Preface : “Which is the Tomei UEL and which is the Gruppe-S UEL header?” That's the only question on everyone's mind. The answer : DOES IT MATTER?! (For the answer, please read onwards...)
Some months back while we were on the topic of the ACE headers with our counterparts in Taiwan, I was asked if we would be interested in doing remote tunes (non E-Tunes) on UEL headers that were specifically, of a certain sort. As they started to describe these headers with their 4-1 collector design, honed runners and surfaced flanges, I had the suspicion that they were actually describing the TOMEI setup that we've been pumping out as of late. A quick picture also confirmed that it was indeed a UEL offering, very close in design with the above-mentioned. That said, there was really very little in the way of discernible differences that we saw, sans the “Tomei” stamp on the flange surface as well as the tacked on name plate that we were accustomed to seeing.
As you can see from the pictures, the quality of construction is top notch. Note that these aren't KNOCK-OFFs as some have described them to be. They're “white boxed” versions of the TOMEI offering. They are in fact, manufactured from the very same machinery used to make the TOMEI headers - there's no variation in material quality, construction but there's a ever so SLIGHT change in design (runner angles) to elude from infringing on IP or exclusivity I suppose. All this comes with a reduction in cost while still being able to attain in this case, the best out of the box results thus far!
As far as installation goes, there's really nothing to talk about. It was fitted without a sweat, process was as expected and flawless.
Enter Gruppe-S : the company isn't new, but I certainly remember them from when we first started our run @ Formula D in 2007. They had reached out to see what our thoughts were and I had told them that we've already since tuned some of them overseas with stella results. I was confident that we could do the same here especially with our 92 Octane gas. Within a few short weeks, I had purchased one for evaluation and here are the results...
Vehicle : 6MT 2015 BRZ
Fuel :
92 Octane Gas
Mods : AVO Dry Panel Filter, Gruppe-S UEL, TRD Exhaust
Given the filter and the exhaust, I wasn't surprised to see the slightly higher baseline number @ 173, but I will certainly say it's the 2nd highest I've ever seen so far in the 150+ twins that we've dyno tuned thus far. They're typically @ 167, and with the UEL header installed, there's a decent gain but unless you have a custom calibration, you won't otherwise be able to optimize the combination of hardware to it's fullest potential.
Which brings us to our results...
So when you ask which of these two is that of the Gruppe-S, the answer is Run #12. For all intents and purposes as you can see, there’s really zero difference in overall performance after the custom calibration is complete. The other dyno run is that of a Tomei UEL on 2014 86, also with an AVO filter as well as a stock exhaust. Both tunes were conducted within 3 days of each other in the heat wave that we've just experienced. Dyno cell ambient temperatures were both well into the high 80s when we started the tuning process.
In comparison, I've elected to post up the 6AT 92 Octane results of the Gruppe-S UEL as well, also with an AVO dry panel filter and with a stock exhaust. (I've since done an AT and another MT.) Results are pretty much in line with what we'd expect from a properly tuned setup. So is the Gruppe-S UEL better than the Tomei UEL? Hardly, and that's to be expected. But is it just as good? Every bit so.
Cheers!
Bob @ Drift-Office, LLC