turbo inlet--not near the hotside compressor pipe. My bypass valve is also recirc right near the turbo inlet. EDIT: here's a pic...it seems like a mess of hoses, but it works pretty well

http://24.59.109.135/pichost/pic//116-1668_IMG.JPG

And, for an unanswered question: How specialized/personalized do they tune their ECU's? Will they take into account the fact that I won't be going over 10 psi, and that I have 94 octane to use consistently, and alcohol injection to prevent detonation? (I've actually brought mine up to 15 psi, no detonation with the alc injection--it works wonders )

I've got the ASP pulley, fidanza flywheel and ACT clutch and all that good stuff too...but I still don't think she's makin 230 RWHP, which is the same as ~265 crank.

What are the specs on your turbo? Mine right now is a T3 super 60, .48 a/r turbine, and .60 compressor (it may even be .63). I found a bigger turbine housing from this guy on ebay that would raise my turbine A/R to .63, for $100, I'm thinking I might try that as well; If I feel that I loose too much boost down low/there's too much lag, I'll just switch back to the .48. I wish they had something in between .48 and .63 for the T3, maybe a .56, I think that'd be ideal for the KA.

We gotta meet up sometime ACE--I just brought my sister back to Uconn like 3 nights ago--it's only about 30 minutes from my house, and it's a nice ride going down, although I'm pretty sure I'm taking my car off insurance this winter--it doesnt deserve to see these horribly messy roads; the winter negates the purpose of a sports car.

[AceInhole]

Sorry Ace, I forgot about you

How do you like this bloody snow? We have about 14" It was fun digging out the cars this morning (not mine of course, she's garaged )

i love the snow. can't stop driving in it :p truck tires for the truck motor

Quote »Hmm...I guess I'd have to call JWT though...god knows they don't respond to my emails--How is there customer service, anyway? I don't want to be dealing with people who dont answer customer concerns, especially if I'm playing around with something as major as an ECU. [/quote] for the most part i've heard they're pretty good to talk to.

Quote »I know orion made more power with his stock ECU, but I think that was in part due to the fact that his timing was substantially more advanced with his stock ECU than the JWT one. So does JWT just keep the timing constant at 15 deg. btdc? Ie, it's not RPM or boost related? Also, I'm not as "ballsy" I guess, as orion--I'd rather leave my MAF in tact and go the sure-footed way by using JWT and an ECU tuned for boost.[/quote]IIRC JWT retards as soon as you go WOT.

Quote »I don't need enough fuel to get to one bar; 10 psi will probably be my max. What ratio does a 4 bar FPR raise fuel pressure in accordance with boost? I know a lot of the FMU's out there are like 7:1 or 10:1, is the 4bar more conservative?[/quote]you're just raising base fuel pressure. the ratio stays 1:1.

Quote »So if JWT DOES retard their timing to 15 deg btdc, and mine is running perfectly at the timing it's at right now, couldnt I just adjust the distributor to the timing it's at right now after I get the ECU installed and decide I'm not happy with how "retarded" hehe their timing is?[/quote] i believe you'd have to advance your timing quite a bit to get it to do that. If base is supposed to be set to 18 for the JWT and you want 20 at WOT, you'll be running a base of 23deg BTDC.

Quote »I have my manual boost controller all tapped right near the turbo inlet--not near the hotside compressor pipe. My bypass valve is also recirc right near the turbo inlet. EDIT: here's a pic...it seems like a mess of hoses, but it works pretty well

http://24.59.109.135/pichost/pic//116-1668_IMG.JPG[/quote]i've found that tapping off the manifold gives more consistent boost and marginally faster spoolup.

Quote »And, for an unanswered question: How specialized/personalized do they tune their ECU's? Will they take into account the fact that I won't be going over 10 psi, and that I have 94 octane to use consistently, and alcohol injection to prevent detonation? (I've actually brought mine up to 15 psi, no detonation with the alc injection--it works wonders )[/quote]i'm not sure how personalized they get, but for the right price i'm sure they'd do it.

Quote »What are the specs on your turbo? Mine right now is a T3 super 60, .48 a/r turbine, and .60 compressor (it may even be .63). I found a bigger turbine housing from this guy on ebay that would raise my turbine A/R to .63, for $100, I'm thinking I might try that as well; If I feel that I loose too much boost down low/there's too much lag, I'll just switch back to the .48. I wish they had something in between .48 and .63 for the T3, maybe a .56, I think that'd be ideal for the KA.[/quote]my turbo is a TD05-12B. not sure of the A/R's on it though. seems about equivolent to a T28 or small trim T3.

Quote »We gotta meet up sometime ACE--I just brought my sister back to Uconn like 3 nights ago--it's only about 30 minutes from my house, and it's a nice ride going down, although I'm pretty sure I'm taking my car off insurance this winter--it doesnt deserve to see these horribly messy roads; the winter negates the purpose of a sports car. [/quote] is your sister cute?? (just kidding. really ) just let me know when you wanna meet up and if i'm not busy (exams this week) i'll be there.anyways: the purpose of a sportscar is to drive sportily. what better sport than to control the "uncontrolable" :p

[Structure240sx]

the guys at jwt are cool guys. jsut call and u will get an answer, u might have to wait like 5 mintues tho. i jsut got my ecu back but im still waiting for my z32 maf before i put it in. the questions they asked me:turbo or nowcompression (9:1 for me)injectorsmafthings i told them:auto - 5spd swap, as it was a spare auto ecu i sent themand that i blocked off the egr, which they said doesnt change anything but they will put a resistor int he ecu possibly removing the check engine light for it

i cant wait to get it in and see what it does

[MarkEmark]

Ace, do you have any more pics of the car? I remember you used to have a site, but you also used to have a DSM SMIC, I see now that you have a FMIC--I'd be interested in seeing how you made it fit; it seems like it's stuck back there pretty far.

I'm gonna call JWT tomorrow....get some specific answers to my specific questions, especially regarding price.

I'm still kinda confused about the timing thing--so they have a set timing when it's idling...and this timing stays consistent even under partial throttle at whatever you have it set at by the distributor, except for WOT, in which case the timing goes to a new setting, and will stay at this throught the whole rev/boost range, so long as it's WOT? Does anyone know how much it actually changes the timing between idling/part throttle (base) and when it starts to really retard it under WOT? I just don't want to be LOSING power with such a retarded timing setup, especially if it's gonna cost me so much money.

Orion just emailed me with answers to some of my questions, and I just emailed him asking about the timing stuff. He said I should be fine with 370cc injectors/stock FPR up to 10 psi or 250rwhp, which is the max. If I actually get to the 250rwhp mark and that's my max, I'll be more than happy

My FSM says the fuel pressure with the stock FPR at idle should be 34 psi, or ~2.5 bar (and 43 psi right after turning the ignition from off to on, w/o stargin tthe engine) and a 4 bar, at idle, is 58.8 psi, right? Meaning, whereas a FMU such as a Vortech 7:1 at 9 psi would be pumping out ~97 psi of fuel, and a 4 bar FPR, at 9 psi, would be pumping out 67.8 psi of fuel. BTW, what's the max pressure the fuel system can withstand? So if I used a 1:1 4 bar FPR along with the 370cc injectors for 9/10 psi, I'd be running quite rich, no? Could JWT's ECU be programmed to run with a 4 bar FPR and 370's? I'm really confusing myself now

What would "tapping" off the manifold entail, and how would I do it? Do you have any pics of your setup?

Where abouts are you in CT when not at Uconn?

Marc

[AceInhole]

Ace, do you have any more pics of the car? I remember you used to have a site, but you also used to have a DSM SMIC, I see now that you have a FMIC--I'd be interested in seeing how you made it fit; it seems like it's stuck back there pretty far.

http://pj.240sxone.com/gallery/working on making a better site than the one I had. not really doing a good job of it lately :p

Quote »I'm still kinda confused about the timing thing--so they have a set timing when it's idling...and this timing stays consistent even under partial throttle at whatever you have it set at by the distributor, except for WOT, in which case the timing goes to a new setting, and will stay at this throught the whole rev/boost range, so long as it's WOT?[/quote]timing should advance as RPM's increase, but AFAIK, the JWT setup does this at part throttle, but retards to 15deg BTDC once full throttle is reached, since there's no air pressure sensor to retard timing according to.

Quote »Does anyone know how much it actually changes the timing between idling/part throttle (base) and when it starts to really retard it under WOT? I just don't want to be LOSING power with such a retarded timing setup, especially if it's gonna cost me so much money.[/quote]If you're gonna go with the JWT, i'm willing to bet you can get them to set it to your specific settings without paying too much extra. Although, if you're just looking for 250rwhp, you're pretty much paying extra for intrinsically nothing.

Quote »My FSM says the fuel pressure with the stock FPR at idle should be 34 psi, or ~2.5 bar (and 43 psi right after turning the ignition from off to on, w/o stargin tthe engine) and a 4 bar, at idle, is 58.8 psi, right? [/quote]yup

Quote »Meaning, whereas a FMU such as a Vortech 7:1 at 9 psi would be pumping out ~97 psi of fuel, and a 4 bar FPR, at 9 psi, would be pumping out 67.8 psi of fuel. BTW, what's the max pressure the fuel system can withstand? [/quote]yup. and the limits of the fuel system will really be dependant on your fuel pump and the quality of the lines. if you've got a walbro or z32 pump, you should be able to go up to 100psi fine. beyond that you're risking poor fuel atomization anyways.

Quote »So if I used a 1:1 4 bar FPR along with the 370cc injectors for 9/10 psi, I'd be running quite rich, no? Could JWT's ECU be programmed to run with a 4 bar FPR and 370's? I'm really confusing myself now [/quote]well, you wouldn't be running rich if you corrected your fuel map to handle it.also, the 4 bar fuel setup was suggested to me by a SE-R owner running a JWT ECU (Jay Haas, back when he was researching the 240).

Quote »What would "tapping" off the manifold entail, and how would I do it? Do you have any pics of your setup?[/quote]just T off of a vacuum line that comes from the intake manifold, like the FPR line.

Quote »Where abouts are you in CT when not at Uconn?[/quote] New Haven, but i'm at UConn pretty much year round.

p.s. you never mentioned if your sister was cute (j/k again)