RyanDavies

Given this disparity of performance based on what was claimed, to try to clear things up: I paid for an e-tune a couple years ago and never used it. I was dyno tuned locally.

I'll pass that use of Gernby's time on so Greg (Neurotic) could get a tune from Gernby, and perhaps compare that tune with his current tune, to see if that's where the power is being left on the table with the Gernpipe. I think it'd benefit the entire community to figure this out, so folks will know whether folks building STR S2000s going forward will find this to be worth their money.

I no longer own my S2000 and will no longer be competing in STR nationally, but think this is worth solving.

Thanks.

Urge

We already offered a retune, but the customer had put up their car for winter after this test due to early snow in the area.
Also, the customer did not have the data logs available to review and look for tuning opportunities.

Once we can get some new data logs, we will gladly offer a retune.

Gernby

Honestly, it's really disappointing that anyone would consider Neurotic's Dyno test as some sort of "issue" with the exhaust system. Neurotic said that he was not "concluding" that his car lost power. He only said that the car lost [peak] power when the last pull with the previous system was compared to the last pull with the Gern-Pipe without SAE correction (4 hours later). He said that the temperature readings on the DynoJet weather station were incorrect, so he didn't feel that the SAE correction was correct. That's totally understandable, but that doesn't mean that Uncorrected results are more correct. Neurotic reported that the temperature did go up, and I don't think he disputed the barometric pressure dropping. If so, then uncorrected results would give the previous results an unfair advantage. After all, the difference in peak power is less than 1%, which is within normal testing error of a DynoJet.

Also, it may not have been clear in my post above, but the run #21 (with the Gern-Pipe) actually made significantly more torque and power across the whole rev range, even without SAE correction. Basically, if that had been the last dyno of the day, Neurotic would have been reporting a 0.6% gain instead of a 0.7% loss.

Gernby

I don't think Neurotic would mind me posting the uncorrected comparison between the baseline and run #21, so here it is.

neurotic

I'd like to clarify a few points.
- I believe the uncorrected values are the most valid
- Runs 19/22 are likely the best of the URGE-Gernpipe runs for use as a comparison
- I think the two configurations make the same peak power
- The URGE-Gernpipe made a bit more power over an ~750 rpm speed range
- The URGE-Gernpipe required timing & fueling changes; simply bolting it on would likely lose power (as with most modifications)
- The URGE-Gernpipe was less consistent on the dyno; see graph and information below

I'll have the car back on the dyno early spring to finalize an intake design/layout and for a general health check. We'll also adjust the tune with the current hardware (maybe with some pulleys) to verify the tune's efficacy; I'll be happy to test adjustments suggested by URGE/Gernby.

The following runs have the same tune/calibration. 'Cooling' time prior to each run:
[70EM] 03: 4 min
[70EM] 04: 5 min
[70EM] 05: 3 min
[URGE] 19: 7 min
[URGE] 20: 3.5 min
[URGE] 21: 13 min (why I didn't use it for the comparison)
[URGE] 22: 8 min
[URGE] 23: 1 min



- I like lists...

Gernby

I really disagree with the red items above, since I think they are both related to your tune. The down-side of using the ignition tuning strategy that you used is that you wind up with ignition timing that is often below optimum. Basically, there is a very wide range of ignition advance on the VTEC cam that will make the same amount of power without knocking (about 6 degrees on my car). Many people target the top of that range, which is dangerous, but you've targeted the very bottom of it. This means that IAT and ECT compensations will often drop you below that range. My tuning strategy is to target the middle of that range, so that it performs more consistently regardless of IAT or ECT. That's also why I really, REALLY wish you had datalogs from the pulls. Dyno plots alone tell half the story...

BTW, you mentioned that you were doing some custom intake testing / tuning, but it wasn't clear whether the same intake setup was used for all the dynos you posted above. Were they all the same?

neurotic

I think we're going to have to agree to disagree on tuning methodology. I prefer minimum timing advance for best torque (MBT), rather than any additional timing advance. With the relative lack of sophistication in aftermarket engine tuning (little instrumentation/control/data), I prefer the additional knock margin. I also think IAT, ECT, etc... compensations should affect output as that's how they provide protection.

Regarding the inconsistency with the URGE-Gernpipe, the car was previously very consistent; using the same tuning and testing methodology and shown by the 70EM dyno graph.

The same intake was used for runs 3-6 and 19-23. Some intermediate runs used different intakes, but they made larger sacrifices than gains.

Gernby

I can agree to disagree with you, and am not going to try changing your mind about it. However, I must do what I can to preserve the reputation of the gern-pipe. I believe your results have reduced sales, which is a shame.

So I'm directing my rest of this post to all the other participants in this thread. I've tuned over 140 S2000's on FlashPro, and am confident that the inconsistency between neurotic's runs is due to the tune. Out of those 140 S2000's I've tuned (all N.A. '06+ on FlashPro), I've never had a tune with so little ignition timing on the high cam as neurotic's tune.

neurotic

It's only a shame if I've misrepresented the product. I have no motivation to do this, and have posted these results so other autocrossers can make an informed decision (which is very rare situation). I intend to use the exhaust as it made more power at some engine speeds, unless it pushes the car over site sound limits.

You're welcome to provide data supporting the marketing assertions/expectations. Although, thus far you've only blamed the tune rather than providing any new/additional information.

As I mentioned in my emails, my car does run less high cam timing than most other S2000's tuned (using the same methodology) by my tuner. Notably, the URGE/Ger-pipe calibration had ~1.5° more timing advance than 70EM at/around peak power. Despite the lack of timing advance, the output is inline/better than other S2000's performance on my tuner's dyno, indicating the non-customary timing is not problematic.

How do my dyno results compare to the car's you've tuned?

Capt. Midnight

Sub'd. Just installed and tuned mine with the Midpipe/T1R dual and intake w/ Flashpro. Car feels significantly punchier and overall much quicker. Will upload Dynos if I can figure out how.