KyS10

After trying for the last couple weeks , I finally was able to make it to the strip for a few runs today. My HHR is completely stock. I just wanted to get some baseline numbers before I started modding anything.

I was able to learn a couple things about the car. First, comp. mode seems that it is going to be completely useless until I do some major traction mods. When I tried to use it I just ended up spinning, a lot. Second, the HHR didn't put down quite as good of times as I thought it would. It wasn't horrible, but I guess I was expecting better. Granted, driver error is always a possibility, but there is only so much you can screw up with an auto. Perhaps running at a track at an elevation of over 3700 ft has something to do with it.

Here's how my best run looked. Still spinning a little off the line, but not too bad.

2.31---60ft
6.45---330ft
9.88---1/8th et
72.3---1/8th mph
15.24--1/4 et
90.5---1/4 mph

foolmoon_design

Here is a time slip from Friday night. Temp was in the 50's elevation about 2000.

Comp mode is useless without slicks. The tires can't handle preloaded boost past 2.5k. the best times i've gotten were walking it off the line. With wot around the 100' mark.
I use ESC OFF, and launch in drive. I also run around 18psi in the tires.most races if fairly well matched are won or lost in the first 60'. I drive an auto which is supposed to be slower, my best friend drives a stick, I always beat him and he has a cobalt with just as many mods. He short shifts to second and then it usually bites and goes. The one time he really dumped 1st, he snapped a half shaft.(I was looking left, didn't see him, glanced at the rearview, and was like OH, **** his wife is gonna kill him. Lol)
Moral of the story leave soft. Spinning the tires cost time, lots of it.

KyS10

Changing tire pressure may have helped me as well. I didn't take an air compressor or any tools with me to the track yesterday. So I just left it as I drive it every day, 32 psi in the tires, spare tire still in, nearly a full tank of gas, ect..

After discovering how useless comp. mode is right now, I've started second guessing my plan for tuning. I had planned on ordering a trifecta tune within the next couple days. My plan was to go with the select-a-tune option and have the tune turn on when I was in comp. mode. I will still be using my HHR as my primary road trip vehicle, so I wanted to be able to turn off the tune when on the highway to keep from hurting my gas mileage too much. Now, I fear that if I do that I will make comp. mode even more useless and won't be able to use my tune while at the track.

Any suggestions from more experienced HHR tuners would be greatly appreciated.

Thanks.

IgottaWoody

From what Im hearing.. the tune actually improves milage..unless of course you cant keep your foot out of it...but hwy cruzin it has to be better as the motor doesnt have to work as hard to maintain the same rpm/speed.
Comp mode doesnt really do much for the auto..best you can do is hold that button until you see ESC OFF and launch around 2000-2500 rpms..that way your driving it and not the computer.

Nazgul 9

I have the trifecta tune and my SS is also an auto.. like FoolMoon said if you roll it off the line then hit it you will get whiplash.... trust me the autos with a tune are very nice :)

SS fan

I put the toggle on the cruse control button, so I still have all the settings to choose from on the traction control. The Trifecta tune gets much better mileage on mine. Went from 23 average up to 29. I very rarely use the stg1 setting, unless I hit the button by accident.

KyS10

Well. I ordered my tune yesterday. I ended up not going with the select-a-tune option. I figured I'd see how I liked it being on all the time. If it hurts my gas mileage too much, I'll just add the select-a-tune later. Now I'm just waiting for my cable to get here.

bigjacksauto

So you can run with the GMTU (stg1) and then
you can switch to the Trifecta tune.

Cruise control on =?

bigjacksauto

Bump

foolmoon_design

Yes, the only real advantage to the gmtu when it first came out was the three bar sensors. Your comp with the 2.5 bars could only accurately read to 22psi after that it was a guessing game for the comp to read those higher boost numbers. Your making more power but the comp can't read it. The three bars UPS the readable limit for fueal, air, boost, etc. with the release of plug and play tmap you no longer need the gmtu. Tons of people started with gmtu and have tuned.over.it with no problems