advancing timing at high rpm?
11-16-04, 11:47 AM
#76
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This is a 3 BAR base map I'm currently running. I'm only running 11.42 psi now, awaiting tuning. Any input on these timing settings (too conservative, too risky, etc.)? If so, what changes are recommended?
Last edited by Roy Johnson Jr; 11-16-04 at 11:55 AM.
11-16-04, 01:43 PM
#78
Originally Posted by rx7tt95
One thing that isn't discussed is exhaust gas temps. RETed said, in a nutshell, that one should calibrate your EGT guage on the dyno with a wideband to know what is "normal" as different EGT guages will read differently on the same car and vice versa.
I am seeing EGT's at about 1000C at WOT on the dyno in 4th, 15 degrees leading adv., 7 degrees split with an a/f ratio of 11:1 or thereabouts. Wondering if I should be reducing my leading or increasing my split to lower EGT's (or will that just raise them?).
I am seeing EGT's at about 1000C at WOT on the dyno in 4th, 15 degrees leading adv., 7 degrees split with an a/f ratio of 11:1 or thereabouts. Wondering if I should be reducing my leading or increasing my split to lower EGT's (or will that just raise them?).
How much boost are you running and at what RPM are you hitting 15 degree advance? You can drop the timing down a few to bring the EGT's down.
Jason
11-16-04, 01:53 PM
#79
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those timing map looks familiar...
Originally Posted by Roy Johnson Jr
This is a 3 BAR base map I'm currently running. I'm only running 11.42 psi now, awaiting tuning. Any input on these timing settings (too conservative, too risky, etc.)? If so, what changes are recommended?
11-16-04, 04:04 PM
#81
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I wouldn't change anything on the timing map.
Will you be modifying them any or will they stay as they are when you tune my car?
Originally Posted by Roy Johnson Jr
Will you be modifying them any or will they stay as they are when you tune my car?
02-03-05, 12:30 PM
#82
Senior Member
EGT's
"while EGTs remain in a safe zone..."
can anybody quantify this statement? <800C is good <950C is good etc...
what is the limiting factor in this temp. apex warpage? preheats next charge? unsafe rotor face temps heating oil?
if someone is having "unsafe" temps is reducing the leading advance the best thing to do. i thought that retarded timing was the cause of high EGT's due to a late combustion process?
currently i run: 13BT ported, 14deg advance, 8 deg split @15psi, 10:5-11:3 AFR's and see ~900C after a long 4-5th gear run
thanks
justin
can anybody quantify this statement? <800C is good <950C is good etc...
what is the limiting factor in this temp. apex warpage? preheats next charge? unsafe rotor face temps heating oil?
if someone is having "unsafe" temps is reducing the leading advance the best thing to do. i thought that retarded timing was the cause of high EGT's due to a late combustion process?
currently i run: 13BT ported, 14deg advance, 8 deg split @15psi, 10:5-11:3 AFR's and see ~900C after a long 4-5th gear run
thanks
justin
02-05-05, 08:17 PM
#83
Lives on the Forum
Originally Posted by pistonsuk
"while EGTs remain in a safe zone..."
can anybody quantify this statement? <800C is good <950C is good etc...
can anybody quantify this statement? <800C is good <950C is good etc...
EVERY engine is different, so one target EGT can kill another engine even with identical mods.
This is why I said to run the car on a dyno and watch the EGT gauge.
Once the engine starts going into pre-ignition, you WILL see the power drop significantly.
Note the EGT.
what is the limiting factor in this temp. apex warpage? preheats next charge? unsafe rotor face temps heating oil?
People say the oil temp gets hotter faster.
-Ted
02-05-05, 08:44 PM
#84
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Originally Posted by pluto
those timing map looks familiar...
Originally Posted by Roy Johnson Jr
This is a 3 BAR base map I'm currently running. I'm only running 11.42 psi now, awaiting tuning. Any input on these timing settings (too conservative, too risky, etc.)? If so, what changes are recommended?
TurboMark7 noticed he had the exact same timing map......on a stock port.
02-07-05, 07:11 PM
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Sure if they came from me. 
Since I probably tuned about 10% of the 3rd gen's out there. (about 250+ out of 3200 registered) I usually don't change the timing much and keep most of them the same for everyone unless I have the EGT gauge to verify it.
Since I probably tuned about 10% of the 3rd gen's out there. (about 250+ out of 3200 registered) I usually don't change the timing much and keep most of them the same for everyone unless I have the EGT gauge to verify it.
Originally Posted by Carl Byck
I'd say alot of timing maps look familiar, wouldn't you say Steve...
02-08-05, 12:32 PM
#87
Mad Man
Steve, I am a little confused as to how a ported motor, and a stock port motor would use the same timing, and be optimally tuned? I realise it's not your job to teach me all you know, just curious. If you have a moment, maybe you could post your thoughts in brief. Thanks, nice talking to you again, Carl
02-09-05, 07:03 PM
#88
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Carl,
Most of the cars I tuned are conservative for reliablilty. The cars are optimally tuned for driveability and WOT a/f ratio in most cases. Even a/f ratio vary slightly from car to car, some likes a little leaner (depending on the ignition setup) while others like richer. There maybe 10 people out of all the cars I tuned that wanted aggressive tuning. (which is why I tuned them a little towards the rich side for most cars and conservative timing). The ignition map that I use for most of the cars came from a ported motor (aggressive SP) that I tuned and reliable for a few years from testing on one of the shop car. Believe it or not, we have accidently ran as much as 40degrees in advance timing and the motor still holds doing tuning. The only thing I changed was the split timing to lower the knock #. You have to remember that 90% of detonation comes from the trailing spark. The most split you have, the safer the engine from detonation. Based on my experience, I used the same ignition map I place on most of the cars unless I have an EGT to monitor for temperature change. Every so often, I would mess with the split timing depending on how the car sounds on the dyno. Some cars require more while others require less. I have to listen to them in order to be able to tell what fits best for a particular car. In most cases, 14 degrees split is a good starting point.
Most of the cars I tuned are conservative for reliablilty. The cars are optimally tuned for driveability and WOT a/f ratio in most cases. Even a/f ratio vary slightly from car to car, some likes a little leaner (depending on the ignition setup) while others like richer. There maybe 10 people out of all the cars I tuned that wanted aggressive tuning. (which is why I tuned them a little towards the rich side for most cars and conservative timing). The ignition map that I use for most of the cars came from a ported motor (aggressive SP) that I tuned and reliable for a few years from testing on one of the shop car. Believe it or not, we have accidently ran as much as 40degrees in advance timing and the motor still holds doing tuning. The only thing I changed was the split timing to lower the knock #. You have to remember that 90% of detonation comes from the trailing spark. The most split you have, the safer the engine from detonation. Based on my experience, I used the same ignition map I place on most of the cars unless I have an EGT to monitor for temperature change. Every so often, I would mess with the split timing depending on how the car sounds on the dyno. Some cars require more while others require less. I have to listen to them in order to be able to tell what fits best for a particular car. In most cases, 14 degrees split is a good starting point.
Originally Posted by Carl Byck
Steve, I am a little confused as to how a ported motor, and a stock port motor would use the same timing, and be optimally tuned? I realise it's not your job to teach me all you know, just curious. If you have a moment, maybe you could post your thoughts in brief. Thanks, nice talking to you again, Carl
03-11-05, 12:35 AM
#89
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re: trailing split
Hi gurus...very intersting thread....no need to say.
I posted my Trailing Split Map....Open in in XL....what do you think? I am running a non sequencial with extended street port FD....
it seems to work for me...oh yes and about 16psi boost...
I posted my Trailing Split Map....Open in in XL....what do you think? I am running a non sequencial with extended street port FD....
it seems to work for me...oh yes and about 16psi boost...
03-30-05, 02:13 AM
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My goddam head hurts after reading all this........ I'm just gonna dump my car off to Dr Dave at KDR and let him **** with the timing.......
05-24-05, 11:30 PM
#99
Senior Member
Posting some more maps would be good......
Let me see if I got this right after reading all these posts.
The split won't help power too much but, will lower egt's and u want the split to about 12 as the rpms and boost go up?
Leading should dip as boost and rpm go up to max torque- then slightly go up to maybe no more than 20 stock port, 17 street port?
I try to scan my maps for u.
Let me see if I got this right after reading all these posts.
The split won't help power too much but, will lower egt's and u want the split to about 12 as the rpms and boost go up?
Leading should dip as boost and rpm go up to max torque- then slightly go up to maybe no more than 20 stock port, 17 street port?
I try to scan my maps for u.