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

[stash1]

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.

Dynojets are very difficult (but not impossible) to fudge numbers on, and most generally don't vary more than around 2% from each other. Judging by the graph/torque figures, OP def has a mechanical issue...once he solves it powa/torque numbers will easily jump by 25-35 pts. His AFR's were lean pre-tune, but post tune, they look fine. Maybe still just a tad lean in the range you mentioned, but certainly not dangerous.

[LSBNick]

Dynojets are very difficult (but not impossible) to fudge numbers on, and most generally don't vary more than around 2% from each other. Judging by the graph/torque figures, OP def has a mechanical issue...once he solves it powa/torque numbers will easily jump by 25-35 pts. His AFR's were lean pre-tune, but post tune, they look fine. Maybe still just a tad lean in the range you mentioned, but certainly not dangerous.

That is the most reassuring thing I’ve heard all day lol

[stash1]

That is the most reassuring thing I’ve heard all day lol

OP, you def have a fueling issue to start with, whether it's the injectors, fuel pump/filter, 02 sensors, etc...you need to get that part straight before doing anything else. Do you, or have you had, any CEL's recently? Are you sure the 02's are good and in the correct locations? After you have that part squared away, perform a VANOS test (as someone else mentioned previously) to make sure everything is within range.

[LSBNick]

OP, you def have a fueling issue to start with, whether it's the injectors, fuel pump/filter, 02 sensors, etc...you need to get that part straight before doing anything else. Do you, or have you had, any CEL's recently? Are you sure the 02's are good and in the correct locations? After you have that part squared away, perform a VANOS test (as someone else mentioned previously) to make sure everything is within range.

Yes, believe the code was for a misfire due to the headers. Was addressed by HTE. Nothing related to O2 sensors though.

[stash1]

Yes, believe the code was for a misfire due to the headers. Was addressed by HTE. Nothing related to O2 sensors though.

Ok, well report back when you get it all squared away!

[LSBNick]

Quick update:

fuel filter definitely had a role in the fueling issue, lol

20 years and 150k miles later

[Tbonem3]

Prolly weighed 10lbs

[m3nt0s]

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"?

I’m currently running Karbonius intake with stock US header back exhaust setup. Eventually I’ll grab euro headers and section 1 as I’m already coded for it, but haven’t actually gotten the hardware yet. Wanted to make sure I had the sound I wanted and an intake that supports any potential ambition I have with power output in the car (FI does not interest me).

[LSBNick]

Prolly weighed 10lbs

Lol probably did. If only I had the same attention to cleanliness as you do 😂

[Tbonem3]

As long as you get there

[LSBNick]

Figured I’d give a quick update here.

Car has great compression, and have since replaced my fuel filter, converted my EKP to a traditional fuel pump relay, and had my injectors cleaned/rebuilt as needed.

Retuned by HTE, car is now putting down 318 whp and 231 wtq.

Definitely an improvement, and glad Hassan was able to make his magic happen.

Currently trying to find a way into a SS V1 set up, and will retune the car again with that new setup.

As for now, car is running like a dream, completely linear power band, and is a blast to drive. Thanks for all those who gave their input and experiences!

[r4dr]

Just curious, are you hoping for substantial change going to SS v1 headers?

[digger]

Figured I’d give a quick update here.

Car has great compression, and have since replaced my fuel filter, converted my EKP to a traditional fuel pump relay, and had my injectors cleaned/rebuilt as needed.

Retuned by HTE, car is now putting down 318 whp and 231 wtq.

Definitely an improvement, and glad Hassan was able to make his magic happen.

Currently trying to find a way into a SS V1 set up, and will retune the car again with that new setup.

As for now, car is running like a dream, completely linear power band, and is a blast to drive. Thanks for all those who gave their input and experiences!

what's with half a dyno graph? lol. i thought we were beyond look at a peak numbers alone.....

to me it still looks like AFR is still trending north of 13:1 but without the graph cant see how lean it gets. Nevertheless the SSV1 should make a big difference as the torque is fairly weak (likely due to the ARH) and we will get a another data point of SSV1 vs ARH so we can bash some more products

[LSBNick]

what's with half a dyno graph? lol. i thought we were beyond look at a peak numbers alone.....

to me it still looks like AFR is still trending north of 13:1 but without the graph cant see how lean it gets. Nevertheless the SSV1 should make a big difference as the torque is fairly weak (likely due to the ARH) and we will get a another data point of SSV1 vs ARH so we can bash some more products

Yeah, ARH have absolutely no low end torque. On top of that, I have a bunch of mismatched exhaust parts so the diameter throughout the system is so inconsistent, I imagine it also plays a big role in that.


Here’s the whole graph. We got it much closer to an acceptable AFR, and we decided to call it there seeing as how many runs we ended up doing that day.

[LSBNick]

Just curious, are you hoping for substantial change going to SS v1 headers?

I’m hoping to get more gains through the entire power band. Having a true 2.5” system from the headers up until the section 2 to 3 connection will allow for a much more efficient flow of gases.

Low end torque and top end power should definitely increase. Ideally the set up would be V1 stepped headers with oversized non catted section 1, 63.5mm dual resonated section 2, and meisterschaft titanium section 3.