Any N55 owners with an upgraded turbo? - JB4tech.com

okelmape6 · 11:23 PM

Currently debating going the next step with the Pure Stage 2 turbo on my 335i and I had a few questions for those with an upgrade turbo.

This car is my daily. Currently has 82k miles and is FBO running a custom 92 octane tune. My goal is to make a more enjoyable power band with more power up top. Right now it's a torque monster that tends to die off around 5500.

My questions to those who have upgraded:

How is the daily drivability? I'm assuming the only difference while cruising is boost takes a bit longer to build.

How much more stress (if any) would this be putting on the motor? My N55 already runs 20 peak PSI, but will running 16-17psi in the upper range put a significantly harder strain on the motor?appvalley tutuapp tweakbox

Is it worth it to upgrade even if I only have access to 92 octane?

Is it recommended to run boost by gear with upgraded turbos to avoid high torque loads in higher gears?

Finally, is a LSD necessary to put the power down with a RWD car?

Thanks!

hi rpm · 09-24-2020, 12:41 PM

Quote:

Originally Posted by okelmape6

Currently debating going the next step with the Pure Stage 2 turbo on my 335i and I had a few questions for those with an upgrade turbo.

This car is my daily. Currently has 82k miles and is FBO running a custom 92 octane tune. My goal is to make a more enjoyable power band with more power up top. Right now it's a torque monster that tends to die off around 5500.

My questions to those who have upgraded:

How is the daily drivability? I'm assuming the only difference while cruising is boost takes a bit longer to build.

Great. Change steering menu 12 to 3100 and the response is great.

Quote:

How much more stress (if any) would this be putting on the motor? My N55 already runs 20 peak PSI, but will running 16-17psi in the upper range put a significantly harder strain on the motor?

All I can say is the same boost is more power with bigger turbos, and "probably" not much harder on the engine.

Quote:

Is it worth it to upgrade even if I only have access to 92 octane?

Better, but worth it depends on how much you like money and hp.

Quote:

Is it recommended to run boost by gear with upgraded turbos to avoid high torque loads in higher gears?

Yes, and I'd ramp boost with rpm too, to minimize torque (and stress) further. You already have a car with too much torque at 3500 and not enough at 5500, so using as much boost as you can at 3500 is just stressing parts

Quote:

Finally, is a LSD necessary to put the power down with a RWD car?

I don't know!

Stools · 09-27-2020, 02:41 PM

With 92 you will need to run meth, if you can't, don't bother upgrading.
I have run 25psi on the VT S2 for years, no turbo related problems. I did run meth, worked well. (E85 now)
I think my LSD was my best upgrade.
Drivablity will stay A O K.
PS2 would be lots of fun.

KevinC39 · 09-28-2020, 09:13 AM

I've never driven or ridden in a PS2 car but I think it would be worth it just to get rid of that high RPM taper. It's so annoying and really kills a lot of the fun. It's like the last 2500rpm is useless. Plus you'd still make more power at the same boost everywhere else as well

tauzins · 09-28-2020, 09:24 AM

just for the LSD side, I think its 100% worth installing, even with my stock turbo, I put down power a whole lot better than before LSD

Ffmcdou · 10-08-2020, 05:39 PM

I recently upgraded to ps2. I had MAJOR ISSUES with drivability and performance on flash only. As soon as I got my jb4/bef back on, it’s been great. I strongly recommend the jb4. Great for a daily and that 5,500 drop off will be history. There is a touch of lag but nothg major. With your pump gas situation, likely need to add a meth kit. I have a BMS kit and it’s great, everythg works with the jb4. I don’t have an lsd, I’m sure they’re good. You can put the power down with a good tire, somethg 200 tread wear or less.

KevinC39 · 10-09-2020, 06:03 AM

Quote:

Originally Posted by Ffmcdou

I recently upgraded to ps2. I had MAJOR ISSUES with drivability and performance on flash only.

Who was tuning your custom MHD map? You shouldn't have had any issues at all

skaper · 10-19-2020, 01:46 PM

Quote:

Originally Posted by Stools

With 92 you will need to run meth, if you can't, don't bother upgrading.

Damn. I am actually planning to pull the trigger on the PS2 when their Black Friday sale hits. Anyone else agree this upgrade isn’t worth doing without meth? I also would be using this as a daily.

hi rpm · 10-19-2020, 01:51 PM

Quote:

Originally Posted by skaper

Damn. I am actually planning to pull the trigger on the PS2 when their Black Friday sale hits. Anyone else agree this upgrade isn’t worth doing without meth? I also would be using this as a daily.

I don't agree with that. The stock turbo, among other things, is intentionally stunted because people were having too much fun with N54s and making M3s look silly. If I were given an N55 car and had to choose a single mod it would be the PS2, even before JB4. It lets it breathe.

blackhat75 · 10-23-2020, 11:45 AM

I've had my PS2 installed for about a year. With all the other supporting HP mods, it puts a smile on my face every morning on the way to work across the valley straights. the xdrive launches are unaffected by traction limitation so it's like being shot out of a cannon.

Ffmcdou · 10-25-2020, 01:54 PM

Quote:

Originally Posted by KevinC39

Who was tuning your custom MHD map? You shouldn't have had any issues at all

@Kevinc39, I’d rather not say bc I think he’s a great guy and the majority of my issues I thk related to mhd. But my overall experience with flash only lacked performance results and came at the cost of boost control, meth control, flex fuel. There seems to be a trend among certain circles to go flash only. I’m in the group that gave it 6 months, had an open check book for suggested upgrades (spent thousands on hpfp, other upgrades), have a meticulously maintained, buttoned up one owner low mile car and after 20+ revisions, overboost, lean, rich, separate meth control system, it was a train wreck. The jb4 and burger in general have been great for me. And I define great by results. Performance results, safety results, customer service results. I trust the jb4.

KevinC39 · 10-26-2020, 06:04 AM

No worries, I just asked because I had problems flash only with my Speedtech kit. I threw a ton of parts at it and nothing helped. After 12 revisions and no improvement, I switched tuners and all the problems went away. My base map from the new tuner was 10 times better than the 12th from the other guy. Just a thought

Ffmcdou · 10-26-2020, 10:45 AM

That’s a good point Kevin. I wonder if mhd, pure, speedtech, others realize the impact these
individual tuners have on their product sales. The flash tuning companies are largely individuals. I’m sure many of them do great work and I’d rather support small business BUT I hear a lot of these jokers are taking your $750 (or whatever), getting you a base tune and then it slows what the F down. Maybe a revision a week, which doesn’t do much good if the revision causes more problems. I mean, let’s be honest, speed is expensive. Doing an aftermarket turbo with proper fueling upgrades is 5k (minimum hardware only). I would have thought the parts players would be more involved in getting their parts dialed in. Offer a complete solution. Anyway, for sure a good point.