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View Full Version : Getting some sweet knock in the VR-4


Alpine TSi
08-16-2005, 11:08 PM
As the title states, I am having problems with knock in my GVR-4.

Car: 1992 Mitsubishi Galant VR-4

Mods: EGR Removal, Custom EPROM chip by LightningGSX(stutterbox, enhanced closed loop, knock display, etc...)

Other Info: 157K miles, only 92 octane from BP is ever put in it. NGK BPR6ES gapped at .030, no boost gauge(I hope I am running whatever stock would still be), factory BCS installed, most free mods done.


Here is the deal, after doing some logs I am finding out that I am good until about 4K RPM, I get a nice stock feeling pull from it, and then the knock starts to go up. On a run where I started logging at 3600 RPM I was getting 29 degrees of timing, 29% injector duty cycle, and .91 volts on o2. By 4000 RPM I was now at 16 degrees of timing, 61% IDC, and the same o2 but with 6 counts of knock. This is where it all starts. Now by 5000 RPM I am at 11 degrees of timing, 75% IDC, still .91 o2 and 22 counts of knock. 6000 RPM I have 11 degrees of timing, 88% IDC, once again .91 o2, and now 36 counts of knock. I pulled out of this run at 6600 RPM with 10 degrees of timing, 91% IDC, .91 o2 and 42 counts of knock.

This is pretty much how all of my logs look for just about any gear. I only get real power for about 600-900 RPM then it starts knocking and I get no timing.

Here are my questions:

Why the hell am I knocking on what I think should be stock boost?
What are my options?
Is it possible that by looking at this info that I am encountering phantom knock?


The car is practically completely stock. I haven't done a boost leak test, nor a compression test since I got it. It still has the stock 450's in it. I do have an old 5 knob AFC mounted in it and within two days should have it wired up. I have a boost gauge and MBC that should be going in shortly thereafter. I haven't checked the plugs since I bought it 4-5 months ago, and I was thinking about changing to BPR7ES's with a .028 gap. I also have some RC 500cc injectors laying around I get get cleaned and tested and throw those in if they would help.

Any other ideas?

Thanks in advance!!!

A//// Guy
08-17-2005, 08:48 AM
With the stock maf and suppposed stock boost you should be much richer than .91, thats actually pretty lean. Stock settings are always set pretty rich, im not sure if you Eprom is programmed to change and AF ratios or whatever but it seems your too lean based on the narrowband.... which isnt very accurate.

Throw a cheap boost guage in there and see what its hitting, then maybe put an AFC in there and see if you can richen it up a tad.

Alpine TSi
08-17-2005, 11:26 PM
BUMP!!!

Thanks!

scheides
08-17-2005, 11:35 PM
what does the knock sensor look like? Maybe consider swapping that out?

Alpine TSi
08-18-2005, 10:00 AM
what does the knock sensor look like? Maybe consider swapping that out?

Good idea, I'll check that this weekend and see what it looks like. Any idea what would be bad looking besides the obvious damage?