Or Goodfellaz, leave it alone and keep the warranty?

 

It seems like the guys over there have already done that mod with great success, but also have learned that when they add a tune, there is no need to adjust the wastegate, and even recommend that you adjust back to stock, as the tunes they are running don't need the adjustment.
I had thought about the 5spd, but wanted to have my wife use it if necessary and therefore the auto. I also had the '07 G5 (base model) w/remote start and let me tell you, this past winter it was nice
I can only imagine how much I will like the remote start this summer with the heat
I will wait for a tune for the auto, not looking for more or less, don't need to add or change any parts, my plans are to leave stock with a tune, that would do me just fine. I may add a muffler or cat-back in the future depending on how good they sound. AUTO it is

 

Yeah, about that! I saw that adjustable wastegate rod. If the General didn't want you to mess with it, why would he make it adjustable? Too much temptation in my book. Warrantee be damned! I can afford the occasional grenaded tranny. I want more power! But I have read that the CPU moderates the tuning once it figures out the boost has increased.

And thanks for the trip back in time, Goodfellaz! Back in my drag racing days, I had a mildly hopped up '88 350 IROC Z and my best friend had an awesome black '87 GNX. I could get him off the line, but he always pulled me hard once we got past 35 mph. And you knew he was coming 'cause you'd hear his tires clawin' start clawin' for grip!

 

Actually, Old Ray, I think the peep's perceptions about the SS auto have been a little skewed. I've just passed 1,450 mi on the odo. So I've started playing with the floor shifter for the auto. I've discovered when you shift to low range while slowing down, the tranny will shift down sequentially to each lower gear when rpm's safely permit. Same thing happens under acceleration. In low range, the tranny will hold each gear to redline even if you're slowing and accelerating again thru corners. Well, I can only verify that for the first 2 gears. I've only had my HHR SS to 100 mph so far. So, even though you don't see each available gear on the gear selector, each gear is still accessible when you want it.

 

I dont think it will go into 4th unless in D. Correct me if I am wrong. (Im too chicken to try it on mine)

 

Oh, and are you ever in for a surprise?

First some background from previous posts;

Quote from nick's dad on 09-11-2007, 06:50 AM :
“I have not found Intermediate gear to be very useful- I have a long, steep hill near me, and I have downshifted every automatic trans I've owned to engine brake on this slope. All have stayed in the selected gear until I up-shifted manually. The HHR held second briefly, but then up-shifted to third, thus defeating the purpose of downshifting for engine braking on a grade!!! Is this some kind of "overheat protection" or is it just the nature of this "I" gear?”

Quote from Black Rose 03-22-2008, 09:40 PM;
“When it hits 4,000 rpm it will shift...that's just the way it's programmed.”

Black Rose 04-02-2008, 08:58 PM :“There are a couple of members here that work at that plant”

Grace Macaluso, Windsor Star Monday, March 31, 2008; “The plant's four-speed transmission is slated to be retired in 2010, said CAW plant chairman Ken Bruner. "The need for a new product is huge."

cc732 04-03-2008, 10:00 AM : “Tooling and conversion costs for new products are nearly triple what they were when we started building the 4T45E in 1994.”

GTOMIKE 04-03-2008, 08:28 AM : “We were always the best tranny plant GM had but that just don`t cut it anymore.”

This transmission is very well built, it just is poorly engineered IMO. Unless the SS is different and I have seen no information to indicate that is so, (there seems to be very little real info on the actual operation of the 4T45E) it would appear that under deceleration these transmissions will automatically (on its own) UP-SHIFT (2 to 3) when in “I” when it reaches 4000 rpm. This is just crazy, (and dangerous) and I’m here to tell you that the first time it happens to you, hang on.

 

Powertrain engineers will tell you that even in manual transmissions they would rather you use the brakes for slowing, todays brakes are much better than years back, and its cheaper to replace pads and rotors than do transmission repairs. The electronic controls they have today allow the engineers to "protect" the transmissions much better than the hydraulics controls did. Try and rock your new auto out of a mud hole or when stuck in snow, or rev in neutral and drop to drive. I believe they are overprotective, but its their money and warranty. One way they have been able to save costs is to use a transmission that hasn't been been rated for the power by reducing power during shifts, and reducing boost and engine power during other times too. Cheaper than upgrading to a bigger or newer trans.
IF you lookup on the GMpowertrain webpage for the HHRSS, you will find the auto trans only rated for 221 lbft of torque, so they had to reduce power of the 260lbft torque SS engine.

 

I guess my SS auto must be a freak from the factory. My 1st gear holds to redline and my 2nd gear holds to redline every time while accelerating from a stop. I still have not pushed 3rd gear all the way to redline.

While decelerating with the shifter set in "L", the transmission will downshift 3-2 and 2-1 at a point that will only cause the engine to spin back up to 4000 rpm. And once I get the tranny to downshift to 2nd or 1st, it will hold that gear again until redline. Hint: You have to keep the shifter in "L".

I watch my tach while playing, so I've learned to anticipate the downshifts for maximum fun factor. And the downshifts are not violent like you are want to imply, Old Ray. I have downshifted a manual tranny behind a 350ci V8 far more violently than anything this little 122ci I-4 can throw at me.

I guess I'm a glass half full kind of guy. I really don't care what people think the auto can't do. I have many reasons to like the auto tranny and look forward to modding it.

I started this thread for other fans of the HHR SS auto, NOT for those who aren't fans, much less even driven one. I'm done kicking this dead horse until someone has something HELPFUL to say in the vein of tips, tricks, modding, aftermarket, etc.

 

JP just so we are on the same page, when you put the auto in "L", I would assume you shift up to "I" at redline? Is this correct? Want to dulpicate what you are doing, but want to make sure I am shifting like you......

 

Leave in "L", it will shift automically at redline. That is a safety feature governing all GM automatic trannys these days. 100,000 mi warrantee, you know.