Magnumpsi

iTrader: (2)

Hello all,

Ok I have spent a good amount of time with the Ecutek software for the Evo X and I have learned a lot about these cars and the tuning that goes into them.

I have put together some data I wanted to share and I will update when I have a bit more time as I have a lot.

First off these cars are awesome. I am happy with them thus far. As with any new car there are some bugs that do need to be worked out but I am sure they will only continue to get better.

To start things here is my timing information. This was done on 91oct crap Arizona gas as are all of my tunes on pump gas.



This is today and it was hot. Like 110F or something insane. So my ability to run timing safely is limited so please bare with me. I will post up some other ones when the temp was lower.

As you can see the Evo X does have the ability to run more timing at peak torque. On 93 and cooler temps I would imagine you could run a bit more timing at peak torque but it is what it is. I think this is either due to a change in head design or just an overall increase in VE within the whole motor. I will look more into this later.

Now I have also been trying to figure this fueling issue out. I know there are some skeptics out there that say the car can not be leaning out with the larger injectors but facts are facts. The facts are that when I am reading a 110% IDC and at that point the car is leaning out, I know that is real deal period. I am not sure why this is but I can say with the modified housing and a standard GSS342 it worked well.

Before:



After:


Now as you can see the IDC came down. The second plot is actually with about 1 psi more of boost actually as we could run it more safely now with the pump. For whatever reason I think there is some sort of restriction in the fueling system and that will be addressed at a later date.

On the same note on fuel I have also noticed something kind of strange. Today I have found that in upper RPM's of the runs if I left the AFR richer than 11:1 the car really fell on its face. At around 11.3:1 the car pulled all the way to redline with no sign of knock. I gained 10 WHP just by leaning out the top end a bit which is strange as previous MY evos didn't have this same problem. They could run 10.8:1 and 11.2:1 in most cases there was a very little change in power. I will print out these graphs and show you what I am talking about later.

I think this is all I have for this installment of Evo X tuning with Mitch M. I have been on the dyno all day and I smell like CO and it is hotter than hell here. ( I mean it I dont think hell will ever be as hot as Phoenix lol)

Edit: Just looking over IAT's and on average they are around 45-48 degrees C!! Hot hot hot!!

Thanks for reading. I will post more up a little later.

Mitch Mckee
Vivid Racing

Magnumpsi

iTrader: (2)

Forgot the dyno sheet lol.




Thanks,

Mitch M

dan l

iTrader: (3)

Being able to run more timing means that flame front speed is slower and more advance places the peak pressure of the longer burn rate more squarely at 15-20 degrees after top dead center.

Engines that take less timing to achieve more brake mean torque are more efficient because the burn is inherently quicker and with less timing the crank is being pushed backward less by a piston on the upstroke being forced back down.

An example of being able to run big timing numbers are the old hemi engines. They were anything but efficient for the given size of the motor. 35+ degrees up top was the norm and with that kind of timing (and that much heat building up as the expanding air/fuel mixture drove a piston back down) preignition and total engine destruction when on the edge was the norm.

You should be able to lean it out a lot. At least to 12.0:1 and up to mid 12's if you want to lower that injector duty cycle. A truly efficient engine will handle AFR's in the 12's all day long and like it as you'll have good air/fuel layering in the cylinder and no lean spots due to a good cylinder head design.

Magnumpsi

iTrader: (2)

Dan you are correct. However I will not lean this car out as the IAT's that are seen and the quality of our fuel is crap and I will not put it that close to the edge on a car that is DD.

I do appreciate the insight and you are correct in terms of overall VE being better with less timing. I do think that the overall geometry of the combustion area on the head has been improved and I do think that VE has been improved, albeit an increase in timing has been seen.

Any other thoughts anybody? Dan hit the nail right on the head but I am curious to see other peoples thoughts, especially those that have been tuned, or are thinking of it.

Mitch

dan l

iTrader: (3)

Who knows what they are doing to the gas in your case. It could be causing all kinds of issues including having to run odd timing advance. Running too rich also slows flame front speed. Too many people do this and "compensate" with more ignition timing. Perhaps you are having to run richer than the engine would otherwise like but you are fuel limited and have to do so. The effect is running more timing that would otherwise be ideal.

I went to tune a car on cali gas once. I told the owner I wouldn't touch the thing the gasoline was that horrible. I feel for you.

Also being an aluminum block it should be more heat tolerant than an iron block motor and hopefully more consistent run to run.

Magnumpsi

iTrader: (2)

Yeah the gas is just no good. I am not of the school of thought on more fuel more timing. This is super safe and the AFR's are safe. I think the best way to do it is find a nice medium so that the car is happy. I would run the car a bit leaner if it wasn't so hot here in the summer but it needs to run on the safe side.

Thanks Dan I always enjoy your input. Very well thought out and direct. You must have done this before



Mitch M

Noize

iTrader: (24)

We're on 93 octane in my neck of the woods, but I'm running a little leaner throughout.

My timing values are higher than yours up top. Usually at the shop, 16-17 degrees at the rev limiter is typical for a 4G63. I'm about 2 degrees beyond that.

This car just keeps responding to fueling without knock much better than I have seen a 4G63 go. I think it would easily go over 300whp, but I want to take things slowly. My idea at this point is to back the timing off a bit and do what Bruce wanted to do in the first place- really dial the Mivec in. I think there is power to be had in the midrange.

Magnumpsi

iTrader: (2)

Let me post up another graph. I was looking through my other logs with our X and this car just would not take timing like ours would. Which does not suprise me it was either that hot outside, or bad fuel or maybe a combo of both.

Shop car:



Kind of strange.


Mitch M

Noize

iTrader: (24)

This is much more like what I expected to see.

dan l

iTrader: (3)

I actually had somebody come to me that accidentally filled up on 89 octane to tune their car. It was a tick above 90 degrees that day and I thought the heat was holding back the car. Then the person found the receipt and it had the price per gallon of 89 octane.

Is the car knocking down low or up high? What kind of boost are you running? If your not pushing the car boost wise you'll be able to run more timing than it will normally take. What does the X run for coolant temps.

Noize I have found tons tons tons tons of power on the IX with mivec changes (on an otherwise stock car). The dual mivec on the X would probably take me 4-5 times longer than a single cam mivec car to figure out but the results should be better than what a single mivec car will take. It should also be very boost dependent on what the car likes for mivec setting as you can really mess with overlap. Hell you could probably do a lot to increase fuel mileage with mivec and cruising but thats another topic all together.

CBRD

iTrader: (60)

Mitch,

have you tuned an 07 sti?

we see 110% IDC on those, but i target richer, and i get richer actual afr...

ive always thought that its because they changed scaling (on same size injectors as previous) to change tip in response etc.... and therefor the calculation on IDC's may be off...

not sure, maybe im just retarded...

what are your thoughts...

Cant wait for X software... we have some CBRD parts ready to go for the X when we can tune them...

cb

CBRD

iTrader: (60)

PS,

mitch, i feel sorry for you and the 91 octane hahaha.... to think i was pissed when they pulled 94 from the pumps out here

cb

Mightygnu

iTrader: (4)

All we have out here in Cali is 91

Thanks for the info Mitch!

evostang

In my past experience (which was all Mustang based as Noize may point out ) valve timing had a huge effect on ignition timing. Once the valve timing is optimized or the specs on the modified engine, I suspect ignition timing will be significantly different. Noize already implied this I believe.

dkstas

iTrader: (3)

We only have 90 octane up here in Alaska. On that note...Mitch say if I ordered the mail-in flash, would it be very mild? Keep in mind our temps up here never get higher than 75 F in the summer, and averages 20-30 F in the winter. Thanks.