Timing ??
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
Timing ??
Can anyone explain to me why some boosted cars only take 15* timing and others can take 20* my car seems to like lots from what my tuners have told me. I know meth and good gas are part of it may be compression too?
thanks for reading this and helping me understand why
thanks for reading this and helping me understand why
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
Timing is an inverse function of cylinder pressure. The more cylinder pressure the less timing it needs.
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
Burning Brakes
Joined: Dec 2003
Posts: 1,243
Likes: 5
From: Loveland CO
ALOT of factors.. Just to name a few:
* Boost Level, Lower boost will accept more timing (traditionally)
* Compression
* TUNE... if the rest of the tune is junk, you will get KR before you maximize the Timing.
* Mods... Headers vs stock manifolds, Cam, Heads... ect..
* Maxing out fuel system.. Too small of Injectors or pump and you will not get enough fuel resulting in KR and again less timing.
In a FI car, Usually a Low compression setup will have Higher boost levels.... resulting in lower timing advance
S
* Boost Level, Lower boost will accept more timing (traditionally)
* Compression
* TUNE... if the rest of the tune is junk, you will get KR before you maximize the Timing.
* Mods... Headers vs stock manifolds, Cam, Heads... ect..
* Maxing out fuel system.. Too small of Injectors or pump and you will not get enough fuel resulting in KR and again less timing.
In a FI car, Usually a Low compression setup will have Higher boost levels.... resulting in lower timing advance
S
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
ALOT of factors.. Just to name a few:
* Boost Level, Lower boost will accept more timing (traditionally)
* Compression
* TUNE... if the rest of the tune is junk, you will get KR before you maximize the Timing.
* Mods... Headers vs stock manifolds, Cam, Heads... ect..
* Maxing out fuel system.. Too small of Injectors or pump and you will not get enough fuel resulting in KR and again less timing.
In a FI car, Usually a Low compression setup will have Higher boost levels.... resulting in lower timing advance
S
* Boost Level, Lower boost will accept more timing (traditionally)
* Compression
* TUNE... if the rest of the tune is junk, you will get KR before you maximize the Timing.
* Mods... Headers vs stock manifolds, Cam, Heads... ect..
* Maxing out fuel system.. Too small of Injectors or pump and you will not get enough fuel resulting in KR and again less timing.
In a FI car, Usually a Low compression setup will have Higher boost levels.... resulting in lower timing advance
S
So would you think my car has a problem if it takes 23*timing to run its best at the track on 16lbs of boost with lots of meth? I always here everyone say dont put more that 17 in a boosted setup?
Safety Car
Joined: Jun 2004
Posts: 4,353
Likes: 22
From: Bella Vista Ca
I've ran mine up to 21 advance at a little over 20lbs of boost with no knock on the dyno and at the track (lots of meth and 93). I didn't leave it there though. I've ran mine a lot at 18 deg. My compression is about 9.6.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
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Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
I've ran mine up to 21 advance at a little over 20lbs of boost with no knock on the dyno and at the track (lots of meth and 93). I didn't leave it there though. I've ran mine a lot at 18 deg. My compression is about 9.6.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
We must have a good tune and build to get away with that much timing .
Drifting
Joined: Sep 2003
Posts: 1,726
Likes: 18
From: Brighton, MI
Given the same conditions as a high compression motor yes....
Even a cam'd engine can take more timing down low and less timing up top.. it depends on cylinder pressure.. the higher the cylinder pressure the less timing.
Usually you will see that vehicles with VVT tend to detonate easier... You augment cylinder pressure (torque output) you then need less timing to get the same or more power.
Timing can inherently be more efficient at a certain point in certain configurations... for the ls1 and 3.62 stroke, it appears to be somewhere in the 26-28 degrees... if you correctly design an engine (cam events, compression, fuel or boost) to run at that timing given the conditions you will get a very smooth power delivery a very smooth graph and more power out of the engine for a given configuration.
Even a cam'd engine can take more timing down low and less timing up top.. it depends on cylinder pressure.. the higher the cylinder pressure the less timing.
Usually you will see that vehicles with VVT tend to detonate easier... You augment cylinder pressure (torque output) you then need less timing to get the same or more power.
Timing can inherently be more efficient at a certain point in certain configurations... for the ls1 and 3.62 stroke, it appears to be somewhere in the 26-28 degrees... if you correctly design an engine (cam events, compression, fuel or boost) to run at that timing given the conditions you will get a very smooth power delivery a very smooth graph and more power out of the engine for a given configuration.
Team Owner
Joined: Jan 2007
Posts: 29,063
Likes: 1,839
From: cookeville tennessee
I've ran mine up to 21 advance at a little over 20lbs of boost with no knock on the dyno and at the track (lots of meth and 93). I didn't leave it there though. I've ran mine a lot at 18 deg. My compression is about 9.6.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
For what all its worth, I know you read a lot about 14 degrees on high boost motors making big numbers... Mine runs a lot stronger with more timing too. I'm not a pro tuner, I just have been lucky and not blown a motor up in the last 8 or so years.
The last guy that tune my car put 20 deg of timing in it said no problems, and looks like it will take more, But didn't see any need in it and pulled it back down to 15 or 16 at WOT.
Burning Brakes
Joined: Dec 2003
Posts: 1,243
Likes: 5
From: Loveland CO
It depends on where you are putting the timing. if you have supporting mods to run more timing safely then do so. more timing down low will also help spool time and the car to make TQ lower as well as better fuel efficenty. My car is NA, My tuner had me up to 26* before Knock, he backed it back down to 25*and no problems. My other car (Supercharged 3800) will go up to 23* timing under boost but with higher boost its backed down to ~18-20* at WOT, and 23+ mid RPM for better fuel economy and drivability. If you can run more timing do so. if you back it down a couple degrees it will sacrifice power for safty. generally the more mods you have the more timing you are able to run... IE Headers, Cam/Rockers, Ported Heads, Exhaust..ect..
Any good tuner will adjust KR attach rate/recover rate and how much timing retard when detination occurs so it will still be safe but also run more consistant. You can also adjust the sencetivity of the knock sensor so you can eliminte false KR from vibrations/engine noise.
S
Any good tuner will adjust KR attach rate/recover rate and how much timing retard when detination occurs so it will still be safe but also run more consistant. You can also adjust the sencetivity of the knock sensor so you can eliminte false KR from vibrations/engine noise.
S
Thread Starter
Le Mans Master
Joined: Jan 2009
Posts: 7,767
Likes: 19
From: East Texas
It depends on where you are putting the timing. if you have supporting mods to run more timing safely then do so. more timing down low will also help spool time and the car to make TQ lower as well as better fuel efficenty. My car is NA, My tuner had me up to 26* before Knock, he backed it back down to 25*and no problems. My other car (Supercharged 3800) will go up to 23* timing under boost but with higher boost its backed down to ~18-20* at WOT, and 23+ mid RPM for better fuel economy and drivability. If you can run more timing do so. if you back it down a couple degrees it will sacrifice power for safty. generally the more mods you have the more timing you are able to run... IE Headers, Cam/Rockers, Ported Heads, Exhaust..ect..
Any good tuner will adjust KR attach rate/recover rate and how much timing retard when detination occurs so it will still be safe but also run more consistant. You can also adjust the sencetivity of the knock sensor so you can eliminte false KR from vibrations/engine noise.
S
Any good tuner will adjust KR attach rate/recover rate and how much timing retard when detination occurs so it will still be safe but also run more consistant. You can also adjust the sencetivity of the knock sensor so you can eliminte false KR from vibrations/engine noise.
S
Thank you that makes sense 