new weird observation.. low launches == better time to 105 than 2k launches ????

[TopherSho]

are you suggesting that brake boosting is building to much heat in the system other than the IAT?

I would say this would start to heat soak IAT2@ right off the bat. The more boost you put through that intercooler without any airflow the hotter IAT2 heats up before you start moving.  Your intercooler is starting to heat soaking when you launch. The higher boost launch gets the initial boost advantage but loses spark up top, the low boost launch is reversed.

this is actually the opposite of what happens when you brake boost from my experience. when your off the gas the throttle blade is closed and just dead ending heat from the heads and block in the manifold so IAT2 spikes. when you open the throttle to build some boost it lets some semi- cool(relatively speaking)air in and cools the MAP/IAT2 sensor slightly. still probably not enough to make any noticeable difference but i've sat there and watched my IAT2 drop a few degrees when i start building boost at the line.



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So here is a ~2000 RPM launch that I held for four seconds before launching... you can see while I am break boosting the IAT's are dropping... FYI...

Holy S^^t,  your IAT2 never even breaks 90f...  Are you using spray?  or just the E30 and getting cooling from the 30% ethanol?

 

[lamrith]

are you suggesting that brake boosting is building to much heat in the system other than the IAT?

I would say this would start to heat soak IAT2@ right off the bat. The more boost you put through that intercooler without any airflow the hotter IAT2 heats up before you start moving.  Your intercooler is starting to heat soaking when you launch. The higher boost launch gets the initial boost advantage but loses spark up top, the low boost launch is reversed.

this is actually the opposite of what happens when you brake boost from my experience. when your off the gas the throttle blade is closed and just dead ending heat from the heads and block in the manifold so IAT2 spikes. when you open the throttle to build some boost it lets some semi- cool(relatively speaking)air in and cools the MAP/IAT2 sensor slightly. still probably not enough to make any noticeable difference but i've sat there and watched my IAT2 drop a few degrees when i start building boost at the line.



Sent from my iPhone using Tapatalk

So here is a ~2000 RPM launch that I held for four seconds before launching... you can see while I am break boosting the IAT's are dropping... FYI...

Holy S^^t,  your IAT2 never even breaks 90f...  Are you using spray?  or just the E30 and getting cooling from the 30% ethanol?

50* ambient temp will do that   sort of like if you or I did a log today with out lower temps.

 

[TopherSho]

are you suggesting that brake boosting is building to much heat in the system other than the IAT?

I would say this would start to heat soak IAT2@ right off the bat. The more boost you put through that intercooler without any airflow the hotter IAT2 heats up before you start moving.  Your intercooler is starting to heat soaking when you launch. The higher boost launch gets the initial boost advantage but loses spark up top, the low boost launch is reversed.

this is actually the opposite of what happens when you brake boost from my experience. when your off the gas the throttle blade is closed and just dead ending heat from the heads and block in the manifold so IAT2 spikes. when you open the throttle to build some boost it lets some semi- cool(relatively speaking)air in and cools the MAP/IAT2 sensor slightly. still probably not enough to make any noticeable difference but i've sat there and watched my IAT2 drop a few degrees when i start building boost at the line.



Sent from my iPhone using Tapatalk

So here is a ~2000 RPM launch that I held for four seconds before launching... you can see while I am break boosting the IAT's are dropping... FYI...

Holy S^^t,  your IAT2 never even breaks 90f...  Are you using spray?  or just the E30 and getting cooling from the 30% ethanol?

50* ambient temp will do that   sort of like if you or I did a log today with out lower temps.

I'm not even close.. i can see 130f temps on 60f days here in eugene.

 

[lamrith]

True, sitting in traffic I am 200 ect and 120 iat2.  Soon as moving iat2 dropped under 100.

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[lamrith]

And follow up, after parking 10min, came out and iat2 over 140 from heatsoak.  Moving dropped to 120, but traffic so not over 25mph...  right back to hot soon as stop...
Need to get ic out in front of trans cooler and radiator, would do wonders, plus a fan to run, or way to override and  command the stockers to run.

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[StealBlueSHO]

are you suggesting that brake boosting is building to much heat in the system other than the IAT?

I would say this would start to heat soak IAT2@ right off the bat. The more boost you put through that intercooler without any airflow the hotter IAT2 heats up before you start moving.  Your intercooler is starting to heat soaking when you launch. The higher boost launch gets the initial boost advantage but loses spark up top, the low boost launch is reversed.

this is actually the opposite of what happens when you brake boost from my experience. when your off the gas the throttle blade is closed and just dead ending heat from the heads and block in the manifold so IAT2 spikes. when you open the throttle to build some boost it lets some semi- cool(relatively speaking)air in and cools the MAP/IAT2 sensor slightly. still probably not enough to make any noticeable difference but i've sat there and watched my IAT2 drop a few degrees when i start building boost at the line.



Sent from my iPhone using Tapatalk

So here is a ~2000 RPM launch that I held for four seconds before launching... you can see while I am break boosting the IAT's are dropping... FYI...

Holy S^^t,  your IAT2 never even breaks 90f...  Are you using spray?  or just the E30 and getting cooling from the 30% ethanol?

So this was after a quick jaunt around town so there was no time for this thing to heat soak.... this is on 93 pump gas only... and with LMS 4+X Race tune...

They use lower boost but higher timing which helps with IAT's significantly. The higher boost tunes create more heat since the turbos are working harder. 

Here is an AJPTurbo datalog that is from a dig.. this one shows the IATs dipping slightly while I am brakeboosting as well... this is an E20 tune...more boost and more timing...

The LMS 93 Race tune netted a 4.2 second 0-60
The E20 AJPturbo tune netted a 4.1 second 0-60

Point being.. I think the data proves that brakeboosting doesn't immediately increase IATs..

 

[TopherSho]

Just bonkers.. 

New log showing same behavior,  lunching low (1515-RPM) netted ::

12.778 sec to 105mph which is way fatser than Brake boosting.
11.50x to 100mph which is way fatser than Brake boosting.
4.747 to 0-60, which is about 1.5-2 tenths off my best 0-60 so far.

My next test will be with coolant logging to tie it all together.  I think that's the metric that will make this all make sense.

interesting as hell ..

 

[lamrith]

Just bonkers.. 

New log showing same behavior,  lunching low (1515-RPM) netted ::

12.778 sec to 105mph which is way fatser than Brake boosting.
11.50x to 100mph which is way fatser than Brake boosting.
4.747 to 0-60, which is about 1.5-2 tenths off my best 0-60 so far.

My next test will be with coolant logging to tie it all together.  I think that's the metric that will make this all make sense.

interesting as hell ..

Looking forward to your testing.  What are you using to calculate 0-60, 0-100 just manual calculating based on the log?  I need to find a flat piece of road up here that I can let the big dog eat and see how it compares.

FYI - Found a place up here in Auburn that has a Dynojet AWD dyno.  At some point hopefully this summer me and another SHO guy up here are thinking of going in to make some runs, see if they give us a discount for more cars, drop me a PM if you are interested when we start setting it up.

 

[TopherSho]

Just bonkers.. 

New log showing same behavior,  lunching low (1515-RPM) netted ::

12.778 sec to 105mph which is way fatser than Brake boosting.
11.50x to 100mph which is way fatser than Brake boosting.
4.747 to 0-60, which is about 1.5-2 tenths off my best 0-60 so far.

My next test will be with coolant logging to tie it all together.  I think that's the metric that will make this all make sense.

interesting as hell ..

Looking forward to your testing.  What are you using to calculate 0-60, 0-100 just manual calculating based on the log?  I need to find a flat piece of road up here that I can let the big dog eat and see how it compares.

FYI - Found a place up here in Auburn that has a Dynojet AWD dyno.  At some point hopefully this summer me and another SHO guy up here are thinking of going in to make some runs, see if they give us a discount for more cars, drop me a PM if you are interested when we start setting it up.

i take the resulting CSV file from the handheld and open it in office.  then find the closet to 60/70/100/105 values and subtract that timestamp from the timestamp that shows the very 1st mph reading from being stopped.

you can also just write down the start of movement time listed on the top left of livelink,  then find the closed number to 60,70,100 and 105 and subtract the two ..

 

[lamrith]

Just bonkers.. 

New log showing same behavior,  lunching low (1515-RPM) netted ::

12.778 sec to 105mph which is way fatser than Brake boosting.
11.50x to 100mph which is way fatser than Brake boosting.
4.747 to 0-60, which is about 1.5-2 tenths off my best 0-60 so far.

My next test will be with coolant logging to tie it all together.  I think that's the metric that will make this all make sense.

interesting as hell ..

Looking forward to your testing.  What are you using to calculate 0-60, 0-100 just manual calculating based on the log?  I need to find a flat piece of road up here that I can let the big dog eat and see how it compares.

FYI - Found a place up here in Auburn that has a Dynojet AWD dyno.  At some point hopefully this summer me and another SHO guy up here are thinking of going in to make some runs, see if they give us a discount for more cars, drop me a PM if you are interested when we start setting it up.

i take the resulting CSV file from the handheld and open it in office.  then find the closet to 60/70/100/105 values and subtract that timestamp from the timestamp that shows the very 1st mph reading from being stopped.

you can also just write down the start of movement time listed on the top left of livelink,  then find the closed number to 60,70,100 and 105 and subtract the two ..

ok, that is the way I do it, just didn't know if you had some other thing going too.

 

[TopherSho]

The super fun/weird thing is it does not feel fast at all.  knocking 400+ms off the time to 105MPH should in my head feel much faster.. but it doesn't

I am going to go back to the 14.5 or 14.0 pound boost tune that made the best time to 105mph previously and do some more testing with the coolant temps listed.  I should get back some of the spark i am loosing on the current test tune which is running the full 15 pounds requested.

I feel WAY more confident going to the track next time. I will be way better off in the current build getting into 12's just by lightly boosting...  This makes tons more sense now why i could not break 12's last time.   

While my 0-60 is amazeballs for practically no mods and no meth.. brake boosting it is clearly destroying my 1/4 miles.