Chevy Trailblazer SS Forum banner
1 - 20 of 26 Posts

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #1 ·
OK so I now have 50+ total miles on my new build and decide to go WOT for the first time. The tune is not dialed in but not off enough to cause a problem, I think I still be able to spin the tires w/o issue right.

So I take it out and try a 0-60 test. Previously with the LS2 H/C I would be around 3.8s with a best of 3.62s (yeah yeah DH isn't exact I realize this).

I launched a little lighter than I used to, brake torgued to 2k rpms and ease into the throttle-a hard ease-not just hammer the throttle. Previously I would spin all 4 this way.
This time not even a chirp and no bogging feeling, it just picked up speed and ran SLOW!!! It ran a 4.13 0-60. I figured with "ALL" the TQ the 416 should spin tires all day long.

Any thoughts? How does it get slower going from an 364 to a 416?
 

·
Premium Member
2007 TBSS AWD
Joined
·
31,504 Posts
OK so I now have 50+ total miles on my new build and decide to go WOT for the first time. The tune is not dialed in but not off enough to cause a problem, I think I still be able to spin the tires w/o issue right.

So I take it out and try a 0-60 test. Previously with the LS2 H/C I would be around 3.8s with a best of 3.62s (yeah yeah DH isn't exact I realize this).

I launched a little lighter than I used to, brake torgued to 2k rpms and ease into the throttle-a hard ease-not just hammer the throttle. Previously I would spin all 4 this way.
This time not even a chirp and no bogging feeling, it just picked up speed and ran SLOW!!! It ran a 4.13 0-60. I figured with "ALL" the TQ the 416 should spin tires all day long.

Any thoughts? How does it get slower going from an 364 to a 416?

I would like to blame the tune, but it could be any number of things such as mismatched parts etc.. I don't know enough about your build to speculate on that though. You don't have old gas in the tank do you?
 

·
Premium Member
TrailBlazer SS AWD
Joined
·
4,063 Posts
Put the bald tires back on. Once that tune is dialed in all those mismatched parts with kick ass when they are told to work in synergy. "It's All In The Tune"
 

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #5 · (Edited)
I would like to blame the tune, but it could be any number of things such as mismatched parts etc.. I don't know enough about your build to speculate on that though. You don't have old gas in the tank do you?
All parts are new except covers, here is the run down:
630/620 cam
WCCH L92 heads
LEP 416
PCm 4in FWI w/ LS7 MAF-IAT side dead, ordered new MAF
7.35 PRs (measuresured correct)
LS7 lifters
walbro 255
42lb injectors
Kooks 1.75in no cat
3in magnaflow catback
UDP
11.13 to 1 compression

Had 4 gallons of 93 oct that was 3-4 weeks old, ran that out and filled up yesterday with 93oct. I would think that I have burned through the older gas prior to fillup, as I am seeing 7.5mpg.

There are too many variables in hard parts to really get into it. Plus your tune isn't dialed...get the tune spot on, do it again and then see what happens...
I'll work with Alvin....email them now
 

·
Premium Member
2006 TBSS AWD
Joined
·
1,656 Posts
Yeah, I had similar results with my 418. weak bottom end but it pulled like a mother fucker over 3000 RPM. I was disappointed at first, but then I liked it because it dead hooked with just a light churp of the tires. Big cam and big heads was my problem. New engine should fill out heads and cam nice now... :)
 

·
Premium Member
2007 TBSS
Joined
·
4,834 Posts
I don't think we've seen one log from the base file to get you going. Plus if I heard right over Kelly you have a bad maf sensor. I would take it easy before you break something
 

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #9 · (Edited)
I don't think we've seen one log from the base file to get you going. Plus if I heard right over Kelly you have a bad maf sensor. I would take it easy before you break something
I haven't sent a log, just emailed Kelly about it 5min ago. MAF itself is working, but IAT side is dead. Will get a couple files to you by tomorrow morning.

Will for sure take it easy.....to much money in it not to.

Why would you beat the snot out of it without a properly setup tune?
Get a tune, and then while data logging that tune beat the snot out of it.
I don't really think 1 0-60 test is beating the snot out of it, I am watching fueling (12.6 )and KR (0.0). Ive been babying it. But I agree, the tune needs to be MUCH closer.
 

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #11 ·
No IAT reading isn't just a small problem. Many parameters of the tune rely on an IAT reading. Let it fit until you have your sensors working properly.
GGGGRRRRRRRRRRRRR.......so many things to learn about the LSx stuff..

the 3800s were a walk in the park, sorry just a little frustration! I was around 3800s for 12years though, literally on the front lines on new mods, testing, etc. Not so much on this, lots and lots to learn.
 

·
Premium Member
2007 TBSS AWD
Joined
·
31,504 Posts
GGGGRRRRRRRRRRRRR.......so many things to learn about the LSx stuff..

the 3800s were a walk in the park, sorry just a little frustration! I was around 3800s for 12years though, literally on the front lines on new mods, testing, etc. Not so much on this, lots and lots to learn.
Just make sure everything is giving an accurate reading and then let Alvin work with you over e-mail until it is driving 80% or so. That should be good enough to get you out there to have him finish it off.
 

·
Premium Member
2008 TB SS AWD 3SS
Joined
·
3,288 Posts
No IAT reading isn't just a small problem. Many parameters of the tune rely on an IAT reading. Let it fit until you have your sensors working properly.
Yea I saw that in an earlier post and its gonna run like crap until it gets an accurate IAT signal.

Jeremiah, without a proper IAT signal you're going to be pulling TONS of spark. Without a valid IAT reading, the ECM uses -32F as its default cell, take a look at what spark values are in that row (might be column in HPT, EFILive and HPT swap axes). Not going to have much advance, if any, at all.

Get it sorted out, then run it. I wouldnt beat on it at all until you get this fixed, heck I probably wouldnt drive it if it were my truck.
 

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #14 ·
Get it sorted out, then run it. I wouldnt beat on it at all until you get this fixed, heck I probably wouldnt drive it if it were my truck.
I don't have an option but to drive it. I'll just continue to baby it, and new MAF is hopefully here by Saturday.
 

·
Premium Member
TrailblazerSS
Joined
·
2,747 Posts
Discussion Starter · #16 · (Edited)
Your local dealer doesnt have one in stock?
They will have one by Saturday...so I ordered from PCM for Less since they are cheaper and should be here Saturday too. And I asked Kelly to test it before shipping. I don't trust the manufactures for this stuff, I see Mexico, China, and Indonesian failure and quality issues every day.

I forgot to mention, if i get it Saturday, Ill only have 20 more miles on it from now. I would think it be ok, I wont be going over 45mph.
 
1 - 20 of 26 Posts
Top