Why does my car hate timing??? on a 50 trim

[dwdsm]

Finished breaking in the motor this weekend and started tuning. I have a SBR G-50 BB that should love pump gas but tunning it said otherwise. I have it on the external wastegate @20 psi and I had to pull back timing to 10 deg to get it to stop knocking.. I'm running 10.9 A/f across the board on 93 pump. (I have wideband). Does this sound correct? What's up here..Could I have got some bad gas? I also should mention that I have a SBR frontmount and my intake temps were at 80deg.

 

[zippyshoe]

Does your DSMLink estimated A/F ratio match relatively closely with what your wideband reports? This may be used to check the basic accuracy of your wideband. If you richen it up using the DSMLink RPM-based fuel sliders, are you able to get rid of the knock? How does your coolant temperature look? Have you checked your base timing with a timing light?

 

[dwdsm]

Does your DSMLink estimated A/F ratio match relatively closely with what your wideband reports? This may be used to check the basic accuracy of your wideband. If you richen it up using the DSMLink RPM-based fuel sliders, are you able to get rid of the knock? How does your coolant temperature look? Have you checked your base timing with a timing light?

I have the wideband wired into the ECU (PLX M-250). DSMLINK gets the reading from this as I have no front O2 (using O2 emulator from wideband). We richened it up from 11.5 to 10.9 to help with knock but didn't really want to go any further. Coolant temps right at 200 degrees F according to My autometer gauge. Base timing is dead on..Yes I've checked.

 

[awddsm95]

I have typically seen aroun 17-19 degrees advance on a 50trim with supporting mods on pump 93-94 gasonline with a Target AFR of 11.2 from peak torque to redline. With the addition of Meth/water injection i have seen up to 23 degrees advance with the same setup and AFR. If I were you I would check your base timing and make sure that it is set right mechanically. Where are you getting the most knock and about how much. I would guess that you are seeing knock from about 5250 rpms and up, and once it starts it keeps getting worse. Are you about 7 counts?

 

[awddsm95]

PM me if you have any particular questions

 

[dwdsm]

I have typically seen aroun 17-19 degrees advance on a 50trim with supporting mods on pump 93-94 gasonline with a Target AFR of 11.2 from peak torque to redline. With the addition of Meth/water injection i have seen up to 23 degrees advance with the same setup and AFR. If I were you I would check your base timing and make sure that it is set right mechanically. Where are you getting the most knock and about how much. I would guess that you are seeing knock from about 5250 rpms and up, and once it starts it keeps getting worse. Are you about 7 counts?

I'll recheck base timing. I was thinking I could get at least 16 degrees advanced timing but no only 10.
The knock was starting around 4,800 rpms and up... And yes it does get worse. The most I saw was 6 counts.

 

[dwdsm]

I think I'll also check for a boost leak, replace my pcv, And try getting some different gas other than the BP gas by my house. Actually now that I think about it I was getting some leakage around my new oil fill cap and blew out my brand new dipstick but only one time..Hmmm to much crank case pressure causing this??

 

[daren_p]

While most have to pull timing when trying to run 20+ on pump when your running aftermarket cams, only seeing 10 deg by redline is pretty low. Sounds like you have forged internals, otherwise I would recommend to lower the boost until you get the issue sorted out. What is the comp ratio now? How much timing are you having to pull on the sliders? Have you tried to add abit more fuel, maybe low 10 air/fuel & seen if you can add some timing back in? Have you verified your base timing & is it now adjustable with the motor swap? Add a boost leak test to your list ofthings to do & go from there.

I have to pull timing as well to run my 3052 at 20 psi (4 deg, with mid rpm range sliders) but am still seeing 14-15.4 deg by redline.

 

[SBR Chris]

Dave,

How many miles are on your new motor? Have the rings even had a chance to seat?

Chris
SBR

 

[dwdsm]

While most have to pull timing when trying to run 20+ on pump when your running aftermarket cams, only seeing 10 deg by redline is pretty low. Sounds like you have forged internals, otherwise I would recommend to lower the boost until you get the issue sorted out. What is the comp ratio now? How much timing are you having to pull on the sliders? Have you tried to add abit more fuel, maybe low 10 air/fuel & seen if you can add some timing back in? Have you verified your base timing & is it now adjustable with the motor swap? Add a boost leak test to your list ofthings to do & go from there.

I have to pull timing as well to run my 3052 at 20 psi (4 deg, with mid rpm range sliders) but am still seeing 14-15.4 deg by redline.

I do have forged internals but I thought that would create less hot spots meaning more boost and timing?? I have Ross 8.5:1 pistons .20 over and Pauter rods. I had to pull a max of 6 degrees of timing on the sliders. I didn't try going any richer because I'm waiting for the ACEs to run through the system. (ACEs is a perrin octane and will raise my octane to 102, my buddy works for the corp.) It will richen things up a bit. I checked base and it was perfect 1,000 miles ago.

 

[dwdsm]

Dave,

How many miles are on your new motor? Have the rings even had a chance to seat?

Chris
SBR

Ahhhh Chris, Yup I used the breakin method that Adam, (I think that's his name...the guy that build my bottom end) gave me. On start up held @ 2,500 RPMs untill hot. Let it heat soak. Drove it on Reg oil now for over 900 miles, (changing it frequently). Break in was on 10lbs. of boost. Driving it hard. OK OK i cut it 100 short of the 1,000 miles I was supposed to but come on...who can wait that long! I'm still not going on synthetic for another few 100. The rings should be seated by 900 miles.

 

[scottsee]

Weird.. Do you have a log or thread on www.DSMlink.com/forums with a log?

 

[daren_p]

I do have forged internals but I thought that would create less hot spots meaning more boost and timing?? I have Ross 8.5:1 pistons .20 over and Pauter rods. I had to pull a max of 6 degrees of timing on the sliders. I didn't try going any richer because I'm waiting for the ACEs to run through the system. (ACEs is a perrin octane and will raise my octane to 102, my buddy works for the corp.) It will richen things up a bit. I checked base and it was perfect 1,000 miles ago.

Reason I was commenting on the forged internals is that low of timing creates extra heat, which isn't a good thing for stock internals but not so bad once you go forged. Was thinking maybe you upped the compression, which is why you were seeing knock, but that doesn't seem to be the case. Where are you pulling 6 deg, the whole rpm range? How much knock are you seeing & how often? What are your coolent temps & what are your intake temps?

A log would really help.

 

[dwdsm]

Reason I was commenting on the forged internals is that low of timing creates extra heat, which isn't a good thing for stock internals but not so bad once you go forged. Was thinking maybe you upped the compression, which is why you were seeing knock, but that doesn't seem to be the case. Where are you pulling 6 deg, the whole rpm range? How much knock are you seeing & how often? What are your coolent temps & what are your intake temps?

A log would really help.

I started to pull timing at 4,500 and pull more as the rpm's go up. the most knock is in the last 2,000 rpms so that's where the 6 deg are being pulled. I looked at my log last night and I'm hitting almost 12deg of timing in the last 1,000 rpms or so. I saw like .5 and then it worked it's way to 6 counts of knock as the rpms went up. coolant 200deg. intake temps 80. but I need to look at the log again..I'm trying to load it on here..I need to get it off the laptop first, (it's old as hell).

 

[dwdsm]

I'm still thinking I got some bad gas..

 

[daren_p]

I started to pull timing at 4,500 and pull more as the rpm's go up. the most knock is in the last 2,000 rpms so that's where the 6 deg are being pulled. I looked at my log last night and I'm hitting almost 12deg of timing in the last 1,000 rpms or so. I saw like .5 and then it worked it's way to 6 counts of knock as the rpms went up. coolant 200deg. intake temps 80. but I need to look at the log again..I'm trying to load it on here..I need to get it off the laptop first, (it's old as hell).

So you are having to pull 6 deg of timing in the upper rpm sliders & you are still getting 6 deg knock retard? (or is that a raw knock count number your stateing?) If you are seeing 6 deg retard & have still pulled 6 deg in that area @ 20 psi, I would say somethings not right. Your coolent temp is good but looks like you'll still lose some timing because of the inlet temp. If you haven't done a boost leak test yet, I'd get that done first. As you mentioned it may be some bad gas, so see what heppens next tank or get some NOS racing octane booster & see what happens.

 

[zippyshoe]

Is your knock sensor fairly new and is it torqued to spec? From what I understand, the knock sensor can be finicky about being tightened to the correct torque. If the knock sensor is in good condition (no oozing from the back of the sensor) and torqued properly, then the signal from the knock sensor should be reliable and this potential problem can be ruled-out.

Also, have you had a chance to check your A/F ratio reported by your wideband O2 against DSMLink's estimated A/F ratio (DSMLink calculates this value based on injector pulsewidth, RPM's, and mass airflow)? This could confirm the accuracy of your wideband.

 

[dwdsm]

So you are having to pull 6 deg of timing in the upper rpm sliders & you are still getting 6 deg knock retard? (or is that a raw knock count number your stateing?) If you are seeing 6 deg retard & have still pulled 6 deg in that area @ 20 psi, I would say somethings not right. Your coolent temp is good but looks like you'll still lose some timing because of the inlet temp. If you haven't done a boost leak test yet, I'd get that done first. As you mentioned it may be some bad gas, so see what heppens next tank or get some NOS racing octane booster & see what happens.

I'll make it a little more clear. After pulling 6deg (from stock timing) I now have no knock with the current tune. I like to tune for 0 knock because better safe then sorry. How could I lower my intake temp?? I have a 6" duct running from the front bumper to the filter...it's almost like ram air.
I am going to get a new knock sensor next week to be sure. (the one I have could have 130,000 miles on it for all I know) ..And like I said before DSMlink logs my wideband so that's not the issue.

 

[daren_p]

I'll make it a little more clear. After pulling 6deg (from stock timing) I now have no knock with the current tune. I like to tune for 0 knock because better safe then sorry. How could I lower my intake temp?? I have a 6" duct running from the front bumper to the filter...it's almost like ram air.
I am going to get a new knock sensor next week to be sure. (the one I have could have 130,000 miles on it for all I know) ..And like I said before DSMlink logs my wideband so that's not the issue.

Oh, okay remove 6 deg & not see knock, that sounds a little more resonable then what I origionally thought you said. As for the knock sensor before you go spending money on a new one I would verify if the knock is real or not. Add some timing back in to where you see some knock & then richen the fuel up & see if the knock dissapears (or run some race gas or octane booster). If this clears it up, then you have legit knock (unless the knock sensor is torqued improperly & is more sensative to knock). There are a bunch of things you can do before you go buying parts but you need to get the basics checked out that are listed above to rule different areas out. Just to note, it is normal to have to pull timing once you start running aftermarket cams on pump gas.

 

[dwdsm]

OK thanks for all the imput...The knock did come back when we added timing back to it with a 11.4 A/F and then goes away by giving it some fuel 10.9, then retarding the timing a bit. Would that be the same as running it super rich with the stock timing? I'll check on the tourque and if memory serves me right it's one of the few things I didn't check tourque. It could be a little sensitive. so again thanks for the imput! I wish I could give you some REP points but that system is long gone...

 

[scottsee]

I know from experience something as simple as having a miss-gapped plug can really destroy a tune. Any other symptoms, or odd issues in fuel delivery or ignition?

 

[dwdsm]

Hmmmm Just put in new plugs and checked all gaps...I have full -6an line from tank up, fuel pressure good, My Buschur COP was messing up before the tune so it was changed...I need to try again, I have a full tank run through with ACES and the car seems much richer now. I'll keep you posted.

 

[olmytsi]

I run 22 psi on my 50 trim with a 6 bolt/2g pistons combo and i had to pull the timing back as well but only up top. I'm using bpr7es gapped at .28 and stock ignition.

My settings are as follows:

2.5k to 4.5k +3 (made a big difference in off boost/spool up response) I also leaned it out a good amount in that range.
5k +1
5.5k 0
6k -3
6.5k to 8k -2

With those settings, im running a peak of 14 degrees from 6500 up. The car will still knock at the top of 4th from time to time. I run 93 octane from bp and sunoco and my plx m300 logged shows 11.2-11.5 til 5000 and then i have it going gradually richer as rpms go up (had to do it to keep knock down).

Every car is different but i just wanted to show you what i had to do to keep knock down.

Definitely check your knock sensor torque specs and boost leaks. Boost leaks will cause knock since your turbo works harder to create a given amount of boost which = more heat.

ps: coolant temps make a big difference in knock threshold. I went from a stock thermostat (1g) to a 160 degree thermostat and that brought my coolant temps down. They used to over around 200 driving and 206-210 at idle and now they are right around 190 cruising and 200 at idle in hot summer weather. In the winter, temps were like 160 (so i had to add an offset in dsmlink for the ecu to go in low enrichment mode).

 

[dwdsm]

I just think my car doesn't like timing...I'm going to run her tomorrow at the track and see what she does...It doesn't seem to want to be leaned out or given timing but the logs look nice and smooth...
I don't know may be this is just how she wants to run.

 

[SBR Chris]

Come on now dave, everyone wants to hear how you ran!