Need some tuning help from some of you Professionals.

[Onefast99gsx]

It's been a while since i posted or even visited here. Been breaking the car in slowly since it has a new clutch and many other things. I've been tuning the car quite a bit over the last week with DSMLINK getting all my global and deadtimes within 1%. I've posted similarily on dsmlink without much good feedback so i thought i'd ask some of you that have way more experience than i do.

In every single log of mine i have knock and it's pulling back my timing. It's weird, it happens in almost the same spot everytime 5200rpm's. You could almost set your watch by it. It pulls back anywhere from 3 to 6 degrees(most commonly 3 to 5). It never happens in 1st gear at all period. It happens in the same spot though 2nd, 3rd and 4th gears. I've tried richening it, leaning it, i've pulled back a couple degrees of timing but all that does is just give me less knock. I just don't think i should have to pull back any timing for the current setup. Head was completely torn apart, ported, each and every lifter was cleaned thoroughly in a 2 step diesel process similar to factory manual method. Motor mounts are all new Protane mounts. The only thing i can say i discovered was a huge exhaust leak last night. The new gasket between the 02 housing and downpipe must have shit out or the downpipe loosened(haven't looked at it yet). I don't know if the loud noise from the leak could create some sort of harmonics that are interrupting the knock sensor? Fuel is 93 octane, boost is at 18.5psi.

Can any of you suggest anything to try or look at? I could really use some direction here.

Thank you!!

99GSX
PTE 50 trim, cut divider, internally gated
PTE 780 cc injectors
Magnus intake
HKS 272's
1g T.B.
Griffin FMIC 2.5" piping throughout
Walbro 255lph rewired
DSMLink
SouthBend DxD OFE Clutch
Fidanza Alum Flywheel
FP Intake pipe
Stage 1 ported head
Stock fuel rail, stock f.p. regulator
3" Exhaust
JAZ catch can
(2) 12" Mr Gasket 1400cfm each, fans
.... all the other supporting usual mods, etc..

[CDeutsch]

The ECU is bumping up your timing with the RPMs. Maybe when you hit 5200 it's too much. How much timing have you tried pulling? You could also try 100 octane and see if it goes away. At least then you'd know if it's real.

What happens if you slowly take it up to say 5500-6000 so you don't get knock and then go WOT? That might help rule out harmonics.

[Onefast99gsx]

I tried pulling -2 degrees all the way up from 5000 rpms on up. That's not alot but if i pull much more it will kill the power on top. On a 3rd gear pull, i really like to see 16 to 17 degrees of timing by the end of the gear. When i get this knock, i might get 13 degrees. I have 5 galls of B33 which is I believe 116 octane. I'll have to run the car more dry because she's got 3/4 tank right now. I'd be best to only have 3-5 gallons of 93 and then mix about 2 galls of B33. I guess the way energy is right now, ya gotta wonder if 93 octane is actually 93 octane at the pump. BP is where i've been getting my gas.

I could also try the slow test that you describe to doing. Rather than driving like at a race, i will ease it from 5k on up and see if easing it vs. beating it makes a difference. These are all certainly good things to try and i appreciate it. It's got me so frustrated because now i want to take it to the track. What's weird is why doesn't it do it in 1st gear at those r's? I guess because the fuel consumption is much greater in the higher gears even at the same rpms. That's my theory.

Thanks.

[95tsi]

Try turning the boost down and see if it still knocks. Might be able to run say 17psi with out knock vs. 18.5 with knock.

[TheBlizzard]

With your mods you should not be knocking at that boost with a 50trim. Like stated above, put some decent gas in your car and see if that helps. My guess from listening to your post is that you have some bad/low quality gas. If that doesn't help then run some logs and see where its knocking and play with fuel and timing in that spot and see if you can get it to go away.

CRAIG

[CDeutsch]

Just be sure to post the results if you fix it. I'm interested because my 2G has similar mods. I'm having other issues, but latetly with the small amount of tuning I've been getting in I've been running about 22 psi on pump, but I have the timing retard 3 degrees starting at about 4000.

What compression pistons are you running?

[niterydr]

If you could post up a log, or better yet, send a log to my email, that would help in diagnosis the problem.
18.5psi on pump gas really isn't that much, granted the griffen fmic isn't the largest, but it should support the boost levels you are attempting to run.
If the ecu is pulling it back to 13 degrees, you must be knocking 10 counts or so? (I forgot what it reads on dsmlink, maybe 3?).
I would double check the gas scenerio, like mentioned.
Following that, I would obviously make sure baseline timing is at 5 degrees, and your not fighting an uphill battle against the ecu. Also, make sure nothing is 'happening at that time' aka harmonic interference (Chris mentioned a VERY good method to rule that out).
Finally, once again, try to post up a little more information to whats happening. Are you seeing a jump in airflow numbers? Injector duty cycle jump?
Keep us posted.
swanny09@yahoo.com if you want to send me a log.
Good luck.

Also, what is the motor setup exactly? (edit* see chris beat me to this).

[Onefast99gsx]

Thanks to all you that stepped in. Not only did you give me something to go on but I think all of it is very useful things to try. Tonight i can try everything above except for the fuel. I don't want add some B33 to 3/4 tank of 93 octane. I want to run the tank more dry. B33 is like $8.00/gall. Niterdyr- I will certainly send you log(s). To anyone else that don't have dsmlink, i will post the dsmlink data in text format to show you what the numbers are in a non-knock area vs. the knock area. I wouldn't expect a posting until later tonight. Gonna go fix the exhaust leak right now. I Gtech'd it last night and ran a 13.32 at 112.x mph. Counting the log seconds on dsmlink showed the e.t. to be pretty accurate. Speed realisticaly was about 105-106ish. I still have yet to learn how to launch a AWD as my r's got pulled way down in the 2k range and killed the 60foot, plus she was knocking pretty good 2nd, 3rd and 4th gears so i was back pedaling it a few times and only getting about 13 degrees of timing at the top of the current gear. I'm guessing at that boost, a good launch and getting rid of the knock, i'd be in the 12's consistantly. Something to look forward to. The power has yet to be unleashed.

Thanks much.

Will post later.....

[Onefast99gsx]

Originally Posted by CDeutsch

Just be sure to post the results if you fix it. I'm interested because my 2G has similar mods. I'm having other issues, but latetly with the small amount of tuning I've been getting in I've been running about 22 psi on pump, but I have the timing retard 3 degrees starting at about 4000.

What compression pistons are you running?

CDeutsch- It's the stock 2g 99GSX motor, including the head. So, what's the compression ratio? 8.5:1 of the top of my head, I think the 2g's are.

[CDeutsch]

Originally Posted by Onefast99gsx

CDeutsch- It's the stock 2g 99GSX motor, including the head. So, what's the compression ratio? 8.5:1 of the top of my head, I think the 2g's are.

My bad. I thought you had a built 2.4 for some reason.

[Onefast99gsx]

As i said i'd post... I'll post more specs and data sometime tommorow. I got other issues going on tonight non-car related. Pet is sick. :-( Did several tests tonight since my last post. First test was to run it on 19psi of boost just as i did yesterday. Knocked pretty good after 5200 r's just as its been doing.

Next test #2, I did the same boost level (19) but turned up the sliders in dsmlink from 4500rpms to 7500 to +8. Result: Knocked pretty good but not quite as much, probably 3.x degrees being pulled.

I checked the base timing then with the timing light. Dsmlink is nice because you can ground it just by clicking on a button on the computer. At about 750-800rpms, she was dancing right around 5 degrees BTDC. Correct me if i'm wrong. First time i did this. On a 2g, on the tbelt cover is the degree readout, the only number that is on there is a number 10. Then a couple of other lines and then what looks like a "T". I'm assuming that T means top dead. Well that's where the little white dot on the crank pulley was hovering around.

My next test #3, Put fuel sliders back to zero. Cranked boost back down to around 14.5psi. All be dammed! No knock in ANY gear. A couple times i had those little .4 degree phantoms but not all the time and hardly at all. Most of the time, it was knock free period. Ran this setup about 4 times with little to no knock.

What does this mean? The 93 octane i put in it the other day is shit? Not really 93 octane? With the refining troubles they're having, i really gotta wonder if we're pumping what its actually supposed to be. How watered down is gas nowdays? I'm gonna first switch to either Mobil or Citgo fuel. I expect the result to be the same though because i think all gas stations around here no matter the name get their gas from the same supplier. I have an alcohol injection unit that i took off the GST before i sold it. I need to get it on the GSX.

I'll post logs tommorow or something. I just got more important things than cars going on tonight. I just wanted to update you.

Good night.

[TheBlizzard]

Like I said, sounded like bad gas to me. By lowering the boost you are lowering your dependency on gas quality and octane rating. Burn that shit out of there while running low boost and then put some decent gas in. Turn the boost back up to around 20psi and set fuel back to where it was and see if you are still knocking. My guess would be that you should be just fine once you have some better gas.

For example, when I get gas from down by where I work (Treasure Island Casino) my car always knocks if I run more than 15lbs of boost. Now if I get BP/AMOCO gas I can run 18-19lbs with no one hint of knock. With that shit gas from down by work I get like 13 counts in 3rd and 4th gear. Thats not a ton but I can definetly tell when I have a batch of bad/low quality gas. Just because it says 93 octane doesn't mean anything to me, its all where you get it from. And Amoco gas works the best in my car with race gas being the alternative.

[Alpine TSi]

What kind of plugs are you running? With that setup you should be at a BPR7ES and gapped at 28 or so.

BTW +1 to Amoco/BP gas, I would knock like crazy on shitty gas, but with BP stuff I never had problems. Also eventhough Holiday offers 93 octane, don't get it.

[TheBlizzard]

Fuck Holiday gas. Its not as bad as Super America but damn close. It will work if you don't run more than 15lbs but anything over that and its knock city on your car.

[dsm10sec]

It's because MOST BPs use UNOXYGENATED, most other places use ethanol. If you register on www.mnsubaru.com they have a listing of 66 non-oxy places throughout the metro.

[LightningGSX]

Originally Posted by dsm10sec

It's because MOST BPs use UNOXYGENATED, most other places use ethanol. If you register on www.mnsubaru.com they have a listing of 66 non-oxy places throughout the metro.

Oxygenated gas is better, ethanol reduces your chances of knock

[Jakey]

Originally Posted by LightningGSX

Oxygenated gas is better, ethanol reduces your chances of knock

Thank you.

[desolate]

I have to agree with the shitty gas around here. Everywhere you go pump 92+ octane it feels like 90 octane or less. You have to richen the shit out of your tune for a knock free run. Then you get weak power. I've tried Amocco, Holiday, SA, whatever. They all feel the same. If I am out for a little weekend throttle I just get 110 and call it a day.

[CDeutsch]

But what if you fuel system is at it's limits? Oxygenated gas causes your fuel system to add more fuel correct? In that case you'd end up running lean, right?

[dsm10sec]

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