Headers, Reprogram computer, Volant Cool-air, Catback, LESS POWER?

[Spenser]

I drop the H2 off at the Dealer here in Phoenix on Monday, Computer reprogramed (preformance) add headers, Catback exhaust, and volant cool-air box. Go in this evening and pick it up, was much louder than promised and it seems to be very sluggish especially after shift from first into second, it seems to "fall on it's face" a bit. I spent a CHUNK of money as the dealer warrants items for the length of the H2 warranty. I'm a bit disappointed, don't see much difference except on the freeway, and wondering what to do next? Any suggestions from the experts will be greatly appreciated. Thanks,

Kevin (casey2)
2005 Stealth Gray H2

[Spenser]

I drop the H2 off at the Dealer here in Phoenix on Monday, Computer reprogramed (preformance) add headers, Catback exhaust, and volant cool-air box. Go in this evening and pick it up, was much louder than promised and it seems to be very sluggish especially after shift from first into second, it seems to "fall on it's face" a bit. I spent a CHUNK of money as the dealer warrants items for the length of the H2 warranty. I'm a bit disappointed, don't see much difference except on the freeway, and wondering what to do next? Any suggestions from the experts will be greatly appreciated. Thanks,

Kevin (casey2)
2005 Stealth Gray H2

[DRTYF? (the imposter)]

NiTrOuS!

[RIC-H0]

I say take it back to the dealer and let them know of the lackluster performance of your vehicle. It seems that it may be a programing issue, and needs to tweaked a little.

Good luck!

Ric-H2

[Fastest H-Town Realtor]

Casey-

Something is majorly wrong. You should check to see if the items paid for are actually installed.

1-The exhaust should not be much louder than stock.See if the parts are actually on.

2-Verify the reprogram...it may need to go back to stock to see if thats the culprit. Was the reprogram a chip, or a tuner? The SOTP-ometer may not be able to detect the increase in HP, but I do not know why this would be accurate. The increase you should have gotten will be detectable. Does the new program call for premium gas?

3-Remove the CAI and replace with stock? Any better?

4-Fianlly, recheck all connections/fittings/routings of the affected items during install. Maybe the dealer forgot to hook up something?

5-Is it spitting a MIL?

Whats this "except on the freeway" difference you mention? Have you done a timed 0-60? Does it ping? Does it idle smooth? Rev freely?

[Spenser]

Well, new development, Yes, all parts are on, but I got a call lastnight from my sales rep wanting to know how I liked "all the new power". I told him of my dissatisfaction, LACK of power, and sluggish response and interior cabin noise. He said he'd call me tomorrow (this morning,) at around 10:00 AM and we'd meet at the dealership at 11:00 as they are open until 1:00 on Saturday, and he was to be there for a couple of hours anyway. The Manager of accessories would be there as well and we could find out what the problem was. Well, no call came, so I, of course, drove to the dealership at 11:00, no one had seen my rep, nor was he suppose to be there, and the manager wasn't there either, so I spoke with another rep, told him of my dissatisfaction, told him I expected it to be as promised, or returned to me in stock condition. His response was, "I wouldn't have went with headers, you should just move up to a supercharger". Gee, now I feel much better! Anyway, they gave me a loner, and I left the H2 there for them to sort out on Monday, hopefully... I see a fight in my future, and I'm ashamed to admit how much I paid them up to now. The wife thinks my money is gone, and I'm stuck with empty promises and less than promised results and performance.
Time will tell, any suggestions? God, I hope they make this right..... Thanks guys..


Kevin (casey2)
2005 Stealth Grey H2 SUV

[Fastest H-Town Realtor]

what type of headers/cat back? Full length headers? How much ya want for the "used " set?

[Denny Crane]

I ran into these same issues prior to supercharging ours as well. There is a lull fall on it's face dead spot between 1500 - 2000 RPM.

The bottomline is you need programming custom tuned to your performance accessories. The dealer can't and doesn't have the program to do it. The problem is with the ECM and Tranny program and how GM manages Tq. Management which protects the vehicle albeit way to far on the safe side especially once you add more power.

The latest programming GM sent out reduced the effect of Tq. Mgmt but didn't take it all the way out like custom prgrm. can do. And the GM programming can't learn you want more and dis able it itself.

I hope this helps.

Denny
03 Lux Adv.
Kenne Bell Supercharged
XtemeFlow Exh. & Intake
JBA Ceramic Headers
ProStreet Wires
Custom ECM Programming

[Allen]

I did the same upgrade + a throttle body spacer. I had it put on a dyno and I was at 403HP. I think the programming is off. Have them redo the programming and WATCH them. I agree, make sure the parts were actually installed. My upgrades made a HUGE difference from 1500 - 4500 RPM. I could not tow my boat up a certain hill leaving Primm, NV at more than 37 MPH - After the mods, I can get up to 63 MPH - same boat, same hill....different H2.

[Fastest H-Town Realtor]

When you say 403hp, do you mean rwhp or bhp figured with a correction factor? Did you do the awd dyno or the regular unit with shafts dropped? Either way though the power gains sound high for the mods..can you post the dyno sheet?

[KenP]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Fastest H-Town Realtor:
When you say 403hp, do you mean rwhp or bhp figured with a correction factor? Did you do the awd dyno or the regular unit with shafts dropped? Either way though the power gains sound high for the mods..can you post the dyno sheet? </div></BLOCKQUOTE>That MUST be engine numbers. Unless he has something crazy going on he's not telling us. Loss on these vehicles is estimated at over 30% through the drivetrain. My rearwheel #s are 358.4 hp and 405.2 torque.