Benefits of the JWT ECU for an NA KA engine?

[BadMojo]

Like the subject says...besides increasing redline and removing the 5th gear speed limiter, what are the major advantages to using a JWT ECU in an NA application (let's say just I/H/E for mods)?

Worth it? Not worth it?

[InsanityInc]

er... you shouldn't really be worried about the rev limiter if you have a stock intake manifold... There's no purpose to revving above 6100 or so, you'll just go slower. It will increase your horsepower and torque overall, but if all you have is I/H/E, you should get some other things first.

[BadMojo]

er... you shouldn't really be worried about the rev limiter if you have a stock intake manifold... There's no purpose to revving above 6100 or so, you'll just go slower. It will increase your horsepower and torque overall, but if all you have is I/H/E, you should get some other things first.

Just for the hell of it, let's say we through some JWT or Colt cams from PDM that have more top end. Would that be worthwhile? I do know all too well that the KA falls flat on its face in stock form after 6K.

Either way, the rev limiter is not a big selling point for me. The KA is a very long stroke engine, so it's not like there's a whole lot of room to work with over stock redline without some serious work.

I guess my question is "what else, if anything, does the JWT ECU offer for an NA KA"?

[InsanityInc]

even with cams, it's been shown that the peak horsepower doesn't go to a higher rpm. It just can't breathe that high due to the intake manifold.

Like I said, you'll gain some power overall. Maybe 4 or 5 whp. There are more cost effective mods that you can do first, and it's generaly best to do all internal mods before getting a reprogrammed ECU, since it can be better tailored to your specific engine.

[:: orion ::]

Insanity...enough with the intake manifold thing...it's not the answer to every KA power question.

I've shown you that the peak HP and TQ can be moved around with cams...in turbo applications, and N/A.

I've used my dyno charts (you seem to think my KA is "magical", so I've had non-typical results)...charts from KA-T.org, etc...

Well, here's one more (this old KA was kinda weak, so the numbers are a little lower than typical):

From Alex Chang (mav1178) over on FA...

"Green is stock.

Red is AEM intake, Hotshot header, 5Zigen Fireball exhaust, JWT ECU, UR underdrive pulley.

Dark Blue is with addition of JWT cams set to factory cam timing..."



See how stock the HP peak was at ~5800...

Then he made the engine breathe better with I/H/E, and added the ECU to optimize things, and the pulley to reduce drag...and the HP peak is still at ~5800.

Then come the cams...and the HP peak is now at ~6200.

Now, we can eliminate ALL the other mods as possible things that changed the HP peak. Here, it is undoubtedly the cams that made this change.

We've agreed that an intake manifold would be a good KA modification, but it's not the damn end-all, be-all of KA tuning...!

- - - - - -

BadMojo -

The ECU will add a few RWHP, maybe 5-6...but it makes the car much quicker feeling and has much better response as compared to stock.

Plus, for drag racing, the higher redline makes it so that you can cross the line at ~91-92mph bouncing off the rev limiter in 3rd, rather than having to shift to 4th and lose time.

Is it worth $600...I don't think so. For $350-400, absolutely. Try to find a used one, they sell in that range.

- Brian

[InsanityInc]

There's no point to being able to rev higher with the stock manifold. Even if your peak power is at 6200, there's still no point to revving past 7000. Also, a 400 rpm shift from cams is not good at all.

[NateDogg]

Ok you asked for it.

InsanityInc: do you have a JWT ECU? No? Well then don't hijack the guys' thread. It's getting annoying, seriously.

Anyway, to answer the question:

Benefits...aka "what does it do?"-Increase mileage-Eliminates Tip-In retard (better throttle response)-Increase top speed-Increase acceleration-Increase octane rating-Decrease pocket depth-Allow for growth. IE You can send it back to them and for $100 they will reprogram it to a turbo program. This can be very beneficial.

I think it's a good investment if you are N/A and going turbo later.

[InsanityInc]

lovely assumption, but you'd be wrong. I have one for my 300zxTT.

An ECU should be the last thing you change, that way, you can give JWT the best information for them to tailor the ECU to your setup.

Quote »-Increase octane rating[/quote]What the hell are you talking about? How would an ECU change the chemical composition of your gasoline?

[Exar-Kun]

insanity: seriously my last dyno with the JWT cams flowed well to ans past 6800..with a stock manifold...above 155hp all the way there- let that point DIE for christ sakes...it dod move the peak HP to 6200-ish, like seen above.

the major benefit of the ECU tuning is:-tunes your fuel curve for your mods-removal of stupid governor...-more agressive timing map-removal or lessening of throttle "tip in" retard settings-removal of the stupid *** governor...

you are correct about saving it for as late in the engine mod stage as possible, so you can get it tuned once and be done with it.

as far as the cams go, see my post about my new mods, suffice to say, I'm thrilled with the 8-15 hp I gained from 6k on up....makes the car feel much more like a sports car.

also, natedogg...wtf was the octane thing about? you already have to run 91 in the KA24DE anyways...its not like the ECU has any controll..or that you can increase that any more

in short, if you arent planning on modding the car much more, and want to improve your HP a little bit, along with better throttle response and removing the governor, go for it..

I'll be shipping mine out shortly to JWT to get the tip in, governor and timing redone.

the tuning is already dead on.-chet

[BadMojo]

[the major benefit of the ECU tuning is:-tunes your fuel curve for your mods-removal of stupid governor...-more agressive timing map-removal or lessening of throttle "tip in" retard settings-removal of the stupid *** governor...

you are I'll be shipping mine out shortly to JWT to get the tip in, governor and timing redone.

Removal of the stinking "tip in" retard settings is almost worth the money itself. I'd love to have better throttle response.

I didn't realize that JWT actually tuned their ECUs for specific NA mods. I knew they had a few setups for FI applications, but didn't realize it was the same for NA.

I'd like to do I/H/E and some more aggressive cams. I can definitely wait until last to do the ECU. Thanks!

LOL...I'm not surprised to see that the intake manifold debate has spilled over in to this thread. It's like the Blob, consuming the KA24E/KA24DE forums.

[InsanityInc]

well, we can set it to rest in a few months when james finishes.

[98s14inaz]

Ok you asked for it.

InsanityInc: do you have a JWT ECU? No? Well then don't hijack the guys' thread. It's getting annoying, seriously.

Anyway, to answer the question:

Benefits...aka "what does it do?"-Increase mileage-Eliminates Tip-In retard (better throttle response)-Increase top speed-Increase acceleration-Increase octane rating-Decrease pocket depth-Allow for growth. IE You can send it back to them and for $100 they will reprogram it to a turbo program. This can be very beneficial.

I think it's a good investment if you are N/A and going turbo later.

I have a 96 JWT ecu in my 98 with the NA program. I have IHE, bkr6e-11 plugs, 91 octane, timing set to 20* btdc, and 91 240 248 cams. I can definitely feel the difference, car is more responsive and the top end screams. My turbo project is sitting in the garage so when upgrade time comes I can call JWT and have a new chip sent for $100. I think it is a little expensive but if you plan on boosting it is the most reliable form of fuel and timing management.

[w1ngzer0]

increased octane rating eh? lol... more myths still slured around

[98s14inaz]

lovely assumption, but you'd be wrong. I have one for my 300zxTT.

An ECU should be the last thing you change, that way, you can give JWT the best information for them to tailor the ECU to your setup.

What the hell are you talking about? How would an ECU change the chemical composition of your gasoline?

What he meant was that you have to use 91 octane or higher. Also who said you have to use premium fuel in a stock KA? That is bs. We did dyno runs with both 87 and 91 octane and there was no difference. Stock KA runs just fine on 87.

[NateDogg]

Thanks for clarifying for me. Obviously I used a wrong word. Can I have a mulligan?

[InsanityInc]

What he meant was that you have to use 91 octane or higher. Also who said you have to use premium fuel in a stock KA? That is bs. We did dyno runs with both 87 and 91 octane and there was no difference. Stock KA runs just fine on 87.

The little sign on the fuel door does. It doesn't make a performance difference, it just stops your engine from knocking.

[w1ngzer0]

The little sign on the fuel door does.<~~(confused on that part) It doesn't make a performance difference, it just stops your engine from knocking.

DING DING DING!!!! give this guy an apple

[InsanityInc]

Open the fuel tank door, on the side with the gascap holder, there's a little sticker that says "premium gas is recommended for best operation" or something.

[w1ngzer0]

for the ka24? i don't think so. My sticker says "unleaded only"

[InsanityInc]

says "Unleaded Fuel Only", then below that it says "Use premium fuel for best performance"

[98s14inaz]

The premium fuel is a mental thing unless you beat the crap out of your engine. If you have a **** load of bolt ons, ecu tuning, and drive it like you stole it I would say use higher octane. You do not have to though. The FSM also says to use a colder spark plug if you frequent high rpms, hard driving, and extended highway driving.

Actually we should make a sticker that says "use boost for best performance" Higher octane doesn't do much on the KA. This isn't like the VQ that knocks and pings like a mother when you put cheap stuff in.

[InsanityInc]

if you put low grade in, it will ping under heavy throttle/high RPM operation. I already said higher octane doesn't increase the output of the engine, it just stops it from knocking. Performance doesn't just mean the output, it also means the engine is working properly in the first place.

[chandler]

higher octane is just slower burning fuel, complete combustion must be done by 40 deg after tdc, this is when it makes the most power, there for if you say 87 takes 37 degrees of rotation to burn completely, you have to retard the timing, but lets say 93 octane takes 60 degrees to burn completely, that way you can advance the timing, higher octane just lets you tune better for more performance, thats all

[TrunkMonkey]

if you put low grade in, it will ping under heavy throttle/high RPM operation.

no, it won't.

i run 87 octane in my convertible, and i ran it in my fastback. i've never had detonation...and you can ask anyone who rides with me, heavy throttle/high rpm operation is my middle name.

-demetrius

[InsanityInc]

what does the compression of those engines test at, though?

[TrunkMonkey]

what does the compression of those engines test at, though?

i don't remember the exact numbers, but they were well within factory specs.

-demetrius

[InsanityInc]

I doubt you'd have to go much below the top factory rating before the problem disappeared... 9.5:1 is pretty much just on the line of wether or not you need premium, so as soon as the compression starts falling, it probably wouldn't be much of an issue, except maybe in hot weather.

For 10 cents a gallon more, though, I'll take the 91 just so I know it won't be knocking.

[skatanic28]

i used to just use 87 all the time, then i tried 91 and 93. this may be a mental thing, but it feels like it pulls a little smoother up top . maybe i was getting slight detonation and the ecu was pulling timing a bit, or could just be all in my head.