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DIY Turbo Discussion greddy on a 1.8? homebrew kit?

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Old 12-05-2006, 05:12 PM   #1
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Default Knock and Link

This is a double post with Maninlt because the Fm Link seems more popular there as opposed to the eManage here.

Either way - if someone can help it would be really appreciated.


I installed the Link and LC-1 loaded the appropiate turbo defaults and set off to tune. I did some runs and logged them into DLL and found that I was getting what appreared to be Knock at the higher revs.

Basically I had zero knock > 5222rpm, then
small knock readings (upto 13) > 6696rpm, then
increasing to a max of 65 at redline 7200 rpm

There are no obvious spikes - just a steady rise.

My knoch threshold is set at the recommended 35

I noticed that the car was not pulling any ign and could not work out why.

As I understand it the threshold near doubles as it approaches redline as you expect greater engine noise. - as long as I am not getting any spikes or going over the threshold (70 at readline) then i'm in the clear for Knock.

I still have some testing to do to establish the engine noise baseline - but is the above correct in concept?

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Old 12-05-2006, 05:26 PM   #2
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Yes - the best way to test for noise vs. knock with Link is stated in the manual. Start your datalog, then drive the car to red line while staying out of boost. The do it again for a second DL so you've got something repeatable to reference. That way if anything comes up that looks like knock when you're making tuning adjustments you can reference these logs to see if it indeed is new. Keep in mind that there's a variety of things in and on the engine that can also appear as knock if they're not tightened down- that may only rattle at or around certain rpms. Just think of knock as a "spike". hth- rob
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Old 12-06-2006, 07:49 PM   #3
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Add 10 degrees of timing and do another run. You'll see if you have real knock or not.
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