Timing pulled-NO KNOCK!! Bad CAS?

[sweet97]

I am having timing pulled without knock occuring. This is at higher rpm's(6k-up) at 3/4 throttle. Would/could this be a bad CAS or should I look elsewhere? The base timing is set on 5*. I do have a KEYDIVER chip with extended maps. I have been in contact with Jeff @ DSMchips also. Suggestions? Thanks guys, Mark
PS: The timing is being pulled to 10* and lower!!

 

[RossY]

Do you have a log that says there isn't knock? It could be a bad knock sensor. I know when mine was takin a crap it would just randomly tell me i had knock and pull timing.

 

[andymoraitis]

Do you have a log that says there isn't knock? It could be a bad knock sensor. I know when mine was takin a crap it would just randomly tell me i had knock and pull timing.

Mark,

I agree with this and would check to make sure the CAS is working properly. After over 12 years in service, my inclination would be to verify that the knock sensor is working correctly and that it's torqued properly. Make sure there isn't a bunch of goo on it when you remove it as that would indicate that it's shot then move on to the CAS.

Also have you had any luck getting a log with your friend's palm?

Hope that helps,

Andy

 

[sweet97]

The knock sensor is 3 months old. CAS is OK. I have confirmed with KEYDIVER that he put a high map into the last chip because i WAS PLANNING TO RUN A BIG TURBO WITH 25+psi ON Pump. What that does is drop the timing to 10* depending on airflow. He has sent a new chip that will not go below 18* after 6000rpm's. Also set it for a 10.8:1 A/F because that is what my motor likes best so tuning will be even easier. I am flowing 3200Hz at redline. My boost is around 25-27PSI on a Holset HX-35/40 which is capable of 73lbs/min so it flows a lot. I may back the boost to 22/23 psi and probably make more power with the 18* timing even with a few psi less. mark

 

[andymoraitis]

Mark,

I'd give it a shot like you recommended and keep going until you see five counts of knock in third on a full pull. Once you hit that point, take it down one or two psi until you only see three and that'll be your sweet spot (no pun intended). I'm anxious to find out how the new chip works for you. It looks like between you and I, Jeff is having a pretty busy weekend.

Let me know how it all turns out.

Andy

 

[mirkoelek]

can anyone tell what means "pulled timing" , i still cant figure it out.... i have dsmlink , i can check pretty much anything with this thing .... but i dont know how to analyse timing and how to set it up...how much my timing is pulled..... is good or not... how to fix it.... i would say thank you to anyone who can clear this up for me ....

im sorry to interupt this tread

 

[sweet97]

Mark,

I'd give it a shot like you recommended and keep going until you see five counts of knock in third on a full pull. Once you hit that point, take it down one or two psi until you only see three and that'll be your sweet spot (no pun intended). I'm anxious to find out how the new chip works for you. It looks like between you and I, Jeff is having a pretty busy weekend.

Let me know how it all turns out.

Andy

Yeah Andy I tune for a few counts. I do believe a few less pounds of boost and the more aggressive timing will make more power. Since me current chip is just a month old if that Jeff did not charge for the new one, definitly a class guy. Gave me a lot of tips and wants to see my car run well. Very cool! I'll keep you posted. Mark

 

[sweet97]

can anyone tell what means "pulled timing" , i still cant figure it out.... i have dsmlink , i can check pretty much anything with this thing .... but i dont know how to analyse timing and how to set it up...how much my timing is pulled..... is good or not... how to fix it.... i would say thank you to anyone who can clear this up for me ....

im sorry to interupt this tread

Mirkoelek, no problem jumping in! We're all here to learn(most of us anyways!). Pulled timing is as I understand it a condition where the ECU sees knock and to protect the motor it "Pulls the timing BACK" which saves the motor but results in less power. I am not familiar with 2G's and link but usually 2g's don't show knock but you can see if the timing does NOT continue to rise with RPM's as it should(Under WOT the timing should rise with rpm's). That would indicate a rpm range that may require some extra fuel to eliminate the knock so you keep making power. Hope this helps some. Andy has a 2G and could perhaps help a bit more. Mark

 

[andymoraitis]

Mirkoelek, no problem jumping in! We're all here to learn(most of us anyways!). Pulled timing is as I understand it a condition where the ECU sees knock and to protect the motor it "Pulls the timing BACK" which saves the motor but results in less power. I am not familiar with 2G's and link but usually 2g's don't show knock but you can see if the timing does NOT continue to rise with RPM's as it should(Under WOT the timing should rise with rpm's). That would indicate a rpm range that may require some extra fuel to eliminate the knock so you keep making power. Hope this helps some. Andy has a 2G and could perhaps help a bit more. Mark

Mark,

The basis of what you have there is absolutely right. The 2G ECU can only read knock if you use an EPROM ECU with a Keydiver stage III or DSM Link. The only way to "see" it on a logger is to watch for areas where the timing goes up and down.

Mirkoelek,

Timing being pulled is exactly what Mark said above. The ECU will see knock PAST 7 counts (on a 2G) and for every additional count it will pull timing, or lower it, to keep the motor safe. In some cases this is something you can physically feel and the car will flatten out, depending on how much timing is being removed to keep the motor from hurting itself. In general there are a few ways to tune out of knock:

1. Add more fuel where the logger shows timing being pulled
2. Cool the intake charge with methanol injection or a larger FMIC
3. Add higher octane to control the burn rate of the fuel and make it less likely to cause knock.

I'm not a big fan of adding more fuel volume unless it's absolutely necessary and the key to running a strong amount of timing and boost is to have a fuel system that can deliver what's needed and an intercooler system that can keep the air charge temperatures cool enough. I don't have DSM Link, but you may want to get onto their user forums since they can tell you how to read the knock counts and adjust the timing maps.

Let me know if that makes sense.

Andy

 

[dnhieu]

in the last couple of days you guys have explained the base of tuning and i understand it alot more now. thanks guys and keep the info comming

also andy what are you running to control your fuel?i dont belive i seen in your profile.

 

[andymoraitis]

in the last couple of days you guys have explained the base of tuning and i understand it alot more now. thanks guys and keep the info comming

also andy what are you running to control your fuel?i dont belive i seen in your profile.

I'm really glad we're all helping out! To answer your question, I ONLY use an EPROM ECU with a Keydiver stage III. I have some custom maps in it that pretty much eliminate the need for an AFC. Jeff at DSM Chips has been awesome in helping me tweak parameters and at the moment, here's what's in the chip:

1998 GSX M/T
11.7:1 A/F Ratio
23 Degrees Timing Advance
Octane Reset
No Fuel Cut
95 CAS Codes (for compatibility with the 97+ CAS)
7500 RPM Rev Limit
No Fuel Cut
550cc Injector Compensation (180 deadtime)
Boost Gauge Measures Knock

At the moment, we're working on some NLTS codes that will allow me to launch with boost on the line. My speed sensor doesn't work so the traditional stutterbox would engage with the car moving and by splicing into the clutch wire and tweaking the codes, I should be able to get my 60' times down from 1.70's into the mid 1.6's or so. I would have to say that the chip has made huge improvements and just be getting the timing and A/F where they needed to be, she's gone from a 14.0 at 100 to a 12.78 at 106.50. I run this daily at 21-22 psi on a mix of Citgo 110 and 93 and I only see 2-3 counts of knock depending on how cool the air is. Once I replace my 1G BOV with something that will hold 25-26 psi, I'll track it with race gas only and see if she can't run a mid 12 before I add cams. The eventual goal is to run in the 12.1 to 12.2 range as a daily driver without weight reduction.

Good stuff eh?

Andy

 

[dnhieu]

damn you ran a 12.7 with just a keydriver chip. thats awsome! did you just keep trying chips untill you found the one just right for your setup? dont the keydriver chips come still needing a little tuning to run a little faster? from what i understood is that he programs them a little rich (like stock), is this true?

thanks andy

 

[andymoraitis]

damn you ran a 12.7 with just a keydriver chip. thats awsome! did you just keep trying chips untill you found the one just right for your setup? dont the keydriver chips come still needing a little tuning to run a little faster? from what i understood is that he programs them a little rich (like stock), is this true?

thanks andy

No problem! It is a bit unusual to run that well on a chip only and nothing else to correct with. I don't advise it for everybody and even Jeff recommends an AFPR or an AFC to tune with if you need to lean or richen it a little bit.

We came to these settings after analyzing the results from my 14.0 passes at 100. I could crank the boost from 17-22 psi and she'd never knock and always blow black smoke. I got in touch with Dave Buschur and also with Jeff and both of them said she'd never be fast on a 9.5:1 A/F. So we started working with leaner A/F ratios and more timing. As it turns out, past a certain point, the A/F didn't make THAT much of a difference but the timing did.

As an example, I ran few similar chips with very different results over the last few weeks:

11:1 at 23 advance - 12.82 at 106.10
11.7:1 at 19 advance - 13.0 at 104.90
11.7:1 at 23 advance - 12.78 at 106.50

In the quest for power, timing, big boost and a lean enough air fuel make the best combination. I have ALL of the same parts I had when I was running 14.0's except for a DejonTool sidemount so it's all in how you put the combination together. What's interesting is that even though I leaned the A/F, taking away timing really slowed me down. I'm not sure where my maximal limits are and the car is still heavy, but for what it has in it, I'm impressed with how well it's done thus far. I'm sure there's more in the tune and Jeff and I will likely be playing with a few more options.

Maybe a 12:1 with 26 degrees on race gas only would be cool, but then again it may stress the motor for a minimal gain. As I mentioned above, I think the current tune is solid and I need to run 25-26 psi on it before asessing it further, which means I need to fix the current BOV arrangement since it keeps leaking above 21-22.

Whew!

Andy

 

[sweet97]

KEYDIVER can set up any A/F you want for a base. My new chip will have a 10.8:1 A/F programmed in along with a minimum of 18* advance above 6000 rpm's. I run straight 93 octane and the richer A/F works best.
I will back my boost from it's current 25-27PSI and start wikth 18PSI and go in 2 psi increments until I find the best setting. I figure a few psi less with the 18* from my current 10* advance will produce more power.
Andy I suggest you look into the Forge BOV. It is a work of art, very attractive and comes with 4 adjustment springs and 2 shims for fine tuning. I will PM you a very helpful vendor, I highly recommend him. I will also post my results with the new chip as 106MPH has been my best 1/4 speed. mark

 

[dnhieu]

No problem! It is a bit unusual to run that well on a chip only and nothing else to correct with. I don't advise it for everybody and even Jeff recommends an AFPR or an AFC to tune with if you need to lean or richen it a little bit.

We came to these settings after analyzing the results from my 14.0 passes at 100. I could crank the boost from 17-22 psi and she'd never knock and always blow black smoke. I got in touch with Dave Buschur and also with Jeff and both of them said she'd never be fast on a 9.5:1 A/F. So we started working with leaner A/F ratios and more timing. As it turns out, past a certain point, the A/F didn't make THAT much of a difference but the timing did.

As an example, I ran few similar chips with very different results over the last few weeks:

11:1 at 23 advance - 12.82 at 106.10
11.7:1 at 19 advance - 13.0 at 104.90
11.7:1 at 23 advance - 12.78 at 106.50

In the quest for power, timing, big boost and a lean enough air fuel make the best combination. I have ALL of the same parts I had when I was running 14.0's except for a DejonTool sidemount so it's all in how you put the combination together. What's interesting is that even though I leaned the A/F, taking away timing really slowed me down. I'm not sure where my maximal limits are and the car is still heavy, but for what it has in it, I'm impressed with how well it's done thus far. I'm sure there's more in the tune and Jeff and I will likely be playing with a few more options.

Maybe a 12:1 with 26 degrees on race gas only would be cool, but then again it may stress the motor for a minimal gain. As I mentioned above, I think the current tune is solid and I need to run 25-26 psi on it before asessing it further, which means I need to fix the current BOV arrangement since it keeps leaking above 21-22.

Whew!

Andy

when he programs a timing advace in the chip does this mean that you reach your desired timing advance at full boost? or at red line? also, why dont you get a safc 2 andy?
im really interested in these keydriver chips but dont really have the money for one right now because im rebuilding my motor.

thanks for the help
david

 

[andymoraitis]

David,

Timing maps actually work the best when they ramp in a gentle curve as opposed to a large spike at full boost. Jeff's maps are more gradual, but they reach the peak a little before redline.

As far as the AFC, I don't have one because I don't need it. I can tune based on knock values and add octane to get to my sweet spot based on boost and ambient temperature. It's a little bit more tricky, but since I have the chip, A/F and timing are mapped for me and I'll never need to play with those. At this point, it's an effort to try and maximize boost and see what I can squeeze out of her.

Let me know if that makes sense,

Andy

 

[andymoraitis]

Andy I suggest you look into the Forge BOV. It is a work of art, very attractive and comes with 4 adjustment springs and 2 shims for fine tuning. I will PM you a very helpful vendor, I highly recommend him. I will also post my results with the new chip as 106MPH has been my best 1/4 speed. mark

Thanks for the link Mark! That Forge unit looks great and it'll recirculate which is just what I need. I really appreciate the info.

Andy

 

[dnhieu]

David,

Timing maps actually work the best when they ramp in a gentle curve as opposed to a large spike at full boost. Jeff's maps are more gradual, but they reach the peak a little before redline.

As far as the AFC, I don't have one because I don't need it. I can tune based on knock values and add octane to get to my sweet spot based on boost and ambient temperature. It's a little bit more tricky, but since I have the chip, A/F and timing are mapped for me and I'll never need to play with those. At this point, it's an effort to try and maximize boost and see what I can squeeze out of her.

Let me know if that makes sense,

Andy

you not having a need for afc makes sense. you add the correct amount of race gas with you premium with every fill up. correct?

as far as the timing map is concerned, instead of reaching full boost and timing all at once you will reach full boost and slowly build your timing? so with with your chip set for a 23 timing advance you will never see anything past that 23 degrees of timing advance? also what about marks chip that will not let him see anything below 18 degrees of timing advance. does this mean that his car can see in upwards of 20-30 timing with out anything stopping him but himself? also if he sees anything past 4 counts of knock and timing starts to get pulled, will it not go below 18 timing advance still?

sorry if these questions seem dumb and thanks for the help
david

 

[sweet97]

David the only dumb ? is the one you don't ask! My new chip will keep the timing at 18*, no lower, at WOT as long as there is NO knock. New chip will also have a 10.8:1 A/F burned in, again at wot. My translator, AFPR can change that though. KEYDIVER diud that just to make tuning a bit easier for me as I won't have to make as many changes to change the A/F that my motor likes. Remember you would need an EPROM ECU that had ben socketed for a KEYDIVER chip. You can search for EPROM ECU. Lots of info out there. Some 1G's and most '95's came with EPROM ECU's. '95 being a 2G car.
OH, my 18* is for 6k rpm's and above. Under that it may be lower and timing advances with rpm's usually. I may see 14* at 4500-5000rpm's as an example. Mark

 

[dnhieu]

David the only dumb ? is the one you don't ask! My new chip will keep the timing at 18*, no lower, at WOT as long as there is NO knock. New chip will also have a 10.8:1 A/F burned in, again at wot. My translator, AFPR can change that though. KEYDIVER diud that just to make tuning a bit easier for me as I won't have to make as many changes to change the A/F that my motor likes. Remember you would need an EPROM ECU that had ben socketed for a KEYDIVER chip. You can search for EPROM ECU. Lots of info out there. Some 1G's and most '95's came with EPROM ECU's. '95 being a 2G car.
OH, my 18* is for 6k rpm's and above. Under that it may be lower and timing advances with rpm's usually. I may see 14* at 4500-5000rpm's as an example. Mark

unfortunately i am one of the 1g's without an eprom ecu. would you guys consider this one of the best mods you can do because you can chip it and get things like studder box,no fuel cut, rev to 8k, and lets not forget how easy it is to tune? also everytime you add a new part are you having to buy a new chip to accommodate for it?

thanks again
David

 

[sweet97]

David have you had your ECU open too be sure it's not an EPROM?
Once you start to mod your car you will find limitations to the common tuning devices, AFC's, MAF-T's, etc. They will usually only tune up to 650cc inj's and the further the size moves from the stock inj's the harder it gets as the timing also changes with the fuel chenges as these tuning devices trick the ECU as to the amunt of air entering the motor so less air means less fuel but more timing. Other options are very helpful like raising the rev limit so if you have a built motor you can rev higher, the stutterbox launch, the forementioned inj compensation, octane reset, etc. Also DSMlink requires an EPROM ECU if you want to go that route someday. The prices are also rising on the EPROM's. I got mine from FFWD for $330. socketed and now they are getting $400. With my big turbo, 750cc's and high boost I could not tune without the chip.
Then look at Andy's accomplishments with less mods, a high 12!!
You will not need a new chip for every new option. Injector changes, yes. 3" exhaust, no. It's a great tuning tool and KEYDIVER adds options along the way! mark

 

[dnhieu]

David have you had your ECU open too be sure it's not an EPROM?
Once you start to mod your car you will find limitations to the common tuning devices, AFC's, MAF-T's, etc. They will usually only tune up to 650cc inj's and the further the size moves from the stock inj's the harder it gets as the timing also changes with the fuel chenges as these tuning devices trick the ECU as to the amunt of air entering the motor so less air means less fuel but more timing. Other options are very helpful like raising the rev limit so if you have a built motor you can rev higher, the stutterbox launch, the forementioned inj compensation, octane reset, etc. Also DSMlink requires an EPROM ECU if you want to go that route someday. The prices are also rising on the EPROM's. I got mine from FFWD for $330. socketed and now they are getting $400. With my big turbo, 750cc's and high boost I could not tune without the chip.
Then look at Andy's accomplishments with less mods, a high 12!!
You will not need a new chip for every new option. Injector changes, yes. 3" exhaust, no. It's a great tuning tool and KEYDIVER adds options along the way! mark

yeah the other day i thought my ecu was messing up so while i had it out i looked to see if it was an eprom and it isnt. i have been waiting for a deal to come along for an eprom but i cant seem to find one. i always seeing them on ebay for like 250 bucks and right now with money being stiff i cant get one. i did not know FFWD sold eproms? what i was thinking was buying a bad ecu and having someone like steve rebuild it. what do you think of this? are all eproms able to be rebuilt or will some be so damaged this isnt possible?

thanks
david

 

[sweet97]

The only place I would buy a used EPROM from would be a yard. Of course some would be beyond repair though usually new caps do the job. I did not check your mods but start with the basics first. mark

 

[andymoraitis]

David,

Sorry for not jumping back in here sooner. Mark did a great job of answering your questions, but as far as the timing is concernered, the beauty of ECU maps are that the timing never exceeds a certain point in the presence of no knock. So technically, the max I will see is 23 advance, but if I'm knocking it will still pull timing. The maps in Mark's old chip are designed to go the other way; to lower timing in the presence of high boost on pump gas. His new one will have a max of 18 advance, but if he's knocking, that too will pull timing. So either way, the chip allows each of us a maximum, but it can still be retarded once the knock sensor picks up a certain amount of knock to keep the motor safe.

In essence, my "fuel tuning" becomes a little dance with octane. It may seem unscientific, but I know what the car needs to run 22 psi daily on a small intercooler, an 11.7:1 A/F and 23 degrees of advance. If I ever get to a point where I'm not tripping knock, turning up the boost a bit more, provided I have a BOV that doesn't leak, will get me back to that three counts of knock tuning sweet spot. If I were to do that with an AFC, I might be adding more timing than I need considering that 23 is already plenty of advance.

Let me know if that helps,

Andy

 

[andymoraitis]

yeah the other day i thought my ecu was messing up so while i had it out i looked to see if it was an eprom and it isnt. i have been waiting for a deal to come along for an eprom but i cant seem to find one. i always seeing them on ebay for like 250 bucks and right now with money being stiff i cant get one. i did not know FFWD sold eproms? what i was thinking was buying a bad ecu and having someone like steve rebuild it. what do you think of this? are all eproms able to be rebuilt or will some be so damaged this isnt possible?

thanks
david

Get in touch with Jeff Oberholtzer at DSM Chips. He usually has some of these on hand and he's already checked them out and socketed them. You can reach him at [email protected].

Have a great day!

Andy