BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
 





 

Post Reply
 
Thread Tools Search this Thread
      02-20-2020, 09:33 AM   #1
onefastredsc
New Member
United_States
2
Rep
12
Posts

Drives: 2011 BWM 128i
Join Date: Jul 2019
Location: Pittsburgh, PA

iTrader: (1)

N52 Tuned with or without Headers?

Hi all. With the weather here in western PA being a little too crumby to wrench on my car (no garage, i know.....), I thought i would create a post to start some healthy debate on a topic that recently crossed my mind. I have a 128i with the N52 motor, on which i installed a 3SI manifold from a N51 motor that i procured from a wrecked SULEV 3 series on ebay. I installed the manifold back in December, as i had to remove the manifold anyway to replace a failing starter motor located under the manifold. I have since put about a 1k miles over 2 months of driving with the 3SI installed on the factory tune without any issues. I do realize that i must install some sort of tune eventually to fully realize the benefits of the manifold (OE style 330 tune or aftermarket), but i've been telling myself to hold off until i NEED to tune the car post header installation.

Which brings me to the headers. I also have a set of AA headers i purchased on sale over the holidays, coated by SwainTech to boot, that have been staring me in the face and tempting me to brave the conditions and install. However, i've noticed that some forum members (here and/or in the E90 forums, can't recall which) have reported issues with idle fluctuations and emissions efficiency CELs after installing catless headers, even with the accompanying tune. I've also noticed that the claimed crank HP increase of the 3SI with tune is approximately 30HP, which approximately totals 260, with another 10-15HP provided by the headers with tune to a total of 270-275.

So then my question is whether or not the headers are worth the hassle of risking a CEL and/or idle fluctuation issues for that extra 10-15hp? Do they provide a significant improvement compared to a 3SI with tune all across the rev range, specifically in regions of the RPM where most daily driving occurs (2k-4k rpm)? Or is their contribution mostly felt near the top of the range where the efficiency of equal length exhaust tubes and their scavenging effect really shines? I guess i'm trying to narrow down the contribution of these mods and weigh them against any possible drawbacks.

Thanks in advance for your inputs.
__________________
2011 BMW 128i - AW / 6-MT / Sport Pkg / AA Headers / StageFP Tune
Appreciate 0
      02-20-2020, 10:55 AM   #2
b1aze
Just one more taste...
b1aze's Avatar
United_States
278
Rep
1,659
Posts

Drives: 2013 128i 6MT MSport
Join Date: Aug 2012
Location: Uxbridge MA

iTrader: (17)

Have you found the 130i tune on BimmerLabs? It’s free and will take (almost) full advantage of the 3SI. That’s my route until I finally decide to put catless headers on.
Appreciate 1
      02-20-2020, 11:45 AM   #3
desertman123
E82 Mudflap Ambassador
desertman123's Avatar
United_States
1836
Rep
1,968
Posts

Drives: '08 128i
Join Date: May 2016
Location: Orlando, FL

iTrader: (0)

Garage List
2008 BMW 128i  [5.00]
2014 BMW 528i  [5.00]
It's really only the N51s I've noticed had issues. Check in with Rmtt I think he had a survey about it.

Yeah the headers shine in higher RPMs, like you said where the scavenging really gets good. I certainly wouldn't remove them, there aren't any drawbacks (like reduced torque at low end).

The CEL took a while to appear for me. Looking at my mod/maintenance log, I went about 5 months before I got a custom tune and I wasn't ever fighting with having the CEL appear all the time.

Buuuut you should look towards Bimmerlabs for their free tune, then StageFP (Bob from BPC) for the custom tune. You won't unlock all that 10-15hp until you tune for it.

I'll say, my N52 with a 3SI, AA headers, MILVS, MAF delete (Euro IAT) and a custom tune is running pretty flawlessly.
__________________

My 2008 128i - Sparkling Graphite/Beige - Sport pkg - 6MT - Click me!
Parents' 2014 528i - Mineral White/Ivory White - fully loaded
Instagram @Andreys_128i
Appreciate 1
Rmtt3766.50

      02-21-2020, 06:14 AM   #4
Rmtt
Lieutenant Colonel
Rmtt's Avatar
United_States
3767
Rep
1,914
Posts

Drives: 2011 BMW 128i, 2008 LS3 C6
Join Date: Jan 2019
Location: South Carolina

iTrader: (3)

Quote:
Originally Posted by desertman123 View Post
It's really only the N51s I've noticed had issues. Check in with Rmtt I think he had a survey about it.

Yeah the headers shine in higher RPMs, like you said where the scavenging really gets good. I certainly wouldn't remove them, there aren't any drawbacks (like reduced torque at low end).

The CEL took a while to appear for me. Looking at my mod/maintenance log, I went about 5 months before I got a custom tune and I wasn't ever fighting with having the CEL appear all the time.

Buuuut you should look towards Bimmerlabs for their free tune, then StageFP (Bob from BPC) for the custom tune. You won't unlock all that 10-15hp until you tune for it.

I'll say, my N52 with a 3SI, AA headers, MILVS, MAF delete (Euro IAT) and a custom tune is running pretty flawlessly.

I did the 3SI and tune from Bob first. I had headers in my garage looking at me for months, because I too was worried about the idle issues.

But I installed them, put the new tune in from Bob, and never had the first issue or CEL. desertman123 put it best in one of my posts...headers were like "clearing the car's throat". Maybe a little less TQ down low but you can't notice it. And it screams to red-line. It doesn't feel "choked" if that makes since.

And as for the TQ, installing MILVS brought all of that back and then some. I did those last with another tune from Bob and the car is a blast to drive.

Add in the 3:73 rear differential which you can buy used, and you have a very fun little daily driver which is plenty in my opinion.

Next step is FI and SteveOStyle I believe has a thread about that. I just don't think the cost of that justifies the increase in power you get. So I think as far us power upgrades go, I'm done and not worried about reliability. Suspension would be next.

But I have a 2nd car that has all the power I need when I want to satisfy that urge!
__________________
Everybody has a gameplan....until they get punched in the mouth.
Appreciate 1
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 07:29 PM.




1addicts
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST