Can't get rid of knock Need more idea's

[DJ23GSX]

I am having some knock issues at 19psi and 93 octane that i can't tune out. I am pushing my idc's close to 95% on the 560's @ 42psi bfp and still can't get rid of it. I can't seem to get knock under 12-15 counts no matter how much fuel i add or take away. My mods are in my profile. I would love to turn the boost down but thanks to the great porting from sbr it creeps to 19psi by 5k.

So far i have fixed or tried these things

1. New Knock sensor retourqued a few times with no change in knock
2. New fuel filter
3. Fixed all boost leaks (including the AFPR)
4. Raised my base fp up to 45psi
5. Different 2g mas
6. New plugs
7. Rewired the 255
8. New caps in ecu
9. Air filter box with hose plumbed with ambient air
10. Took foglight out and trimmed the i/c duct to fit the mkiv i/c better
11. Checked the fuel pump seal and cleaned the pump bag filter


I get pk when the car is cold and driving normal but it goes away after the car is warmed up. I don't think its pk i am seeing under boost though as it does go up and down if i add or take fuel away. I just can't tune it for 0 knock. It doesn't seem like i should have to add this much fuel. The next thing i would like to try is bringing my base timing down a bit. I also have a set 650's but i don't think i should need that much fuel for this set up from what i've been reading in other threads with similar mods.

 

[DJ23GSX]

Damn I would have an extra one id sell you when i sell this gst because im setting this car back to stock injectors, mass and chip before I sell it but i dont know how soon its getting sold. And this eprom is in mint condition never had leaking caps.
The awd im getting already has an eprom ecu... But anyways porting the o2 is fairly easy if you have a hand held dremel.. Take off the four bolts to the o2 housing, pull out the o2 sensor, and take off the two bolts that hold the o2 housing to the downpipe and boom there you go. And get to porting and reinstall in exact order....

I have a 90 so those eproms aren't cheap or easy to find.

I already said i ported the hell out of another 2g o2 housing and i'm waiting to put it in. Is anyone reading what i am posting here? I don't think i would ever attempt to port with a dremel. I use an air compressor with a die grider and double cut carbide burrs. They work like a charm.

I am more worried about pulling the turbo and having to port the turbine housing. I don't want to snap any bolts or studs trying to pull the turbo off.

 

[oldman]

SO WHAT!!

Again, I'm only here to correct mis-information.

Anything less than 10 counts usually wont pull timing

 

[SBR Joe]

Again, I'm only here to correct mis-information.

You are teh only one applying it as mis information. But in reality is it truth.



Joe Shuler
Slowboy Racing INC

 

[blazebolt]

I can concur that the ECU pulls timing for anything over 3 counts if I read my logs correctly. Staying under 7 counts is good.

I'm in the same boat as you, but I'm running 91oct and only 15psi on my DD with a Dejon SMIC. I believe it is heat soak as well and have heard from 2 people who switched to a FMIC, from a SMIC on very similar setups, that switching reduced their knock and let them increase their timing by 2*. I currently have it at 3 counts of knock, but I've retarded my timing to 10* via DSMLink.

 

[DJ23GSX]

You are teh only one applying it as mis information. But in reality is it truth.



Joe Shuler
Slowboy Racing INC

I'm not taking sides but timing starts getting pulled in my car around 6-7 counts of knock. With 0 knock i see 21* timing and by the time i hit 8-9 counts of knock its already down around 17-18*

Bottom line is i want to see no more than 3-5 counts of knock and i don't feel dumping a ton of fuel is the smartest way to achieve this with the heatsoak issue. This is my daily drive it's no track whore so i'll give up some hp for safety anyday.

 

[SBR Joe]

I'm not taking sides but timing starts getting pulled in my car around 6-7 counts of knock. With 0 knock i see 21* timing and by the time i hit 8-9 counts of knock its already down around 17-18*

Bottom line is i want to see no more than 3-5 counts of knock and i don't feel dumping a ton of fuel is the smartest way to achieve this with the heatsoak issue. This is my daily drive it's no track whore so i'll give up some hp for safety anyday.

True, but that also depends on the setup..and teh car. You know as well as everyone no one dsm acts the same as another. Mine that was ok doesnt mean that yours will be teh same way, but in general..anything uner 10 counts is ok, still...17-18 degrees of timing is plenty. And teh fuel wont help the heatsoak issue, but bringing the DC down will help alot with consistency and who knows, may help your knock issue.


Joe
SBR

 

[jtmcinder]

You are teh only one applying it as mis information. But in reality is it truth.

Actually, even I knew that what you were saying was nonsense. I went to click the neg-rep gizmo, but it doesn't seem to work any more. And the person with whom you were arguing didn't seem to need any backing up, given his title, so I ended up sitting here and watching the show.

But, since you asked, and because it appears that you were taking the silence of others as evidence that Bruce didn't have support, I remain lurker no more!

Anyhoo... as to the question on the last page about IDCs starting over 100% and then dropping, even after more fuel is dialed in: is it possible that, during the over-100% run, the engine was not (yet) fully warmed up?

- Jtoby

ps. another vote for a better IC; I knock in third gear of every run, even with a Dejon, and my IC is too hot to touch, even after the cruise back to the pits

 

[DJ23GSX]

Anyhoo... as to the question on the last page about IDCs starting over 100% and then dropping, even after more fuel is dialed in: is it possible that, during the over-100% run, the engine was not (yet) fully warmed up?

- Jtoby

ps. another vote for a better IC; I knock in third gear of every run, even with a Dejon, and my IC is too hot to touch, even after the cruise back to the pits

i am pretty sure it was fully warmed up on the first pull besides my second pull was literally 5 seconds after the first one. I even saw 100% on the 3rd pull as well and added 1% fuel but had more knock.

I know before i fixed my big boost leaks i was seeing my idc' start at around 90% and jump up to around 110% on the next pull without even touching my safc settings. I haven't noticed that yet after fixing the boost leaks but then again i am constantly changing my safc setting lately.

P.S.
A fmic is what i would really like but its out of reach financially

 

[nightspeed87]

I'm not taking sides but timing starts getting pulled in my car around 6-7 counts of knock. With 0 knock i see 21* timing and by the time i hit 8-9 counts of knock its already down around 17-18*

Bottom line is i want to see no more than 3-5 counts of knock and i don't feel dumping a ton of fuel is the smartest way to achieve this with the heatsoak issue. This is my daily drive it's no track whore so i'll give up some hp for safety anyday.

My chip is set up to give me 16 degrees timing advance on the top map therefore probably why I dont have the same knock issues.

P.S.
A fmic is what i would really like but its out of reach financially

I fully understand what you mean...

But check out this kit, an awsome kit for not too expensive, a large enough core that will support your goals and has everything you need to put it together including the elbow and jpipe and tbolts and couplers and also its short route... I was a actually going to get this...
http://punishment-racing.com/1gstreetcoreintercoolerkit.html

 

[GVR4592]

I got tired of reading after only a few of SBR Joe's posts. My suggestion to everybody reading this thread is to disregard everything he has said about tuning. He has absolutely no idea what he's talking about.

 

[DJ23GSX]

I fully understand what you mean...

But check out this kit, an awsome kit for not too expensive, a large enough core that will support your goals and has everything you need to put it together including the elbow and jpipe and tbolts and couplers and also its short route... I was a actually going to get this...
http://punishment-racing.com/1gstreetcoreintercoolerkit.html

I've had my eye on that kit for a while but again finanacially that would be a stretch. I have a mortgage a 2.5 year old son and a wife who spend more than she makes.

I am looking into meth injection at the moment becuase if i were to sell my extra set of injectors i would only have to put in $50-60 out of pocket. I've been doing a lot of seaching and reading on meth injection lately and i like what i've seen so far.

 

[jtmcinder]

Before you commit to some form of extra injection, you want to sit down and decide what the purpose of this system will be.

If you are merely trying to make up for an undersized intercooler, then water is what you want to inject. The specific heat of water is a heck of a lot higher than any alcohol, so it does a much better job of cooling the air.

If you are trying to add more fuel, to make up for undersized injectors, then, OK, inject alcohol. But keep in mind that pumps that can deal with alcohol are more expensive than the standard Shur-Flo pumps that many of us use for water. Plus, all simple injection systems (i.e., those in your current budget) do not take boost into account, so they inject less when you have more boost, which is the opposite of what you want.

In summary, I'm a big fan of keeping fueling and cooling separate. If you want to inject more fuel, raise your fuel pressure or get larger injectors. If you want to get the intake charge cooled, then get a bigger IC or add water injection.

Experts will probably disagree with me. I am highly biased in favor of keeping things simple and separate, which will only get you so far.

- Jtoby

 

[gixrman]

I have a very simple idea for you, this what I did when I was heat soaking my supra SMIC. Take the rear windshield washer supply line and re-route it up to your IC, hook up a somesort of spray nozzle(s) , I used 2,and direct it towards your IC. Wire the pump up so it comes on at WOT (I used a NOS switch). Very cheap, very simple. Worked verywell for me. My EVO16g would'nt do anything under 20psi and was pulling timing like crazy in the summer on hard 3rd gear pulls. I lowered knock by 7 doing this.

But I do agree adding more fuel is not the answer you only masking the problem. Doing street tuning and getting consistant results is difficult.

 

[DJ23GSX]

Before you commit to some form of extra injection, you want to sit down and decide what the purpose of this system will be.

If you are merely trying to make up for an undersized intercooler, then water is what you want to inject. The specific heat of water is a heck of a lot higher than any alcohol, so it does a much better job of cooling the air.

If you are trying to add more fuel, to make up for undersized injectors, then, OK, inject alcohol. But keep in mind that pumps that can deal with alcohol are more expensive than the standard Shur-Flo pumps that many of us use for water. Plus, all simple injection systems (i.e., those in your current budget) do not take boost into account, so they inject less when you have more boost, which is the opposite of what you want.

In summary, I'm a big fan of keeping fueling and cooling separate. If you want to inject more fuel, raise your fuel pressure or get larger injectors. If you want to get the intake charge cooled, then get a bigger IC or add water injection.

Experts will probably disagree with me. I am highly biased in favor of keeping things simple and separate, which will only get you so far.

- Jtoby

I am looking for a way to supress my knock when the heatsoak happens without having to dump $400-600 for a fmic. Like I stated before this is my daily driver no track whore. I'm not looking to run 25psi. I am sure water would do the trick for the setup currently on my car.
I think i might actually go ahead and port the turbine housing so i don't have to run 20psi all the time. That is the cheapest and probly the most logical thing for me to do right now.

I have a very simple idea for you, this what I did when I was heat soaking my supra SMIC. Take the rear windshield washer supply line and re-route it up to your IC, hook up a somesort of spray nozzle(s) , I used 2,and direct it towards your IC. Wire the pump up so it comes on at WOT (I used a NOS switch). Very cheap, very simple. Worked verywell for me. My EVO16g would'nt do anything under 20psi and was pulling timing like crazy in the summer on hard 3rd gear pulls. I lowered knock by 7 doing this.

But I do agree adding more fuel is not the answer you only masking the problem. Doing street tuning and getting consistant results is difficult.

I've read about people trying this with no positive results. It has crossed my mind a few times though.

 

[SBR Joe]

I got tired of reading after only a few of SBR Joe's posts. My suggestion to everybody reading this thread is to disregard everything he has said about tuning. He has absolutely no idea what he's talking about.

HAHAHA...riiight. Thats why my cars run well and make power...if your sandy you-know-what doesnt like the way i liek to tune things...then SHUSH. For the last time if it couldnt or shouldt be done, i wouldnt say anytghing about it, and all the things that i say or suggest were based of MUTIPLE personal accounts. So, mi friend...until you make a few cars with real power with your suggested methods...then hit me up.


joe
SBR

 

[GVR4592]

There's no point in arguing with me, it's just going to make you look stupid. Give it up.

 

[DJ23GSX]

Well i've got some more info on this thats not making too much sense to me.

First off i swapped ecu's today and now my knock isn't as bad as before. I made 5-6 pulls (2nd gear) in a row and was only seeing knock around 10-12 counts max which isn't what i want but with my other ecu after that many pulls my knock would be off the charts. My only issue is i couldn't get it under 12 counts no matter how much fuel i added or took away. I also bumped bfp up to 43psi.


Could either of these ecu's not be reading knock correctly?

 

[SBR Joe]

There's no point in arguing with me, it's just going to make you look stupid. Give it up.

If you say so.


Joe
SBR

 

[DJ23GSX]

If you say so.


Joe
SBR

Come on guys i'm having real issues here and getting some good replies for the most part i don't want to see this thread get locked cause people can't stay on topic.


Thanks

 

[tkelly27]

I've forgotten most of the rest of the thread, but I'd check at lower boost levels if you get knock. If you can't shake it with lower boost levels, or no boost at all, then there is probably something going on with the ECU's/knock sensor.

If you can get rid of it with lower boost, maybe try different gasoline? I forgot, is it a new engine? Some old engines can have lots of carbon buildup and ping real badly. If your intake cam timing is off it can raise the dynamic compression ratio and cause problems too.

Just tossing out things it could possibly be, I'm stumped

 

[DJ23GSX]

Well i just tossed in my 650's (42psi bfp) and new plugs (bpr7's) and did some more tuning. I set the boost controller to 20psi as well


I still get knock and saw 98% idc's but here's what i noticed. I can run the car up to 5.5k rpms and let off see 0 knock and idc's around 75-77% but as soon as i run it over 6k rpms the idc's shoot up over 95% and i get knock. Still around 12-14 counts and can't get rid of it with more or less fuel. I leaned the safc out to -14% @ 6-7k (idc still hovering around 90%) and knock went up i then set 6-7k to 0 and knock came down to 12 again but again same as the 560's i can't get it any lower with more fuel. I also noticed that my egt's barely hit 1400* when i run it up to 5k and let off.

I know for sure my afpr doesn't leak and i have one tiny boost leak so why does the car knock only at 6-7k rpms?? I am unsure now that its heatsoak anymore due to the fact the knock doesn't seem to get worse the more pulls i make with this new (used) ecu.

Then engine was rebuilt with all brand new stock internals with a 3 angle valve job a ported head and intake 12k miles ago.
Now when you say dynamic compression would that cause wacky compressoin reading when doing a compression test? I did a compression test a few weeks ago and got 155 on all four cylinders.

 

[nightspeed87]

Well i just tossed in my 650's (42psi bfp) and new plugs (bpr7's) and did some more tuning. I set the boost controller to 20psi as well


I still get knock and saw 98% idc's but here's what i noticed. I can run the car up to 5.5k rpms and let off see 0 knock and idc's around 75-77% but as soon as i run it over 6k rpms the idc's shoot up over 95% and i get knock. Still around 12-14 counts and can't get rid of it with more or less fuel. I leaned the safc out to -14% @ 6-7k (idc still hovering around 90%) and knock went up i then set 6-7k to 0 and knock came down to 12 again but again same as the 560's i can't get it any lower with more fuel. I also noticed that my egt's barely hit 1400* when i run it up to 5k and let off.

I know for sure my afpr doesn't leak and i have one tiny boost leak so why does the car knock only at 6-7k rpms?? I am unsure now that its heatsoak anymore due to the fact the knock doesn't seem to get worse the more pulls i make with this new (used) ecu.

Then engine was rebuilt with all brand new stock internals with a 3 angle valve job a ported head and intake 12k miles ago.
Now when you say dynamic compression would that cause wacky compressoin reading when doing a compression test? I did a compression test a few weeks ago and got 155 on all four cylinders.

Sea foam the engine and just try to get it cleaned up because carbon can raise the compression... Your running the stock piston compression ratio right? And your knock sensor is new also? Sorry if I missed that bit of info some where...
Also fix your small boost leak, my friends car had a small boost leak at the tb and it was ignored for a while considering it was small but when he fixed it he said he gained back 5% idcs just like that... So you never know, every little bit counts...
But good to hear the 650s are making the car run a little better. And what boost controller are you running, because some hold boost lower better than others... Like i said i can hold 10psi to redline on my evo3 with full 3in exhaust no cat or muffler on my gst and all i did was port out the o2 housing and I hogged it out pretty good.

If you can keep knock under 7 counts for the time being youll be alright till you get a front mount. Once the front mount goes on i think all your knock will go away and youll be able to do those pulls a lot more consistently.
Just a thought though, try running your intake pipe to cold air after you get the fmic.
Like run it into the fender well were the stock sidemount used to sit, just run it straight across with a little downwards angle instead of making it do a 90 deg bend to get it to drop down into the upper intercooler hole. This may not be much but may help some as it did on some ppls dsms. Id recommend shielding it with sheet metal or something for rain...

Other wise good luck.

 

[tkelly27]

Fix all your boost leaks

Unless you've been venting your BOV, or bumping it off the rev-limiter you're probably ok on the carbon. Sea-foam never hurt anyone though.

Dynamic CR can affect it, but it would tend to be higher than expected if it's going to lead to knock.

I tried to wade through the muck that is this thread, what gap are you running on your plugs?

Have you set your base timing yet? If you're still @ 7 and you're supposed to be @ 5 that could be the last little bit and you're computer is putting you where you should be.

Using the AFC you might have it at a funky spot in the spark/air map that will try and advance the timing @ 6k too. I'm not incredibly familiar with the maps yet : (

 

[SonySlave]

As DJ23GSX has already said, he can't afford a FMIC which would only cost him $489 from Punishment. That being said, that definitely means that he cannot afford to be replacing headgaskets and cracked ringlands from all the knocking.

To put it simply, right now he cannot afford to purchase the devices needed to help reduce knock right now (FMIC, Keydiver chip, etc...). Therefore, he needs to stop trying to make his car push the limit at 19psi. It sucks, I know, but that's what needs to be done. I personally think that adding meth injection right now is just not the right path for you yet. If you can keep the knock down below 5 counts, you aren't doing too bad, unless you are hitting it nonstop throughout the powerband. Then you need to fix something.

My recommendation is to leave your settings where they are at, borrow at timing light from AutoZone or wherever, set your timing down to 5* BTDC because you are running a little aggressive at 7* base timing. I was running 9* BTDC after my timing belt job and was knocking quite a bit. The minute I turned it back down to 5*, my knock nearly disappeared completely. Do that and see what happens. If the knock problem doesn't change, still leave the timing at 5* BTDC since that is where you should be, and then try to figure out what else to change.

 

[nightspeed87]

As DJ23GSX has already said, he can't afford a FMIC which would only cost him $489 from Punishment. That being said, that definitely means that he cannot afford to be replacing headgaskets and cracked ringlands from all the knocking.

To put it simply, right now he cannot afford to purchase the devices needed to help reduce knock right now (FMIC, Keydiver chip, etc...). Therefore, he needs to stop trying to make his car push the limit at 19psi. It sucks, I know, but that's what needs to be done. I personally think that adding meth injection right now is just not the right path for you yet. If you can keep the knock down below 5 counts, you aren't doing too bad, unless you are hitting it nonstop throughout the powerband. Then you need to fix something.

My recommendation is to leave your settings where they are at, borrow at timing light from AutoZone or wherever, set your timing down to 5* BTDC because you are running a little aggressive at 7* base timing. I was running 9* BTDC after my timing belt job and was knocking quite a bit. The minute I turned it back down to 5*, my knock nearly disappeared completely. Do that and see what happens. If the knock problem doesn't change, still leave the timing at 5* BTDC since that is where you should be, and then try to figure out what else to change.

Agreed, even though the meth isnt a bad idea.
And i am aware he cant afford a fmic but i said its just going to be on his to do list,
and my best advice is to just not take the rpms past where it starts to knock and just deal with not being able to get full pulls until he gets the hardware needed for it to run correctly because everyones car is different and just because one person can tune there car to run safely all the the time with ten counts of knock doesnt mean your engine will behave appropriately to it. I think you should try to port out the waste gate more in the mean time, i mean hog it out, I wish I had pics of mines because like i said I can hold 10lbs till redline...