SpinMonster

My preference is a dry shot and the reasons will surprise most people. My dry shot set-up is a bit more advanced than most and I will share the trade secrets.

The biggest complaint about the dry shot is tuning it. The biggest complaint about a wet shot are the variables of bottle pressure, fuel solenoid reliability and what happens during a failure. If a fuel solenoid fails which I have seen quite a few times, you get a lean condition. If it leaks you get a backfire. If the nitrous solenoid doesnt fire its a rich stumble you get.

My system didnt install the way other dry systems do. The tuning for a dry shot is to use one dry nozzle pointing toward the MAF to get a concentrated shot of air on the MAF making it think the incomming air is filling the entire volume of the MAF unit and the PCM commands more fuel to be dumped. I dont like the freezing of the MAF element and you also had a hard time adjusting it a little richer or a little leaner. Another variable is if the nozzle's aiming gets changed and it shoots over the MAF element you get a very lean condition. A second nozzle has been used by some to tune but again its all about where the N2O is pointing as it comes out. Timing is adjusted with a timing tricker box and you never know if its working because they intercept the signal from the crank and the scan always shows the commanded timing even if the timing is being pulled.

Harris speed works has an active circiut to adjust fuel and timing curves to suit the fuel and spark retard of any application and it goes inline with the MAF. Its advantage is that it can be adjusted to any amount of fuel or timing. It is an active circuit and it can fail. Its tuning is another matter.

My final methodology for tuning was to make a passive circiut with parts from radio shack and have the dry nozzles pointing away (thats right, I said AWAY) from the MAF on my dry shot. The N2O would mix evenly prior to getting to the MAF and the even flow of air keeps the PE exactly at the commanded PE which is 13:1. To maximize the car's N/A operation, I wanted the circiut to pull timing and dump additional fuel only while my thumb is pushing the trigger button on my T-handle and not when the system is armed. Off the button my car runs the hottest max effort tune I could do to my car. OK, for those keeping score my car is now going to run at 13:1 on a nitrous shot as commanded (no we arent leaving it there). It is even and it is predictable. No nozzles to come loose and change where they shoot and no pointing the nozzles with a try and guess and hope reiteration to get 11.8:1 which is my target.

Nozzle location: sorry the install isnt stealth which I just dont understand. It not a curse to have a bottle. Its a legit power adder with drag race classes.


I intercepted the signal at the MAF and installed a relay to to change resistence to the MAF's IAT sensor. For those not familiar the IAT is a themal resistor and varies its resistance with the temps it is subjected to. The IAT or intake air temp sensor does exactly what it says; it measures the temperature of the incomming stream of air. In the case of my firing the nitrous the resistance is changed to make the car think that the incomming air charge is 199 degrees. Now unless you live and drive on the surface of Venus, the IAT's will never hit 199. The amount of timing is one degree more in the summer. I pull 1.5 degrees per 50HP. A nitrous shot is variable from 0-150 on a single nozzles and somewhat higher on a dual nozzle. Now for the cool part of the tuning. The IAT not only controls the timing curve from the IAT base spark table but on the fuel tab there is an IAT vs. Injector flow rate table (this is on the general fuel tab for C6's and the PE tab for C5's...in the C5's case its an adder for the commanded PE). In this table IFR is changed according to IAT temps. In the following screen shots of my HPtuners editor, the IAT base spark and IAT vs injector flow rate are pictured. In this first you can se where I typed in -4 degrees in the high end of the table. When I first did this mod I used the lower end of the table so the IAT could be in series with the new resistor and they both contribute to the amount of timing pulled. For example if it is 95 degrees out the car is going to pull one more degree than lower temps. On actual hotter days the IAT would vary the resistence and pull the extra degree by accessing the next hotter verticle line on the IAT spark table but my ever knowledgeable brother, whom I believe at times is supernatural, spoke some words of wisdom. A teacher by discipline, he led me to my faulty thinking by asking questions and facilitating the absorbtion of knowledge. He asked why I wanted different values for the IAT temps. I responded with the, "Duh, cause on hotter days it needs to pull more timing." "Why would you do that?" he asked. I said, "because of the hot air comming in." He then said,"Well, nitrous is so cold when its shot that it cools the air intake temps by 70 degrees doesnt it? It dawned on me that the hot air charge would always be under the 95 degree line and therefore not need anymore timing pulled so it isnt an issue. Frady cats can pull another degree if they want in the summer but it really isnt needed.



Now I have to take a second to dispell 2 myths: first the IAT needs to have its resistence tricked with a resitor. The nitrous comming in wont cool the IAT fast enough to think you can have it pull the timing with cold temps listing the timing as -3 or -4 in the colder areas. After a few seconds on a hit the Iat never moves on my scans more than 1 defree. Second for the guys that say the cylinder airmass on the shot is so much higher than N/A that you can just command 3 or 4 degrees less in those areas. BS. The scans I took of my car hitting the shot always hits cells in the mid to high parts of the N/A affected timing cells so that doesnt work either unless you are going to tune for N2O and done care about maxxed out N/A operation.

In this next table the IAT vs injector flow rate adjusts the fuel to where I want it. Smaller values richen the shot. The IFR is lowered making the PCM think it has smaller injectors so it makes them dump more fuel:
For the C6 guys:


For the C5 guys:


In my case the 199 degree input instructs my car to dump 8% more fuel than normal. If I want 1% less I type that change in If I want 2% more I type that in. The best part is that it all shows up in the scans. Wet shots need to have constant bottle pressure to maintan a a/f ratio (which it never is) and the only way to richen it up is to change the fuel jet. I just type in what I want and it works flawlessly.

Initially, I scanned the car safely in my driveway (later in use with a 22 shot then 50 then 75 then 100...)and bypassed my WOT switch to allow the IAT circiut to adjust the timing -4 degrees and add 8% fuel while sitting safely in my driveway and simply revving to 3500 where my shot pops in to make me go retarded fast. The scan showed 42 degrees at that load and rpm and without moving up or down on the gas pedal and triggering the circiut, the timing fell to 38 and the long term fuel trends jumped down 8%. I wish I had saved the scans to show some screen shots but the system workd flawlessly and ends the debate in my mind of wet vs. dry.

Now some safety issues. The relay in the IAT tricker needs to be operating to supply the ground for the relay that triggers the solenoid so if the tricker doesnt function, the N2O doesnt fire. The nozzles point away from the MAF so it doesnt freeze and potentially damage the element. I dont have to worry about a dry hit heading over the MAF and leaning out. I have consistency and a degree of control no wet system has. In the case of my speed density tuned 2005 I dont need the MAF to even be there and the MAP/VE would calculate the fueling and still compensate to the commanded PE. I have a permanantly mounted XD-16 Lc-1 wideband to monitor fuel. The fuel curve never spikes lean on the shot engagment due to the extra time it takes for the N2O to reach the combustionchamber since it has a bit more time from being pointed away from the MAF. The N2O is pointed away and takes time to hit the MAF and then the motor and the IAT commands the IFR to dump more fuel instantly. When you come off the pedal the car isnt under load anymore and doesnt need a sustained rich state. I couldnt get the car to spike lean before or after the shot even staying on the pedal. I didnt invent the IAT resistor trick first but I invented it to myself and later checking on the internet found that I wasnt the only guy to do it.

Now with all this safety and simplicity I want to see a guy make an argument for a wet shot over this. You can keep the fuel solenoid and the fuel in the intake manifold idea. By the way, dry shots hold hold the record in that drag class. If you are going to do this you need to get the MAF patch to extend the frequency limits for the MAF or you can potentially max out the MAF. I believe I saw 9800hz on the 100 shot so the guys thinking the MAF is maxxed out must have been thinking it prior to the MAF frequency patch. For those that dont know what it is, on the editor click the operating system button in the upper left corner. It has the add on licenses for speed density where available and the TCS and MAF patches. A write-entire must be done to enact these changes. If anyone has questions about this system or is close by and needs a hand with its install, shoot me a PM. All my work is shareware and I share secrets. (I guess that means they arent secrets)

I have run a 35 shot and a 50 shot. Those who say its not worth it to run such a small shot is a very narrow vision. On the street even with a great tire (mine are r-compound) as I run there are limits. First gear cant have any shot. On drag radials, a 22 shot 2nd gear can break the tires loose. It actually does it N/A unless the tires are really warm. 3rd gear has a 50 shot limit. In the summer I would have better traction so a 35 shot in 2nd and 75 shot in 3rd will likely stick the ground. Now I can understand when a car is stock or near stock that you would be wasting your efforts for a small shot but the jet or jets are easy enough to change. A max effort H/C car on the street is going to be slower with a 100 shot if he isnt running an R-compound tire. It will be a spectacular burnout at 50mph though. My car is never going to be able to be floored in 1st gear on any size shot. What shot you run is entirely up to your rear tires and the power level you have N/A. A guy running near 500rwhp on the street isnt going to run a 175 shot. Another issue is that a 50 shot is 85+rwtq. Most H/C cars wont be able to use it on street tires. A 50 shot isnt insignificant unless you have no power N/A in which you lean your car (and ego) off the bottle. 50 shot guys will have plenty of shots per 10lb bottle so its a good situation. Keep in mind that the fuel injectors need to be big enough to supply the needed fuel for the additional requirement. If you have 90% duty cycle with a H/C car and you add a 125 shot you are over the line. Think 40lb'ers for a 500rwhp car which is likely more than 550rwtq. Go bigger for silly numbers. Also remember that the fuel pump isnt going to support 600/700 without a boost-a-pump. 600HP from a supercharger isnt like the 600rwhp from the bottle. The TQ is 500 for a 600rwhp S/C car and close to 700rwtq for a 475 rwhp H/C car on a 125shot. They call it TQ in a bottle

Beer99C5@FastbirdPerf.com

Great info and STICKY WORTHY!


Hope to detail similiar Dry tuning with COS5 early May.

1%r

Nice work, Guy.

Robert56@RNS

I have been tuning the dry hits for years and trying every trick known to man concerning the dry hits; I have come to an ultimate conclusion: The Interface from Harris, it's the tuning bomb these days for dry and wet. (the EFI COS 5 is not far behind, though the Interface doesn't need a tuner program and thus less expensive; also, the HPT has many tuning tricks that can be employed, see my web)

I didn't get a chance to read all of your post but I cam across this below qoute. The HSW Interface will shut down the complete N2O system if any kind of failure or misreading is had. There isn't an easier, safer, cheaper control for Dry hits out there. The Interface can be used with the nozzles before or after the MAF, on Dry Direct Port, on Wet Direct Port and any other combo. there is a dual stage model coming. The Interface will also show the true timing pulled on your logs. I have a thread at tech showing how it all works and screen captures as you have done. I will link it later.

Trust me when I say this is the easiest method for dry tuning, bar none. You can check my web for some additional tuning concerning the dry hits. I did notice a couple things in your write up, but likely will not be able to get back to this thread until tomorrow. With all that said, Kudos to you for your dry knowledge/understanding, most in the industry (vendors and tuners) have no real clue how the Dry hit really works, and normally rec the end user to run a wet hit, lol. My current question to the wet guys, "Give me one good reason to run a wet hit on the LSx/EFI platform." No takers, because it's an old school 40 year old technology designed for carburetors.

Robert56@RNS

One thing about aiming the nozzles away from MAF. This is OK only if tuned like you say, or with a HSW Interface. Other wise, the standard is close and directly at the MAF. freezing of the MAF is an old wives tale. How on earth could the guys drive their cars on the freeway in Chicago when the the temps hitting the MAF wires would/can be 40 below zero, it just doesn't happen. You may be mistaking air dynamics up close that can cause sputtering, or inconsistent reading as a froze MAF. We have run up to 300rwhp shots verified on the dyno with nozzles 3 inches from MAF wires and worked flawlessly. then again, a 100 hit up close like this can have problems, so nozzle tuning is a little finicky and thus the Interface. Everything you state above can now be done with dip switches and you just decide what size hit and a/f and dial it in. also this is how the timing pull works, all on dip switches. The IAT and resistor tricking has been around for years, but has never taken off because it's just to confusing to the average user, and this includes tuners and vendors. Many talks on this subject have been had over at tech.

Robert

SpinMonster

I like the Harris unit but it is still an active circiut....even the protection safety points are based on an active electircal circiut. A silly story to illustrate what I am getting at is with a VCR I had years ago. During an electrical storm the VCR was on a line that got zapped. The TV was fried but the VCR taught me a lesson; I will never forget. The VCR seemed to function perfectly. It played tapes and recorded. The picture was perfect. It had one thing that was not right: the clock was counting 40 seconds for each minute. In other words every two hours would show 3 on the clock. In the electronics world, counting is the basis for all silicone circiuts. Errors in counting can mess up a digital tach as easy. The harris speed works unit may function in every aspect except the counting conditions that lead to shut down. A passive circiut is always used in switching where human safety is involved. The best example is a traffic light. The red and green lights are mutualls exclusive with switching. If the red is on the green switch is disabled. In measuring the amount of airflow to tune a dry shot such an error can cause a wrong value in the MAF resistence.

I will take a 6 dollar relay anyday. If it doesnt fire, the N2O solenoid mechanically is disabled. There cant be a power surge to knock off the operation of a circiut. The HSW unit is 160 bucks and my total circiut was 11 bucks. The relay can be slid out of its socket and replaced in its project case box in minutes. I only present the option of the part and the sharing of the tech which is remarkably similar in operation.

Thanks for the opinion and input. I really like when a vendor or tuner takes the time to have some input on tech like this. Those that share nothing and only care about selling what they have isnt the spirit in which I do these things for free for fellow members.

SpinMonster

In the initial install I was intent on getting the A/F right. Timing was easy since it was a resistor trick. If you point the nozzles away from the MAF the car can never go leaner than the commanded PE value. If you point it at the element and the nozzle shifts slightly raising the target to just over the element it will be a disaster.

In the initial install to see exactly where the N2O gas was aimed, I bypassed every switch and brought up the bottle pressure and fired the solenoid to see where the stream was hitting. This was done with the engine off and the airbridge disconnected after the MAF. So the front of the air cleaner assemby, nozzles, and MAf were held in place exactly where they are in operation. The freezing that occurs isnt with cold air as you would have on the hiway in -40degree temps. It had a complete encasing layer of thick frost on it. There is no way it will function properly for the short time after the hit and accounts for why the initial runs like that were excessively lean when the shot ended but I remained on the gas pedal. Comming off the gas always does that but if the hit ends from the window switch and the car still runs 300-400 more RPM's at full load it was reading close to 15:1 on my wideband. If the nozzles are pointed away the car reads it as higher air not concentrated at the element and the fueling is always the commanded PE. I did it so many times before I raised the shot level. If the car is tuned to 13:1 and the nozzles are away from the MAF the gas mixes evenly with the incoming ambient air and the MAF reads the increase in volume and maintained the 13:1 evey time.

If its a 100 shot and ther timing wasnt pulled you would see 4 degrees knock retard at best. Not detonation. If the MAF failed it would rely on a proper VE table to fuel it.

Your points are valid and make sense. Its just a discussion. Many people have no issues with the point and pray method of tuning a dry shot but the beginners have to be careful of some things. I went some time without tuning more and went to check things under the hood and the nozzle had worked loose and changed its direction slightly higher which was over the element. I knew this idea had to be scrapped immediately. Nozzle direction is so critical in that type of tuning that it shouldnt be used. Pointing away gives the most predictable result.

For many people the HSW unit is the way to go for simplicity. I dont see any advantage in my case. Either way, the nozzle's direction shouldnt be relied on so heavily. This thread was to defend the dry shot over the wet shot and to give another option. It wasnt to bash the HSW unit which I would get in a heartbeat. For those that can do it this way I see no advantage other than the cost savings and it being a passive circiut.

SpinMonster

I see no advantage of that system on our car with this method available. Its a simple 4-5 wire hook-up, costs 11 bucks, and tunes the same way.

Beer99C5@FastbirdPerf.com

I agree, the HSW interface was not an option when I purchased EFI Live.

It is another way to do the same thing, and worth documenting as many have EFI as well.

Robert56@RNS

Robert

Robert56@RNS

I missed this the first time. Thanks for the compliments. I feel the same way on the vendors and input. We have many that won't take the time unless they think a sale is at hand, or they can pimp their stuff. No so bad on this sight, but some others are really bad. I hope when I get my new site and product line available that more people will notice the hands on approach. Again thanks, not many notice.

Hey, Beer, I haven't forgot ya buddy. I have some good things in the works with your name on em.

Edit: For those reading along. I have no current $$ connection what soever with HSW. I am just a product user and have the Interface for my new Direct Port Dry.

Robert

383LQ4SS

I am going to have to disagree here a bit. The reason you werent able to get the timing retard to work on your cylinder/airmass table was because you are running such a small shot. really for the shot you are running no timing retard is needed.

One other greater advantage of using the gms/cylinder route is dual stages. With an IAT setup you are limited to ONE retard. I suppose you could rig up some additional relays so that when the second stage comes on it triggers additional resistors to equate to yet another IAT temp and then assign two amounts of retard for two IATs and have the corresponding IAT as each stage hits...but thats too difficult.

The Gms/cyl table works AWESOME for this. I ran a dual stage 150 shot (300 total) for years with this custom tuning setup. If you use the GMS/cyl table...you can customize it to pull more timing as more nitrous is introduced and pull timing smoothly.

I had it on my old 385 where it was 25 degrees max NA and then when the first stage 150 came on I pulled 4-6 degrees and then the second stage 150 came on I would pull another 4-6 for 8-12 total. The stage where done by rpm...so I would pull 4-6 basically from 3000rpm until the second stage came on around 5000 rpm at which point I would typically be in the range where 8-12 degrees would be pulled. It was flawless and very simple. Max timing must be pulled at peak tq. Ther is no better way to calculate what the timing requirements will be needed than gm/cyl for the expected cylinder pressure that will result. Tq-cylinder pressure. This is the way turbo cars are tuned as well. One point to know about this method is that the MAF must be reasing the nitrous well. If you ar running 13 to 1 on a dry shot of any substantial size then the MAF isnt really seeing anything.

I ran the above setup for years in the 650-750 rwhp range and it was the most reliable setup I have ever used bar none.

One other option no one mentioned was the PURELY MECHANICAL NX dry maf setup. Its basically intedned for 50-150 shots out of the box and will adjust AF ratio with the turn of a ****. Its as relaible as a basic mechanical valve. and very very simple and requires no add on boxes...no laptops...no tuning software and no tricks.

BANDIT HPT

NX needs to kick the R&D department into over drive and build one for the one piece MAF guys.

Robert56@RNS

Good input Al. Yea, I forgot about the new NX kit, though we haven't got our hands on it yet. You are the only one that has used one, and it's really a killer deal. We need one for the 90mm...

Something else we have talked about in the past was using a Potentiometer (variable resistance on a dial). This way we could dial in the exact amount of timing pull, and/or fueling. There was some talk on be able to get a Pot of quality that would be effective in this style of use. I do have one, but I got side tracked trying to use it on a MSD pill style window switch, no more pills, just dial in the rpm sought...

We can clearly see in my screen captures (web site timing pull write up) timing being pulled with the method described. You can see it in actual log as it's running through out a ¼ run. We could, and I have messed with this slightly, run a timing curve to what we like at peak tq, then add some as we progress towards redline. Tuning is such a fun part of this game, IMO, and having others that have been there, or are getting there, is great for the whole industry as it helps everyone understand how this works.

Robert

Beer99C5@FastbirdPerf.com

On topic with Dry System consideration, here is the EFI Live Solution (Pricey though unless you enjoy tuning). This is another way to accomplish the same thing.

The COS 5 (Custom Operating System 5) is really a one wire hook up to enable these tables. No trickery involved. Red connector Pin 56 when grounded PCM uses these tables with COS 5 Loaded in the tune.

These are rough starting points for my testing in May. This will be tweaked with some NA logging prior.

Timing


VE Multiplier


The 2400 to 3200 Multiplier is to offset a lean spike when the system fires, as the MAF reads the Nitrous to goes to low 11's maybe high 10's for AFR so the Multipier tapers the fuel to shoot for 11.3-11.5 (My target AFR).

SpinMonster

Mutiple stages are a good point.

The Grm/cl table method is laptop required trick as you call it. If you are saying the timing for you jumps immediately over the normal loads for N/A with no overlap with N/A cells I will believe it when I see it. If you have the scan please send it to me. Also for the shot sizes dont dismiss small shots as not worth it, or insignificant. There are some people running on the street who regardless of tire will never see the size shots you run. My car has 500rwhp on its own and isnt going to ever get a 100 shot down so for some its 35-75 for their application and therefore the timing tuning as you describe it does in fact run an overlap of cells for the two applications. When I tried a 75 hit in 3rd with the table method only changing celss over .96grms I got Knock retard until the load went over the line to the 1.00 cell. Ther overlap cells were from 48 on. If it works different with huge hits I will never use then please send the scans to me so I can have a look. It will be eveident at that point if the load jumps from say .64g to over .96 without touching another cell in between I will believe it.

A last note is that what some people call a trick is no different than any tuning device works. A timing box interupts the crank signal and the Harris speed works unit does it by interupting and manipulating the MAF signal. What makes one better while my laptop and tables referencing the same signal, is bad advice for people, I dont know. I have a safe system that is predictable and easy to tune. If I get 11.7 on the wideband and want 11.75, I can change it. If I want a one degree more retard then I enter it on a table and I see no reason to believe that an active circiut with DIP switches manipulating an MAF signal is any different or safer.

The NX set-up doesnt work on C6 vettes with the mitsubishi sensor and none of the Z06's. Its 85mm MAF use only. It doesnt handle timing fixes which still need that laptop. I have a 100mm MAF now and have 4" ducting throughout. I realize this is a C5 section that I shared this in but we cant all assume that the cars in question fall into the same parts arena.

Lastly I appreciate the input and welcome all opinions especially if I am wrong about something. I want to learn too. From your input I see that there are differences that come up such as 2 stage hits and large hits that dont work on the street. I have a system that I can reproduce for 11 bucks for anyone looking for it. I am selling nothing, I am not a tuner, and I make no money on installs I do for people. Just making friends.

Lastly anyone looking to do any type of N2O install absolutely needs a laptop in the equation and a wideband to make sure a system is functioning safely. No exceptions.

SpinMonster

Great system and I wish it worked on E40 and E38 PCM's in the C6's.

I posted in the C5 section thinking it would be an asset but it looks like there are plenty of fixes that are available for C5's that arent available for C6's.

Does anyone know if this system will be available for C6's?

SpinMonster

On the street with 500rwhp and 11.7:1 compression I get a 1-2 degree knock retard with a hit and nothing while n/a so I guess its how agressive the tune is. I definitely need a 2-3 degree adjsutment.

SpinMonster

Whoa there. I think it was you that said you didnt read the entire first post:

...and thereofore you definitly got that entire concept way wrong. I do not run the same curve N/A as I do on the shot. The reason it is imperative to make sure the MAF interprets the N2O airflow exactly as it does N/A is because it uses the level a/f ratio as a base for a constant mutiplier. If the shot wasnt predictable and varied for any reason from normal operation without my circiut, then the a/f ratio would vary on the shot with my circiut installed since the multiplier is a constant.

Next who said I dont have a varying injector duty cycle? It most certainly goes up. In fact I clearly stated in the first post to make sure you have enough injector for the job:

Next I am not running lean at all. Where did that come from? The only thing that may look lean to you is thinking I run the same a/f as I do n/a before the injector flow rate table adjusts the fuel by a multiplier. In the event of you driving any car and you accelerate to some arbitrary speed and take your foot off the gas pedal, the car most certainly does go lean while decelerating.

My wideband's guage is set to a high limit of 15:1 (XD-16 lets you increase the resolution by narrowing the range). If you set it from 10.2 to 20, there are less LEDs used in the critical 11.3 to 15:1 range where you need to see. If I'm driving and need a quick read I can see the LEDS in the 11.5-11.9 are all set to purple so if I see a different color during tuning I would know something was wrong. It still reads full resolution on a scan. Deceleratiogn of all cars will read 20:1 on a wideband under no load while decelerating. I should have clarified this but I was talking about testing for a lean condition off dry hit. I was making the distinction that if you had a high a/f and you were still on the gaspedal but off the firing button, its from the shot.

If your car doesnt it isnt mine that isnt function right. I said:

My scan showed a 11.7-11.8 hit with 4 degrees pulled. I stated clearly that there were no lean spikes at all:

Pointing the nozzles away from the MAF with this method is critical to being assured that the N2O doesnt richen up the mixture disproportionately with a falsely concentrated amount of air at the element. I want the injector flow rate modifier to do it. I wanted the same a/f on the shot so the multiplier could be the adjutment....it is always 13:1 so adding 8% more fuel (or any amount I want) has the same a/f ratio to mutiply by as in N/a operation: so on the shot its 8% richer than 13:1. Clear?

Please reread the entire first post before saying things like this. It makes me look bad as if the system doesnt work when it fact it works flawlessly. I know its long but it clearly stated all the resoans for everything I did.

At least have it right before saying:
What I was reffering to is that when you come off the gas pedal OFF the shotall cars go lean on deceleration. Its why you have to switch that function off when you do speed denstity tuning. I was distinguishing the deceleration lean from a lean condition at the end of a dry hit, if it exists, and it doesnt exist in my system.


Your assumptions were all wrong becasue you skipped the read. Everything this system does is exactly how the HSW unit works. The exact same signal at the MAF is where the units fools the PCM with adjusted signal manipulation. It actually changes the frequency of the incomming air to reference a higher airflow signal to make the PCM dump more fuel. The HSW unit uses an Op Amp to have an input frequency and it adds to the frequency amount then sends that on to the PCM. The connection is made at the MAF connector. I have the N2O measured evenly and not concentrated on a single area of the element and then it uses the actual unmanipulated reading to access the IAT vs IFR table to dump more fuel. Not so fair to me who is trying to share something. If you wont read through then please dont comment. I was and am respectful to all of you.

Thanks for taking the time to input.

I hope this clears things up enough to take back the bad advice statement.

I will forward scans as soon as my new wideband (permanantly mounted one) is in so I can save a scan next time.

OK new score card: the car runs 11.7:1 with 4 degrees pulled for a 75 shot. My injector duty cycle is 88-90% on the shot and 79% off the shot. If the MAF failed which is unlikely, the speed density tune of this car would likely still run 11.7:1 and the same timing pulled while on the shot. I'm curious if the MAF failed and the HSW unit uses the MAF's reading as the input for a frequency adjustment, what happens. There would be no reason to think the error signal from the MAF would be interpreted as a failure of the system. Active circiuts can have an error and a units own active circiut used as a test of its own operation doesnt sound as promising as a simple relay that if it doesnt work, the N2O solenoid doesnt get its ground to fire.

Beer99C5@FastbirdPerf.com

Yes there is a request in for them to do the COS's for the LS2/7's PCM's, they been busy getting Black Box Logging stuff working in Beta, adding serial port WB input support, and prepping V8...hopefully when thats done, they will get to it .

I have a friend with a LS2 GTO we are chomping at the bit to load the COS if and when it comes out. We just pulled timing from his tables on his Wet kit with the first time around.

I appreciate the time and effort you posting your setup, not many do, dry tuning is usually a big secret, the latest advances with the HSW interface, the custom HPT and EFI Live stuff, resister tweaks, and the NX Dry MAF coming out, these techniques should be a sticky so those thinking dry can get keywords to search and plan with...