The results are in! And they’re, well..

[LSBNick]

Not what I was expecting.

Car is currently running this set up:
- ARH 6-1 headers with race cat and dedicated section 1
- OE section 2
- Meisterschaft Titanium section 3
- TMS CSL box V2

Tuning was done by Hassan @ HTE Performance tuning on a dynojet. Initial results were promising, with the car laying down 297whp after Hassan’s first adjustment.


The shop only had one functioning AFR sensor, and it ended up dying on us. So with no accurate way to gauge AFR readings, we were kind of left in the dark on most of the adjustments.

Additionally, car seems to be having some form of fueling issues. HTE suggested cleaning injectors (rebuilding in the worst case), and a new fuel filter, just to start.

As far as the dyno info, correction was set to Smoothing 1.

A friend of mine also suggested converting the EKP over to a traditional fuel pump relay, as US cars were the only ones to come with EKPs, I assume that were for emission reasons.

I won’t have time to get the maintenance items on the car done and back on the dyno for about two-three weeks, but once it is I’ll be updating this post again.

HTE seems to be confident this should be a 320-330whp car. I’m sure the fuel filter being original, and the injectors definitely play some role into the results I got.

If anyone has had similar experiences in the past, please chime in as to what you did to address those issues, and what your end results were. Planning on doing a compression test on the motor as well. While I’m not worried about losing compression, I don’t have any records of the car having a compression test done, so it’ll be good to add to my maintenance records.

[r4dr]

Have you done any previous dyno runs with the ARH headers?

[LSBNick]

Have you done any previous dyno runs with the ARH headers?

I have not, this was my first run. From my research, I haven’t been able to find many write-ups where people were running them on their cars. I’m fine with being a test dummy though, at least this way we’ll have some decent documentation of how they perform on dynos.

[ra2fanatic]

Your numbers are essentially what I saw w/o headers.

At the time when I made 297whp, it was stock headers, CPI rasp elim sec 1, sg section 2, and dixis ti muffler, with Evolve CSL intake race box.

after euro headers and OE CSL cams, I made 336whp.

[eacmen]

I have not, this was my first run. From my research, I haven’t been able to find many write-ups where people were running them on their cars. I’m fine with being a test dummy though, at least this way we’ll have some decent documentation of how they perform on dynos.

There was a fairly exhaustive thread on the old forum regarding the ARH. The consensus was that they were equivalent to Euro headers for making more power and being 6->1 versus 6->2 they caused more problems than they solved. Probably not what you wanted to hear. Not saying you can't get them to work well, but several people before you have had issues making power with them. If Hassan cant dial them in I doubt anyone would be able to do better.

As far as maintenance, I would do a VANOS test with DIS make sure your response times are good. Can also check VANOS oil pressure. Swap out plugs for new. Get injectors cleaned. Basically typical stuff before trying to dyno tune a car.

[joefresh]

I own ARH headers and have talked with Hassan about tuning. He has made great power with this header. IIRC our chats back on m3forum I asked him about adding a second bung to run both o2 sensors and a wideband and that seemed to be his recommendation for optimized tuning.

[LSBNick]

I own ARH headers and have talked with Hassan about tuning. He has made great power with this header. IIRC our chats back on m3forum I asked him about adding a second bung to run both o2 sensors and a wideband and that seemed to be his recommendation for optimized tuning.

as in two wideband sensors for the two pre cat O2s? Could work.

[Arith2]

I see two things. Your delta is 44whp so that is REALLY good. I'm not sure why that final number matters. It's completely arbitrary. There's a very good chance your car is not making 297whp with your set up. If it is, something is wrong. I blame the dyno for just reading low.
Another note is you are dangerously lean between 4500 and 6000. Notice that's where you had your original power dip along with hitting a 16 to 17 AFR. That is exactly how you blow up a gasoline engine. Afterwards it's not as bad but it's still quite lean. Your original lean condition may have caused damage.

[LSBNick]

I see two things. Your delta is 44whp so that is REALLY good. I'm not sure why that final number matters. It's completely arbitrary. There's a very good chance your car is not making 297whp with your set up. If it is, something is wrong. I blame the dyno for just reading low.
Another note is you are dangerously lean between 4500 and 6000. Notice that's where you had your original power dip along with hitting a 16 to 17 AFR. That is exactly how you blow up a gasoline engine. Afterwards it's not as bad but it's still quite lean. Your original lean condition may have caused damage.

For that specific reason is why I’m planning on doing a fuel system overhaul. Even after tuning to draw more fuel, Hassan said the car was still running lean, meaning there’s something bad with fuel delivery. Will be addressing these issues soon!

[jbfrancis3]

I went through a lean fueling issue during tuning and followed the normal paths: check fuel pump, regulator, got injectors cleaned (they didn't need it @110k original miles). None of those were the issue.

On a CSL converted DME, it turned out to be incorrect intake temp sensor readings caused by improper grounding. I had used the so-called spare ground on pin I forget on connector I forget, which clearly did not work in my application.

So check the IAT readings - if they are erratic at standstill (130F, then 40F) that's almost guaranteed to be your problem (assuming CSL software).

[LSBNick]

I went through a lean fueling issue during tuning and followed the normal paths: check fuel pump, regulator, got injectors cleaned (they didn't need it @110k original miles). None of those were the issue.

On a CSL converted DME, it turned out to be incorrect intake temp sensor readings caused by improper grounding. I had used the so-called spare ground on pin I forget on connector I forget, which clearly did not work in my application.

So check the IAT readings - if they are erratic at standstill (130F, then 40F) that's almost guaranteed to be your problem (assuming CSL software).

Car is using Alpha-N tuning. We discussed relocating the IAT sensor to the brake duct instead of its original position due to heat soak issues. Definitely something that’s going to be happening that hopefully not only prevents heat soaking, but also gives us more accurate readings.

[jbfrancis3]

Got it. It would be well worth checking the live reading before exploring other physical systems.

[sina]

Your numbers are essentially what I saw w/o headers.

At the time when I made 297whp, it was stock headers, CPI rasp elim sec 1, sg section 2, and dixis ti muffler, with Evolve CSL intake race box.

after euro headers and OE CSL cams, I made 336whp.

You had a CSL intake with stock US headers? I feel like I never see anyone do that, but as someone who is more interested in an intake than any other mods (just because I care more about the experience/drama over power #s), I was always curious why it seemed like everyone who had a CSL intake had done headers first. Are there any downsides to CSL airbox + US headers, or is it just an illogical order to do if you are after "gains"?

[sc_tr0jan_m3]

You had a CSL intake with stock US headers? I feel like I never see anyone do that, but as someone who is more interested in an intake than any other mods (just because I care more about the experience/drama over power #s), I was always curious why it seemed like everyone who had a CSL intake had done headers first. Are there any downsides to CSL airbox + US headers, or is it just an illogical order to do if you are after "gains"?

The intake compatibility is not based on the headers. But if you want to optimize your whp then the headers will be the biggest constraint.

Yes it’s cool, hell yes it’s a boatload of money, is it worth it? Ehhhh... you can get similar figures with an afe intake.

It took me a full year and too much money before my karbonious setup operated how I wanted to.


Sent from my iPhone using Tapatalk

[ra2fanatic]

You had a CSL intake with stock US headers? I feel like I never see anyone do that, but as someone who is more interested in an intake than any other mods (just because I care more about the experience/drama over power #s), I was always curious why it seemed like everyone who had a CSL intake had done headers first. Are there any downsides to CSL airbox + US headers, or is it just an illogical order to do if you are after "gains"?

eh, I wasn't necessary into an all out whp gain. But when there's a deal from a local seller for euro headers with all the bungs set in place so you have nothing dangling about, I figured I wouldn't pass up the deal. I didn't need an extremely loud exhaust since I had sec 1-3 covered at that point anyways, but since I was doing CSL cams already, figured it was time to add the euro headers.