Denso or Bosh & why? Which one for best Tune?

[MyBoosta]

Hello guys,

I've been playing with my car for these last 2.5 weeks trying to find her sweet spot on pump gas before heading out to the track (it's tough for me due to work). So I'm doing much of my tuining late at night on empty streets late at night, and here is what I got:

For some reason I am getting O2 readings in the 790 to 810 low and 725 to 765 high, often in the 742 range for most of 3rd gear and NO KNOCK

My static fuel has been in the 45psi to 48psi range but it seems to like the 45psi best. My boost is set to 17psi but I've seen it creep up to 19psi on a few occassions and NO KNOCK whatsoever on 93oct Chevron gas. TPS is set at .42 idle and 4.78 WOT.

Ever since I changed my O2 sensor from the Denso to the Bosh, my car has been running like this. I felt that it was a huge sin to run this amount of boost on 93oct with readings in the high 720's to mid 740's in 3rd! The Denso's was getting old. I bought the car with it, so I say it was at least 2 years old.

On two occassions I checked a few plugs right after a run and then changed then later and they all had a nice brown coloring to them...NO white coloring it all after the runs and at home during the swap.

Has any one else experienced or are experiencing the same?

Here is my set up:
TT chip 93oct street
TE-44
3" THDP w/dump
Scanmaster 2.1
340 walboro hotwired
50* injectors
Hooker 2.5 dual exhaust
D5 stalled to 2,800
160*
Stock IC with Dutt neck
Autolite 24 (.035)
Fuel press reg

Thanks:biggrin:

 

[bison]

At 19psi you should have 64-67psi of fuel pressure. I always used bosch sensors. They are the most active ones ive found. Tuning off of the stock location O2 sensor is not the most accurate thing to do since it gets really hot and may read leaner in 3rd gear than actual. I have a single wire bosch in mine right now and have .780-.800 millivolts at 26 psi. The indicated a/f ratio on the dyno at those numbers was about 12.0-1. How long does it take to count from minimum to maximum on the cc feature of your scanmaster when the engine is in closed loop?

 

[MyBoosta]

At 19psi you should have 64-67psi of fuel pressure. I always used bosch sensors. They are the most active ones ive found. Tuning off of the stock location O2 sensor is not the most accurate thing to do since it gets really hot and may read leaner in 3rd gear than actual. I have a single wire bosch in mine right now and have .780-.800 millivolts at 26 psi. The indicated a/f ratio on the dyno at those numbers was about 12.0-1. How long does it take to count from minimum to maximum on the cc feature of your scanmaster when the engine is in closed loop?

Do you mean 64-67psi w/ vac? I would think 64 to 67 static would be way too high!

I will have to check on the CC count.

Thanks.

 

[Ormand]

"Do you mean 64-67psi w/ vac?"
His post said "with 19 lbs boost"- that's not vac.
That's 19psi, plus a static setting of about 45, to get a total of about 64.

 

[MyBoosta]

"Do you mean 64-67psi w/ vac?"
His post said "with 19 lbs boost"- that's not vac.
That's 19psi, plus a static setting of about 45, to get a total of about 64.

His post does not specified if it is boost press OR fuel press

So, what FUEL press do you guys typically run with lets say 17 to 19psi of BOOST on 93oct to obtain O2 Mv readings between 775 to 800?

Again, my car with my new BOSH sensor shows around 790 to 800 at the begining of the run, then it falls to around 738 to 742 at middle and towards the end of 3rd gear with OUT KNOCK!

So, should I even worry about the O2's readings if my car is NOT knocking w/17 to 18psi with 740 O2's?

Thanks

 

[TurboDave]

At 19psi you should have 64-67psi of fuel pressure. I always used bosch sensors. They are the most active ones ive found. Tuning off of the stock location O2 sensor is not the most accurate thing to do since it gets really hot and may read leaner in 3rd gear than actual. I have a single wire bosch in mine right now and have .780-.800 millivolts at 26 psi. The indicated a/f ratio on the dyno at those numbers was about 12.0-1. How long does it take to count from minimum to maximum on the cc feature of your scanmaster when the engine is in closed loop?

His post does not specified if it is boost press OR fuel press

So, what FUEL press do you guys typically run with lets say 17 to 19psi of BOOST on 93oct to obtain O2 Mv readings between 775 to 800?

Again, my car with my new BOSH sensor shows around 790 to 800 at the begining of the run, then it falls to around 738 to 742 at middle and towards the end of 3rd gear with OUT KNOCK!

So, should I even worry about the O2's readings if my car is NOT knocking w/17 to 18psi with 740 O2's?

Thanks

Take a closer look, I believe he did specify; First sentance.

 

[VadersV6]

If you plan on running race gas, the lead will kill O2 sensors. The Denso is more lead resistant but will still go bad eventually. The Bosch ones cant handle lead, but they are FAR FAR more active. The O2 crosscounts will cycle far faster. It was about 90 seconds with a Denso O2, and about 10 seconds with a bosch one. That means far more fueling control. I was preaching the bosch O2 thing a couple years ago and alot of people fought it (like with everything that isnt conventional wisdom), but it seems more people are catching on. if you're going to run alky for your anti knock needs, then go with a bosch. Ive had the same one in my car for 50,000 miles and LOTS of alcohol.

 

[bison]

His post does not specified if it is boost press OR fuel press

So, what FUEL press do you guys typically run with lets say 17 to 19psi of BOOST on 93oct to obtain O2 Mv readings between 775 to 800?

Again, my car with my new BOSH sensor shows around 790 to 800 at the begining of the run, then it falls to around 738 to 742 at middle and towards the end of 3rd gear with OUT KNOCK!

So, should I even worry about the O2's readings if my car is NOT knocking w/17 to 18psi with 740 O2's?

Thanks

Let me clarify this. All fuel pressure readings for our WOT tuning purposes are no vacuum applied to the regulator for a baseline. You stated 45-48 psi. I assume with no vacuum on the regulator. With that setting, applying 19 psi of boost to the regulator the fuel pressure should be 64-67. You should gain 1psi fuel pressure for every 1psi of boost vs. the baseline setting with the vacuum line off. Fuel pressure initial settings are always set with the vacuum line off the regulator. As far as your inquiry about the fuel pressure and the O2 millivolts, there are a lot of things that will effect these readings. Here are some:

injector size and pulse width
fuel pressure
type of sensor
temp of sensor
type of fuel being burned
inlet air temperature
boost pressure
engine rpm
exhaust leaks
timing (more timing usually raises the millivolts)
exhaust pressure

Im sure there are a lot of others also. You have to find the best number to run at. I would try and stay around .800 most of the time except at the top of 3rd you may drop to .770-780. These are the typical safe limits that most adhere to. A wideband datalogger like an Innovative LM-1 is much more accurate and a much better tuning aid than the factory located O2 sensor and can sample about 8 times a second and store all that data for you to analyze later allowing you to get much more repeatable and reliable numbers.

 

[MyBoosta]

Thank you very much everybody...especially VadersV6 and Bison.
Conventional wisdom says to stay in the 780 range for 3rd gear...correct?
I tried doing that and it seems that the car runs better with lower numbers. With the fuel jacked up to get better/higher O2 Mv's the car feels flat!

I know that many will cry and say that leaner is not always meaner... I know this, but it seems that this car likes to be on that leaner side of the spectrum. Trust me guys, I hear ya...it just seems that I am all alone on this 740 O2 reading and NO Knock with great looking spark plugs to show for.
I am really that ALONE on this? No else is running good with O2 readings like these...ever?

Let's see, I've gone through 3 set of plugs (autolites, Ac delco's and NGK's) and they all looked about the same. I've used three O2 sensors (2 bosh and 1 denso) and the bosh seems to work better.

I see your points about the more fueling...but how do you explain my lack of knock (audible or on the scanner) and the good readings of my plugs?
Hell, I even added 2* degree extra of timing to my WOT setting and still did not get any kind of knock on straight Chevron 93 oct to boot!

Thanks

 

[TurboDave]

Thank you very much everybody...especially VadersV6 and Bison.
Conventional wisdom says to stay in the 780 range for 3rd gear...correct?
I tried doing that and it seems that the car runs better with lower numbers. With the fuel jacked up to get better/higher O2 Mv's the car feels flat!

I know that many will cry and say that leaner is not always meaner... I know this, but it seems that this car likes to be on that leaner side of the spectrum. Trust me guys, I hear ya...it just seems that I am all alone on this 740 O2 reading and NO Knock with great looking spark plugs to show for.
I am really that ALONE on this? No else is running good with O2 readings like these...ever?

Let's see, I've gone through 3 set of plugs (autolites, Ac delco's and NGK's) and they all looked about the same. I've used three O2 sensors (2 bosh and 1 denso) and the bosh seems to work better.

I see your points about the more fueling...but how do you explain my lack of knock (audible or on the scanner) and the good readings of my plugs?
Hell, I even added 2* degree extra of timing to my WOT setting and still did not get any kind of knock on straight Chevron 93 oct to boot!

Thanks

What you're experiencing is not totally radical. There are cars out there that seem to like the kind of readings you're getting. Mine is one of them. It seems to like the 760 or so range, and I keep a close eye on knock retard, and seldom see more than .5 with .8 being about the highest I see on a shift.

 

[MyBoosta]

What you're experiencing is not totally radical. There are cars out there that seem to like the kind of readings you're getting. Mine is one of them. It seems to like the 760 or so range, and I keep a close eye on knock retard, and seldom see more than .5 with .8 being about the highest I see on a shift.

Cool Dave...thanks, so I am NOT crazy. Correct me if I am wrong, but I've been reading some of the threads on this forum and it seems that if person goes past the conventional wisdom, then that person may be face with a chewing like what a dog does to Kibbles & Bits.

All cars are different, GN's included. For a minute there I was all caught up in this "you must" have at least this level of O2 readings and/or fuel pressure or you will blow up. Whatever! After reading and hearing many of the advices and opinions given here, I simply put on my old school tunning cap and I decided to see what my car likes instead of falling trap to the general cookie cutter approach. Lesson learned...NOT all GN's like 800 O2 readings....NOT all GN's like only 16psi of boost on 93oct...Not all GN's like 43 to 46 psi of static fuel pressure.

Thanks:biggrin:

But hey, you guys are still a great source of info.

 

[TurboDave]

Cool Dave...thanks, so I am NOT crazy. Correct me if I am wrong, but I've been reading some of the threads on this forum and it seems that if person goes past the conventional wisdom, then that person may be face with a chewing like what a dog does to Kibbles & Bits.

All cars are different, GN's included. For a minute there I was all caught up in this "you must" have at least this level of O2 readings and/or fuel pressure or you will blow up. Whatever! After reading and hearing many of the advices and opinions given here, I simply put on my old school tunning cap and I decided to see what my car likes instead of falling trap to the general cookie cutter approach. Lesson learned...NOT all GN's like 800 O2 readings....NOT all GN's like only 16psi of boost on 93oct...Not all GN's like 43 to 46 psi of static fuel pressure.

Thanks:biggrin:

But hey, you guys are still a great source of info.

Depends on how far you want to get away from conventional wisdom.

What O2's work and what doesn't is a matter of where you are in the country at the time you give such advice.

When I was in Kalifornia and only had access to thier really crappy 91 octane (barely), I always said (and my car required) you must see at least 800 O2's to be safe in street trim, and absolutely nothing more than 15# of boost, and still got knock retard.
Now that I'm in TN and have access to good quality 93 octane, I find that I can run with my O2's in the 760's, at 20# of boost and never get over 1° of knock retard.

There are always good rule of thumb, but a little tweeking can yield different results (depending on lot's of variables).

 

[VadersV6]

Theres alot of things that need to be "unlearned" here.
Make sure your knock sensor module's connector is totally clean. All the pins and sockets have to have all that gorilla snot cleaned out.
When it comes to tuning with a factory O2 sensor, its completely unreliable. Its a sensor where its entire voltage curve only indicates a couple points in the A/F curve. 20 millivolts can be around 16.5:1 and 1000 millivolts can be 11.5:1. But the voltage range from 12:1 to 14:1 is HUGE. That sensor is like an on off switch because the curve is so steep and dramatic. A change in O2 volts by like 20 millivolts can be the difference in half a point of A/F. Tuning with that factory O2 sensor is asking for trouble..IF, what you're doing is shooting for a magic number. The only thing that the sensor is useful for, is for finding the "magic" number that your car likes, and keeping it consistent. My car likes O2's in the mid 800's. But I may have the same exact A/F as another guy who's O2's are reading 730. Add timing, add boost, and pull fuel until you get knock, then add fuel. Keep an eye on the scanmaster because at least with mine, it will show KR happening under WOT, but it wont be there at the end when I hit the recall button. Its almost like it takes an average KR and shows you in the end. Also, I get a SEVERE marbles knocking sound, that always sounded way too loud to be detonation, so I ignored it, thinking it was an exhaust problem or noise in the intake tube. It was detonation that wasnt showing up on the scanmaster AT ALL. If I pulled some timing or added fuel, the noise would go away, so I knew thats what it was. It seems the scanmaster only shows 1 of 2 bad conditions...pre-ignition and detonation. So tune around what your car likes...not some magic number you heard on the internet.

 

[MyBoosta]

Once again, you three guys (TurboDave, VadersV6 and Bison) are in the same page as I am.

You are so right Dave, when I lived in Chicago, my older brother there tuned his GN a little more radical than my cousin in Florida. The overall cooler climate in Chicago allowed him to dial in more timing and more boost. My cousin in Florida couldn't do the same; it was knock city for him. I truly belive that I found a local gas station that has giving a little extra edge of tuning flexibility. Like you, I often see my boost gauge flash 20psi with 742 O2 readings and no knock whatsoever...audible or in the scanmaster.

To your point VadersV6, at first I was trying to shoot for that magical number everyone seems to throw at there. I finally said: "screw that" and decided to see what my car likes...I'm still playing with her. And yes, screw that O2 sensor deal...it helps, but it is NOT my end of all my final tuning. I am using the old school method of reading the spark plugs and listening for knock.

The TT chip allows for fuel and spark adjustments to be made into the chip, and I've been playing with the timing portion of it. Believe or not, I added 2* of timing at WOT (total of 18*) and I still have no kind of knock on pump gas and 740's O2 readings!

You guys suggestions regarding the addition of fuel and boost until knock is detected (hearing it and/or scanmaster) then back off from there is my next move. I already adjusted the WOT fuel parameters of the chip to the highest level (+ 20.0%). I also lean out my fuel parameters for 1st ONLY for faster spool up and thus better 60' times. Even with the 1st gear lean out to (-17.2%), I still see O2 readings in 1st gear in the 790's to 810 mark and NO knock. Eric Marshall must have built in plenty of fuel or something into my chip.

Tonight, I am adding straight 117 leaded gasoline, where do you suggest I take my boost levels to? I was thinking about twisting the actuator until I see 22 to 23 psi and taking the timing from 18* high to 22* high AND from 16* low to 20* low...I have a TE-44.

Thanks for your deep knowledge and understanding

 

[RUQWKNF]

Very good info guys and good thread too.
If you are going to run pure 117 leaded race gas with no 93 left in the tank, then you have a lot left. Whenever I have run straight C16, I would have the timing at 26* in all gears, base fp (depending on ambient temp) between 44-48 hose off static and could run the boost up to 26-30. Also depending on which combo and turbo. Ex: With this gas, on a TE-45 turbo, stock motor, 009 42.5#ers, external Bosch pump, no intank, with ported M&A heads, ported stock intake, 70mm t-body & PTE plenum, stock headers, 3" dp and 3" single shot, that combo really like .740s with less than 1 degree of knock and 30psi. And this was in MS fall weather.

With your combo and 117 octane, I would throw a set of Autolite 23's gapped at a tight .032 gap (you're gonna run higher boost and higher timing then you have with the AL 24 plugs) change the factory fuel filter, and start out with the timing at 24* in all gears, static fp at 45, and boost at 22 for the very first run. With your fuel settings, you are probably going to be in the high 700s with zero KR. It will also depend if you still have any 93 left in the tank or not. From here you can do two things.

- Leave the timing alone and turn up the boost 1-2 lbs.
- Or turn the timing up a degree or two and see how she responds.

Some might call this jumping right in on the tune, but to me on C16, you have a lot of room for error, IE knock retard. Really, on straight 117 octane race gas, anything less than 25* timing is really a waste. Just take things in steps and write down every change you make before making another. Keeping a race log is an excellent idea when pushing a combo.

The TE-44 can be run up there into the crazy range, but it really likes 26-27. One last thing, the higher you turn up the boost, the lower the KR will need to be. Once you get up there in 27+ land, we want to be in the zero to less than 1 degree of knock to keep the head gaskets happy.
Don't forget that fuel filter.
HTH

Patrick

 

[VadersV6]

There was a time when I was running 25 degrees of timing on 89 octane and 18 psi with no knock....according to my scanmaster. I knew the knock sensor worked and the scanmaster showed knock retard, (it had shown as high as 14 degrees when I had a bad set of injectors) but for some reason, it wasnt telling the whole story. I had this high speed popping, or crackling is a better word, at WOT. Ive heard knocking in engines most of my life, and this sounded nothing like that. It was way too loud and sounded like popping popcorn. The scanmaster showed maybe .2 degrees of KR but most of the time nothing. I thought maybe I had a hole in my head gasket or maybe the timing chain was really stretched out and causing a little combustion to pop its way into the intake tract, or the spark was blowing out...had all kinds of theories...but it sure wasnt knock according to the scanmaster. I knew for years that there was a difference between pre-ignition and detonation, but somewhere along the line, I forgot there was a difference. Someone on the board reminded me, so to speak. even though I had no KR, I pulled out 4 degrees of timing to see what happened. The year straight of crackling was gone. It wasnt a weak spark or a bad head gasket...it was likely pre-ignition, and our knock sensors are only picking up 1 frequency, which is kind of lame I think. Theres no reason they couldnt have 2 sensors, each tuned to a different frequency. All we have is this one crappy one that has such a wide frequency range, that banging downpipes set it off, and noisy lifters and everything else but pre-ignition. I cant believe my engine still runs after so much pre-ignition happening. I think the fact that I never stayed in the throttle for more than 4 seconds is what saved it. So forget about the magic number everyone says the TR's like...like every TR is a clone of the one before it. Add as much timing as you can throw at it. Add fuel until the KR goes away, as well as any audible knock or "crackling". If you have to add so much fuel that you're blowing smoke out the tailpipes like a diesel, then pull a couple degrees of timing and start over. Log that O2 number, and thats the number to shoot for...assuming every batch of gas is the same, and the weather conditions are the same, lol....thats a futile effort to say the least. Any high strung motor will have to be adjusted all the time, with different batches of gas, and in different seasons and weather conditions. If you want it to last, just keep it rich, like in the 11-11.5:1 range and run about 3-4 degrees less timing than you can hit before you start getting KR. Dont take it to 25 degrees, and say you have no knock, then take it to 26, then you have a little knock, and then back it off to 25 again, and think you're safe. Run 22 degrees. You'll thank yourself in the future, and so will the guy who buys your car. And keep oil out of the intake manifold! Run a catch can...this is another great thing about alky systems. They blow all the carbon off the backs of the valves (which is like getting another .100" of valve lift if the buildup is bad), and it flushes all that detonation and pre-ignition causing oil out of the intake manifold. If you feel like extracting every last hp out of it, and want to set records at the drag strip, then push it. But for a street car, unless you have deep pockets and alot of spare time to rebuild engines, keep it in the safe zone. It will by no means be boring. I personally like 20-23psi with alky set to turn on at about 12psi (eliminates that transitional rich spike), and 23 degrees of timing. Also, another thing that goes agains conventional wisdom, is the heat range of spark plugs. There are alot of assumptions and misconceptions about them. I have actually had a repeatable history of having LESS KR with stock heat range plugs than 23's...and Im not the only one on this board. I also run as much spark gap as I can get away with, and the power to be had is very obvious. Plus it cruises way smoother and idles great. Ive run as much as .045 with no blow out with a 90 dollar autozone ignition module and my old coil packs that ohm all over the place. But this is with Autolite double platinums. I havent found the same behavior with other plugs. Using a diamond file, I file the ground electrode back (without touching the positive electrode) to where all thats left on the ground electrode, is the platinum pad. I file a nice curve all the way around in all directions..eliminating all sharp edges, and then currently my gap is about .038...although like I said, I can run it even bigger with these plugs. This ground electrode trick is old school. Racers have been doing this for ages. Its adds a decent amount of torque, and the elimination of all sharp edges is something I tried on my own to eliminate glow spots and sharp disruptions in the flame front, first in my blown cobra (for some reason I could run more timing than anyone else..and guess what? They were stock range plugs and everyone was freaking out on me, saying theres no way itll last and it will blow up...never happened, and I made the most power out of a Novi 1000, on low boost out of everyone. The people out there who are the record setters, are usually the ones who ignore what everyone says and searches to find the truth on their own. Doing what everyone else doesnt end up anywhere but chasing your own tail.

 

[MyBoosta]

THIS IS WHAT I AM TALKING ABOUT...getting info. from guys who have ignored the so called "conventional wisdom" and experimented on their own seeing what works and what does not on their applications. Thank you very much Patrick (RUQWKNF), VadersV6, Bison and TurboDave, you guys have given me so much info these last two days that I am so pump up to see what can this car really do.

I like the fact that you guys are not chewing me out for not being one of those cookie cutter GN guys who only seem to follow what every one else is saying and/or doing. Vader, I too was an old 5.0 guys with a Vortech back in the day, I can’t tell you how many times people were calling a liar because I ran faster than them with less mods. Why? Because I did not follow the so called rules of tuning; I sat down and experimented with my car seeing what she liked. Yes, it was time consuming but it was worth it; I wasn't popping head gaskets or breaking other silly parts either.

Patrick, like you suggested, I've been writing every thing down, from the day I purchased my GN when it felt like a mid 14's car. I’ve been logging everything, even tire pressure settings. I've been going to work on 4hrs of sleep for most these last few days because I’ve been going out late at night around town testing and re-tuning my changes; I think I'm pretty much there now. Weather permitting; I'll be going to the track this Friday to see if all these efforts have gotten me somewhere. That is why I ran out all of the 93oct stuff and adding the 117oct leaded gasoline.

This will be my very first time with higher boost levels with this car, and I am taking you guys’ advice. I will start with 23psi of boost and timing in the 22* (1st and 2nd) and 20* in 3rd. I will test this combo tonight and report back; my little 215/65/15 tires are in for a rude awakening.

So, should I get another bosh O2 sensor for the track only? I believe this leaded 117 is going to kill this sensor…right?

Thanks

 

[pacecarta]

too much here to read through but the stock o2 whether bosch or denso or ACdelco suck for tuning as all will respond different in turbo application due to the immense heat and pressure that the sensor lives in , for emmisions and economy any sensor should be fine
if you must insist on relying on an O2 delco is just fine ,denso's design helps to protects the element from lead deposits if running leaded fuel

but for tuning O2 is not so much an indicator of lean rich but the amount of unburned O2 , but once you know where your car is it does help you judge if its going richer or leaner based on past #s (provided you arent loosing spark )
you should tune for MPH , no nock and
avoid high egt . its not just a sign of lean but also over rich and isnt good , if rich it takes toll on headers/turbos and if lean pistons /valvesheaders/pistons , 1500 is a nice place to try to be but 1600 has worked for me too

as for tuning with #s get a wideband and run what the car likes

my o2 (denso) shows 715-720 in third and at that number its at 11.2 AF,

 

[RUQWKNF]

Good stuff VadersV6.
Yep, get another O2, but I would suggest running a full tank of 93 through the car to help burn out all the leaded 117 before putting in the new replacement. There's no sense fouling out a brand new one cause you had a half a gallon of 117 leaded gas still in the tank. I always used the Bosch O2 with the OEM connector from Autozone. The other neat trick is, AZ gives you a 3 month warranty on them. Constantly replacing single wire O2 sensors and running leaded race gas are the price we pay to play. BTW, AZ came down on the cost of the Bosch OEM O2. When I purchased one back in January, it was $19.99. I can remember paying $35.99 for the exact same sensor at the Zone back in '99. Post up some results when you get them.

Patrick

 

[pacecarta]

sparkplugs.com
should run you under 40 bucks for two denso O2s with shipping