[JETmn]

One other thing to remember is that the descriptions for the maps are from the N54 and are not N55 specific. With the small gains we see from DP's, there is not that much back pressure being created. If you have seen the size of the turbine housing on our turbo you will know that the DP is the least of our worries :P The turbo is creating WAY more backpressure than the DP is.

[SpeedFreak]

OP,

Why don't you just ask Terry, seems to me he would be the one who could better answer anyway. Just my $.02.

FWIW, I just added a JB4 and charge pipe to my N55 car and after a week of running Map 5, I switched to Map 2 just to try it out. It DEFINITELY pulled harder than Map5. However, heading BMS's advice, after one full throttle run I switched back to 5.

[evo335xi]

Temp is going to have a big impact along with gas quality. Last summer before my intercooler, I would run map 2 to get 14-15psi because map 5 would only get me 12-13. Either way the heat made the car a slug as it wouldn't boost much after a few pulls and it would heatsoak from the humidity.

[-Wingman-]

Got another question for you guys, but it's kind of irrelevant to this thread.

I raced my friend'a n54 335i which is stock. I have a bms intake and jb4 was set on map 1. I was confident I was going to win, maybe not by a lot, but still win. I ended up losing? Is this normal?

Both cars are xdrive, 6mt, except he has an e90

[JETmn]

I think he lied, you should have smoked him if he was stock. What RPM were you shifting at?

[-Wingman-]

We did multiple runs so I tried shifting at different rpms to see if it would make a difference. I tried around 6.5k rpms, and around 5.8k rpms a few times.

[JETmn]

You should be shifting around 5k. Power drops off hard after 5.5k.

[-Wingman-]

But should that even make a difference in whether I should have lost or won?

[Johnny Boost]

Originally Posted by -Wingman-

But should that even make a difference in whether I should have lost or won?

You should have definitely won that race. Have you taken any logs in map 1? Did you try racing again in Map 5?

[-Wingman-]

Originally Posted by Johnny Boost

You should have definitely won that race. Have you taken any logs in map 1? Did you try racing again in Map 5?

Nope, I was going to log today but it's raining pretty hard. I didn't get a chance to run in map 5 because I didn't want the car to have to adapt. Plus, I feel like I shouldn't have to resort to that.

I was hoping to get some commentary from people who have raced a stock n54 car on map 1...but I'm supposed to race another stock e90 n54 car this weekend to see if it happens again. If it does, then perhaps something is wrong with my car like a boost leak or something from the charge pipe area.

[Johnny Boost]

Originally Posted by -Wingman-

Nope, I was going to log today but it's raining pretty hard. I didn't get a chance to run in map 5 because I didn't want the car to have to adapt. Plus, I feel like I shouldn't have to resort to that.

I was hoping to get some commentary from people who have raced a stock n54 car on map 1...but I'm supposed to race another stock e90 n54 car this weekend to see if it happens again. If it does, then perhaps something is wrong with my car like a boost leak or something from the charge pipe area.

AFAIK map 1 of the jb4 is similar to stage 1 sport for the Cobb. The bump up in hp is pretty small. Which means it could still be a close race. Was DTC on? How old are you tires? Did you launch from 2nd? Were you running e85?

[-Wingman-]

Dtc was on. I'm awd anyways, and a 6mt so I wouldn't launch from 2nd. My tires are relatively new.

Traction wasn't an issue cause we did most races from a roll. I was only running 91.

[JETmn]

You did remember to take the o-ring from the stock CP and put it on the new one, right?

[-Wingman-]

no, but i don't see how that would make a difference when I saw that I was reaching around 12psi according to the fuel gauge.

[-Wingman-]

But I'll try to log this Wednesday if it clears up.

[JETmn]

Originally Posted by -Wingman-

no, but i don't see how that would make a difference when I saw that I was reaching around 12psi according to the fuel gauge.

You will until about 4k, then it falls on its face. Don't ask me how I know :P Made 306/408 on they dyno when I should have been ~340 (map 5 + E40).

[-Wingman-]

Originally Posted by JETmn

You will until about 4k, then it falls on its face. Don't ask me how I know :P Made 306/408 on they dyno when I should have been ~340 (map 5 + E40).

For me, it feels like the power output climbs until about 4k, then remains steady, then falls after 5.5k. With the jb4, i can definitely tell that the n55 is holding power for a bit longer.

What type of dyno were you on? without a baseline, i would say you really couldn't gather much from what your car was putting down on e40. just because you put down low numbers doesn't mean your gains were low. I know that some lower reading dynos will rate something like an sti to produce as low as 200whp while something else like a dynojet which is the most common type of dyno will rate them at like 240whp.

but regardless of all that and taking into consideration what a stock n54 xi car should be putting down stock, my car should be producing more power and more tq on map 1.

[JETmn]

It wasn't as noticeable on the street, but on the dyno you could see the power fall off too early. Basically it hit 4k and the dyno chart looked normal, but started to slowly fall off at that point. Now that the o-ring is in there it is very noticeable that the power is much stronger up top.

[-Wingman-]

Hm, I'm going to have to check out this o-ring thing.

[Jeff@TopGearSolutions]

Originally Posted by -Wingman-

no, but i don't see how that would make a difference when I saw that I was reaching around 12psi according to the fuel gauge.

It would make a difference in some respect as you need to now over-spin the turbo's to meet target due to a potential small boost leak. Over spinining the turbo's creates excessive air intake temperatures, reducing overall efficiency and power.

[JETmn]

Originally Posted by -Wingman-

Hm, I'm going to have to check out this o-ring thing.

You have a CP that uses the stock clip to attach on the engine end, correct? The other possibility is the t-bolt clamps on both ends.

[Schmidty335i]

I ran Map 2 for two weeks with no issues with a stock DP. all i have is the jb4 bms intake and 91 oct chevron gas (cali) pulled hard. ordered a DP should be getting it today so i should be better off now haha