Well I have my EGT gauge around an inch from my #4 cylinder. With the car completely cold when I turn on the ignition the gauge goes straight to or just below 200 degrees. Does this mean that my gauge is off 200 degrees since its not reading at 0 when its completely cold? Its the newer NV series that reads to 2k. I have my daily driving down decent. At idle I am around 800 degrees....driving through traffic it will get to around 1200-1300, but at a redlight will get down to around 1k. At 75mph its just below 1400 degrees with a mid 14 a/f. I tried yesterday doing a few pulls just straight off the wastegate in 3rd gear(18psi on GT35R turbo). It stutters just a bit, but soon as it hits I get low 12's a/f and then the a/f starts getting richer. It goes from low 12's to lower 11's to high 10's within a few seconds. While this is going on my EGT's are climbing up quick. When it gets to 1700 I let go of the gas and I am around 5k or so. I am saving to get the car tuned by a professional soon, but had hoped to get some decent low psi tuning done before I brought it in. So I guess my question is whats the EGT suppose to be at WOT to be safe?
Also I think off hand I am running around 22-23 degrees of timing through boost. I have the bottlekneck mod, high flow fuel pump, and returnline with -8an feed so plenty of fuel. I am running the lowest boost I can, but I am guessing since my a/f gets decent then I just need to add timing to burn that fuel and help the EGT's go down? What I do notice is that when I did quick WOT runs(2-3 seconds worth) when I let off the gas and am in neutral the RPM's hang at around 1-1.3k for some reason. They will not go down to normal unless I come to a complete stop or slow down enough to put it in a higher gear and make the rpm's go down. This happened before awhile ago when david was tuning my car on the 50 trim and he said it was normal with the megasquirt, but I dunno it doesnt seem right. I made a small datalog from last night so will post that up when I get home. Whats weird is my first datalog I was able to run to redline(7k) in 3rd gear and only got up to around 1600's on the EGT gauge. When I stopped and looked the datalog over I richened up the fuel just a tad near the beginning to get the stumble away down low and changed some timing since the cells it was referencing down low had way to high of timing. Well after the change it got rid of the stumble, but my egt's went up alot faster to 1700 and I let of the gas real quick......Well when I get home I will post up the datalogs.
I would say that's normal. EGT probes/gauges aren't designed to be accurate down low, seeing as there's a bigger problem than your probe if you're only running at 200 degrees. As for your tune, I would encourage a little more timing at cruise. 1200 is a hair hot. 1050 is what I would aim for at cruise.
I would say that's normal. EGT probes/gauges aren't designed to be accurate down low, seeing as there's a bigger problem than your probe if you're only running at 200 degrees. As for your tune, I would encourage a little more timing at cruise. 1200 is a hair hot. 1050 is what I would aim for at cruise.
Well at cruise I am at 38 degrees of timing....I had 42 degrees at cruise, but both 42 and 38 netted the same temps. I figure if its the same temps having a lower time would be better. I am hoping when I bring it in for a tune he can fix everything. Just trying to get it as good as I can so I dont eat up so much time on the dyno. Dyno time ='s mucho money if on there too long Well worth it though if done correctly. People say he is good so all I can do is hope. I will trailer the car anywhere for a tune....well within reason.
if your car is started, the gauge reads the flame from your compression stroke. Its certainly going to be hot, so 200 is probably right. I have the NV gauge and it always read fine.
I'd bring the timing at cruise back to 42, if the temps are the same. The EGT is a secondary means of tuning, A/F 1st then check w/ EGT for timing tweaking.
Just shoot for 11.5 A/F, listen for knock, and add timing
if your car is started, the gauge reads the flame from your compression stroke. Its certainly going to be hot, so 200 is probably right. I have the NV gauge and it always read fine.
All I do is turn the key to the "on" position and it reads 200 degrees without me even cranking it.
Quote: Originally Posted by SpeedEuphoria
I'd bring the timing at cruise back to 42, if the temps are the same. The EGT is a secondary means of tuning, A/F 1st then check w/ EGT for timing tweaking.
Just shoot for 11.5 A/F, listen for knock, and add timing
K I will listen, but what am I listening for...never heard it before. At times the car shakes as its going up in rpm's a little, but I figured thats normal.
sounds like gravel hitting the underside of your car or rice falling on tin foil, well not literally, but similar. You can wot under an overpass or in the city w/ lots of buildings to help hear it. But If your exhaust is loud, well then you may not hear it till its too late, then
sounds like gravel hitting the underside of your car or rice falling on tin foil, well not literally, but similar. You can wot under an overpass or in the city w/ lots of buildings to help hear it. But If your exhaust is loud, well then you may not hear it till its too late, then
you can hear it w/ this home made stethascope(??) ~3deg before you would hear it w/ just your ear.
Basically if you hear knock w/ you ear, then retard 3deg, if you hear it w/ this device then retard 1deg and should go away
Well thats an idea and I havent heard anything like that.....I just wish my aeroforce gauge would read knock from the pcm.....I think it still may since it use to read off the odb port. Just nobody can confirm if it still actually reads knock when its present. I would think it should since it hasnt been disconnected right?
I have a 3 inch dump under the car and when I floor it botht he exhaust is loud as well as the wastegate dump. So I guess the only real thing to do is either make a set of those headphones or wire up the knock sensor to the MS. I just heard its a PITA to hook up the knock sensor to the MS unit...is it?
sounds like gravel hitting the underside of your car or rice falling on tin foil, well not literally, but similar. You can wot under an overpass or in the city w/ lots of buildings to help hear it. But If your exhaust is loud, well then you may not hear it till its too late, then
you can hear it w/ this home made stethascope(??) ~3deg before you would hear it w/ just your ear.
Basically if you hear knock w/ you ear, then retard 3deg, if you hear it w/ this device then retard 1deg and should go away
Well thats an idea and I havent heard anything like that.....I just wish my aeroforce gauge would read knock from the pcm.....I think it still may since it use to read off the odb port. Just nobody can confirm if it still actually reads knock when its present. I would think it should since it hasnt been disconnected right?
I have a 3 inch dump under the car and when I floor it botht he exhaust is loud as well as the wastegate dump. So I guess the only real thing to do is either make a set of those headphones or wire up the knock sensor to the MS. I just heard its a PITA to hook up the knock sensor to the MS unit...is it?
well if you read through that thread, you'll find that no add on knock sensing equip is as good as the factory, they are "tuned" from the factory for certain frequencies, and they read voltage, but voltage goes up w/ rpm b/c the engine gets noiser. So if you have lets say, .5v from the knock sensor @3000rpm, it will pull timing, but if you have .5v @6000rpm, thats perfectly fine. The aftermarket stuff doesnt do this, so it will becaome a hinderance.
I have one on my standalone using the stock sensor(I wouldn't even think about it w/ a different "universal" sensor), SDS EM4F, I dont use it b/c it gives false knock alot and w/ stiff motor mounts ect.. it will be more of a pain
Last edited by SpeedEuphoria : 10-16-2007 at 04:56 PM.
well if you read through that thread, you'll find that no add on knock sensing equip is as good as the factory, they are "tuned" from the factory for certain frequencies, and they read voltage, but voltage goes up w/ rpm b/c the engine gets noiser. So if you have lets say, .5v from the knock sensor @3000rpm, it will pull timing, but if you have .5v @6000rpm, thats perfectly fine. The aftermarket stuff doesnt do this, so it will becaome a hinderance.
I have one on my standalone using the stock sensor(I wouldn't even think about it w/ a different "universal" sensor), SDS EM4F, I dont use it b/c it gives false knock alot and w/ stiff motor mounts ect.. it will be more of a pain
Well could you point me to a link on how to hook up the stock sensor?
I wont get to drive the car till probably friday due to the rain, but here are the last two datalogs I did. I will end up adding another degree or two to see if it helps with the timing. Check out my car how it hangs at idle though....sucks.
Psst... To answer your phone msg. Dave's in Arlington TX.
I'd recommend the "Det Can" headphone setup for tuning. The knock sensors have to be tuned themselves, and how are you going to do that? With "det can" headphones. So either way you have to listen for knock with your ear.
I told you how to check the scan guage. Start the car, run the car up to 3000 rpm and TAP the side of the block next to the knock sensor with a hammer. You should see knock on the scan guage.
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Psst... To answer your phone msg. Dave's in Arlington TX.
I'd recommend the "Det Can" headphone setup for tuning. The knock sensors have to be tuned themselves, and how are you going to do that? With "det can" headphones. So either way you have to listen for knock with your ear.
I told you how to check the scan guage. Start the car, run the car up to 3000 rpm and TAP the side of the block next to the knock sensor with a hammer. You should see knock on the scan guage.
K I will end up doing that to check the scan guage. There are some tuners over there in texas that are willing to let me use there dyno, but were in dallas....wasnt sure how far away that is from arlington.
Well I turned the timing up to 27 degrees at WOT and 15psi with a 11.5-11.7 a/f and the egts just kept going up from 1600-1700 quick so I let off....I am just going to bring somewhere....I dunno whats up or if my egt gauge is off. Only staying in it for about 2k and it gets this hot. It stumbles a little at the beginning so that may be whats causing it to get hot I dont know. I hear 1500's are max for WOT and I hear 1600's are ok, but also hear stock its 1700's...........
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Tuning :)
Well worth it though if done correctly. People say he is good so all I can do is hope. I will trailer the car anywhere for a tune....well within reason.
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