mazzuri super headers
03-09-08, 06:16 PM
#271
well 93 octane seems to be working for the one guy. my question is why wasn't he filling up with 93 in the first place? isn't that the recommended type for our car? only the 350?
i think the sound is fantastic on the 250 from what i hear, hope the 350 isn't all too loud. i'm sure it will be powerful regardless. u go daniel
i think the sound is fantastic on the 250 from what i hear, hope the 350 isn't all too loud. i'm sure it will be powerful regardless. u go daniel
No 93 in CA, only 91 and 100 sold at some places...
03-09-08, 08:39 PM
#272
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lol I don't see how this is really a fix even if 100 octane takes care of the problem. 100 octane must be like 8 bucks a gallon or something. Maybe for a track car or something it's worth considering.
If these are the kind of problems that we can expect then these headers are in no way ready for primetime yet.
If these are the kind of problems that we can expect then these headers are in no way ready for primetime yet.
We in CA don't have anything above 91 if a formula can be figured out to where we can figure out the right amount of 100 to be mixed with 91 to get 93 it may not be that expensive. It may take 2 gallons of 100 per tank or something I don't know.
03-09-08, 09:07 PM
#274
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I guess I'm getting confused here. I have done alot of exhaust and header combinations on alot of different cars and trucks over the years and I have never had this issue before. How is the header creating misfires? I know in turbo applications, you have to close the gap on the plugs as the air rushing in can cause blow out, which causes misfires. In this case, could we may be seeing some of that happening? I know we aren't seeing any where near that amount of air pressure, but maybe due to the direct injection?
I think raising the octane just sounds like a band-aid fix at most.
I think raising the octane just sounds like a band-aid fix at most.
03-09-08, 09:13 PM
#275
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Supra tanks hold 18.5 gallons. 4 gallons of 100 octane with 14.5 gallons 91 octane yields slightly over 93 octane. I used to do this all the time. Just another reason I left California - 93 at the pump here in GA.
With that said, I'm not confident this is octane related without seeing the codes from the ECM. Engine fail-safe mode for knock does not clearly limit rpm, it only limits ignition advance to fully retarded. I'd bet this is an O2 sensor issue, not a fuel issue.
With that said, I'm not confident this is octane related without seeing the codes from the ECM. Engine fail-safe mode for knock does not clearly limit rpm, it only limits ignition advance to fully retarded. I'd bet this is an O2 sensor issue, not a fuel issue.
03-09-08, 09:16 PM
#276
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BTW, a/f ratio will also affect spark. There is a "sweet spot" when you get it right and even a poor ignition system will work. Unfortunately you may need a high powered system to find the sweet spot. The high powered system only helps mask tuning issues when you are tuning an engine because it will fire when other systems would rightly fail.
Last edited by lobuxracer; 03-09-08 at 09:23 PM.
03-09-08, 10:54 PM
#277
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I guess I'm getting confused here. I have done alot of exhaust and header combinations on alot of different cars and trucks over the years and I have never had this issue before. How is the header creating misfires? I know in turbo applications, you have to close the gap on the plugs as the air rushing in can cause blow out, which causes misfires. In this case, could we may be seeing some of that happening? I know we aren't seeing any where near that amount of air pressure, but maybe due to the direct injection?
I think raising the octane just sounds like a band-aid fix at most.
I think raising the octane just sounds like a band-aid fix at most.
To fix it, you need higher octane which will NOT ignite as easy (and thus cause knock or a misfire) or you need to add fuel to the mixture to cool the combustion area down to also prevent the same thing.
Raising the octane is not at all a band-aid fix, it is a "fix", because it will keep the engine happy. In a sense, if you go by your logic, SAFC would also be a band-aid fix.
The more I think about it, the more all the facts point to what I am thinking it is.
03-09-08, 10:59 PM
#278
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Supra tanks hold 18.5 gallons. 4 gallons of 100 octane with 14.5 gallons 91 octane yields slightly over 93 octane. I used to do this all the time. Just another reason I left California - 93 at the pump here in GA.
With that said, I'm not confident this is octane related without seeing the codes from the ECM. Engine fail-safe mode for knock does not clearly limit rpm, it only limits ignition advance to fully retarded. I'd bet this is an O2 sensor issue, not a fuel issue.
With that said, I'm not confident this is octane related without seeing the codes from the ECM. Engine fail-safe mode for knock does not clearly limit rpm, it only limits ignition advance to fully retarded. I'd bet this is an O2 sensor issue, not a fuel issue.
I want to pick your brain a bit and see why you think it may be an O2 sensor issue? Are you talking about the main ones? or the second ones that are now simed?
I am 99.9% positive it's an octane issue, because Jim is not having this issue with 93 and I didn't with 100.
03-09-08, 11:06 PM
#279
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So you're saying there's more than a 20% fuel adjustment to run with the headers? The primary O2 should be setting stoich on part throttle cruise - it aims for 14.7:1 unless you're more than 20% off the stock maps, then it will for sure set a DTC.
Knocking during cold cycle is the least likely of all possibilities. Knock is caused by too much heat in the chamber from compression of the a/f mixture. If the piston and head are in cold cycle, there's plenty of opportunity to remove heat and prevent detonation. You're looking through the wrong end of the telescope here with your analysis. Stop and go is also NOT when you have knock problems. You have knock problems when you have a heavy load on the engine. You could run 50 octane at part throttle cruise and never have any problems because it isn't possible to get too much heat in the chamber. You need 100+ motor octane when you're running a heavy load on the engine - like accelerating hard away from a stop.
Besides, you are straight guessing without looking at the DTCs.
Finally, your own dyno says you are wrong - if you were having issues with fuel or detonation, you'd see it on the dyno as break up under load. You're not making more than 20% more power, so you shouldn't be outside the range of adjustment for the OEM fuel map correction factor.
Pull the DTCs and quit guessing.
Knocking during cold cycle is the least likely of all possibilities. Knock is caused by too much heat in the chamber from compression of the a/f mixture. If the piston and head are in cold cycle, there's plenty of opportunity to remove heat and prevent detonation. You're looking through the wrong end of the telescope here with your analysis. Stop and go is also NOT when you have knock problems. You have knock problems when you have a heavy load on the engine. You could run 50 octane at part throttle cruise and never have any problems because it isn't possible to get too much heat in the chamber. You need 100+ motor octane when you're running a heavy load on the engine - like accelerating hard away from a stop.
Besides, you are straight guessing without looking at the DTCs.
Finally, your own dyno says you are wrong - if you were having issues with fuel or detonation, you'd see it on the dyno as break up under load. You're not making more than 20% more power, so you shouldn't be outside the range of adjustment for the OEM fuel map correction factor.
Pull the DTCs and quit guessing.
03-10-08, 09:31 AM
#281
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So you're saying there's more than a 20% fuel adjustment to run with the headers? The primary O2 should be setting stoich on part throttle cruise - it aims for 14.7:1 unless you're more than 20% off the stock maps, then it will for sure set a DTC.
Knocking during cold cycle is the least likely of all possibilities. Knock is caused by too much heat in the chamber from compression of the a/f mixture. If the piston and head are in cold cycle, there's plenty of opportunity to remove heat and prevent detonation. You're looking through the wrong end of the telescope here with your analysis. Stop and go is also NOT when you have knock problems. You have knock problems when you have a heavy load on the engine. You could run 50 octane at part throttle cruise and never have any problems because it isn't possible to get too much heat in the chamber. You need 100+ motor octane when you're running a heavy load on the engine - like accelerating hard away from a stop.
Besides, you are straight guessing without looking at the DTCs.
Finally, your own dyno says you are wrong - if you were having issues with fuel or detonation, you'd see it on the dyno as break up under load. You're not making more than 20% more power, so you shouldn't be outside the range of adjustment for the OEM fuel map correction factor.
Pull the DTCs and quit guessing.
Knocking during cold cycle is the least likely of all possibilities. Knock is caused by too much heat in the chamber from compression of the a/f mixture. If the piston and head are in cold cycle, there's plenty of opportunity to remove heat and prevent detonation. You're looking through the wrong end of the telescope here with your analysis. Stop and go is also NOT when you have knock problems. You have knock problems when you have a heavy load on the engine. You could run 50 octane at part throttle cruise and never have any problems because it isn't possible to get too much heat in the chamber. You need 100+ motor octane when you're running a heavy load on the engine - like accelerating hard away from a stop.
Besides, you are straight guessing without looking at the DTCs.
Finally, your own dyno says you are wrong - if you were having issues with fuel or detonation, you'd see it on the dyno as break up under load. You're not making more than 20% more power, so you shouldn't be outside the range of adjustment for the OEM fuel map correction factor.
Pull the DTCs and quit guessing.
Again you are talking about part throttle, which is not when this issue happens.
This is not a fuel issue that happens all the time, in 3 weeks it happened to me 1 time when the car was cold and I floored it. It never happened on the dyno to show in anyway.
I was sent a fail safe sheet by Lance, not sure if it was you or who ever, but it confirmed everything I was thinking and saying that it was knock as the code that showed up for me was P0328.
Last edited by mazzuri; 03-10-08 at 09:34 AM.
03-10-08, 09:35 AM
#282
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03-10-08, 09:45 AM
#283
On the dyno there was no part throttle, it was all full throttle at all times, I am no tuner but even I saw it was lean to up about 3/4k RPM. This problem occurs only when you floor the gas pedal, it doesn't happen at part throttle.
Again you are talking about part throttle, which is not when this issue happens.
Again you are talking about part throttle, which is not when this issue happens.
AN ISSUE WITH THE HEADERS. I need some help on.
Twice so far when I am in traffic the check engine light has come on, and a warning that says CHECK VSC. The car goes into some kind of safty mode and I am forced to find a place to pull over.
All I need to due, to recover is turn off the car and turn it back on and I am good to go. Both times it happened I was in traffic coasting between nuetral, 2nd, and 3rd gear.
Should I be worried? What can I do to prevent this?
Twice so far when I am in traffic the check engine light has come on, and a warning that says CHECK VSC. The car goes into some kind of safty mode and I am forced to find a place to pull over.
All I need to due, to recover is turn off the car and turn it back on and I am good to go. Both times it happened I was in traffic coasting between nuetral, 2nd, and 3rd gear.
Should I be worried? What can I do to prevent this?
He said every time it happened to him he was coasting, NOT at full throttle.
03-10-08, 10:09 AM
#285
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Well all I can tell you is that this weekend I put anouther 100 miles on the headers, and spent 2 hours in traffic going from burbank to anahiem, and the issue didn't pop up again. This morning I spent a hour in traffic again no issue.
Now here's something. This weekend and including today I drove the car differently than I ussally due. The two times I got the error was in traffic shifting between 2nd and 3rd.
Would driving out of 3rd at really low speeds cause this problem?
This weekend and today I made sure I down shifted to either 1st or 2nd, based on how slow I was going. Where normally I would stay in 2nd and 3rd.
Daniel did any folks in Cali with an automatic transmission buy the headers? Are they having any issues?
Now here's something. This weekend and including today I drove the car differently than I ussally due. The two times I got the error was in traffic shifting between 2nd and 3rd.
Would driving out of 3rd at really low speeds cause this problem?
This weekend and today I made sure I down shifted to either 1st or 2nd, based on how slow I was going. Where normally I would stay in 2nd and 3rd.
Daniel did any folks in Cali with an automatic transmission buy the headers? Are they having any issues?