trailblazer ss tuning?

[hot-dog]

Im having some trouble figuring out why the throttle response is so bad on this thing. i notice when i chop the throttle it goes to -10 degrees of timing for a second and then eases into normal timing, i cant figure out what part of the tune does this. any help is welcome, im new to gasser tuning.

[hot-dog]

is it in the p.e tables?

[XLR8NSS]

It's not just one part of the tune that screws with the timing on these things. I wish I could be of some help but, I haven't messed with it in a while and can't remember off the top of my head which tables to look into.

I'll try to go through my tune tomorrow and give you some ideas. :)

[hot-dog]

i have already played with allot of b0515 with no help, i tried playing with pe delay stuff and that seemed to help a little, tomorrow i will try 0ing b2522 and maxing out 2517...

im tuning this car for my mom and i was honestly a little disapointed with the performance being it has an ss badge on it! the throttle response is just lame. also any pointers on how to make it a bit faster would be appreciated. i dont think i understand the spark tables well enough to mess with them yet, but im sure some power could be had with a little timing?

im new to tuning gassers so be easy on me, its allot different then tuning a duramax, less to play with and less room for error...

[GAMEOVER]

Post up your tune...
and data log....
Any Mods?

[gmh308]

Im having some trouble figuring out why the throttle response is so bad on this thing. i notice when i chop the throttle it goes to -10 degrees of timing for a second and then eases into normal timing, i cant figure out what part of the tune does this. any help is welcome, im new to gasser tuning.

This sounds like burst knock retard function. i.e. predictive retard to minimise/eliminate knock on rapid throttle opening.

To echo Gameover: are you logging etc?

:cheers:

[GTPprix]

There are a ton of negative cells on the left hand side of the timing table, its probably hitting those if you are seeing this from a dig and you are just matting it.

[Chevy366]

Someone told me once on a LS1 , which may be different , that setting minimum spark advance to a positive number would stop this , from factory it is -10* , so I have been told .

[hot-dog]

alright i figured the burst knock out and got rid of the torque manegment and it responds allot better. but i still have a few questions, for one it feels like it realy just lugs and makes a bunch of noise untill it gets into the higher revs, is this normal for a performance gas engine with a (bone stock other then intake/exhaust) or is there some limiting factors that make it feel this way? also it feels like the first half of the pedal does all the work and the second half just makes a bunch of noise until it revs out, once again i drive a diesel, i don't know if this is just how it is or if its in the tuning? in general it feels like it has no nuts (relatively speaking compared to upper rpm power) until the rpms are screamin, so i guess im just asking if this is limiting in the tune or just the normal powerband for this engine?

[hot-dog]

also, i added 2 degrees to pretty much the entire spark table, is this ok? the timing is still pretty mild, but i dont know how much it affects afr and i don't have a wb02 to tell me.

[GAMEOVER]

Post up the tune.....:)
If you post up the tune then we can look at it
Otherwise:nixweiss:

[hot-dog]

sorry i kept forgetting to...

[hot-dog]

i dont have any good logs as of yet.

[GAMEOVER]

What fuel are you using? i.e octane
Post up a log of your Trans. tune

[hot-dog]

regular 87 octane. i know im not providing enough info and im sorry, i just dont have any damn logs yet! hopefully tomorrow i will get a few logs for you guys to look at. just with what i did so far the throttle response has gotten allot better, but it feels like theres got to be more left in her.

also what kind of 0-60 do these bad boys run, its been a pretty hot topic with my budys if my truck is faster. i just logged a 5.35 0-60 at full weight spinning through all of first and just reving the crap out of 2nd in my truck, im sure i could do better.

[hot-dog]

alright, did some logging today and figured out why it feels like such a dog, it runs at retarted low amounts of timing due to knock retard. i got rid of the burst knock and torque limiting stuff and it still pulls like 15 degrees of timing at certain points. i guess it just needs to run premium? another thing i was a bit concerned with was he intake air temps, they seem blazing hot to me, and they never realy cooled off as speed increased like im used to seeing when i log my truck. it has a k&n kit which im sure would be hotter then stock but still?

heres some logs

[hot-dog]

the first two are with a completely stock tune, the last one was with no torque limiting/burst knock, not much difference, allot of timing being pulled on both. also it 0-60 in around 7.8, which i thought was very weak.

[gmh308]

the first two are with a completely stock tune, the last one was with no torque limiting/burst knock, not much difference, allot of timing being pulled on both. also it 0-60 in around 7.8, which i thought was very weak.

Looks like it is simply your low octane table on the mark. As GTP pointed out, plenty of lo/negatives on the RHS of this table.

Only 1 deg of KR. Octane scalar should tell you whether it is full in to the low table.

I'm no tuning guru though :) !

[hot-dog]

yea, i just looked at the low octane table and its lamer then i thought. but still i had a few other logs that showed 3 or 4 degrees of knock retard on top of that, maybe its just bad gas.

[GAMEOVER]

Did you remove any TM from your transmission tune?

[hot-dog]

not much, but that only works during shifts i thought?

[hot-dog]

alright i brought it to the track and my best time was 9.70 with a 2.28 60'... i put 16gal of 91 in her on top of what low octane was left, wast good enough still running on the low octane table and still pulling timing down to .5 degrees at some points and finishes the run at 11 degrees.... i know its 10.9:1 compression so i guess you have to be careful with what gas you put in it, maybe 6 gal of reg is enough to dilute the tank down? plus i don't know if sams club gas is decent quality or not, and i know octane boosters don't work for shit so i didn't even bother with that. this thing feels slow how its running, it got beat by a bone stock lighting, it was embarrassing. another thing i was concerned with is throttle response, please tell me this isn't just how it is on these engines?!

i will post a few logs later

[hot-dog]

here was the best run of the night...

[ScarabEpic22]

I just got an 08 TBSS yesterday and played around all day with it. Definitely use premium (91+ octane) at ALL times, its a friggin LS2 motor. You paid a bunch of $$ for it, spend the extra 5 bucks a tank to make it run right. No idea what it'll run, but its a he|| of a lot faster than my I6 TB thats for sure. And yes, 6gal of regular will still dilute your tank of premium down a bunch. Burn through the rest of this mixed tank, then put some 91+ in there and start logging. Im back in Spokane and had to leave my SS in Seattle for a few months, but once I get back Ill be logging like a maniac trying to figure out the E67/T42 combo as its a ton different than my P10.

[The Alchemist]

" Definitely use premium (91+ octane) at ALL times, its a friggin LS2 motor. You paid a bunch of $$ for it, spend the extra 5 bucks a tank to make it run right."


What he said...low octane fuel in these engines is simply a waste of space, when we use it at the customers request ( why by a V8???? ) it kills 3 deg timing out of full load to avoid knock.
With high octane fuel use shud aim for about 18 to 19 deg fully loaded as you past through 2000rpm, rising up to 23 deg over 3200 to 4200rpm, pull out to 18 deg at peak torque, usually 4800 to 5000rpm then slowly rise up to 23 to 24 deg at the rev limiter of 6500rpm. Do a log at full load , plug those numbers in your spark map at the highlighted areas, blend the map to tidy it up and give that a go :) Thats just saved you a fortune in time :cheers: human hours....
Timing is everything :rockon: ignition timng .....

Mike

[hot-dog]

yea, i found that the iat tables were also pulling allot of timing, once i fixed that i had her running to the fullest of the low octane table, 10 degrees at wot is better then 1-2 degrees... im just waiting for a full tank of all 93 before i try any more logging/tuning.

[The Alchemist]

yeah forgot to mention that too. some IAT spark tables need a rework to suit your ambient temps you see on your logs in your particular setup. Basically set it to "0" at your average running temp constant speed then rework to suit.
Mike

[hot-dog]

yea, thats what i did, any reason why the iat read so hot? i read that the iat is part of the maf on this car, so is it just getting heat soaked and isnt an acurate reading?

[ScarabEpic22]

TBSSs are notorious for heat soak, all TrailBlazers are (my I6 is bad, I cant wait to see how my my SS is this summer ugh).

Thanks for the advice about timing Mike, Ive read a lot about the LS1 PCMs but the E67s are a completely different beast that Ill spend the next few months reading about before I start playing around.

[The Alchemist]

yeah the E67 I haven't had a play with over here in NZ.....we have the LS1 ECU, the Awful E40 on some LS2's and then the E38's on all the new Holdens
http://www.holden.com.au/www-holden/action/vehicleentry?vehicleid=4

http://www.holden.com.au/www-holden/action/modeloverview?modelid=100003

these are a nice car..... :)

MIke

[ScarabEpic22]

Well I hear the E67 and E38 are pretty similar, and the TBSS had the E40 in 06 but for 07-09 its an E67. Lots and lots of reading in my near future I predict, any other sites anyone knows of for more info on how to tune the E67?

[JAY4SPEED]

" Definitely use premium (91+ octane) at ALL times, its a friggin LS2 motor. You paid a bunch of $$ for it, spend the extra 5 bucks a tank to make it run right."


What he said...low octane fuel in these engines is simply a waste of space, when we use it at the customers request ( why by a V8???? ) it kills 3 deg timing out of full load to avoid knock.
With high octane fuel use shud aim for about 18 to 19 deg fully loaded as you past through 2000rpm, rising up to 23 deg over 3200 to 4200rpm, pull out to 18 deg at peak torque, usually 4800 to 5000rpm then slowly rise up to 23 to 24 deg at the rev limiter of 6500rpm. Do a log at full load , plug those numbers in your spark map at the highlighted areas, blend the map to tidy it up and give that a go :) Thats just saved you a fortune in time :cheers: human hours....
Timing is everything :rockon: ignition timng .....

Mike

Fantastic info! Thanks!