AlwaysinBoost

iTrader: (17)

I've been tuning my bolt on EVO for the past couple of months in the sweltering heat here in the NE. Recently its been 100* with 100% humidity. I have the car 'feeling' better then it ever has before. A/F is between 11.2-11.5 @ WOT in 3rd & 4th, 5th gear is in the 10s. Timing is very conservative and there is virtually ZERO knock at any load with the exception of one or two counts @ part throttle which I'm still working on.

The question I have is how much, if any, will I need to change my tune in the winter when the temps are in the teens or below?

If I don't change anything will I be leaving a lot of power on the table?

Also what if you tuned your car in the middle of winter. Would you lose a lot of safety then driving it around in the summer with the kind of heat we are currently experiencing in the NE?

MalibuJack

iTrader: (5)

Actually the hotter it is, the less dense the air is, so you will actually pick up power as it gets cooler and the air is more dense..

Fortunately the ECU does a decent job of heat and barometric compensation, but severe changes like sweltering heat, and frigid winters, will probably require a bit of a retune.. And not in the way you expect... you may find that the cells your tuning in will rise as the air gets more dense, so your summer tune may be in the 220% range, and winter may fall into 230% Even if boost level doesnt change much..

Also, the car will run a bit leaner in colder weather if you tune for the summer.. again, the ECU should mostly compensate for it, but expect to make minor changes.

Also, this is assuming you have an EBC that can compensate for changes in air density altering boost levels.. If you have an MBC, you probably will have to retune slightly.. If you make adjustments in the hot weather, then come back in the cold weather, you should have a tune that works great all year around and you shouldn't have to follow it up again.

Honestly the best time to tune is on cool nights when the air temps are 65 degrees or cooler.. Its better to run richer in hot humid weather, than leaner on a cold snap..

MalibuJack

iTrader: (5)

This is the poster child for why we have High octane and Low octane maps.. super hot days can result in lots of knocking and pinging that will drop your octane number.. So make sure your low octane maps are nice and safe..

Mad_SB

iTrader: (8)

Hey Always,

Can you pm me one of your recent logs? I would like to compair your timing to mine, i've about got it sorted but Just want to see where it falls in comparison.

Back on topic,
I think what you will find (at least it is what I am keeping my fingers crossed for) is that durring the colder months, you will shift load cells to the right, so you can probably tune accordingly and rich tapper the fuel maps to the right of your current peak load cells a bit and retard tapper the timing maps.

Like Jack said, you will probably need to do another round in the winter.

AlwaysinBoost

iTrader: (17)

Thanks for the detailed response.

I do use a MBC instead on an EBC, and no doubt I run a high and low map

AlwaysinBoost

iTrader: (17)

when I get home from work I can post screen shots of the logs. If you want I'll even email you the tune. I wouldn't mind seeing yours either to compare...

Mad_SB

iTrader: (8)

Sounds good man,

I may go for another logging run tonight so I will have some fresh logs to export running on the most recent map. I'm using ecu+ for logging so I will have to export to csv unless you want to download the ecu+ software.

AlwaysinBoost

iTrader: (17)

here are the log screen shots I mentioned.






The above two logs are 4th gear and part of fifth. The top on is the DataLog Lab from EVOScan showing knock, TPS, RPM, & Timing. The other one is the LogWorks log showing RPM, TPS, Boost, and A/F ratio.

Below is the same two programs showing 3rd and part of 4th gear.







Input is welcome.

Mad_SB

iTrader: (8)

timing curve looks nice and smooth, but the images are too small to see the actual values, what is your peak advance @ 7000 and min advance around 3750-4250?

AlwaysinBoost

iTrader: (17)

peak TQ timing is around 4* when doing a pull starting between 2-3k. Up top in 4th gear @ 7k I have it advancing to 15-16*

Mad_SB

iTrader: (8)

Sounds exactly like mine.

Nice smooth curve man looks good. I imagine you are getting better midrange than me cause I can't seem to ramp up the timing until much latter, I'm only bumping 9-10* at 6000, any more than that and I start getting timing pulled in 4th gear pulls.

Just yesterday and today I started hitting over 300 load between 3750 and 4000.... when slapping the gas between 3k and 3.5k so I need to rescale a little bit. I'm also hitting about 1800hz on the maf up top since making some changes to my boost control. Once I get the map stable, I will shoot it over to you to take a look at along with some logs.

l2r99gst

iTrader: (2)

AlwaysinBoost,

Nice logs....great data.

Once thing I noticed in your logs is that you have a rough fueling transition right around 6K RPM. This could possibly trigger some knock(although big timing transitions are more likely to than fuel), so you may want to smooth out that transition. At the least, it will help you get a more consistent tune. What do your fuel maps look like around 5500-6000? Are there big jumps there?

Other than that, great logs.


Eric

Mad_SB

iTrader: (8)

Hey Always, I see you have the spool up camel hump in the afr too... I thought that had to do with accell enrichment changes i made but I guess not.

I see the same thing afr drops to the 11's durring spool up then back up to 12's then transitions down to 11.2-11.5 by peak boost.

Interesting... gotta figure that one out, could be the mythical lean spool..... I've noticed it does not do it if you get in it around 4K or so, only when you tip in lower in the rpm range.

AlwaysinBoost

iTrader: (17)

good observations Eric.

I'm still working on the fueling side of things since I recently hooked up the LM-1/RPM converter to be able to log A/F & RPM instead of going be sight and memory like I was before. My tune is constantly being adjusted, although not by much.

I only have 3 days left on my trial version of DataLog Lab so I hope the new version of EVOScan comes out soon...

AlwaysinBoost

iTrader: (17)

Yeah I'm trying to keep it lean until about 3500 with a little bit of timing to make the most amount of heat to spool the turbo. My map sensor shows it takes less then 2 seconds to go from 4psi to 20psi in 3rd or 4th gear @ 3500RPM.

Like I mentioned above I'm still working on the fueling side.

I really did everthing backwards by adjusting the timing first and then the fuel but I guess thats how it goes when your just learning. Its AMAZING the amount of info I've learned in the last couple of months.

Once everything is all figured out I'll send you my maps for comparison.