Same here if luck wills it these wheels will be with me for years to come.

Daryl

 

Passing any emission test isn't rocket science.. Many yrs ago we had em in Fla.

Just a mix of 1 part De-natured alcohol, & 1 part gasoline. Mixed together & run it thru the test.
Vehicle will run crappy, but will burn clean as a whistle, & no harm to any components, etc..
After passing test, go straight to gas station & fill up tank with Good Hi-Test.. & enjoy life..

(Disclaimer): I would never do this, cause that would be wrong.. nome sain ?

 

Yes, but things are supposedly more high tech now, that is what concerns me. In the old days it was a visual and sniffing your tail pipe. Nowadays it's a rolling chassis test bed + sniffing the echaust while under load and I assume a com hookup to your on board PCM

But we're getting off topic....

 

Kevin's Tune is great news. Just remember I have the Loaner Program, You can always go back to your stock tune for the emissions test. I have had more purchase the cable just so they can swap to stock at any time they need.

Lately, It's been fun with all my cables out for tunes and working at keeping one handy here at the Shop. We are getting it done.

 

Man, I'd love to see a dyno-sheet before & after on a 'tune' for our 145 cu inchers

I know mods make a big diff too..& are a big variable depending on what work was & wasn't done.

 

Its good to see we are finally getting some MODIFIED milage racked up for reliability issues.. and its looking good...as far as this site goes..I'm sure there are people out there who had problems but thet arn't here to tell us...its starting to look like GM really under estimated this cars potential....

 

I've read all this subjective impressions of Trifecta ECM calibration with passing interest.

Has anyone not connected with Trifecta ever run a proper A/B chassis dyno test of one of their "tunes" with a 2.4 in an HHR?

 

Interesting that no one posted an answer to my question. If the Trifecta ECM cal is so good, I'd have expected some info.

I've run my HHR on the chassis dyno several times in the process of writing product reviews, some of which have been on this web site.

I can tell you that the reason the person who made the first post felt a noticeable difference at 3000 rpm is tha, the stock 2.4 calibration is lean at WOT in the mid-range due to a long delay before and late onset of power enrichment. GM calibrates this way to improve fuel economy and it makes a significant difference because the way many people drive small engines in relatively heavy cars is with a "heavy foot" in the mid-range. When you calibrate out the delay and the late onset of power enrichment, you'll see a noticable decrease in fuel economy but a noticeable increase in performance.

You can easily feel this. When power enrichement comes on at 3500-4000 rpm, there can be quite a surge in acceleration. You also can see it in any air fuel ratio data taken during a chassis dyno session.

Another issue with the OE calibration for 2.4s is that, in order for the engine to run on 87-oct gas, the spark calibration has a wide range of operation. I'm going to guess that most HHRs run on 87-oct, especially in the summer, will be running on the "low octane fuel" spark tables because of constant detonation sensed by the ECM. Whenever I'm chassis dyno testing or whenever I know the driving I'll do needs the engine's full performance, I switch to 91-oct gas. The difference can often be felt when driving the engine hard, ie: to the 7000 rpm rev limiter in lower gears.

Any reasonably good tuner, Trifecta or otherwise, is going to 1) minimize any delay in power enrichment, 2) enable power enrichement at a lower rpm and 3) may even make power enrichment more rich, but...that depends on what the AFR is and, that in turn, may depend on modifications done to improve intake air flow or exhaust flow.

Right now our HHR is equipped with a Flowmaster cat-back exhaust system and a K&N "FIPK" intake kit. The last time I ran the car on the chassis dyno, on 91-oct, I had no detonation but the engine was decidedly lean, even at WOT, high-rpm and in power enrichment. In the mid-range, before power enrichment it was way lean.

Some kind of custom ECM cal is the next thing I do.

Lastly, there was a comment about the effect of a "Trifecta Tune" or similar recalibraton on the car's passing the California enhanced "Smog Check". In short, it's a non-issue. The Smog Check tests at 15 and 25 mph and at part throttle with the ECM in closed-loop. The Smog Check does not test at wide open throttle above 3000 rpm where the power enrichment change would occur. But, even if the Smog Check did test there, if the ECM cal is done properly, the engine should run very clean.

 

Hey Hib,

Thanks for explaining the tune in leymans terminalogy! A couple of things I would like to add to anyone curious about our tune! One reason I haven't chosen to Dyno our panel is that with the tune I asked for is 75% of an all out programing thus the numbers would not be what a full tune would be able to produce! Second our ride as it sits now would not be able to compare it to a stock non-tuned set up as we have installed to many mods to get any type of stock un-moded dyno numbers (say having the tune turned off)! It is also my understanding that factory HP numbers can very from vehicle to vehicle as much as 8 to 10% (don't quote me on that) so saying ours produced a certain at the wheel horsepower number in stock trim would be a guess and not factual!

 

Now that helps...I may consider a tune