Torqued Tahoe question - Check my tune

[JefTek]

Hello, I have rebuilt my 2001 5.3 Tahoe engine and it is now a 5.7. I have changed the motor size, the cylinder volume and (tried) to shut-off all TCC on Engine and Transmission tables. January will have it sportin' twin turbos but for now I want it running as well as it possibly can be running with stock every-thing, except 53" BFG T/A's all 'round. I MEAN 33" BFG's oops!!! (lowered to 28psi for winter shenanegins)
It starts-idles-runs and transitions very well but, like someone else mentioned on this site; there is NO low-end torque? I know I do have to check my fuel pressure, but everything seems fine...Plugged-up cats? When I put her in 2-wheel Drive and lightly hold the brakes, I can NOT for the life of me get any wheel spin unless I'm on wet leaves or mud? On my front lawn you can feel the passenger wheel slip a bit for just a second before the G80 diff locks-up and brings the drivers' side wheel into action,(cool beans I didn't even know I had a posi 'till now!) On pavement, however, the tachometer only shows 1800-1900 rpm's and that is it! I cannot get it above 2000 rpm no matter what I do. (I lowered PE to 0 sec and 0 rpm.) Is that normal with these trucks? The engine sounds healthy; no knock or rattle, but no balls either? If I break-it-loose rounding a corner it sounds wicked, strong, and powerful. It'll do over 100 km/hr in no time and runs great with the egr shut-off with a LS1 plate.
When the motor was being rebuilt/re-bored I rented a Ram Sportsman 1500 with the 5.7 hemi and it brake-torqued like crazy, even though I hated every single thing about that Truck; the stupid shifter, the 'dead' feel electronic steering, the non-connected throttle, I HATED that truck for all it was worth and if you floored it fast from a stop it would read TPS fault (I kid you not!), it would stumble and fidget looking for 500* of timing or whatever but it still brake-torqued!
Will someone please give this tune a look over and I will buy you a beer or an AFR or something...
Primo Pre-Turbo Tune by Jef Tek.hptneighhborhood.hpl
I hope I attached these right and THANKS,
-jef

[JefTek]

Anyone?

[JefTek]

Thanks..........

[2xLS1]

except 53" BFG T/A's all 'round

Sorry, avatar too annoying. And how did you fit 53" tires in the wheel wells? That is probably a lot of your torque loss.

[JefTek]

You are too annoying - I have 6" Fabtech lift if you'd bother to read my profile, Jack!

[2xLS1]

You are too annoying - I have 6" Fabtech lift if you'd bother to read my profile, Jack!

Then your problem should be obvious.

[JefTek]

did you read the tune????

[JefTek]

is this some kinda discrimination based on my avatar???

[mbray01]

comparing a new ram with a 5.7 hemi to a 01 tahoe with 53" tires. Just simply turning off torque management is not going to all of a sudden make it break the tires loose. It is going to take addressing the extremely low launch timing these things have. Also with those huge tires a stock converter is not going to work. It is going to take a fairly large converter to get the motor into the powerband, the correct timing, and then hoping you have enough motor, even then I still don't believe you are going to spin those 53's. I really think your asking for a lot from little

[JefTek]

Hey Michael,
Thank you. That's all I wanted to know. Is this tuned as well as expected for the new 5.7 with Mahle pistons, ARP hardware and Fel-pro gasket set, double-row timing chain etc., I just want confirmation that I'm on the right track and have not changed anything unnesssessary or damaging to the new motor. I want that nice fuzzy feeling. I posted this last night and expected a better reply than that LS1 dood gave me.
So, should I work on the VE table and Torque Spark tables, or not?
Should I install the 60lb/hr Dietchwerks injectors before the turbos?
There's a new post with all the specs for 60lb Dietch's right now on the forum, can I use his INJECTOR flow and minimun tables for mine?
Thanks,
Jef

[JefTek]

Nevermind the injector question about using another's tables; his LS3 tune has injector flow vs. pressure and I don't have that OS yet. But,

Should I change the injectors and tune BEFORE or AFTER installing the twins? That is still the question. Thanks

[Lakegoat]

I would think that you should change them now, just to get one more thing done before the turbo install. You can clean up the tune and make sure it is running right. Other than that, It doesn't make any difference because you will have to retune anyway.

[5FDP]

Looks like he made a typo, he's only running 33's on some 20in rims.

Nobody makes a 53in tire for 20's, that straight up tractor tire size LOL.

[JefTek]

Yea 33" I did'n have the glasses on for that! I was thinking metric again...
33"

[JefTek]

Thanks "Goat, I'm too excited, can't wait 'till January...

[Lakegoat]

I didn't look at your tune but your rear gear ratio and 1st gear ratio in the trans makes a big difference with the taller tires. Is this still in the Tahoe? If you want low down torque, maybe you should opt for a Magnuson TVS instead of the turbos. A PD lower and the right cam will give you all the grunt that you will need. I got a custom cam recently that was supposed to extend my high rpm power but instead it gave me toooo much power at the starting line. It would just blow off the tires every time and I had to swap to a different cam. Sounds like it would be a good one for you. I don't have any idea what you are doing so this is just me exercising my fingers. Anyway, the right combo will make a nice driver.

[IARLLC]

I was wondering how in the world you stuffed 53" mudders under a 6" kitted Tahoe. A 6" kit will fit you 35" with the right wheel offset and a bit taller if you trim the edge of the bumper, with fender cut-outs 38" will fit OK and if you take the body up 3" more I have gone into the 40"s but 53" was just messing with me. So I can sleep better now...but it is bugging me that we have not really dealt with your issue. The 5.3 in my Tahoe Z71 rips the 31.5" tires so easy that I started using Auto4. I have about 2000 stall. But even without the stall converter, bumped up to 5.7 I don't think 33" tires are going to make it feel too bad off the line. Depends on which gears it has though. Z71 has 3.73.

Either way what I am getting at is that I fully expect good tuning can get you a lot more grunt! And having said that I have to excuse myself for not checking out your tune because I am in the middle of a few tune projects and don't want to upgrade to 3.4 yet. One of the real experts on here can surely hook you up though.

By the way...there are a lot of guys on here from all over the World...including Australia, Middle East, Central Asia, Europe. Everybody treats each other pretty good and I am proud of that.

Jeff

[JefTek]

That's what I'm trying to say,Lakegoat, It is limited in some way when you attempt a brake-torque with 33" tires. I just feel it should have more, I need to know what to tune next, don't I? thanks you guys for being patient with me, I just realized that the OS's can change/upgrade so that makes it hard to look at my tune, and I'm really really sorry for the 53" confusion thing, i apologise to one and all over that simple number mistake.
What to do....

[JefTek]

Real Experts, where are you? Come out come out wherever you are...
I can't brake torque over 1900 rpm, my rear brakes are not that good! Everything else seems strong, just no low-end grunt and I do have 3.73 gears. When the rear wheels do break loose they seem fine, torque/rpm will rise then but with foot on brake and accelerator to the floor it just sits @ 1900, it that normal, even with the stock tires it never had any boogie but now that the motor is brand spankin' new; you know? The 5.3 and 5.7 vortec both use the same cam, is that my problem, or can I tune this?

[5FDP]

Have you done any Primary VE and MAF tuning yet? To me they still look factory but I didn't compare them yet.


If not, you need to start there. Then past that you can work with timing and WOT fueling.

Remove the abuse settings on the engine side, raise the enable table from 1,600rpm to 6,000rpm or something. That way it won't enable drivetrain abuse.


You can lower the PE EQ ratio some too, they run pretty fat up top. Something around 12.0 AFR to start with without a wideband should be alright. If you do have a wideband, that is still a good target AFR to start with.


Past that, you really just have too much working against you. The lift kit makes it harder to spin the tires with near stock power levels. The oversized wheels that are at the minimum 20-30lbs heavier than the stockers make it harder to spin. The oversized tires are heavier than stock and make it harder to spin them, as well as them being offroad tires that will want to grip the road.