Background:
A couple of months ago I reinstalled an IS20 turbo in my Mk7 GTI to collect data on some products when matched up with the stock turbocharger.
Deciding upon which tune to use was an immediate decision I faced, which took me back to the subject of the Stage 2 tune list that I started about three years ago.
Along with that list, I posed the question about what the “best” tune was and offered a $500 reward to the person who could prove what was best.
Although I was serious about paying the reward I also knew that it was an impossible task given the different goals and priorities people have, it was meant as a rebuttal to people who claim one tune is the best.
Planning:
Although identifying a single best tune is unrealistic, collecting a comprehensive body of data on several popular tunes is not.
I decided I would do this with a few popular Cobb-based tunes, namely Sneeky Tuned, EQT, and Stratified. To establish a baseline to make a comparison with the stock GTI IS20 tune would also be evaluated.
Cobb offers a much-maligned tune with the Accessport which was another candidate to add to the lineup.
Off-the-shelf tunes would be the product used since results from custom tunes would be relevant only to my car.
More details about the planning are provided on this page. Mk7 GTI Cobb OTS Tune Comparison Plan
Execution:
Data was collected on the street, the results of which are found on this page. Mk7 GTI Cobb Tune Street Data Collection
A trip was also made to a DynoJet dynamometer to log similar information. Mk7 GTI Cobb Tune Dyno Data Collection
Reporting:
Finally, it was time to sift through the data logs and develop summary data for comparing trends between the various tunes.
The street data summaries are available on this page. Mk7 GTI Cobb OTS Tune Street Summary
The summary of dyno results is located on this page. Mk7 GTI Cobb OTS Tune Dyno Summary
Conclusions:
As the data shows, each of the tunes functions differently from the others and what is the “best” fit for one person is likely not the “best” for other people.
The benefit of having comparison data is that allows individuals to weigh their priorities against the attributes of the different products to decide what fits their needs the best.
The data I was able to record does not support the poor reputation that the Cobb OTS tune has. The tune appears to strictly follow the OEM Knock prevention strategy and the lower boost and timing that it operates at would provide additional safe operation. The tradeoff is in power production, but with a bump of roughly 40 whp and 50 wtq over the stock GTI tune, it’s a decent step up for no additional cost.
For my part, I prefer the Stratified tune on account of the negligible difference it has from the OEM Knock prevention strategy – a topic discussed in detail on the Noise & Knock page. The tune delivers solid power and good overall acceleration. At $100 it’s also quite a bargain if you already own a Cobb Accessport.
Great work as usual. Let the MK7 kids eat cake!
Thank you!
Wait…so am I correct to say that EQT’s tune while making the most peak power also has the most amount of knock sensor “numbing” which allows the tune to push further w/r to timing advance for a given boost/AFR? I’ve always been confused by the knock numbing bit…I run a Uni IS38 tune on my Sportwagen…the timing is v. aggressive vs. these tunes, my timing advance can reach 14 degress + at redline during a third gear WOT pull. However, boost is more moderate with peak boost around ~21 psi tapering to ~19. On winter blend 93 here on the east coast/mid-Atlantic I get quite a bit of KR so much so that for pounding it, I run 2-3 gallons of E85 as effectively an octane booster to min. knock retard/allow full timing advance/power….the KR can get get in the -4 to -5 range which if you try to sustain that acceleration the ECU will say “I’m out” and flip the EPC/put the car into limp mode. In this case, wouldn’t that support that Unitronic isn’t actually numbing the knock sensors v. much at all? Thanks for the good work here and continuing to beat back the bro-science/MK7 kids nonsense!
The short answer is yes. In this example it’s more accurate to say that the threshold for where the ECU implements safety measures using timing reduction is being raised with the EQT tune. They aren’t shutting it off, just making it less likely that knock will be acted upon. In the FR it mentions the probability of detecting knock should be 90%. By raising the threshold that probability of detection has to be less.
I think if you’re adding E85 and seeing the amount of timing retard go down then that points to knock happening with the straight 93 fuel.
Correct so if knock is happening then it’s unlikely at least how I understand this that they have numbed it all…b/c why not numb it so you don’t see it/have issues? If EQT un-numbed their tune, you would see more KR for sure/not achieve that power level. To me it seems like Uni didn’t touch the knock sensor sensitvity at all but again, I’m a bit shaky on all of this.
It’s hard for me to use the examples I have and try to deduce what is happening with the Unitronic tune. Based on what you’re seeing my guess is that they don’t modify the knock settings, at least not in a meaningful way.
Although EQT does make the car feel a bit more peppy, I do prefer my Stratified Stage 2 tune. Without any comparative data, my car feels like it runs better on Stratified.
Great work here Jeff. Outstanding as always – I am curious to see how anyone attempts to refute this data and am happy to see Cobb utilizing OEM level knock control on the MK7 much as they do with DAM control on the VA.
Cobb receives a lot of flak for lower power tunes from people who only judge tunes on how much power they have.
Again, invaluable research here. Thank you.
Desensitization of the knock sensors in low load scenarios is expected on vehicles that have aggressive knock sensor routines. We did it on hptuners on LS2’s and even LSJ/LNF. We did it on hondata with k20’s and k24’s if the build was going for a positive displacement blower. And we did it on cobbs software on FA20’s both turbo and even NA (on e blends especially)
I dislike eqt over their bullshit intake crap but what they’re doing is normal if it’s only desensitizing the knock sensors in low load scenarios.
Also, on turbo fa20’s. A motor that will drop its damn DAM if U look at it wrong. It’s practically mandatory
These are full throttle pulls in 3rd gear on the street and 4th gear on the dyno. I don’t think of those as low load scenarios, is there a higher load scenario you have in mind.
Hello, good work. Modified Stock can handle 460whp?
Thanks! I don’t understand the question.
Sorry about my poor English.
The original modified intake ( pikey 600) supports 460 whp? Thank you.
Yes, with a few simple modifications it should be able to support that power level. I haven’t reached that level yet, but tests against aftermarket intakes show the stock airbox is competitive.
Sorry Jeff, I can’t reply in line with your response. I think I might be doing something wrong
But to answer your question. I’m not sure, I’ve never tuned an ea888 nor do I know any Vw tuners. Sorry
Typically, we wouldn’t desensitize in high load unless the car really did need it due to super touchy knock sensors. But I’ve personally no idea how touchy the knock sensors on a ea888 are
I’ll say it does look super aggressive compared to the other tunes
As an ots tune, it’s gotta fit more climates and elevations. Maybe that’s why they did it? So less customers would bother them about knock or events where timing gets yanked?
With the stock tune I did 25 street pulls and 3 on the dyno. There was no timing retard occurrence on any cylinder. I don’t know if that gives any indication of whether or not the stock thresholds are a touchy setup.
Strange the reply function seems all different now here but replying to Jeff re my Uni tune…I agree, it would seem they kept or at least are close to the OE knock sensor sensitivity as I understand it.
I haven’t changed anything with the format or settings for the comments. I don’t know why there has been a change.
I assume you have not asked Unitronic if they make any changes to the knock related tables with the tune?
This is why eqt is the best, look at all that power midrange
I’d expand the criteria for determining a “best” ECU tune, perhaps considering how much midrange boost is being required and the potential long term reliability considerations. Also, since EQT has raised the knock threshold there’s very likely knock occurring through the mid-range that isn’t being managed.
Yeah, I’m not sure about best but it looks clear to me given the variables shown here that Eqt did a better job addressing the torque drop in the mid 3k range where it appears strat ignored it.