Huge variations in torque output based on minor temp changes???

[cctman]

I'm running a stage 2 set-up Injen intake, Levels FMIC with plumbing and Stage 2 93 octane Cobb AP.

What I have noticed is in Indiana area, on 85+- degree days, I have seen torque averages hitting at only around 234+- but yesterday it was 55 degrees outside and I actually hit 274 at one point averaging 260+- the entire day. Thats a spread of almost 40 lbs of torque for only a 30 degree variation.

Is this normal? Could this be a restriction of the temps on my stock downpipe and exhaust? Its not a fluke either. You can feel a major difference between the two torque readings seat of the pants. The difference is felt by hardly being able to break the tires loose in second gear vs. breaking them loose through 2'nd and even 3'rd easily when the temps are down around 55 or below.

I'm wondering if by swapping out the down pipe if this will eliminate a lot of this.

 

[dyn085]

It's not a fluke; there are substantial power differences associated with denser, cooler air-more so with forced induction than normal aspiration. It's the fundamental reason that we call cooler temperatures 'boost weather'. 40ft lbs seems excessive (offhand, without doing the math), but there are definitely noticeable gains.

P.S.-Datalog and V-Dyno for comparisons.

 

[MegaBuster]

Defiantly normal. my car is much quicker in the morning at 60 degrees than it is in the afternoon at 90 degrees. on top of that the car starts to pull timing when intake temps rise above 105 I believe

 

[cctman]

Defiantly normal. my car is much quicker in the morning at 60 degrees than it is in the afternoon at 90 degrees. on top of that the car starts to pull timing when intake temps rise above 105 I believe

Sorry! What do you mean by pull timing?

 

[cctman]

It's not a fluke; there are substantial power differences associated with denser, cooler air-more so with forced induction than normal aspiration. It's the fundamental reason that we call cooler temperatures 'boost weather'. 40ft lbs seems excessive (offhand, without doing the math), but there are definitely noticeable gains.

P.S.-Datalog and V-Dyno for comparisons.

Thanks for the advice. Thats good to know even though not necessarily good news.

 

[westcoaST]

According to Randy at Mountune, Torque readings in Accessport are accurate for Stage 0 only. I believe he posted this yesterday in response to a question on Torque.

 

[dyn085]

Sorry! What do you mean by pull timing?

As temperature increases, timing is reduced to help prevent pre-combustion (knock). For example, you may have 15 degrees tuning advance at the top of the rpm range on an 100 degree CAT and only 12 with a 130 degree CAT.

According to Randy at Mountune, Torque readings in Accessport are accurate for Stage 0 only. I believe he posted this yesterday in response to a question on Torque.

True, but it's a mathematical algorithm that will still be comparable between similarly-equipped vehicles. Accurate to a dyno, no, but close enough for government work. I still prefer and recommend V-Dyno though.

 

[koozy]

it's normal and designed as planned. with Accesstuner one can see within the map parameters that torque output is based off a number of factors that include coolant temp, air intake temps, etc. As these temps increase the limiters kick in. The easiest way is to prevent torque truncation is ease up on the limiters with Accesstuner. The OTS maps are designed with safety being paramount for a broad user base, environments, scenarios, etc.

 

[cctman]

it's normal and designed as planned. with Accesstuner one can see within the map parameters that torque output is based off a number of factors that include coolant temp, air intake temps, etc. As these temps increase the limiters kick in. The easiest way is to prevent torque truncation is ease up on the limiters with Accesstuner. The OTS maps are designed with safety being paramount for a broad user base, environments, scenarios, etc.

So are you saying that its the AP that is actually restricting the torque based no temp? And do you have to have a Pro tuner to be able to "ease up on the limiters"?

 

[koozy]

So are you saying that its the AP that is actually restricting the torque based no temp? And do you have to have a Pro tuner to be able to "ease up on the limiters"?

Yes, the maps that I have scoured through shows that based on temps and other parameters power output suffers, which isn't always a bad thing when safety is factored in. You need Accesstuner Race or Pro to make changes to maps that are unlocked like Cobb's OTS maps.