Dealing with boost creep and running lean

[Alpine TSi]

Let me give you all some background on my car:

92 TSi AWD

Used to be an automatic, now a manual
14B (Burns oil at anything over 15 lbs, but still boosts fine, little shaft play)
510 CC injectors
2.5 Catback
Ported 2G O2 housing

I have no fuel control for the 510's (I know, I know...)
I also have a set of cams from a manual that I am getting ready to put in Tuesday.


Now here is the problem:

I typically run 10 lbs to avoid having to deal with the bad turbo(I intend to replace but am poor). This works fine but anytime I decide to actually drive it and have fun I get some nasty creep at 5K from 10 lbs to where my gauge maxes out at 20 lbs until I shift out of that gear.
Now I also assumed that since I was running a stock turbo with bigger injectors I thought I would be fine with a slightly too rich A/F ratio.

Now here is what my datalogger tells me:
(Keep in mind I have no real idea how to read this)

Third gear:
Throttle position: 55%
O2 Voltage: 0.86
Knock Count: 0-2
Fuel Trims (For some reason they don't change, at all, is this right?)
Low: 138%
Middle: 116%
High: 83%
Timing Advance: 21 Degrees

Fourth Gear: (I was only in this gear a little until some old guy cut me off)
Throttle position: 100%
O2 Voltage: 0.84- 0.86 (Dropped to 0.80 when at max knock)
Knock Count: 0 (When I started to get boost creep it ended up at 18)
Fuel Trims
Same as third gear
Timing advance: 21 Degrees and dropped to 17 when creep started and went up to 41 when knock was at max.

From other logs I have noticed that my knock only appears when I start to creep. The lower the initial set boost the lower the knock. But at 15 lbs the knock gets maxed out at 43...

I also run 92 Octane all the time have NGK BPR6ES plugs gapped at .032. Ihave thought about running a range colder to see what happened or pull the gap out on these plugs.

Oh yeah and she has just past the 169K mark with near perfect compression in all cylinders with no rebuild yet.

Thanks in advance and for the space.

[john]

In the third gear pull, it says that you were only at 55% throttle. Those numbers dont mean much then. You have to fix boost creep, not deal with it. Since you do not have a large downpipe, I would check for a kinked/pinched vaccum line. Try taking off your boost controller and mending the hose together. If it still creeps, you know it has nothing to do with the boost controller itself. Check what is with that other boost controller that came with the car. Maybe it is still connected in some way. I haven't heard of many creep problems on a 14b before.

BTW, the boost creep is causing your car to run lean at higher rpms when it is creeping.

[1ViciousGSX]

Are you running the stock MAF or is it hacked?

When the timing jumped up to 41 deg were you still at WOT or had you let off the accelerator?

Put BPR7ES plugs in it, that may help with the knock also.

The O2 housing and cat-back could be contributing to the creep.

Regardless of the boost creep, it is still running lean under power. The O2 voltages need to be over .90 which should also help with the knock. .90-.94 is close to where you want to be, but this varies with each car and set-up. The ECU adds fuel based on airflow, boost creep or not it is running lean on you.

[At-Least-It's-An-Evo]

Is your o2 sensor good/new/accurate? I had my 02's at .84 or .85 but on the dyno it read under 10.0:1 so obviously it wasnt accurate and I wasnt about to believe the o2s. Who knows, maybe someday I'll go get a good o2 sensor?

[Alpine TSi]

1ViciousGSX:

Are you running the stock MAF or is it hacked?

Stock

When the timing jumped up to 41 deg were you still at WOT or had you let off the accelerator?

I had just let of WOT and actually had a knock of 11 that went up to 18 at the same time.

The O2 housing and cat-back could be contributing to the creep.

I had nasty creep before yesterday that got slightly better when I put the new O2 housing on.


. guest .

Is your o2 sensor good/new/accurate?

I don't know, it was pretty white when I did the housing, but if needed I think I have a new one in my glove box to change it with.



Thanks for the responses, but why would I run lean on 510's? Any ideas?

[1ViciousGSX]

Originally posted by Alpine TSi@Nov 1 2003, 12:05 PM
Thanks for the responses, but why would I run lean on 510's? Any ideas?

Stock fuel pump?
Not re-wired?
Un-metered air getting past the MAF?

[Alpine TSi]

Stock fuel pump?
Not re-wired?
Un-metered air getting past the MAF?

Yeah stock pump, not rewired, don't know about unmetered air getting past MAF.
I intend to buy one of those 255 Walbro's I see for like 85 on Ebay. Think that would help?

[1ViciousGSX]

Originally posted by Alpine TSi@Nov 1 2003, 12:22 PM

Yeah stock pump, not rewired, don't know about unmetered air getting past MAF.
I intend to buy one of those 255 Walbro's I see for like 85 on Ebay. Think that would help?

Might or might not.
Are you lean throughout the entire boosted rpm range or only at the highest rpm?
If it only leans out on the top side, then it probably would help. Be sure you get the 255lp and not the 255hp.

[JET]

I am suprised noone else caught that he is gapping his plugs to .032. You should gap them to .026-.028. .032 is ok for stock boost, but raising it you must lower the gap.

It sounds like there are more problems that just that, but it is a good place to start.

[john]

When I logged your car, you were knocking under creep. That is the biggest reason why you are knocking. If your car is setup to 15psi and you are creeping to 18, that will cause you to run lean. Get the boost creep figured out before you worry about the knock. JET or Raptor will gladly fix that for you. 510cc injectors doesn't mean you can run all the boost you want.

[1ViciousGSX]

Originally posted by JET@Nov 1 2003, 07:31 PM
I am suprised noone else caught that he is gapping his plugs to .032. You should gap them to .026-.028. .032 is ok for stock boost, but raising it you must lower the gap.

.032 wouldn't cause boost creep or a lean condition unless it was miss-firing which he didn't indicate.

[Alpine TSi]

Are you lean throughout the entire boosted rpm range or only at the highest rpm?

Like John mentioned from his log and the ones I have, I only get knock under creep. But I also get a low high fuel trim and low O2 outputs all the time.

[john]

Well, you will not be able to change the fuel trims until you get an SAFC. The low o2's show that you are running lean. Not much else. Fixing the boost creep will cure or for sure help your knock problem.

[john]

Originally posted by 92tsiawd84@Nov 2 2003, 12:31 PM
Well, you will not be able to change the fuel trims until you get an SAFC. The low o2's show that you are running lean. Not much else. Fixing the boost creep will cure or for sure help your knock problem.

BTW, o2 values are not signifigant until you hit WOT (100%). Dont worry about o2's until you are at WOT.

[PSI2HI]

Stock O2 sensors are not accurate enough for WOT tuning. Go by Knock, keep it around 10 counts. you want timing to be around 20, but higher is better with the 14B, as long as your engine can handle it.

Get a fuel pump and rewire it ASAP. then you will be able to run that boost safely.

[john]

I dont think that he will be able to run 18-19psi safely if he only gets a fuel pump. He has to control boost before he worries about doing anything else.

[niterydr]

Originally posted by PSI2HI@Nov 2 2003, 01:07 PM
Stock O2 sensors are not accurate enough for WOT tuning. Go by Knock, keep it around 10 counts. you want timing to be around 20, but higher is better with the 14B, as long as your engine can handle it.

Get a fuel pump and rewire it ASAP. then you will be able to run that boost safely.

this isn't always true.
I've seen cars grenade at 3 counts of knock, you just have to know the difference between pinging and 'artifical knock'. Also just 'tuning' by knock isn't important, its nice to look at intake temps, injector duty cycles, o2 voltage, egt readings, a/f ratio, coolent temps, etc... all play a factor in a well tuned car, but since he has nothing to tune with, we won't go any further.
Anywho, most dsm's are safe to run up to 10 counts of knock, due to the fact that all the 'noise' they make, but in his case he is actually detonating from running lean. Please refrain from using blanket statements when it comes to tuning cars, it angers me.
Now alpine, here is what you need to do.
1) fix the boost creep, get it to a more manageable 14-15psi.
2) check for boost leaks, before and after turbo (unmetered air like mike suggested).
That'll get you by relatively cheap.
3) Obtain some form of fuel management, just because you are running '510cc's', since you are on the stock 1g fp which runs 36psi (your injectors are probably rated at 43psi), they are actually smaller than that. Look into a fuel pump, or at least check the voltgage at your fuel pump. Next look into getting some sort of fuel controller, choose your poison. (I prefer s-afc, its plug and play, and fairly easy to learn the basics about).
from there it can go any-which-way, pending if you want reliability or speed, keep us posted.

[1Fst14B]

3 Counts of knock?? where do you mount your knock sensor? Unless you have a crazy sensor, messed up electrical or computer, i dont see that happening, unless you are pushing high HP on the stock motor...then even properly tuned it will grenade.
i ran 12.4's all day with 20-40 counts of (Real) knock, pushing 20 some pounds of boost on the 14B.
Basically , IMO, if you grenade @ 3 counts of knock, you prolly got another problem.

Whats wrong with 18lbs with 510's and a fuel pump?? the car should easily be capable of that.

Adam

[A//// Guy]

20-40 counts of knock = beaten motor... not good....

It all depends on what your willing to risk, I would never keep stepping on the throttle past 8-10 counts of knock as I dont want my engine to blow up.

We'll see whos motor lives longer by using your "knock" theory. My car might be slower but atleast I wont have to rebuild it every weekend.

[john]

Originally posted by 1Fst14B@Nov 4 2003, 06:54 PM

i ran 12.4's all day with 20-40 counts of (Real) knock, pushing 20 some pounds of boost on the 14B.

You could have run quicter then. In my experiences with knock, it seems like I am going no where. Car makes alot of noise but doesn't move.