Tuned my KAT and took it for a ride today!

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bruinbear714
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Woke up early today and started tuning my KAT around noon in 80 degree weather, and I must say tuning a car was quite an experience. :) Granted, the car isn't fully tapped for power cause of the conservative settings (I hope).

Controlling the fuel was easy since I had a wideband, but ignition was another story as I have no way to monitor total timing. What I ended up doing was setting the base timing down to 15 degree and adding back a few degrees in the ignition map regions that were around the idle area. Throughout the rest of the map, I backed down timing even further by as little as -1 degree to as much as -9.

First few slow runs were done to see what the A/F were under part throttle - car was running slightly lean as boost was building so I richened that up a little. I had to play that game for about an hour and pushed the car slightly harder every run until I got an A/F of 11.5-12.5 throughout the rpm band.

Although the car runs decent (~6.6psi), it runs extremely hot. So hot that the chassi metal around the shifter is hot to the touch. My tranny was also pretty hot and about 1/2" low on gear oil so I filled it up again but havn't test drove it again to verify if that was causing the heat.

Why does it run so hot, and is it normal? Could the engine be running hotter because I've backed off timing too much?

I attached a picture of my emanage map settings in case any experts want to chime in! WARNING: I assume no liability for anyone wishing to use these maps.

Now for the fun part - the car builds boost at around 2400ish and hits full boost by 3300-3400. I feel that it should build boost around 2200 and hit full boost by 3200 because my off-boost timing seems a little retarded? When the engine gets past 3500 rpm though, the car really scoots!



MikeMurphy
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bruinbear714 wrote:Why does it run so hot, and is it normal? Could the engine be running hotter because I've backed off timing too much?


Yes. I would put my money on that. Fix that before you boost anymore otherwise you are asking for trouble.

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boost infested
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what size of injectors? 370cc? what size of to4?

bruinbear714
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MikeMurphy wrote:Yes. I would put my money on that. Fix that before you boost anymore otherwise you are asking for trouble.


Well I increased timing a little today and the car is running slightly cooler, although the manifold is giving off a lot of heat.

Tuning with an emanage and stock ecu is starting to get frustrating. The damn ecu does some weird things during the first couple of minutes of startup to cause my engine to ping slightly when slowly accelerating from a standstill. This still occurs even after the car has warmed up and gets restarted.

Boost: I'm running the Tomei 555ccs with a T4/T3 turbo.

Structure240sx
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turbos generate a lot of heat. your base timing isnt so bad to make a difference. guess you dont have an egt gauge. when you in full boost your around 1400 degrees at the manifold

tunning ont he stock ecu is a little frustrating, your're right. it can be inconsistent and weird. i just try to get used to it. its making a jwt look pretty damn good again

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chandler
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isnt it at about 1500 deg that the pistons start to turn molten? n e ways, I wonder how much jwt will charge to dyno tune an ecu?....... =) chandler

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TrunkMonkey
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chandler wrote:isnt it at about 1500 deg that the pistons start to turn molten?
i'm sure the pistons have a melting point, but where'd you get 1500 degrees?

the only temperature i know of that pistons start to melt is detonation ;) .

-demetrius

Structure240sx
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i've heard the same thing. then i hear guys runns 1600 degree egt's. people that have said 1500 i beleive were saying thats the melting point of aluminum

bruinbear714
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Structure240sx wrote:i've heard the same thing. then i hear guys runns 1600 degree egt's. people that have said 1500 i beleive were saying thats the melting point of aluminum


Melting point of aluminum is 1220 degrees F. Why doesn't it melt when EGTs are higher than 1500? I'm not sure, but my guess is that the pistons, block and head have enough thermal capacity and cooling capability to prevent the pistons from remaining higher than 1220 F over the long term.

Anyhow, Structure240sx, the emanage pulls about 0.5V off the MAF to compensate for larger injectors and that kinda throws off timing a little. Added to that another -5 degrees of timing by rotating distributor. On top of that, it seems like the ecu is running in cold start mode for a minimum of 3-5 minutes when the car is first started, no matter how warm the engine is.

I can start to see how all these variables are adding up to turn ignition tuning into a nightmare. A/F isn't a problem as I have a wideband to tune - my A/Fs are about 13 under light cruising and drops down to high 11s under heavy load and boost. I have since then modified the timing you guys see in the picture above and added another 1 to 2 degrees to that map.

Emanage is great, but can't handle big upgrades. In hindsight, I should have worked on wiring up a PowerFC to a KA from the get go.

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chandler
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1500 is what I was told would melt pistons by a teacher at school, who tows a horse trailer with his turbodiesel dodge, he says he keeps it at about either 1499 or 1599, right at the melting point so he has to wait a while to cool it off, maybe he said it was 1600 for the pistons, either way that some cookin heat there, lets get some brats

TheOne
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it not always goes on the pistons, it usually stays on the exhaust manifold and the turbo, should check some of those vids where they show the engine bein dynoed, the exhaust manifold turns red.

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huguetpj
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I've gone past 1.600F... couple of times

Nathan
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Jeeze...ya'll are making my 1250F high seem pretty cool! I've never seen it go over that, although it is measured in the collector.

Structure240sx
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mine is probed in the 4th runer an inch fromthe head. the highest i ever get up to is like 1450F possibly 1500F. it also makes a big difference that you afr's are in the 10's nate. i would still love to making your kind of power

Nathan
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Hahahaha...it actually cools down under boost ;) It runs hottest when I'm cruising at around 80.

Cusp
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temps in the combustion chamber are not as hot as temps in the exhaust manifold, thats part of the reason aluminum's melting point isn't usually an issue. The other is that aluminum pistons contain an amount of silicon which raises their heat tolerance.

Exhaust is still heating up as it leaves the cylinder head. The temps you see from an exhaust runner or from the collector are hotter than the piston surface temperature. The combustion process happens so fast, that alot of potential energy is lost through exhaust heat. That's what makes turbos so cool, they tap that wasted energy.

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Red-KAT
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bruinbear714:

RUN MAP!

Get the Greddy pressure sensor... That made my car WAY WAY better to tune... Now its easy becuse things happen in the same spot all the time.

Also it will let you retard timing based on pressure... And let me tell you thats hella better.

bruinbear714
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Red-KAT wrote:bruinbear714:

RUN MAP!

Get the Greddy pressure sensor... That made my car WAY WAY better to tune... Now its easy becuse things happen in the same spot all the time.

Also it will let you retard timing based on pressure... And let me tell you thats hella better.
How do you account for the larger injectors? Emanage doesn't directly shorten the injector pulse width. It does it by altering the MAF voltage. Even with 370ccs, the MAF voltage gets altered enough to throw timing off a little throughout the rpm band.

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Red-KAT
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How should I know?

I tell it that I had 270cc injectors and that I have 380cc injectors...

And it just works...

bruinbear714
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Red-KAT wrote:How should I know?

I tell it that I had 270cc injectors and that I have 380cc injectors...

And it just works...


Be careful, while it may work superficially, if you look carefully on the "Real-time Display" window with the MAF in and MAF out voltage, you'll see that it alters the MAF voltage.

In your case, the altered value may be less than mine (I'm running 555ccs), but it'll be enough to trick the ecu into thinking there is a lighter load than what it really is. I had to add anywhere from 5% to 22% of fuel in the additional injection map because the MAF voltage was alter so much by going from 270cc to 550cc.

TurboKA37
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how does the ecu figure load from the MAF voltage?

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boost infested
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bruinbear714 wrote:Be careful, while it may work superficially, if you look carefully on the "Real-time Display" window with the MAF in and MAF out voltage, you'll see that it alters the MAF voltage.

In your case, the altered value may be less than mine (I'm running 555ccs), but it'll be enough to trick the ecu into thinking there is a lighter load than what it really is. I had to add anywhere from 5% to 22% of fuel in the additional injection map because the MAF voltage was alter so much by going from 270cc to 550cc.


i noticed my maf voltage in and out are slightly different in the real time display.

will you guys post your injector size and your fuel map?

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huguetpj
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TurboKA37 wrote:how does the ecu figure load from the MAF voltage?


MAF V * VQ MAP = linear CFM

CFM vrs RPM = Load

So it uses a 2d table (CFM vrs RPMs) and finds a injector pulse

There are other things, like k, TPmax, TPmin... but that is the main idea.


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