STILL HAVING ISSUES, no low end power
02-08-2013, 03:05 AM
#1
On The Tree
Thread Starter
iTrader: (4)
Join Date: Jun 2002
Location: Los Angeles
Posts: 175
Likes: 0
Received 0 Likes
on
0 Posts
STILL HAVING ISSUES, no low end power took my car to the track last night and it ran like crap...
it completely bogs out of the hole. when it finally gets going it hauls *** but it takes way too long...
i have a 237/242 603/609 cam and cnc heads with a 3600 stall 373 gears.. last night it ran 7.9 with a 1.9 60 foot and a 91 mph....
it ran the exact same speed and time with a horrible tune on it and with NO HEADS. it had the exact same stall. after putting the heads on the numbers on the dyno went up drastically but the track time does not reflect. before the heads the car launched extremely hard out of the hole and then died out on the top end. now with the heads it has huge top end and no ou8t of the hole power. Im not saying its the heads im just giving a reference . the car was tuned by CMS so its no like anybody just tuned it...
when i drove it last night i manually shifted the car. the 7.8 was my best time, i tried to race it in regular drive and the car bogged even worse out of the hole and ran a 8.1 at 88 mph, it also dropped rpms way to low on each shift as it went through all of the gears. id say it dropped the rpms about 1k too low on every shift while it was in drive. it seemed like it lost more and more power on each shift.
the car can only hold the tires to about 2k before they start to roll. i tried stalling it as high as i could and i also tried flashing the stall to only about 12-1500 rpms and the same result everytime.. no power out of the hole
id say its a stall problem but i had this same stall before the heads and it launched hard as ever out of the hole... is this a possible stall problem a tune problem or some sort of other problem... im running a stock intake and throttle body is the motor not getting enough air at low rpms?
acceleration on the freeway at speed when going WOT is still poor
any help is appreciated...
it completely bogs out of the hole. when it finally gets going it hauls *** but it takes way too long...
i have a 237/242 603/609 cam and cnc heads with a 3600 stall 373 gears.. last night it ran 7.9 with a 1.9 60 foot and a 91 mph....
it ran the exact same speed and time with a horrible tune on it and with NO HEADS. it had the exact same stall. after putting the heads on the numbers on the dyno went up drastically but the track time does not reflect. before the heads the car launched extremely hard out of the hole and then died out on the top end. now with the heads it has huge top end and no ou8t of the hole power. Im not saying its the heads im just giving a reference . the car was tuned by CMS so its no like anybody just tuned it...
when i drove it last night i manually shifted the car. the 7.8 was my best time, i tried to race it in regular drive and the car bogged even worse out of the hole and ran a 8.1 at 88 mph, it also dropped rpms way to low on each shift as it went through all of the gears. id say it dropped the rpms about 1k too low on every shift while it was in drive. it seemed like it lost more and more power on each shift.
the car can only hold the tires to about 2k before they start to roll. i tried stalling it as high as i could and i also tried flashing the stall to only about 12-1500 rpms and the same result everytime.. no power out of the hole
id say its a stall problem but i had this same stall before the heads and it launched hard as ever out of the hole... is this a possible stall problem a tune problem or some sort of other problem... im running a stock intake and throttle body is the motor not getting enough air at low rpms?
acceleration on the freeway at speed when going WOT is still poor
any help is appreciated...
Last edited by chevyrunner; 02-08-2013 at 03:10 AM.
02-08-2013, 02:41 PM
#3
took my car to the track last night and it ran like crap...
it completely bogs out of the hole. when it finally gets going it hauls *** but it takes way too long...
i have a 237/242 603/609 cam and cnc heads with a 3600 stall 373 gears.. last night it ran 7.9 with a 1.9 60 foot and a 91 mph....
it ran the exact same speed and time with a horrible tune on it and with NO HEADS. it had the exact same stall. after putting the heads on the numbers on the dyno went up drastically but the track time does not reflect. before the heads the car launched extremely hard out of the hole and then died out on the top end. now with the heads it has huge top end and no ou8t of the hole power. Im not saying its the heads im just giving a reference . the car was tuned by CMS so its no like anybody just tuned it...
when i drove it last night i manually shifted the car. the 7.8 was my best time, i tried to race it in regular drive and the car bogged even worse out of the hole and ran a 8.1 at 88 mph, it also dropped rpms way to low on each shift as it went through all of the gears. id say it dropped the rpms about 1k too low on every shift while it was in drive. it seemed like it lost more and more power on each shift.
the car can only hold the tires to about 2k before they start to roll. i tried stalling it as high as i could and i also tried flashing the stall to only about 12-1500 rpms and the same result everytime.. no power out of the hole
id say its a stall problem but i had this same stall before the heads and it launched hard as ever out of the hole... is this a possible stall problem a tune problem or some sort of other problem... im running a stock intake and throttle body is the motor not getting enough air at low rpms?
acceleration on the freeway at speed when going WOT is still poor
any help is appreciated...
it completely bogs out of the hole. when it finally gets going it hauls *** but it takes way too long...
i have a 237/242 603/609 cam and cnc heads with a 3600 stall 373 gears.. last night it ran 7.9 with a 1.9 60 foot and a 91 mph....
it ran the exact same speed and time with a horrible tune on it and with NO HEADS. it had the exact same stall. after putting the heads on the numbers on the dyno went up drastically but the track time does not reflect. before the heads the car launched extremely hard out of the hole and then died out on the top end. now with the heads it has huge top end and no ou8t of the hole power. Im not saying its the heads im just giving a reference . the car was tuned by CMS so its no like anybody just tuned it...
when i drove it last night i manually shifted the car. the 7.8 was my best time, i tried to race it in regular drive and the car bogged even worse out of the hole and ran a 8.1 at 88 mph, it also dropped rpms way to low on each shift as it went through all of the gears. id say it dropped the rpms about 1k too low on every shift while it was in drive. it seemed like it lost more and more power on each shift.
the car can only hold the tires to about 2k before they start to roll. i tried stalling it as high as i could and i also tried flashing the stall to only about 12-1500 rpms and the same result everytime.. no power out of the hole
id say its a stall problem but i had this same stall before the heads and it launched hard as ever out of the hole... is this a possible stall problem a tune problem or some sort of other problem... im running a stock intake and throttle body is the motor not getting enough air at low rpms?
acceleration on the freeway at speed when going WOT is still poor
any help is appreciated...
Last edited by Ryne @ CMS; 02-08-2013 at 02:48 PM.
02-08-2013, 06:48 PM
#4
On The Tree
Thread Starter
iTrader: (4)
Join Date: Jun 2002
Location: Los Angeles
Posts: 175
Likes: 0
Received 0 Likes
on
0 Posts
also with the car dropping the rpms extremely low during shifts (in drive) it leads me to believe the stall is not keeping the rpms high enough...
not to mention that this started to happen once i took the car back to johnny for the drum being cracked... after i picked it up from you that day it left extremely hard as well even with the cracked drum..... so i dont know what happened since the drum has been fixed but i will be taking it to him this week.. ill let you know what happens when i get the new stall in....
Trending Topics
02-08-2013, 09:43 PM
#8
On The Tree
Thread Starter
iTrader: (4)
Join Date: Jun 2002
Location: Los Angeles
Posts: 175
Likes: 0
Received 0 Likes
on
0 Posts
umm idk i doubt it .. I dont know enough about drums and stuff.. I would think the tune would stay the same no matter what..... Im really hoping that its a stall problem that can be fixed next week when the new stall gets here..... The car has absolutely no power from a dead stop
02-08-2013, 11:06 PM
#9
TECH Resident
iTrader: (6)
Join Date: Sep 2008
Location: SoCal, SFV
Posts: 793
Likes: 0
Received 0 Likes
on
0 Posts
If the car is tuned around a broken trans..and then fixed and now trans is operating properly wouldn't: the tune now be off? Its not that the tune changed. The trans did. I don't know enough about Transmissions or tuning but its just putting 2+2 together in my head. Car runs perfect. Fixes trans, same exact stall, but now its not performing right.. just my 2 cents.
02-09-2013, 01:11 AM
#10
On The Tree
Thread Starter
iTrader: (4)
Join Date: Jun 2002
Location: Los Angeles
Posts: 175
Likes: 0
Received 0 Likes
on
0 Posts
If the car is tuned around a broken trans..and then fixed and now trans is operating properly wouldn't: the tune now be off? Its not that the tune changed. The trans did. I don't know enough about Transmissions or tuning but its just putting 2+2 together in my head. Car runs perfect. Fixes trans, same exact stall, but now its not performing right.. just my 2 cents.
02-11-2013, 01:07 PM
#11
from what i was told the trans was not un-tuneable however it was just redlining going into certain gears... but i believe ryne was still able to tune the car.... it ran like a champ even with the cracked drum.. the only thing the drum was doing was making it hit the rev limiter a few times before it shiftin into a gear
02-11-2013, 08:35 PM
#12
On The Tree
Thread Starter
iTrader: (4)
Join Date: Jun 2002
Location: Los Angeles
Posts: 175
Likes: 0
Received 0 Likes
on
0 Posts
ryne will be taking it to johnny to have stall replaced tomorrow, ill hit you up and let you know the results after its put in.... im keeping fingers crossed this was the issue
02-12-2013, 01:03 AM
#14
Good info from TCI
Converter Stall Speed Explained One of the most exciting things about a performance street/strip vehicle is its launching power. And with an automatic transmission, much of the take-off is determined by the stall rpm of the torque converter. In this section, engineers at TCI® answer a few commonly asked questions about torque converter stall.
What are the differences between flash stall and brake stall?
Flash stall is the true stall of a torque converter. Brake stall, or “foot brake stall,” is the rpm that occurs when the engine overrides the brake system and the car begins to “push” forward. You simply hold the brake and slowly accelerate until the car bogs the engine down and then begins to move forward.
Which one is the more effective measurement of the two?
Brake stall is NOT an accurate way to properly check the stall because there are too many variables that affect it. Some of these variables include the type of brake system (drum or disc) and brake adjustment. Therefore, when measuring the stall of your torque converter, the flash stall will always be the more effective option of the two.
For the typical street/strip application, the easiest way to check torque converter stall, as TCI® rates it, is by “flash stall”. This can be measured by pressing the accelerator all the way to the floor (full throttle) when the vehicle is in high gear at the lowest speed before it downshifts, and watching the tachometer. The rpm to which it instantly “jumps” is a pretty accurate measurement of the stall rpm of the torque converter. This method works even better if you have a full manual shift transmission.
The second way to measure flash stall in a street/strip vehicle is to floor the throttle from a dead stop off of idle. Look at the tachometer and whatever the rpm jumps to when the car starts to move is the stall rpm. If the cam is too big for the converter or if the rear end gear is too low, it will dramatically affect the stall rpm by decreasing it. In other words, a car with a 3.73 gear will flash stall a converter at a higher rpm than an identical car with a 4.10 gear.
For more information about torque converters or any other drivetrain questions, please call our toll free TRANS HELP® line at 1-888-776-9824, or visit our website at www.tciauto.com.
Attached Thumbnails:
Converter Stall Speed Explained One of the most exciting things about a performance street/strip vehicle is its launching power. And with an automatic transmission, much of the take-off is determined by the stall rpm of the torque converter. In this section, engineers at TCI® answer a few commonly asked questions about torque converter stall.
What are the differences between flash stall and brake stall?
Flash stall is the true stall of a torque converter. Brake stall, or “foot brake stall,” is the rpm that occurs when the engine overrides the brake system and the car begins to “push” forward. You simply hold the brake and slowly accelerate until the car bogs the engine down and then begins to move forward.
Which one is the more effective measurement of the two?
Brake stall is NOT an accurate way to properly check the stall because there are too many variables that affect it. Some of these variables include the type of brake system (drum or disc) and brake adjustment. Therefore, when measuring the stall of your torque converter, the flash stall will always be the more effective option of the two.
Note: Using the flash stall to launch from idle is also the more efficient way to “leave the line”, as it doesn’t have any effect on the engine during take-off.
How do you check the stall in your torque converter? What variables factor in, etc?For the typical street/strip application, the easiest way to check torque converter stall, as TCI® rates it, is by “flash stall”. This can be measured by pressing the accelerator all the way to the floor (full throttle) when the vehicle is in high gear at the lowest speed before it downshifts, and watching the tachometer. The rpm to which it instantly “jumps” is a pretty accurate measurement of the stall rpm of the torque converter. This method works even better if you have a full manual shift transmission.
The second way to measure flash stall in a street/strip vehicle is to floor the throttle from a dead stop off of idle. Look at the tachometer and whatever the rpm jumps to when the car starts to move is the stall rpm. If the cam is too big for the converter or if the rear end gear is too low, it will dramatically affect the stall rpm by decreasing it. In other words, a car with a 3.73 gear will flash stall a converter at a higher rpm than an identical car with a 4.10 gear.
For more information about torque converters or any other drivetrain questions, please call our toll free TRANS HELP® line at 1-888-776-9824, or visit our website at www.tciauto.com.
Attached Thumbnails:
