the.jack

After some great service from Hahn Racecraft, I am unfortunately, looking at a rather disappointing dyno.

Now, I'll preface by telling the forum what the owner told me: his is not a "feel good" dyno, but using the whp he asserts the 1/4mi times will be accurate (i.e. no rosy-colored glasses here).

He also said the tune is "solid" and "safe" and he didn't think he could squeeze much out of it. Further that tuned Cobalt turbos (this was his first HHR) that had stock internals and turbo tended to get 205-220 whp, so mine was a little stronger than he expected.

Still, the upshot is an estimated 270 crank hp and 370 crank tq, but with a pretty solid drop off from the 3000 RPM torque peak (thus the low peak HP). The dyno graph is pretty clear.

With full 3" DP to exhaust tip (test pipe), metal charge piping, GMS1 followed by Trifecta mail order tune... I expect more like 350 hp - 350 tq crank or 290 hp at the wheels.

What am I doing wrong here? It's not heat soak: he did 10 runs and only on the 10th did he see a drop in the peaks. Runs were consistent even with the stock intercooler. I use 93 oct, always. It's a relatively fresh K&N... I just don't get it.

DrLoch

From my experience I agree, those numbers do appear to be low. Do you happen to know what kind of dyno was it? Mustang, Dynojet, Mustang...

Oldblue

Welcome to the site, perhaps a conversation with the tune people, Trifecta should be able to address any problems.

prod

Auto or 5spd?

aradmahogany

Also just remember not everything is about numbers... I have an LT with the 2.4 that made about 174 HP/ 168 tq FROM THE FACTORY.... now to the wheels who knows and furthermore with 172K on the ticker I doubt its still pumping out the same numbers as factory. All things considered I would be damned if I didn't tell you my HHR moves its weight pretty damn well and still has nice pull and decent power at least by feels. I would not be surprised if I dyno it and I got 130 HP but our engines do hold there own regardless of numbers.

the.jack

Thank you! I've actually been on for a while, but as a lurker. First thread, though.

You "can't"; you have to go through the retailer. I have an inquiry in with them. Again, I am running on the assumption that something was set up wrong by me. Hahn gave me the cable adapter, sent me the download after sending Trifecta my information and mods. Afterward I took data logs for a good long drive (two actually) and sent those back. Trifecta says "looks great!" (with exclamation).

And its driving "fine" - I was looking to see if the tuner could squeeze a little more out of it and then the dyno does what it does, he stops there and I'm scratching my head.

the.jack

Sorry! I apparently haven't set up my sig:

2010 SS
5-spd stick
Hahn downpipe, test pipe and open "muffler" (not much muffling!) 3" front to back
Hahn intake charge piping
GMS1 (3-bar sensor)
Trifecta canned tune
Turbo Tech rear sway bar

the.jack

It still feels fairly strong, compared with before. I have the Trifecta on the "Competitive Mode" and GMS1 on the "regular" mode (I'd have to confirm whether "Traction Off" is GMS1 or Trifecta). There's a very notable difference between default and Competitive. Clearly something is happening. Even GMS1 should put down closer to 240 whp, but let's say his dyno is "pessimistic", I can buy 224 from GMS1... But for a tune that is noticeably stronger? Something doesn't feel right. And the torque fall off... I don't believe our turbos are so "wheezy"... Something feels off here.

the.jack

Here are the charts I failed to attach previously.

DrLoch

Something I'm not understanding here, is this calculated in wheel RPM or engine RPM? Torque and hp should crossed at an engine rpm of 5252. Torque and HP are linearly related by the formula hp = (tq*rpm)/5252 which is why the lines always cross at 5252. Your are crossing at 3750