What are you high boost guy's seeing for timing numbers at full boost on average with good iat control ? Just looking for some input, Thanks

 

That's a dumb question as tuners tune different with timing.Stock should be 18 peak with ait around and under 90 on a cold day..

 

I am at 21 degrees btdc in 95 degree summer heat so down 3 degrees at least. I am running 14 psi 77mm FSP with meth. I hold timing steady through a pull but have yet to see what I get with ambients down low like they are now. This is at open loop full throttle.

 

a lot of variables there ,fuel,iat,load ,boost,everybody prob different ,you have to ask your tuner what he set max at ,IMO

 

Well i checked with him and he said it is set to 24 degrees. I only see 16 at 100* IAT. Before this tune I had a Kleeman tune and saw 0 degrees at full boost so this new tune REALLY woke this engine up but I still feel there is more to be had {safely}with more timing. Just have to figure out why it's being pulled or.... its normal. I will investigate more after I swap the rear diff out this weekend but it's real cold here now..35-40 degrees so i don't like to test in that temperature since it's not realistic for when I race it. Thanks for the input.

 

24 ? That’s
high unless your on race fuel or on E85 ,again IMO
19 20 max on 93 and even then ,if your running Zeitronics you can monitor timing and see knock retard

 

I run 104 mixed with 93...not sure how diluted that becomes but i am thinking around 95-96 octane and that"s what i'm tuned for.
cnterline...will you be at next years Slipstream event? I think it will be the same month , July.

 

if I go it will be March ,went to their pocono roll race in Sept ,

 

If you seeing not your full 24 it;s cause at 100 its pulling 3 * .

Your most likely on stock heat iat timing stages

.Like i said to you in the pm it all plays a factor weather fuel ,temps..


If you seeing 20 that's decent if it's 93 octane and if you not willing to take risks leave it.

 

The highest recorded timing number I've seen is 22. Usually around 20ish though. That is with meth and IATs < 95. Also the 3/6/9 timing pulls based on IAT have not been super accurate or consistent through my logs. I can almost guarantee you wont see a 3° just because you drop IAT 5°. and get below the 95° IAT threshold. That being said I do feel like 16 is pretty low. I was hitting 19 peak when my IATs were 150+. (not through the entire RPM range, but peaking at 20)

 

Interesting to hear guys. Just to see what I get for readings I will test out tomorrow morning on the way to the shop. Temps plummeted here on the east coast and Sat. morning will be around 15 degrees F. It will be interesting to see what the IAT and timing will be {and boost} since I have never driven it hard at those low temperatures. Thanks for the input.

 

Here are a bunch of my track logs without meth, and the one good 110mph pull with meth I was able to make just to give you an idea of what my timing is, and the differences I saw with sub 95 IATs. These are logged with torque, so I attribute some of the fluctuation to slow sample rate and laggy communication, but it gives you a good idea of where the numbers are.

Unfortunately actual 1/4 mile passes with meth will have to wait until spring :-[

Also, I have a 77mm CSP BUT I only hit 11 PSI, I am at 4200ft.

 

Here here, that's exactly what I been saying recently. The 3/6/9 timing pull I havnt seen on my logs at all even when my iat's have been in the 9 pull bracket. That is a massive amount of timing pull, but the dumping of fuel and afr's going rich yes definitely. To the OP my timing peaks at 19' no matter what my IAT is that is what it Max's out at.

 

I peak 23* temps don't pull * till i hit 130 but my tuning is different then many .

..then again all setups are different on who tunes it for each person.

 

You know when you think of it there is no reason to pull timing at say "up to 110-120" IAT. That is not very hot at all for an engine.
Hell I remember my Renegade engine with no air to air inter cooler hitting 275-300 degrees under hard "25psi" of boost. That was normal !!! Totally different engine I know but low 20* timing is plenty safe with good gas mixed with race fuel. It's the fueling that really protects the engine.
Also on another note I know of some one that moved his IAT sensor to the air intake side to measure actual ambient temps like the old days and just kept on eye on everything and never had an issue.Ran like hell like that and timing was always low 20-24 on his E55.

 

that’s means he’s reading pure iat 1 not iat 2 ! I wouldn’t run the e55 engine past 180 max!

 

Oh hell no your right !! ....180 is really warm for these engines but if you can keep it around the 110-120 I would think you would be very safe. Again plenty of fuel and good octane.
Also what do you think about when spraying Meth right before/at the IAT sensor? Does that not really cool down the sensor reading? Seems kind of counter productive and also just tricking the computer as well.

 

Meth tricks it !!

This why I love how whipple places there sensor many say omg these blowers run it’s actually reading correct heat iat 2 reading Vs e55 which is really iat 1.

This why benz sets the timing pull at 95 to be on the safe side cause actually it’s like 110 when reading iat2 .

 

Sorry I'm lost here, are you saying there is another secondary IAT sensor, (No. 2) located further downstream of the IAT sensor we know about? Or you saying that the intake air temp still rises further after the air passes the current IAT sensor.

 

The meth definitely sprays the IAT sensor and cools it down lower than the intake air temp at the cylinder, ie false reading. In saying this everyone seems to have had no issues with this setup.

 

yes sir !!

 

Sorry but that is not correct. I have been in and around the SC and intake manifolds pretty thoroughly and I am pretty certain there is only one IAT sensor.


There is also this little snip-it showing one sensor as well, but I haven't found the statements about retarding timing to be correct so I can't exactly swear to this documents accuracy haha. I assume the title of "example for full load" means the timing retard based on temperature is much more complex than three simple set points. They just picked a few points to display as examples, but there are likely more parameters involved with determining what exactly the timing retard will be out of a large table of possibilities. Haha, just my guess.

 

Your only one sensor but your reading iat1 reading not 2 ..I never said it had 2 sensors if you go back and re read the other member got all confused about this .

No offenense this why I don’t like I get into timing and ecu temp aspects cause many have no idea on this and hard to teach on this subject .

The real term actually is not air intake temperature ,you really need to read direct air charge for proper readings

 

Bud I think you confusing things talking of 2 IAT readings. Now if there is only 1 and there is on 1 IAT sensor then how can you read another IAT2 that you keep talking about? So yes if the air travels past the IAT sensor and keeps warming up before reaching the cylinders doesn't matter, there is no further temp reading happening, only for those that have moved the IAT sensor to the intake plenum(surge tanks)
The ecu pulling timing has other variables that need to be met together with the 3 stages of intake air temp before ecu will pull timing.

 

your wrong

learn what iat 1 is Vs iat 2 ..I said the ecu pulls timing that low due to it reading iat1 and not fully reading iat 2..iat 2 is intercooler blower reading (true temps ) iat 1 is Intake which your e55 got .Benz does this on those stages to be safe ,pulling timing at 95 is a joke !


relcoate your sensor closer to the Intake and report back more then likely your engine might pop.To read iat 2 you would need a gauge and sensor located at the blower ..I read iat2 temps I like real reading and see how hot it truly gets