A little disapointed - Power Plate

[Buick Beginner]

First off, this may be a problem that the Power Plate can't fix, I don't know. O.K. here goes - My signature below has my mods. I've posted my DS numbers before and everyone said they looked O.K. with one exception, injector pulse width. I've got Tomco 32# injectors, only slightly bigger than stock. I consistantly get 5 degrees of knock retard from 93 pump gas, 17 PSI boost in 1st, 15 PSI in 2nd and 3rd. Gary Mitchell burned me a chip with a little less radical timing than Pitt bull I was using. It helped but still I'm getting 5 degrees retard. The Power Plate install was easy, but still 5 degrees retard, fuel pressure is dead on, new CAS fpr is dead on, so I'm starting to lean towards, (no pun intended), bigger injectors, am I starving for fuel? Here are the DS numbers:

Idle - WOT
TPS - 0.46 - 4.84
LV8 - 50 - 253
MAF - 7 - 229
IAC - 26 - 61
INJ.P/W - 4.4 - 30.3
MAT - 81 - 95
Spark Adv. - 25.8 - 20.9
Knock Ret. - 0 - 5.1
Knock Cnt. - 0 - 3
AF Ratio - 14.8:1 - 11.9:1
O2 Volts - 298 - 800
O2 X-Count - 52 - 79
INT - 137 - 128
BLM - 116 - 128

Help is appreciated! Thanks - BB

 

[RareT]

Try lowering the boost to 16 if you have an adjustable wastegate or add a pound or two fuel pressure and see how it does. Some cars can't run 17# of boost on pump gas before KR occurs.

Ed

 

[Buick Beginner]

Thanks Ed

Any others? - BB

 

[FlyinGN]

Heres what you can try.. Set the boost where it is and with pump gas you are getting 5 degrees retard.. correct?
Do you have access to 100 octane or BETTER race fuel? If so, drain the tank (or get it clse to empty) and fill 1/2 tank with the highest unleaded race fuel you can find.. and retest. If the KR is exactly the same, its a lean out because of lack of fuel. If the KR is less or even goes away, its octane related. If it is the first, upgrade the injectors.. If it is the second. lower the boost.

 

[Quick6]

have you changed your fuel filter recently? Also I assume your still running a stock IC, if so have you cleaned it both inside and out? What are your engine temps are you running hotter than you should be? Bring your boost down to 16 as said before and maybe try a different brand of gas, but don't keep running it hard with 5 degrees of knock.

 

[BM Computer Src]

Send me your directscan file, and I will look it over to help you find the problem. Email it to

webmaster@bmcomputersource.com

Bob

 

[YGETV8]

I realize that no two of our cars are alike, but for what it's worth, with Gary's standard Z93 chip in my GN with green stripe 30 #ers, I couldn't run over 16 psi boost without some KR. My solution was ALKY! Still running that chip, and it is running great, thank you! BTW, that was at 62psi fuel pressure... every time I turned up the fuel, the car went faster!

 

[Steve Wood]

Where in the run does the timing get retarded?

 

[Eric Stage I]

It looks like you're programmed for 20.9 degrees at WOT. I believe that is still too much. You probably want about 18 degrees for 93 octane.

The pulsewidth does seem strange for wot. 30ms is a lot (that's pretty much static I believe).

Eric

 

[Steve Wood]

I would agree, 21 degrees is too much for 17# with a stock cam.

 

[gnxis]

try a 30% xylene mix and a couple of ounces of marvels mystery oil for lube.

 

[TR Custom Parts]

False knock possibly? Is your downpipe hitting the frame? Where is the knock occuring?

 

[Black Car]

Hi Tom,

The ATR one had 24* and the stock chip runs 22*.
There is no problem with redo the timing for you on the chip.
If there is any other tweaks needed let me know when you send it back.

Like many have said before lets see if it is false or real knock.
Unleaded race gas is preferred 100 to 104 octane but if not available then the home brew works well.

If you can get some xylene or toulene, even 1 gal from the hardware store. Drain or run the fuel level down to 3-5 gal and add to the tank. This should reduce the knock if it is real.

Let me know.

Regards,
Gary

 

[Turbo__Tim]

If you go larger on the injectors, you will gain a couple psi, without knock.

Alchy will get you 19-20 with your current set-up.

I like the alchy idea. Run 100 percent de-natured, and this will act as a 7th injector as well.

 

[ES1]

I used to run 19psi on 93 with no knock.
Started changing things and started getting knock.
Instead of running down the knock problem, I started buying stuff. Alky, no change, PP, no change. I added 104 octane and knock is gone. Moral - do what Flying GN suggetsed.

 

[Sleeper]

I wouldn't blame the Power Plate

IMHO You are out of injector. If the ECM is commanding a 30.3 PW you are way over 100% Like 151% !!! Figure that the 32's aren't much bigger than the stock injectors and you are pushing the boost over the stock levels by quite a bit. Why take the chance pushing them and risking your motor.
Before the flames start... I know lots of people have run very fast on small injectors by pumping up the FP, but are running way over a safe duty cycle (85-90%).
Leave yourself a margin of safety, especially if you want to go faster. Another good reason is that the injectors are much easier to control and are more efficient when they are operating in the 85-90% range.
I also feel that the timing is a little high for pump gas, and as said before many times "every car is different" so IMHO I would look to see where you are getting the KR and get Gary to pull some timing out at the problem RPM areas for now, but would still think seriously about going to a larger injector.

Paul

 

[Steve Wood]

Isn't the 30 ms pw commanded by the chip as per programming at wot rather than by what the o2 sensor might call for?

I am not sure that this 30ms pw is indicative of a shortage of fuel.

 

[Two Lane]

The Power Plate may not be the cure, but it isn't the problem, either...

I'd get some 50 or 55# injectors with your combo, & would betcha a case of Wolf's Head 30W ND (left over from my Flathead V-8/60 with Ardun heads) that your car will run better.

Anyway, I'm betting it's a FUEL problem.

HTH

 

[Buick Beginner]

Thanks 100 times!

Gentlemen,
As usual I've got some great ideas from the board, I'll have to work through them 1 at a time, but these ideas have brought up some great points! I'm going to start tinkering tuesday, and I'll send out the DS file as soon as I get back in town. Thanks again guys, - BB

 

[Buick Beginner]

A Little New Info

Gentlemen:
Well, I mixed a pretty powerful batch of Xylene home brew and took the GN out for a DS run. At 17 psi boost, I had no knock retard at all. So, with that in mind, it looks like I am either running too low of an octane for 17 psi or too much boost for 93 octane. Six of one, half dozen of the other. Anyway, just thought I'd let everyone know. Thanks. - BB