HectorM52

iTrader: (5)

Guys,

We just swapped an L33 engine w/ 4L60E into a Blazer. Above 5000 rpm the thing runs like a banshee. But down low, it has literally ZERO power. Will not turn the wheel over, even when line locking it.

It seems that when we stomp it from a stand-still or from 5 mph it just takes too long to "spool up" (NO, we don't have a turbo).

The engine has an LS6 cam and is running the flex-fuel injectors.

Torque management & axle abuse have been disabled within the program.


Can you guys think of any reason for this? We're thinking the issue lies somewhere in the tune, but we're not 100% positive on this theory.

Any thoughts???

Exidous

iTrader: (11)

Without posting the tune its nothing more than a WAG.

Do you know what your AFR's are at the "limp" ROMs?

Hotwire

iTrader: (1)

Funny thing, we're stuck with LS1edit. Trust me, it's been told, learned, and understood, no need to add to that topic. I can post the tune if you can read it. It's basically L33 all the way through w/ LS6 timing and VE table. I've got ltft about to 0 @ idle, +6-10 driving around, still working on getting to WOT, then will disable maf and get ve table dialed in. Just converted to 93 octane too, was trying to get 87 dialed in. Using Shell gas. Had extra bungs welded in and am using an Innovate LM-1 wideband w/ rpm converter as well as LS1scan and torque app on my phone with bluetooth adapter for datalogging.

https://docs.google.com/file/d/0B8kv...it?usp=sharing

The setup is an 02 S10 blazer, 2wd, 4dr. 4 wheel disc brakes, napa premium ceramic pads all the way around.

Had an 2002 L59 (flex fuel 5.3), found current 2006 L33 (HO aluminum 5.3), sold L59, lapped the valves in the 243 heads, new gaskets/seals, 2002 L59 ECM (0411 ecm), 2002 L59 injectors, 2004 brand new LS6 cam from stealership, new LS6 (blue) springs, new lifter trays, new NAPA lifters, comp cams 7.425" one piece pushrods, gm timing chain, GM (felpro) MLS stock head gaskets, AC Delco iridium plugs, taylor plug wires, 02 L59 coil packs, truck intake, 02 L59 DBC throttle body, custom intake piping, maf in "stock" location behind cone filter, cleaned maf elements, still has screen.

Exhaust is 1 5/8" primary, 2.5" collector shorty swap headers, 2.5" through high flow cats to 50 series big block flowmaster dual in, single 3" out, exiting in stock location.

Have a 8.5" 10 bolt rear with 3.42s and 275 40 17 cooper tires (ss rims). Blazer 4L60-E was rebuilt using all the good parts, red alto clutches, wide 2-4 band, billet servos, new solenoids, new sunshell, new vanes in pump, opened up holes in seperator plate, new pistons, seals, etc. I cheaped out and got a rebuilt s10 torque converter, it's stalling around 2200 rpm with this setup.







I can do a brake stand and mat the gas and it just WON'T spin. It turns the tires over very slowly if it does "break loose", but never increases rpms. It sometimes will push the front tires over spinning. I've held it for a couple seconds and it just sits there bowed up like an rabid dog but doesn't do anything. Let off the brakes and it'll pull you back in the seat but waits until 5000+ to really suck you in, chirps 2nd, and keeps on pulling. That's the reason we're asking about tune. I know I'm rich @ wot, but am waiting to get everything else sorted before dealing with it, still learning the tuning aspect of it.

HectorM52

iTrader: (5)

Well damn, that's more info than I had.

Hotwire

iTrader: (1)

Just filling in all the blanks. Not that it matters but I also ported the oil pump and shimmed the relief spring, 40 psi @ idle hot, ~70psi high rpm.

thunderstruck507

iTrader: (18)

Make sure "burst knock" is disabled. It pulls timing when the MAF sees a drastic increase in airflow for no good reason.

Only other thing is the combo of a lot of tire, lack of low end torque, and too tight of a converter.

For reference my cammed ls1 wouldn't do a burnout with a stock converter either. I would say you need at least a Trailblazer SS converter but a 3000+ would be better. The ls6 cam in a 5.3 is going to want some RPM.

68 SS

iTrader: (23)

Sounds like low timing and a combination of what was said above.

Hotwire

iTrader: (1)

Thanks guys, greatly appreciate the info / advice.

I'll 0 out the burst knock and give it a go.

I've got one datalog where a neighbor stopped me as I was headed and and told me to lay on it. Had 24 degrees advance, 100% tps, ~2200 rpm, .64 gms/cyl maf flow. Tune has Max timing set to 26 degrees @ that spec. That sound right? more, less?

Mike@Diablosport

iTrader: (2)

When I put an LS6 cam in my otherwise stock 99 LS1 F-body, with the stock converter, burnouts became difficult. I would imagine the issue would be compounded even further with a 5.3 and a tight converter. The cam has simply moved the torque curve up past the converters efficiency point. Keep in mind, GM never built a vehicle with an LS6 cam and an auto trans, seems there was good reason for this

A converter swap will help quite a bit.

Bowtie316

iTrader: (1)

Going from memory, the numbers in your datalog seem in line with my baby cam 5.3. Timing is good, probably still giving up a bit due to being rich unless you have done wideband tuning.

Even so, it's not going to have a bunch of torque out of the hole due to the LSA of that cam. Need more converter or different cam.

Hotwire

iTrader: (1)

Thanks guys. Welp.. looks like my wife is going to stay happy for a while as I'm stuck with the combo for some time. That means I won't be on first name basis with the tire shop. dammit.

Purchased the cam thinking I'd be saving some dough and have a decent cam for the setup, then had to purchase the pushrods and blew the original intent.

Once you wind it up, it's fun, but definitely need some grunt off the line. Especially since I WAS hoping to tow with the combo. Living and learning.

jimmyblue

iTrader: (11)

On a '99 5.3 truck, changing the burst knock trigger
thresholds to Camaro values fixed the couldn't-spin-
tires problem - also gave it way more first gear pull,
the CylAir run-up with RPM was enough to trigger
the stock truck burst knock retard.

You probably can't see the delta-cylinder-air values
in the scan tool, they are derived from air mass and
you'd have to derive the delta (in Excel, or something)
and convert from scan tool frame rate to PCM "tick"
to get the same basis as the table uses.

Hotwire

iTrader: (1)

Thanks for the info, will DEFINITELY try that tonight!!

To get the delta-cyl-air values I used the following formula: Gms/cyl=15*MAF(g/sec)/RPM

HectorM52

iTrader: (5)

Wow, lots of knowledge pouring through LS1Tech. As the innocent bystander in the project (just helping) I'm happy that we at least have some ideas on how to fix the issue. Jeff (Hotwire) is the one that gets to spend the money...or live with it!

So THANKS from this guy!!

Hotwire

iTrader: (1)

I appreciate it. I went the route of keeping the SBC bellhousing / converter and got a 4L80-E spacer for the flywheel from GM. I have a nice selection of converters to choose from, but have critical CPR on the truck fund to get it going again. After getting everyone's input I'm most likely leaning towards a cam swap before I do a different converter.

To add, not that this has any data value, but this is basically how the truck runs, you can see what we're talking about, this is flat foot 100% wot @ ~ 34 seconds in.

https://docs.google.com/file/d/0B8kv...it?usp=sharing.

You can see how it lags a little, then freakin starts wailing around 5k. anything after 44 secs is boring, just showing drivability.. I know PE kicks in @ 5k in the tune, but don't have anyway of verifying w/ the datalogging capability I have.

I am watching the wbo2 and I've seen as rich as 10.8:1 @ high rpm, working on getting drivability down, MAF first, then VE, THEN working on WOT. Just wanted to be sure I wasn't going lean.

jimmyblue

iTrader: (11)

That is cylinder air mass. The delta cyl air is frame to
frame, difference in that value (you can also log cylinder
air mass directly). But the delta is not a single reading,
but the sequential difference. The scan tools have no
short term memory and won't do the math. And it applies
to the 12.5mS PCM "tick" while frame period is 5, 10, 20mS
depending on the PID count. So you have to scale for
that after doing the frame-frame subtraction to see
things on the same basis as the PCM acts upon.

https://ls1tech.com/forums/pcm-diagn...e-pinging.html
https://ls1tech.com/forums/pcm-diagn...ck-retard.html

Bowtie316

iTrader: (1)

Thanks for this jimmyblue, I changed my burst knock triggers to that of a 2000 A4 camaro and noticed a nice increase in throttle response from a dig. Where it used to overcome the tires okay, now it is more instant and in an more authoritative way. I had never logged burst knock before, now I wish I had.

01WS6/tamu

iTrader: (37)

The cam you have is a great cam for DD. Change the converter first before you go any further. My 6.0 sonoma was a dog off the light with LS6 cam and stock truck converter. I put in a TBSS OE gm converter and it was a day and night difference and then put in a 3000 stall yank converter later for even more improvement. That cam is built for a light vehicle with loose converter.

Hotwire

iTrader: (1)

Preciate the input. The one thing you had going for you was the extra displacement.

Toying with the idea of getting adjustable timing setup and advancing the cam to bring the power in sooner.

Dialing in the tune, set the burst knock to z06 settings, have WOT down to 12.5-12.8:1, and ltfts are now - 2 to +5. Getting there.

Can now start turning the tires if I quick flash the converter while line locking but the weak springs are wrapping and I've got a ton of wheel hop.

Mike@Diablosport

iTrader: (2)

wait...you do have the PE delay disabled, right?