A Must Read For Budding Tuners, Or Those Interested In "knock"

[STATUS]

Nope. And that proves it works fine.

He has a extremely good reputation.

The drag car he sponsors is tuned at the track using egt sensors and transducers in the spark plug to monitor cylinder pressures.

that is no-where close to just ears... those sensors will tell all.

I have had guys tuning for years (like 20) say they dont need this fancy gear and that they can hear det.... even on str8 out exhaust cars and external gate cars.... impossible and proved it with the k-mon... i increased timing a degree at a time and told the the guys to tell me when they heard it.... they heard it 3 degrees after i did through the head phones.

[DVS JEZ]

That came across the wrong way. The 2nd part was seperate.

Where do u mount ur sensor for ur headphones on rb26?

Only spot i can find really is the inj rail but waay to much noise interference

[O2 Autosports]

I can't believe there are tuners out there who would tune without some way of monitoring knock.

Edited April 19, 2011 by O2 Autosports

[STATUS]

That came across the wrong way. The 2nd part was seperate.

Where do u mount ur sensor for ur headphones on rb26?

Only spot i can find really is the inj rail but waay to much noise interference

a quick easy place on a gtr is to remove one of the fuel connector 8mm bolts (10mm head) under the inlet plenum, i have an adapter (8mm bolt with 10mm (12mm spanner size) nut welded on top) which i screw in to the removed 8mm bolt. This gives good amplification of knock but requires a little less gain to cut out the solid head and inj noise.

[DVS JEZ]

Thanks Trent. I ended up making on very similar but onto the back of the throttle bracket near the TPS.

Same thing welded a m6 to a longer bolt then welded an m8 ontop so i can bolt my knock sensor on.

I msgd kmon and they tried to tell me i can get to the stock GTR knock sensors lol. After he did some research he realised its literally impossible/impracticle.

[STATUS]

Thanks Trent. I ended up making on very similar but onto the back of the throttle bracket near the TPS.

Same thing welded a m6 to a longer bolt then welded an m8 ontop so i can bolt my knock sensor on.

I msgd kmon and they tried to tell me i can get to the stock GTR knock sensors lol. After he did some research he realised its literally impossible/impracticle.

yeah on the bigger stuff i swap out the front GTR knock sensor, possible but yeah you need three wobbly ended 3/8 extensions... tricky and time consuming. Similar to below but 2 of the medium and one short.

[zebra]

should be able to pick it up way before you hear it with the k-mon or knock block. the software logging will show you well before you hear it. You need to log it run at a time so a maximum of 15 seconds to get the best resolution.

on the 1jz i use the spare spots on the head exhaust side front and raise the sensitivity on general tunes but on bigger setups i go to the block

you talking about where the hook goes to lift the engine out?

[STATUS]

you talking about where the hook goes to lift the engine out?

yeah, but ive found a nice spot on the 1jz intake manifold latley which is better.

[zebra]

Care to share?

[STATUS]

Care to share?

depending on vvti or not there is either 8mm or 10mm bolts i back out and fit an adapter into on the plenum.

[zebra]

Does it matter where abouts on the plenum? I'm assuming as close to the head as possible?

[STATUS]

Does it matter where abouts on the plenum? I'm assuming as close to the head as possible?

remove one of the throtlle bracket 12mm headed bolts.

[zebra]

Cheers

[SargeRX8]

Do you guys think its a shit idea to use a length of rubber hose with an ID of 6mm over a bolt you place in the head or block or where ever, then stick the hose in your ear to listen to knock? Apparently this is a cheap and effective method as it cancels out higher frequency noises, kind of like a doctors stethoscope.

[Rolls]

Do you guys think its a shit idea to use a length of rubber hose with an ID of 6mm over a bolt you place in the head or block or where ever, then stick the hose in your ear to listen to knock? Apparently this is a cheap and effective method as it cancels out higher frequency noises, kind of like a doctors stethoscope.

I've heard reputable tuners say it is quite a good method. Another tuner I know just uses a microphone wrapped in a towel and wedged under the intake manifold with no filtering, he said the towel blocks out most the noise and is really good, this is providing you use proper isolation headphones, eg good quality canal ones.

Microphone and a cheap PA is very cheap if you build it from parts at jaycar.

Edited December 15, 2011 by Rolls

[ARTZ]

haha..now theres an idea..

I left my phone in my pocket on record at a Metallica concert and the playback sounded great....

filtering, it works..

Anyway, carry on....

[GTR_JOEY]

First would like to say very interesting and informative read. thanks for sharing

second i just want to highlight a couple of paragraphs from the original post that the guys running E85 may find very interesting

"The other technique is a little more subtle but usable if attention is paid to EGT (Exhaust Gas Temperature). Detonation will actually cause EGTs to drop. This behavior has fooled a lot of people because they will watch the EGT and think that it is in a low enough range to be safe, the only reason it is low is because the engine is detonating.

The only way you know what is actually happening is to be very familiar with your specific engine EGT readings as calibrations and probe locations vary. If, for example, you normally run 1500 degrees at a given MAP setting and you suddenly see 1125 after picking up a fresh load of fuel you should be alert to possible or incipient detonation. Any drop from normal EGT should be reason for concern. Using the "Tin Ear" during the early test stage and watching the EGT very carefully, other than just plain listening with your ear without any augmentation, is the only way to identify detonation. The good thing is, most engines will live with a fairly high level of detonation for some period of time. It is not an instantaneous type failure."

Now im about half way through Guilt Toys E85 thread and already there has been a few poeple mentioning lower EGT's. A few opinions have emerged that lower EGT's are a better occurance but according to the above statement this is not the case at all

as far as ive figured out E85 burns at slower rate therefore timing can be advanced a great deal more then PULP

it also had a higher Octane rating makig it harder to ignite

becasue of its high alcohol content alot more fuel is needed to compared to PULP to get your bang for buck, this in turn would keep cylinder temps down and reduce EGT's

Are the E85 guys missing something here and having their engines detonate without them knowing or is the low EGT's just a safe by-product of E85?

[Lithium]

I've also heard mention that E85 "sounds different" to detonation on petrol, and is very hard to identify. I've done some tuning on ethanol blends and never heard it (I use a G4 Knockblock) though haven't YET used exhaust temp monitoring... admittedly the only car I've tuned on E85 was naturally aspirated and 13:1 compression so potentially not likely to get knock before MBT anyway.

Has anyone identified detonation tuning E85 yet? And can they confirm if it "sounds" the same as petrol det?

[Galois]

Sorry Lithium, newb tuning question, why was the NA car with 13:1 compression unlikely to get detonation before MBT?

[Lithium]

I missed out "so likely", and I was talking in reference to using E85 as the setup was definitely getting detonation on pump gas before we stopped getting torque gains. I figured people go way past the point they get knock limited on pump gas with E85 using forced induction without trouble, surely NA... even with semi aggressive compression shouldn't be too at risk?

I don't know for sure, hence using "protection" and also asking here to see what peoples thoughts are. The car's factory knock protection setup is still running too, and that hasn't got any issue with anything but I have heard people commenting on E85 knock coming through differently.... which is something I currently struggle to see how, so come here asking