eyefi Posted June 5, 2003 Share Posted June 5, 2003 where is a good place to mount a stethoscope to listen for det? do u have to mount it to the block or just in the engine compartment? Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 Knock sensors are usually mounted in a rigid location on the block or on the head. They work by sensing the shock created by the detonation, so the key to their positioning is a solid path for that shock to travel along, from any sensor to the cylinder. If you wanted to listen for it, try the side of the block near a cylinder head bolt, or the side of the head on the intake side (to save burning your fingers!) Steer clear of the cam cover as its probably isolated from the head with a rubber mount. You should be able to hear it with the naked ear but I gues you want to be more sensitive than that. Quote Link to comment Share on other sites More sharing options...
Nathan Posted June 5, 2003 Share Posted June 5, 2003 Yep, I would agree with Darren. Only one point I would raise is that if you CAN hear det on a Mk4 with the naked ear you are well on your way to meltdown. Believe it or not, 'det cans' (a stethoscope with a bit of metal at the end to attach it to the block) are still widely used by a lot of tuners and engine dyno operators today, and do work very well. In conjunction with a piezo unit as a backup, the two combined are exactly what we use here. Cheers Nathan TDI PLC Quote Link to comment Share on other sites More sharing options...
eyefi Posted June 5, 2003 Author Share Posted June 5, 2003 thanks guys. Quote Link to comment Share on other sites More sharing options...
mos Posted June 5, 2003 Share Posted June 5, 2003 What are the ways to reduce det, i mean do octane boosters really help or is it simply better to retard the timing and take the power loss Quote Link to comment Share on other sites More sharing options...
Alex Posted June 5, 2003 Share Posted June 5, 2003 Originally posted by mos What are the ways to reduce det, i mean do octane boosters really help or is it simply better to retard the timing and take the power loss The ECU automatically retards our ignition but its not enough usually. Higher octane fuel (optimax is the prefered choice - see poll in General) Octane boosters - some work some don't - too many discussions on this so try the MartinF-Search-Button-O'rama Better intake cooling. Better SMIC or complete swap to an FMIC. WI - Water Injection - can save your ass but don't rely on it More Fuel! - if you are running lean you'll be prone to det. and lastly TURN THE BOOST BACK DOWN!!! Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted June 5, 2003 Share Posted June 5, 2003 I agree with Darren & Nathan. I have an electronic stethoscope with 4 micro clamps. These an be in 4 different locations & you select a channel for each. Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 Originally posted by mos What are the ways to reduce det, i mean do octane boosters really help or is it simply better to retard the timing and take the power loss You need to run cooler, richer, or more retarded. Just like me! Quote Link to comment Share on other sites More sharing options...
Ian C Posted June 5, 2003 Share Posted June 5, 2003 Originally posted by Darren Blake You need to run cooler, richer, or more retarded. Just like me! Or, unlike Darren, blow less hot air -Ian Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 WhyIoughta.... Quote Link to comment Share on other sites More sharing options...
mos Posted June 5, 2003 Share Posted June 5, 2003 The reason i asked is that on the dyno i got 205 rwhp (im N/A) but we heard the dreaded tinkling at the top end (about 6500). anyway we retarded the timing and i lost the power down to 196rwhp. I was wondering if i ran millers and introduced some better cooling would that be enough to allow timing advance again Quote Link to comment Share on other sites More sharing options...
mos Posted June 5, 2003 Share Posted June 5, 2003 Forgot to add i am running 12.5 on my wideband at that point Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 Not a bog standard NA then? Or is it an SZ-R? Quote Link to comment Share on other sites More sharing options...
mos Posted June 5, 2003 Share Posted June 5, 2003 Its not an sz-r just an sz but have cats removed, x-erd header and went back to standard air box after my hks power flow gave me a big loss (sucking in too much hot air). Also have fuel reg (leaned off) and hks super afr and my wideband. Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 Sounds like you need a bit more fuel. Why have you leaned off the fuel regulator? With the cats out you'll need more fuel if anything. Quote Link to comment Share on other sites More sharing options...
mos Posted June 5, 2003 Share Posted June 5, 2003 On the dyno at standard the N/A runs super rich at the top end so we leaned off on the requlator and then compensated with my afr at the lower rev points, it was in the 10's at one point (wideband not 1/4 mile- how i dream) This got me the 205 but the little tinkling noise was there. Quote Link to comment Share on other sites More sharing options...
Digsy Posted June 5, 2003 Share Posted June 5, 2003 Well, like I said, det can be caused by running to much spark advance, too lean a mixture or generally to hot a combustion process. Still sounds like fuelling to me. I have an AFR curve for my car at home. I'll have to look at it to see if I go rich at the top too. Quote Link to comment Share on other sites More sharing options...
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