Marcus Frost

Primarily, yes, the ECU will pull timing. In extreme IAT situations, the ECU will disengage the supercharger completely.

High IATs do not LEAD to a lean condition, however the higher your IAT the less power your engine will make from combusting it.

-m

E55KOMPRESSED

Marcus,

Thanks for this thread!!

Looking for comments on the attached datalogs from those that have experience. They look ok to me but I am new at reading these, please post your opinions.

Thanks!

Marcus Frost

Dave,

Excellent logs. Your car looks like it is running well. Good IATs, good recovery, there are a two instances that I see timing jump to -20deg but it may be just because of the sample rate being caught between your light throttle and WOT conditions.

You can also see how my IATs are a good 30-50F higher than yours, hopefully I will have a solution for my issue in the next couple of weeks, because it isn't due to any of the usual suspects (pump, air in circuit, etc).

-m

Luke_M

How hot out was it during those runs? The IAT start off pretty high it seems. Mods?

E55KOMPRESSED

Thanks Marcus, that's a relief particularly the timing advance. I did change out all the plugs and they looked real good. Next will be to log the AFR's, I had a bung welded into the exhaust just in between the resonator and the muffler (easy access).

I will keep posting, its great to compare to others so post em up if ya got em!!

E55KOMPRESSED

Luke,

Temp was at 59 degrees, humidity about 35%, altitude 4800 feet.

IAT's were probably at normal operating temperature because I had to drive down to "Mexico" to make these blasts. So the car was fully warmed up.

172 pulley, LET tune, Air Filters everything else stock.

blackbenzz

I might sell my autoengenuity datalogger that was used once. It has the mercedes specific add on and cost me close to $500 if I remember correctly.

You want the wideband sensor plumbed closer to the engine. Preferably pre cats for a more accurate result

Marcus Frost

Ideally you want 8 widebands... one per cylinder

-m

Jakpro1

Wellllll, interesting news.

Here are my datalogs from tonight.

Pulls were in Mexico in 3rd from roughly 40 mph up to redline.

Column F is throttle position and column D are my IATs.

B is timing of course.

I dunno guys, what do you think? Pretty aggresive.

This was the LET tune before they split up.



Here is pull #2. Same scenario.

Temps chilly in the upper 40's
in the clouds. Bout 4300ft.

Car was hot from few quick pulls before these monsters.

E55KOMPRESSED

yeah I know, but I figured that if a dyno gets its AFR from a tail pipe sniffer then this will get me a fairly good reading at least, plus I can access it without jacking up the car

I forget though, if read after the CATS would the reading be leaner or richer than actual?

E55KOMPRESSED

Jim,

If I look at my graphs closely it looks like my timing jumps up toward the end of the pull also. I wonder if its just lag from the ODB port or what, maybe its OK? I wish there was a way to log what the KR (knock retard) was, then we could see how much timing was being pulled>

bassn_07

I'm no expert Jim and never claimed to be one but IMO I think your numbers are quite aggressive. I never see anything close to that with 91, a matter of fact not even with 100 octane. Have you ever logged AFR's off the dyno?

Ever since I've changed tuners my car has been running great and strong. Everything is exactly where I want it and most will agree, at least the ones that are fortunate enough to see my logs...lol. My logging system is no joke and it came at a pretty penny but it's something worth seeing. The info I get on the dyno while be tuned is priceless.

bassn_07

Either way I don't think your timing should be that high under full throttle. Like I mentioned, I'm no expert but just based on what I've learned and see with my own car.

I'm also hooked up to my factory knock sensors, both front and back. If my knock sensors see any activity I'll receive a reading in volts.

Zod

Been thinking more and more about getting a data logger.

saw this and it cought my attention, what u guys think?
http://www.youtube.com/watch?v=S7V-mOTeiM8

alan what can u recomend that is simple but good?

blackbenzz

You are getting one sample per second? Damn these things have a slow sample rate! Logging rpm would have helped.

I believe the MB specific autoengenuity software can log the knock as well.

Luke_M

The reason I ask is that in the first log your IAT's are >100 degrees before you hit it. Maybe this was right after a previous run and you hadn't recovered yet but that's just a guess.

I've got a datalogger on the way and I'm especially interested in learning what I can after hitting it 3 times the other night and feeling like the car was dead on the third blast. I didn't go over 90 and it's bone stock. It was also cool and dark out but I did have a full tank and 4 people in the car. With that said I think my first mod in the next week or 2 is going to be a bigger HE and pump. I've got it waiting, just haven't done it yet. Can't cool it off to much ya know?

E55KOMPRESSED

Luke,

I hear you, I don't know what the IAT's should be or at what point the ECU pulls timing because of the IAT??

Here is the raw data from my short blasts, still need to do a long run like Jim did but alas it is snowing as we speak

E55KOMPRESSED

Search is my friend...

Looks like IAT at 140 degrees F the ECU starts to pull timing.

Marcus Frost

Jim,

To put it bluntly - I would not feel comfortable running that kind of timing on my car. First of all, it probably doesn't make any more power, and second of all... I don't know if you've been reading some of these threads lately... but... bad things can happen with too much timing.

Just my opinion. More timing does NOT always equal more power.

-m

930chas

That is a ton of timing, and is very similar to the timing that was on my car, also a LET tune, and I have had more then one person tell me it was a ticking time bomb. I would see about having your car retuned ASAP!

bassn_07

This exactly the reason why I had my tech bypass the OBD on all logging parameters except for IAT and timing. My tech is still trying to figure out how to get real time data, at least up to 15 times per second on the timing feature. As for the IAT's that will also be bypassing the OBD in the next couple of weeks.

Plain and simple, contact Rob from Needswings and he'll set you up. Zeitronix is a awesome product and I would highly recommend it to anyone.

Here is a affordable product for anyone looking to datalog. IMO it's a must have.

http://www.zeitronix.com/Products/zt2/zt2.htm

Luke, which one did you end up going with?

I totally agree with everything Marcus has stated. I've said this plenty of times and I'll say it again, LOG YOUR *****!!!! I don't want to get into details but my logging system saved my a$$ once and that itself paid for it 20x over. Pay if you want to play and don't be cheap.

lowprofile

Marcus and Alan, you both agree that his timing is too high. Can you share with us what timing figures do you feel is acceptable in 3rd WOT? If I'm reading this correctly, in the first log he hits a peak of 23.5* with a 106* IAT. In the second, he hits 22.5* with a 104* IAT.
Your opinions are appreciated.

Jakpro1

Thanks you guys. I just cannot thank the engine blowing guys enough for posting the info on their cars. (other threads)

Honestly I would have never checked it (I knowwww I knowwww) but I am getting to be a bit lazy in my later modding years and I just never imagined they would stick me with that much timing. Everything seemed so silky smooth on the dyno when we tuned it and the car has run pretty nicely. Love what someone said though....you are one bad tank of gas away from pop tarting a piston.

Off comes the ole LET tune then....

Thanks again for the input guys!

bassn_07

When you get a chance give me a call and I will discuss it with you.

I hear ya Jim. If I were you I would be doing the same thing because if something were to happen I would never forgive myself. You now have enough info from various members to make a informed decision based on both knowledge and opinions from both sides.

Give me a call when you're ready and we could all meet up. After you get your car taken care of Sac is just a hop, skip, and drive away. Let's get it done.

930chas

I bought the Dashdaq/Zeitronix package from Dave at HPF. Pricing was really good and shipping was fast. Anyone deciding to start datalogging, this package seems to be the way to go.