5.3 terrible performance
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
5.3 terrible performance Gen 3 5.3
all new internals all forged
forged +2.9 pistons (mistake, i realize they are dished)
243 heads, stock machining aside from .010 over exh
Tbss intake
Holley 100lb injectors
BTR stage 2 turbo truck cam
long tubes
CAI
double valve springs
roller lifters
Stock 342 gears
Stock height tires
2wd
87 mm tb
Professional tune
2200 stall converter
4l80 trans
Will install terminator x and 7876 turbo once it runs ok
Truck has less hp than stock. Extremely lazy off line. Starts to come to life above 3500 but expectations are very low due to lazy take off.
Tuner told me something about not being able to get low end timing to stay. Told me to get term x. I know ppl run stock ecm with far more than i have.
Any ideas why this truck is so bad? Stock 1500 2wd will smoke it
i know compression is low already. Its missing more than the 10 hp another compression point would add.
Ideas please!
all new internals all forged
forged +2.9 pistons (mistake, i realize they are dished)
243 heads, stock machining aside from .010 over exh
Tbss intake
Holley 100lb injectors
BTR stage 2 turbo truck cam
long tubes
CAI
double valve springs
roller lifters
Stock 342 gears
Stock height tires
2wd
87 mm tb
Professional tune
2200 stall converter
4l80 trans
Will install terminator x and 7876 turbo once it runs ok
Truck has less hp than stock. Extremely lazy off line. Starts to come to life above 3500 but expectations are very low due to lazy take off.
Tuner told me something about not being able to get low end timing to stay. Told me to get term x. I know ppl run stock ecm with far more than i have.
Any ideas why this truck is so bad? Stock 1500 2wd will smoke it
i know compression is low already. Its missing more than the 10 hp another compression point would add.
Ideas please!
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
I havent installed turbo yet. I will once i get na running right. The large injectors and fuel pump are for anticipated turbo install.
I made a mistake on earlier post. Its a stage 1
stick, .222/222 .598ish.
I made a mistake on earlier post. Its a stage 1
stick, .222/222 .598ish.
Last edited by elg180; Jan 7, 2024 at 06:56 PM.
I am assuming you originally had a 4l60, since you refer to what the truck felt like stock with a 5.3. This means you went from a 3.06 first gear ratio to a 4l80 with a 2.48 ratio. You also added over 80lbs of transmission weight. This alone would make a stock motor much slower off the line. However, you now have a higher performance cam, which also makes less power at off-idle rpm ranges. You say you also dropped compression, so there is additional off idle power lost. You kept the stock rear end gear, so that is not helping you regain any torque to the wheels like a steeper 3.73 or 4.10 would. You mention a 2200 stall speed, which is almost stock, so no help there. Bottom line is you need a steeper rear end gear and higher stall converter to keep the truck from being an absolute dog off the line. And fire your tuner if he does not know how to achieve desired timing on a factory ecu.
Post a log and tune.
How are we supposed to give any decent advice?
The internet jockeys will be in here shortly to give a list of reasons based off nothing.
A log and a tune...
How are we supposed to give any decent advice?
The internet jockeys will be in here shortly to give a list of reasons based off nothing.
A log and a tune...
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
Thanks folks, ill see about getting data from tuner to post.
Another tuner told me a lazy tuner suggest terminator x right off the bat. I do get feeling hes brushing me off bc his business is more high end cars.
Reason for this question is so i could get my S together before o go pay another several hundred for a tune.
additiong the final drive to high rear gear are definitely not ideal. Just didn't expect so much. Wont even spin tire in brake stand. Its awful
Another tuner told me a lazy tuner suggest terminator x right off the bat. I do get feeling hes brushing me off bc his business is more high end cars.
Reason for this question is so i could get my S together before o go pay another several hundred for a tune.
additiong the final drive to high rear gear are definitely not ideal. Just didn't expect so much. Wont even spin tire in brake stand. Its awful
Trending Topics
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
I also want to add another bit of info. Seems super rich. Getting ~8mpg abd truck wont start on first crank. Have to turn key off and then start. Acts like its priming or something occasional farting and popping on highway if i get off and back in gas
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Verdad Gallardo Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
When i first built engine it was mated to a 4l60e with 3100 converter. It was around 300 hp at wheels on 2nd gear pull. Tuner didn't go 3rd. Mentioned fear of 2 pc driveshaft....
4l60e fried and did segment swap to 4l80. Tuner touched up and now its crap.
Need someone new in orlando area. Mostly Import guys everywhere
4l60e fried and did segment swap to 4l80. Tuner touched up and now its crap.
Need someone new in orlando area. Mostly Import guys everywhere
Personally, I’d go ahead and go Holley electronics AND the turbo now, and re-tune. I know an excellent Holley tuner that remotely tunes. He will get that truck running superbly, with or without the turbo in place. You’ll be glad you did.
When i first built engine it was mated to a 4l60e with 3100 converter. It was around 300 hp at wheels on 2nd gear pull. Tuner didn't go 3rd. Mentioned fear of 2 pc driveshaft....
4l60e fried and did segment swap to 4l80. Tuner touched up and now its crap.
Need someone new in orlando area. Mostly Import guys everywhere
4l60e fried and did segment swap to 4l80. Tuner touched up and now its crap.
Need someone new in orlando area. Mostly Import guys everywhere
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
The 2nd gear pull is somewhat common on those trucks. The factory speed limiters are set to 98mph on them, so driveshaft critical speed is never an issue in factory trim. With the limiter removed, they are definitely capable of enough speed to cause serious, and possibly catastrophic damage when spun up too high. I did the math just out of curiosity, and you would have to go even deeper than 4.10 rear gears to equal the same total gear reduction with first gear in the 4l80 that you had with the 4l60, so it is a huge difference. That is close to a 19% difference in seat of the pants take-off torque to the wheels.
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
Likes: 7
If you want to share info id be up to try. Im convinced my issues are primarily final drive and gearing. Ill probably go to 4 10s, install turbo and terminator then retune.
https://ls1tech.com/forums/member.php?u=10881
Thread Starter
Teching In
Joined: Jan 2024
Posts: 48
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Sure thing. Here’s a link to his personal info page here on Tech. He worked for Holley for a while. Seriously considered the best Holley tuner anywhere.
https://ls1tech.com/forums/member.php?u=10881
https://ls1tech.com/forums/member.php?u=10881
TECH Addict
Joined: Dec 2017
Posts: 2,166
Likes: 961
Low compression for N/A
Injectors are ridiculously too big (about 4 times stock size)
Terrible gears
Poor cam choice (for N/A, that is)
Not enough converter (nowhere close)
This is why you build EITHER a turbo motor, OR a N/A one. Your combo might be appropriate for a turbo; I'm not going to try to argue that one way or the other; but it's ABSOLUTELY BASS ACKWARDS for N/A.
All the talk about gears vs 4L80E is spot on. The 80 is much closer ratio than the 60, therefore needs more rear gear for the same "leave", all else being equal.
Injectors are ridiculously too big (about 4 times stock size)
Terrible gears
Poor cam choice (for N/A, that is)
Not enough converter (nowhere close)
This is why you build EITHER a turbo motor, OR a N/A one. Your combo might be appropriate for a turbo; I'm not going to try to argue that one way or the other; but it's ABSOLUTELY BASS ACKWARDS for N/A.
All the talk about gears vs 4L80E is spot on. The 80 is much closer ratio than the 60, therefore needs more rear gear for the same "leave", all else being equal.
TECH Resident
Joined: Oct 2006
Posts: 993
Likes: 173
From: Euless, TX
I noticed very little difference in leave after swapping to a 4L85E and the 85E was quicker to 60 mph. Makes me wonder if the tuner has the 4L80E segment in place and it is even getting 1st gear.
I am assuming you originally had a 4l60, since you refer to what the truck felt like stock with a 5.3. This means you went from a 3.06 first gear ratio to a 4l80 with a 2.48 ratio. You also added over 80lbs of transmission weight. This alone would make a stock motor much slower off the line. However, you now have a higher performance cam, which also makes less power at off-idle rpm ranges. You say you also dropped compression, so there is additional off idle power lost. You kept the stock rear end gear, so that is not helping you regain any torque to the wheels like a steeper 3.73 or 4.10 would. You mention a 2200 stall speed, which is almost stock, so no help there. Bottom line is you need a steeper rear end gear and higher stall converter to keep the truck from being an absolute dog off the line. And fire your tuner if he does not know how to achieve desired timing on a factory ecu.
