possible engine problem?
Thread Starter
Racer
Joined: Jul 2013
Posts: 265
Likes: 27
From: Moncton NB
possible engine problem?
Not sure if I have an issue or not; but I'm sure I will get some good info from the forum.
I was out for a cruise. I have a GS, Auto and was driving in Sport mode. using the paddles, I was cruising a back country road around 80mph in 6th gear.
What I found concerning was that if I was on any amount of grade and wanted to accelerate, there was NO acceleration in 6th at all. I always had to shift down to 5th or sometimes 4th to get any power.
Is this normal? I don't use 6th all that much, unless I am being lazy and just let the car do the work, so not sure if this is typical.
thanks.
I was out for a cruise. I have a GS, Auto and was driving in Sport mode. using the paddles, I was cruising a back country road around 80mph in 6th gear.
What I found concerning was that if I was on any amount of grade and wanted to accelerate, there was NO acceleration in 6th at all. I always had to shift down to 5th or sometimes 4th to get any power.
Is this normal? I don't use 6th all that much, unless I am being lazy and just let the car do the work, so not sure if this is typical.
thanks.
Melting Slicks
Joined: Oct 2013
Posts: 2,056
Likes: 211
From: Central Ohio
It is normal - if you left the car in auto it would downshift to accelerate.
You are in sport mode - the car expects you to do the work.
At 80 MPH you are only at 1700 rpms or so - you are well below torque band of an LS3
Torque multiplication is your friend shift gears for more fun
You are in sport mode - the car expects you to do the work.
At 80 MPH you are only at 1700 rpms or so - you are well below torque band of an LS3
Torque multiplication is your friend shift gears for more fun
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
Although I have a Z51 base with lower gearing, at 80 mph I have no problem gaining speed up a grade. Unless your car was pulling back timing because of it being very hot out, I would think you should be able to gain speed with no problem.
Sounds like a problem, or expecting to much out of your car. And what do you define as NO acceleration.
Sounds like a problem, or expecting to much out of your car. And what do you define as NO acceleration.
Team Owner
Joined: Aug 2006
Posts: 25,105
Likes: 3,156
C6 of Year Finalist (appearance mods) 2019
Depends on what you call power. My tuned LS2 has plenty of passing power in 6th gear at 80. Would be doing well over 100 when passing a semi. Now for pin you back in the seat power yes you must downshift. 
Thread Starter
Racer
Joined: Jul 2013
Posts: 265
Likes: 27
From: Moncton NB
not even close. on an upgrade I did good to maintain speed, no acceleration at all.
Team Owner
Joined: Sep 2000
Posts: 25,019
Likes: 2,714
From: Far NW 'burbs of Chicago
St. Jude Donor '13
The biggest variable would be the steepness of the hill.
Also relevant would be the density altitude (elevation/temperature/barometer) and how much weight you had in the car.
As extrapilot said, the computer pulling timing to prevent knock could cost a lot of power- low octane gas, hot engine and air temp would be factors.
Is your car stock? How many miles, and how many miles on the plug?
How does it go when you just put it in D and accelerate 0-100 from a standing start?
Also relevant would be the density altitude (elevation/temperature/barometer) and how much weight you had in the car.
As extrapilot said, the computer pulling timing to prevent knock could cost a lot of power- low octane gas, hot engine and air temp would be factors.
Is your car stock? How many miles, and how many miles on the plug?
How does it go when you just put it in D and accelerate 0-100 from a standing start?
Thread Starter
Racer
Joined: Jul 2013
Posts: 265
Likes: 27
From: Moncton NB
The biggest variable would be the steepness of the hill.
Also relevant would be the density altitude (elevation/temperature/barometer) and how much weight you had in the car.
As extrapilot said, the computer pulling timing to prevent knock could cost a lot of power- low octane gas, hot engine and air temp would be factors.
Is your car stock? How many miles, and how many miles on the plug?
How does it go when you just put it in D and accelerate 0-100 from a standing start?
Also relevant would be the density altitude (elevation/temperature/barometer) and how much weight you had in the car.
As extrapilot said, the computer pulling timing to prevent knock could cost a lot of power- low octane gas, hot engine and air temp would be factors.
Is your car stock? How many miles, and how many miles on the plug?
How does it go when you just put it in D and accelerate 0-100 from a standing start?
Last edited by yellowGS; Aug 27, 2014 at 05:49 PM. Reason: More info
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Melting Slicks
Joined: Sep 2011
Posts: 3,021
Likes: 171
From: Vancouver Island
Sounds normal to me. 6th gear is for maximum fuel economy, not really intended for acceleration, though on a flat surface you can slowly roll on a little more speed, but that's about it.
Pro
Joined: Jan 2014
Posts: 731
Likes: 156
From: New Albany Indiana
Your car sounds very normal. You have to keep engine RPMs a minimum of 3,000 RPM, that's where your engine starts to make real horsepower. Your gearing allows you to move up and down the horsepower band. 6th gear @ 1,700 RPM is for cruzing fuel economy not for spirits driving. Keep the engine pumped up on the cam and it will set you back in the seat when you punch it...
perfectly normal. If you get in that scenario again, take it out of paddle mode, and it will downshift and sit you back in your seat 
Melting Slicks
Joined: Nov 2012
Posts: 3,163
Likes: 686
From: SUFFIELD CONNECTICUT
Not sure if I have an issue or not; but I'm sure I will get some good info from the forum.
I was out for a cruise. I have a GS, Auto and was driving in Sport mode. using the paddles, I was cruising a back country road around 80mph in 6th gear.
What I found concerning was that if I was on any amount of grade and wanted to accelerate, there was NO acceleration in 6th at all. I always had to shift down to 5th or sometimes 4th to get any power.
Is this normal? I don't use 6th all that much, unless I am being lazy and just let the car do the work, so not sure if this is typical.
thanks.
I was out for a cruise. I have a GS, Auto and was driving in Sport mode. using the paddles, I was cruising a back country road around 80mph in 6th gear.
What I found concerning was that if I was on any amount of grade and wanted to accelerate, there was NO acceleration in 6th at all. I always had to shift down to 5th or sometimes 4th to get any power.
Is this normal? I don't use 6th all that much, unless I am being lazy and just let the car do the work, so not sure if this is typical.
thanks.