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Re: 2008 Trailblazer SS

Posted: Thu Apr 05, 2012 10:54 am
by oldvettedad
Oh boy! Another man vs computer battle for the ages :!:
maybe we will need to put this match up in a cage :mrgreen:

Re: 2008 Trailblazer SS

Posted: Thu Apr 05, 2012 11:13 am
by Maverick
I'm gonna need a bigger engine. :mrgreen:

Re: 2008 Trailblazer SS

Posted: Thu Apr 05, 2012 11:15 pm
by oldvettedad
Maverick wrote:I'm gonna need a bigger engine. :mrgreen:
No, just visualize your Maverick like this.
Image

Remember....See it in your mind...and you will do it :roll:

Re: 2008 Trailblazer SS

Posted: Sun Apr 08, 2012 2:15 pm
by wxo
With some help from a nice fella on the HP Tuners forum, I was able to get my 1-2 and 2-3 shift RPM close to where I want it (6400).
At 6400, the next gear picks up near the top of the torque curve. I think that's about the best I can get it. The shifts seem to be nice and quick with no lingering now. :D Unfortunately I've burned a lot of premium fuel getting there. :mrgreen:

Re: 2008 Trailblazer SS

Posted: Sun Apr 08, 2012 7:36 pm
by Basement Paul
You mean "fortunately"...

-BP

Re: 2008 Trailblazer SS

Posted: Fri Aug 10, 2012 5:20 pm
by wxo
Just for entertainment value, since things on TireSmoke have been quiet lately, I thought I'd post a picture of my exhaust cutout. It's a three-incher and was installed before the muffler and resonator so it eliminates both. I'm not sure of the performance value, but it makes it sound more like a race-car. Henry's welded the bolts on from behind so that with the wingnuts, it was very easy to uncap it.

Image

Tempus fugit!

Posted: Sun Jun 28, 2015 10:46 am
by wxo
Whew! I can't believe my last post was 2012.
On our trip back from Georgia a few weeks ago, it was a hot day and I noticed that the cool air from the AC vents was getting warmer.
The next day I started the truck and found that the AC was working again. I checked the AC pressures and they looked OK, but I added a small amount of R134, but stopped because I was unsure of exactly how much to put in. Anyway, it got really hot down here in Raleigh and I noticed a similar decrease in cooling, so I thought about Maverick's fan/air flow problem in the Lincoln. Investigating, I observed the two electric fans while cycling the AC on and off as the engine temp increased. I saw that the LH fan came on at 196 degrees with the AC off. With the engine cold, the LH fan also came on when the AC was turned on. But I never saw the RH fan come on.

This truck came from the factory with a large, belt driven, non-computer-controlled fan. I replaced that with some LS1 Camaro electric fans and a harness that allows the ECM to control the fans. It has run this way since 2011 and I've noticed no problems. I think it has been running on only one of the two fans most of the time.

Investigating further, I learned how the truck's computer controls the fans and dug out my HPTuners stuff and hooked it up. With some great help from Kelly at PCMofNC.com, I was able to change the tables to make the RH fan come on at 203 degrees instead of 217 and then keep it running until the temp drops down to 199. This should provide double the airflow for the AC when the summer temperatures start hitting 100 again. Here's what it looks like in HPTuners:

Image

Re: 2008 Trailblazer SS

Posted: Sat Jul 11, 2015 9:28 am
by wxo
OK, now that I've started tinkering again, it has got me thinkin...
So I talked with PCMofNC about the next common sense upgrade for Smoke. I know, I know...I can hear the dominoes starting to fall already (click...click...). My good friend, Kelly, told me about a weakness in the TBSS oiling system that attracted my attention. It seems that the stock oil pickup is a bit too far forward and can cause problems on hard launches as the oil moves backward. I checked it out and there are lots of guys talking about spun bearings. It may be an issue with many Chevy trucks with LS engines, but I didn't investigate the full scope of it. PCMofNC has designed an oil pickup that fixes the problem. I'm thinking it would be worth getting the parts and do the mod. It's about $300 in parts.

The other thing I considered was headers. The more I looked, the more I could hear the dollar signs ringing up. Without other changes, the exhaust system doesn't give much bang for the huge buck (~$1500 - $1800). I was told by a reputable source that the stock exhaust on a TBSS will support up to 400 HP. I'm sitting at 340 now so I still have some maneuvering room. Using Smoke 99% on the street, I don't see much sense in building it up to race only occasionally. So, my strategy is to get as much performance out of it by maximizing efficiency as it sits now. I don't plan to change the exhaust or the converter. Now having said all this, I think there is one thing I can do to get a bit more out of Smoke; a cam and springs upgrade using the stock exhaust and converter. Its my understanding that the heads and exhaust will support a little more cam. I've read 30-40 HP promised with this setup. Being a bit cynical, 20 - 25 would satisfy me. If I get this far and do the cam upgrade, I think I could get a few more ponies with another dyno tune. Just thinkin'..............................

Re: 2008 Trailblazer SS

Posted: Sat Jul 11, 2015 11:56 am
by Maverick
Glad the tinkering bug is biting. Additional 10% HP sounds great. Think I remember you saying you like the shift points but don't know if you were talking about WOT or not. Another potential easy improvement?

Re: 2008 Trailblazer SS

Posted: Sun Jul 12, 2015 12:14 pm
by Basement Paul
Not to mention it will sound a lot cooler at idle and WOT with a bigger cam.

I hope you do it!

-BP

Re: 2008 Trailblazer SS

Posted: Sun Jul 12, 2015 5:43 pm
by GMJohnny
I had my cam shaft installed professionally. I got a solid 3 tenths and 4 mph in
the quarter from it. This going through cast manifolds and a complete exhaust
system. You definitely could feel it in the seat of your pants, which is the part
I like most!!

DO IT!!

GM

Re: 2008 Trailblazer SS

Posted: Sun Jul 12, 2015 10:24 pm
by wxo
So the vibes I'm gettin' here are saying I should move on past the thinkin' stage. I think I'll start trying to figure out which cam I think would be best for my situation. So I've emailed Comp cams to see what they think.

Re: 2008 Trailblazer SS

Posted: Wed Jul 15, 2015 9:49 am
by wxo
Well, the email dialogue with Comp Cams Customer support went like this:

Hello,
>> I have a 2008 Trailblazer SS with the LS2 engine. It has stock exhaust
>> system and stock converter. The truck comes stock with a 410 rear gear.
>> It weighs 4600 pounds. This truck is 99% a daily driven street truck. I
>> hit the drag strip only once or twice a year.
>> I would like to upgrade the cam for more power without changing the
>> exhaust or converter. At this point I have no plans to change the heads,
>> exhaust, or converter. Can you suggest a cam and kit that will work within
>> these parameters and give me some idea of the total out-the-door cost to
>> me. Also what power increase can I expect from the cam and kit.
>> Many thanks,
>> -Walt

> On 7/13/2015 1:34 PM, Cody Williams wrote:
>> Walt,
>> Look into the cam part number #54-456-11
>> And let me know what you think?
>> Cody

> Cody,
> I was hoping for a bit more from you. Is this my only option? Will it effect my gas mileage? What other components are required? How much will it cost me in the end? How much power can I expect with stock exhaust? Will I be able to feel it in the seat of my pants? Tell me, as a cam specialist why you chose this particular cam for me. I'm technically competent, but I'm not good enough to evaluate cam specs and make a choice. I guess that's why I call on you. Have I selected the wrong cam company? I heard that Comp Cams was one of the best.
> -Walt

On 7/14/2015 9:41 AM, Cody Williams wrote:
> No its not the only option. you have to tell me what you think about it.
> If you like that one them i will give you all the other stuff you need not all cams take the same parts,
> With your info i gave you the best cam i could with what you are looking to do,
>
On Tue, Jul 14, 2015 at 9:20 AM, Walt Ostack <ostackw@earthlink.net> wrote:

Well, I don't know any more than I can read, and I've done that. From what I can read, it looks like it might work well. However, I read where guys are using it in vehicles besides trucks and it made me wonder if it will work just as well in a 4600 pound vehicle with a 410 rear and stock exhaust. Heck I don't know. I guess I'm just frustrated because I can't really tell you how I like it or give you what you need from me. I'm also frustrated, because you seem to be not addressing the kind of things I'm Interested in knowing. Maybe email is not the best way to get going on this.
Let me know what you think.
-Walt>
>

Well if you don't now more than you can read that's why you email me to tell you what you need and being
the daily you want it to be this is the cam i would go with,
Thanks,
Cody

Re: 2008 Trailblazer SS

Posted: Wed Jul 15, 2015 10:20 am
by ttamrettus
Time to find another cam vendor.

Re: 2008 Trailblazer SS

Posted: Wed Jul 15, 2015 11:41 am
by Maverick
There must be some reasonable LS custom grind cam guys. There are a few BBF suppliers on the 460 forums. They say they will fit your application better than any off-the-shelf cam and be close in price. Guys that use them are all very pleased as far as I know.