Dyno trouble shooting session of Z4M ESS VT - 525

[tikamak]

This was AJ's reply in case he don't have time to reply today:

"We have never been able to replicate this in house on any of our test cars. If the brake booster system or the vacuum sensor does not work 100% it will trigger a power reduced limp mode to prevent high speed with a lack of brake power. Since we have never seen the issue on any of our test cars or any of our in house installation cars it is very difficult for us to pinpoint what may cause it. I have seen a similar issue on the E9x M3 if the brake vacuum sensor is bad or the sensor wires are saturated in brake fluid from the overspill valve."

[sales@ESSTuning]

Originally Posted by tikamak

This was AJ's reply in case he don't have time to reply today:

"We have never been able to replicate this in house on any of our test cars. If the brake booster system or the vacuum sensor does not work 100% it will trigger a power reduced limp mode to prevent high speed with a lack of brake power. Since we have never seen the issue on any of our test cars or any of our in house installation cars it is very difficult for us to pinpoint what may cause it. I have seen a similar issue on the E9x M3 if the brake vacuum sensor is bad or the sensor wires are saturated in brake fluid from the overspill valve."

This is correct, we have not seen this issue on any of our in-house cars or test cars over the years. We will bring in one of our test cars and look into developing a fix for potential vacuum pressure related errors in the brake booster system. Like most modern BMW's the Z4M is very sensitive to sensor feedback there is always the possibility of the car going into reduced power mode with or without forced induction.

I will update once we have had a chance to look into this over the next few weeks.

[seank]

Has anyone have any thoughts on whether it needs more pressure or less for the brake booster sensor.

Couldn't we just set up a gauge to a stock car to see the pressure on the intake boot at the stock location?

If it is seeing too much pressure with ess, that would be easy to fix

[gmd2003]

Originally Posted by seank

Has anyone have any thoughts on whether it needs more pressure or less for the brake booster sensor.

Couldn't we just set up a gauge to a stock car to see the pressure on the intake boot at the stock location?

If it is seeing too much pressure with ess, that would be easy to fix

Sean the sensor in a NA car never sees positive pressure, there is a stock valve and tube diameter change apparatus that amplifies vacuum located upstream from the sensor . What I tried was putting an additional one way valve between this vacuum amplifier and the manifold to keep the boost out of the system . Apparently this does not work . Our only choice is to either trick the sensor , or code it to always see the vacuum it expects .

[seank]

Originally Posted by gmd2003

Sean the sensor in a NA car never sees positive pressure, there is a stock valve and tube diameter change apparatus that amplifies vacuum located upstream from the sensor . What I tried was putting an additional one way valve between this vacuum amplifier and the manifold to keep the boost out of the system . Apparently this does not work . Our only choice is to either trick the sensor , or code it to always see the vacuum it expects .

Based on your information, something else must be going on. Is it possible it is seeing too much vacuum?

[pandusr]

Originally Posted by gmd2003

Please tell ESS you have had the same issue , they keep telling me I'm the only car they have ever heard of this happening which is not the case .

It happens to me with CFR525 kit.

Palantirion also had the same problem.

Are also happens because bales in the winter, with low temperatures (winter).

Problem never solved.

[Gt4]

I will put my Z4MC for sell soon. I will go back to another E46 M3 (3rd for me). I will switch all my mods on it and maybe the ESS kit also cause this problem doesn't seems to happen on the ESS E46 M3

[seank]

Originally Posted by pandusr

Are also happens because bales in the winter, with low temperatures (winter)

What does this mean?

[pandusr]

Originally Posted by seank

What does this mean?

Sorry.

AJ has always maintained that depended on high temperature engine oil.

It is not true. To me it just happens with low temperatures.

[Beedub]

Why do some have this issue and others not?? Never seen a limp mode on my car for 4 years supercharged.... ???? This seems like a z4m problem as above I never see the e46 guys talking about it.... I remember planituron (sp) having these issues however....

[gmd2003]

Ok a little update on my research into overheating on track. So the setrab oil cooler in our kits is model number 50-925-7612. It is a 25 row oil cooler that is designed for engines with a 400-470 crank hp rating (straight from setrab website)
http://www.setrabusa.com/products/oi...ine/index.html
Yeah thats an issue lol. The one we should have is 50-934-7612 which is a 34 row cooler that is rated for up to 550 crank hp. It is literally the same design same width as the 24 row just 3 inches taller vertically and 200 bucks more expensive. As I rebuild my car I will be swapping out the 25 row for the 34 row Setrab. Even the same brackets and lines should work with minimal modification. This was extremely weak on ESS part IMHO, undersizing our cooler by a large margin and claiming the kit was trackable. I am still waiting on the Brake booster limp fix as they are having a hard time getting a car to test on.
Final tally on my off track excursion repair bill is going to end up being around 7k ouch!
George

[pokeybritches]

Are these oil coolers FI-specific? 550 hp on a naturally aspirated engine won't cause the same oil temps as 550 hp on a supercharged engine. Seems like an odd way to rate them. At least you're replacing the original undersized oil cooler!

Edit: Just saw the btu/hr range too.

[gmd2003]

Originally Posted by pokeybritches

Are these oil coolers FI-specific? 550 hp on a naturally aspirated engine won't cause the same oil temps as 550 hp on a supercharged engine. Seems like an odd way to rate them. At least you're replacing the original undersized oil cooler!

Edit: Just saw the btu/hr range too.

I think approx 90k BTU/hr or 20 k more than what comes on the 525 kit will be plenty . Going too big would cover up too much radiator and be back to having water temp issues . And Yes an FI motor needs more oil cooler than a NA motor , which makes the undersize of the kit cooler worse .

George

[seank]

Originally Posted by gmd2003

Ok a little update on my research into overheating on track. So the setrab oil cooler in our kits is model number 50-925-7612. It is a 25 row oil cooler that is designed for engines with a 400-470 crank hp rating (straight from setrab website)
http://www.setrabusa.com/products/oi...ine/index.html
Yeah thats an issue lol. The one we should have is 50-934-7612 which is a 34 row cooler that is rated for up to 550 crank hp. It is literally the same design same width as the 24 row just 3 inches taller vertically and 200 bucks more expensive. As I rebuild my car I will be swapping out the 25 row for the 34 row Setrab. Even the same brackets and lines should work with minimal modification. This was extremely weak on ESS part IMHO, undersizing our cooler by a large margin and claiming the kit was trackable. I am still waiting on the Brake booster limp fix as they are having a hard time getting a car to test on.
Final tally on my off track excursion repair bill is going to end up being around 7k ouch!
George

I don't think they have temperature issues because they are tuning and running these cars in colder climates.

I am not positive, but I also think setrab recommends placing the hoses at the top, rather than the bottom for flow efficiency.

Please keep us updated and I am glad that you aren't calling it quits yet.

[gmd2003]

Thanks Sean will def keep everyone updated . Yeah when I was sliding towards the woods backwards at 100mph I actually had quite the conversation in my head about what car I would get to replace this POS . Lol . But I've decided I'm in for a penny in for a pound at this point .
George

[Finnegan]

Good info. And sorry to hear about the damage. I'm glad you're okay and the car can be fixed.

[Str8 RippiN]

would be curious to know if ESS has found anything on their side yet

[gmd2003]

Originally Posted by Str8 RippiN

would be curious to know if ESS has found anything on their side yet

They have an idea how to stop the brake booster fault but haven't had a car to try it out on yet + AJ has been out working on a Merc project. Will let everyone know when something is figured out as I'm going to be the real world tester for the fix . I will also let everyone know the temp change on track from going to the 34 row Setrab cooler .
George

[seank]

Originally Posted by gmd2003

They have an idea how to stop the brake booster fault but haven't had a car to try it out on yet + AJ has been out working on a Merc project. Will let everyone know when something is figured out as I'm going to be the real world tester for the fix . I will also let everyone know the temp change on track from going to the 34 row Setrab cooler .
George

Soon, your going to make us feel like we owe you money for being a tester.

[Str8 RippiN]

Originally Posted by seank

Soon, your going to make us feel like we owe you money for being a tester.

seriously though

[gmd2003]

Originally Posted by seank

Soon, your going to make us feel like we owe you money for being a tester.

Ha thanks guys ,the kind words are more than enough payment . This is what an online community is for IMHO !
George

[tikamak]

Originally Posted by gmd2003

Ha thanks guys ,the kind words are more than enough payment . This is what an online community is for IMHO !
George

+1 very glad to own a Z4M and be a part of this online community

My supercharger build will be fed with more pics and reviews and such soon enough