[scalbert]

Originally Posted by FunRevn

Any update ??

Yes and no, we found the first solution was not ideal for all situations. However, there are several other options on the table that are being explored. Unfortunately I am heading out of town but will be back tomorrow afternoon. At which point I will doing some wiring and testing of another simple circuit.

Concurrently, a new map is being tested by some which has a change in it that may address the overboost/spike issue significantly. More should be known shortly but after discussions and my understanding of it, this may help the matter greatly.

[FunRevn]

Thanks and Have a great trip

[chris b.]

scalbert: how do you think low ambient temp affects boost pressure? if the stock dme is going to trim boost at cold ambient temp is there some way us in really cold climates can figure out the max boost that should be seen given the low ambient temp?

thanks for all your work.

[scalbert]

Originally Posted by chris b.

scalbert: how do you think low ambient temp affects boost pressure? if the stock dme is going to trim boost at cold ambient temp is there some way us in really cold climates can figure out the max boost that should be seen given the low ambient temp?

First off, the lower ambient temps will affect boost. With the current methodology, there is no way around that and it is not a problem. If you are in very cold weather you can bump up the UT values some, provided you have a boost gauge, to an acceptable level. However, these may need to be brought down when things warm up a bit.

[cn555ic]

Originally Posted by scalbert

First off, the lower ambient temps will affect boost. With the current methodology, there is no way around that and it is not a problem. If you are in very cold weather you can bump up the UT values some, provided you have a boost gauge, to an acceptable level. However, these may need to be brought down when things warm up a bit.

These variables of cold temps are only applied to people with just V2 tunes and otherwise stock car...YOu can bump the UT....If you have free flow mods and intake it wouldn't be wise right??

[scalbert]

Originally Posted by cn555ic

These variables of cold temps are only applied to people with just V2 tunes and otherwise stock car...YOu can bump the UT....If you have free flow mods and intake it wouldn't be wise right??

The V1.x, JB, JBS2 (with H pill but not the R), XEDE, etc. are all susceptible to boost changes with varying ambient temps.

However, only the V2 allows you to bump this up, if you chose to, when the weather permits.

[cn555ic]

Originally Posted by scalbert

The V1.x, JB, JBS2 (with H pill but not the R), XEDE, etc. are all susceptible to boost changes with varying ambient temps.

However, only the V2 allows you to bump this up, if you chose to, when the weather permits.

Yes I agree but the most important thing for V2 users right now is getting a boost guage to know for sure what your boosting if your bumping up the UT!!!

Thats what I am doing at the moment...Lowering UT to default until my guage is installed!!!

[scalbert]

Originally Posted by cn555ic

Thats what I am going at the moment...Lowering UT to default until my guage is installed!!!

That is a safe thing to do. Although I am beginning to feel that the DME will safe gaurd ultimately based on what people are doing here and with other tunes.

[chris b.]

Originally Posted by scalbert

First off, the lower ambient temps will affect boost. With the current methodology, there is no way around that and it is not a problem. If you are in very cold weather you can bump up the UT values some, provided you have a boost gauge, to an acceptable level. However, these may need to be brought down when things warm up a bit.

i understand all this. what im asking is how do i know what my max boost pressure should be given the low ambient temp since dme is trimming boost at low temp.

ex: its 30 deg ambient temp, should my max boost pressure be 13 psi? instead of 15?

reason i ask is since im logging/adjusting ut% in cold climate i need to know what the limit is for the given ambient temp.

thanks for the response.

[scalbert]

Originally Posted by chris b.

ex: its 30 deg ambient temp, should my max boost pressure be 13 psi? instead of 15?

reason i ask is since im logging/adjusting ut% in cold climate i need to know what the limit is for the given ambient temp.

To be honest, I do not have the depth of vehicles sampled to know the correct answer but I can take a stab at it. Eliminating any spikes, in cool weather (30 - 40 F) 12 PSI may be the max. In warm weather (80 - 90 F) about 15 PSI. But remember, this is a guess based on what I have seen.

[Supramano]

Originally Posted by scalbert

To be honest, I do not have the depth of vehicles sampled to know the correct answer but I can take a stab at it. Eliminating any spikes, in cool weather (30 - 40 F) 12 PSI may be the max. In warm weather (80 - 90 F) about 15 PSI. But remember, this is a guess based on what I have seen.

its about 22 degrees here in ny...i found 100 octane and mixed about half 100 and half 93 just to be safe when adjusting the tq curves to high. At 94% i am consistent at 15psi in decent weather. i bumped all the way to 100% and still could not get overf 13.5 psi. Rikght now i left it at 96% and im getting about 13psi max. i hate the freezing cold.

[FunRevn]

When might we get some additional information??

[chris b.]

Originally Posted by scalbert

To be honest, I do not have the depth of vehicles sampled to know the correct answer but I can take a stab at it. Eliminating any spikes, in cool weather (30 - 40 F) 12 PSI may be the max. In warm weather (80 - 90 F) about 15 PSI. But remember, this is a guess based on what I have seen.

thanks man. i appreciate the help.

http://www.e90post.com/forums/showth...ight=overboost

see this post? alot of views but no one has any info for me.

[midlife]

Originally Posted by scalbert

To be honest, I do not have the depth of vehicles sampled to know the correct answer but I can take a stab at it. Eliminating any spikes, in cool weather (30 - 40 F) 12 PSI may be the max. In warm weather (80 - 90 F) about 15 PSI. But remember, this is a guess based on what I have seen.

thanks scalbert, we realize your opinions are educated (i would like to stress well educated) guesses. taking your examples of max 12 psi in cold weather and 15psi in hot, how would you personally set the boost taper after 5,500 rpm in these 2 weather/temp scenarios....and is 5,500 rpm the best rpm to start the boost taper?

btw, i am certain many procede users would be interested in your opinion.

thanks

[scalbert]

Originally Posted by midlife

taking your examples of max 12 psi in cold weather and 15psi in hot, how would you personally set the boost taper after 5,500 rpm in these 2 weather/temp scenarios....and is 5,500 rpm the best rpm to start the boost taper?

In a mean temperature of about 65 F, I wouldn't try to run these snails to maintain much over 12 PSI at redline as of today. We need to learn more about what does and doesn't work with these two turbos.

[scalbert]

Originally Posted by chris b.

thanks man. i appreciate the help.

http://www.e90post.com/forums/showth...ight=overboost

see this post? alot of views but no one has any info for me.

I can't say for sure, did the freeze frame data show what the level was?

[scalbert]

Originally Posted by FunRevn

When might we get some additional information??

In a few minutes in a new thread I am about to start.

[FunRevn]

Cool !!!!!!!!! Thanks for all your efforts

[chris b.]

Originally Posted by scalbert

I can't say for sure, did the freeze frame data show what the level was?

unfortunately. i erased the log before i got to view it. my fault. it hasent happened since so im not too worried, but kinda weird ya know?