NITROUS OXIDE ( nos / n2o ) advice forum

As a follow on from the discussion going on under the Dave Bailey thread, have opened this thread discussing AFR's, fuelling, fuels and any related points.
Steve

Got it thanks Steve...

Am guessing in the ideal world each cylinder should have its own lambda sensor, and the ECU/ Nitrous controller should read each one individually.
I dont know if there are any ECU's out there capable of this, certainly all of the stand alones ive looked at cant.
So Johnny, are you saying measure each individual cylinder with a run for each to ensure uniformity across all cylinders then read the average once you know each cylinder is right? Or would you use multiple units to log multiple cylinders per pass?
Also how do you know what is the right AFR for each individual engine. As engines use squish bands to use unburnt fuel to cool and protect piston and ring lands etc i assume this wouldnt show up in the results? Or is it just a case of starting safely rich then leaning out for optimum results?
Also what correlation is there between AFR readings and EGT's?

Steve

Wow thats alot Steve so i will answer like this...AFR only on this post and this is for nitrous engines as turbos and blowers really dont need them in each cyl as there tune ups are more a batch fire even the better EFI firing systems richen that bank NHRA Pro Stock use 8 of them becaue they have a carbs and there watching the entire RPM band thru each shift and helps them better tune there carbs for a smoother curve

1st. AFR and where to mount or monitor the WB/O2 is in each cyl. header tube 8 to 12 inches from the exhust vavle it self and in a manner where if you have a liquid pass it wont get to the sensor..so that would usally always be on the top side of the tube and weld in bungs in the same location..on your bikes its easy as there are all right there the same..If you feel you will have extreme heat they make a double bung that sheilds it and madelike a sink....follow manufatures intsruction.

Having a gauge only that then gives highest value really isnt the trick as it should be a recorder and there out there so you can down load and see spikes to help you with your delay of the nitrous to fuel start time.It is amazing to see what they do under a load like on a shift or when you are slipping the clutch because your engine will pull on the carbs differant through the RPMs and also wont pull near enough if the clutch slips severly. The relitive number though on a graph next to RPM shows you what your motor is doing more then a number..everyone is so hung up on a number the dont see what the real use is...Automatics and Manual transmissions work differantly with reguards to carbs and tunnng and camming on big nitrous motors but thats another thread all together also..... If you bog your motor on the launch you can see big problems and this is a cause for severe detination. But you wont see anything if its not recorderd so thats why i feel there a waste of money when not used right...you use thast money better else where till you can do so...even with the WB/02 your still tunning to the plug but seeing where it goes is for a baseline for your engine and if you have a EGT you will see some things also but EGT's are in no way used the same.

There are alot of them out there on the market but you get what you pay for and few record..Innovate is one but there quality as i see it has gone down hill..racepak has started using other manufactures i belive for there data recorders...Daytona is another..anyway you can look over the net...thay all buy there 02 sensors from a few companys..and now you have China making them so guess what happens to quality.....Innovate and a few others make a dual WB set up and recorders so 2 for you all will ahve alkl 4 coverd

The one I have is OUCH 1700.00 and only monitors and I had to hook it up to my data recorder a simple 0-5 volts...The brand is ECM and they are the company that makes all the diagnostic eqiupment for O2 and there 8 set up for me with there stand alone recorder was about 9000.00 so you see it can get costly so how i would do it is get one and you onluy have 4 i had 8..lol to tune and get a base line on a single cyl for that tune up and write all down...now if you can find a dyno that has a 5 gas to go along with the WB/02 now you got the best...The other good thing about this one is the lack of problems I had with it..its free air self calibarating and is spot on as i had it calibrated for ethanol ..there tech people are the best tech line I have ever used and yes one guy is a rocket man,,serious he has a jet engine in his late modle VW bug.....I will give you the web site a little later...My data recorder i had set for 100 bites a sec per channel..thats alot
Also maintaning your sensor and heating it up for a few minutes before starting the engine is a must...There was a Hot Rod article with a shoot out of 8 WB/02 sensors on the market...they didnt use a ECM unit..but the Collage that had the dyno used ECM calibration equipment to messure them before the dyno pulls....ECM is also what the auto makers use for test equipment and the EPA here in the states...that why i spent 5 to 6 times what all the others were I could have gotten more but if i had issues like i read on the boards it was money wasted but mnost of all my time i didnt want that and i didnt have one issues and know others with the same brand and used it for 7 years and even sent it back to recalibrate it from a petrol/n20 to a methanol for blower..same 02...that says alot

Now as i said if you have a leak in your headers it will pick this up and will show lean when its not..so you dont tune to them.The ideal as i said in another post would be a dyno that also had a 5 gas analiser so you would know exactly what your exahust was putting out because WB are not the tell sensors there made out to be.but once you get a tune up leave alone and then place it down streme..02's have nothing to do with EGT's and thats another post in its self and how to read and whats going on when looking at it in reguards to timing,fuel and and speed..very very slow. I will answer the other questions in another post...

This is a add on to the top to go along with the the above post...

What i am saying isnt opinion ok,its facts researched and verified by people that do know and those companys more importantly the company ECM who makes the WB/O2 i use and the testing equipment used by many labs and testing facilities around the world,this is how it was explained to me and understanding it,so i will do my best to put into words why and how for the placement of 02's for N/A carb and nitrous engines and even N/A EFI .
V-8 and 4cyl bikes are close in the there 4 cyl a banks,so this is how we will look at this. Each cyl is 25% of the exhust forming in the collector ok...If you have 3 cyl that are running 10 to 11 and then have one cyl that goes 14 to the average down streme wont be over 11.8 I bet and thats if everything is calibrated correctly and you will have hurt that cyl. if your runnning nitrous and if your setting for a fail safe you can see it wont work and this is even worse because its so far down streme by the time it see's it there not correct.Now if you have more then one it wil see more but its so far down and the response time will be slow enough to have still done damage

This is why ECM says the placement for correct AFR mesurment of that cyl is 8 to 12 inches from exhust valve... This is food for thought so when your green you grow and when your ripe your rotten...I am only trying to help all of you from falling into the pit falls of monkey see monkey do that runs rampent in racing..people do things becuase they see others do it...that doesnt make it right....

"You get what you pay for..."

http://pullingworld.blogspot.com/2008/0 ... ystem.html

Maybe you ask for a price. With 12 cylinders this is something i can only dream of.

Thomas

http://ecmmotorsports.com/index.asp
this is the ecm site for 02 and neat equipment we can all dream about

Well thats funny that you posted that,as i know the injection system very well on the tractor and who developed it the one on the Green Monster is the 2nd by Kams and that was a 08 version and I spoke with Terry Kell a few weeks ago and he has one that makes that slow and the 08 is so far ahead of everyone of the so called big end of ECM's....easy to tune with alot of neatstuff and the fastest data recorder made...the 3rd edition he said he only has 10 of so i added my name to the list and its distributed by Micks Perfoformance and you dont a web site really and not advertised as Terry is trully a one man show when it comes to doing things..Mick has one of if not the fastest Vortech Supercharger Street cars in the world..6.20's in the 1/4 at 2800lbs i think...with a automatic

He decided over a decade ago that there was no ECM to do what he needed for his turbo motors as far as feeding and the features he wanted and even the high end couldnt do it...He did a deal where he did mech fuel injection on turbos that swtiched on and was fine tuned thru electric injectors..pretty cool but he got a partner to make his ecu's all in one coil over plug fastest response in the ecm automotive world....When i spoke to him in 07 he was comingout with his 08 and the way he said was what he heard was Motech finaly cought up after 10 years...i laughed as he didnt say this as a put down and didnt really care but it was time to upgrade with all the fatser components he could use....

I am a carb guy but want a ECU to control my fuel side of my nitrous better with faster response as well as more control over the nitrous and i am a data whore so the speed of this ecm is unreal what the record rate is.to the point you have to go and adjust it back or most info would be a blur....He also has developed there own 02's for a super fast response rate to where he thinks he can control each cyl with its own 02 in a closed loop no one has anything like this and what I have been waiting for....

Theres some good info there Johnny. I knew that 02 sensors should be placed a lot closer than they usually are. The giveaway being take a look under the bonnet of any modern car and they are usually no more than 12" away from the valves, and often shielded too.
I will certainly take a look at the websites you've posted, although for now, i think i will be priced out of the market. I have found a few that data record as well as just read at a reasonable price, but unsure of the sample rates.
For the future this is possibly an area where Trev can take a look for at least the max extreme race, being able to read multiple sensors, as undoubtedly this will truly help save engines from damage using nitrous. Previous failures ive had using nitrous ( On NOS gear) have only ever been on one cylinder at a time, the biggest being a blockage in a fuel line due to some careless use of PTFE tape. Fortunately for me anyway, i was just the rider, but this was a major expense that finished the season on the opening round! But now i run my own bikes i would like all the protection i can get. The prices you are talking about come to less than one full rebuild, so its only got to work once to pay for itself.
So for those that run a system similar to Daves, the best bet would be to set the window very close to the base line, say .5 AFR to allow for dilution of other cylinders, or certainly no higher than 1 full point?
There was another interesting point you raised in Daves thread, regarding unburnt fuel causing det, this is something that may go towards solving the issues ive had, as being very reluctant to lean up untill issues solved, it may be im running too safe?
Steve

Well, i can honestly vouch for sunoco maxnos, running problems now solved, and bike quicker NA too, how big a shot it can handle remains to be seen, but it dealt with 120BHP on a cr of 12:1 with no issues....

Im also curious as to how much the density of the nitrous effects the fuels ability to burn. As a denser hit would mean a reduction in intake temps, i would imagine this would have an effect on ignition timing, allowing more time for the fuel to reach evaporation temps.

Going back a bit, i dont know if Trev have has followed this thread at all, but would be interested in his opinion of how far away multi AFR channel nitrous controllers are? As its generally accepted amongst us here on this forum that WON products are ahead of the game, this is probably only a question he can answer......

Steve

Hi Steve,glad you have things sorted and running well. I think density of nitrous controls several things. I think the density towrds how the fuel burns is more of the state the fuel is in when it starts to burn.Just my opinion though....the fuel side is still the unknown factor in all this as it takes more research and funds then the nitrous side does. If you dont belive me look at the auto makers still trying to get it right as well its how the fuel is made and what it is made for....I think thats what controls it all

Hi Johnny
So basically what you're saying is that we come back round to how well the injectors work and positioning of them as regards to the state the fuel is in? I would imagine then that once the fuel is vapourised it will tend to stay that way, but any in liquid form still would be likely to freeze?
In that line of thinking, especially for larger hits, do you think it could be beneficial to jet the fuel at each cylinder at high pressure, say 100psi, through small orifice jets, possibly even multi orifice jets (like a miniature shower head or watering can head) to actually atomise the fuel at point of injection, as does a diesel injector? Or would the sudden drop in temp as it meets the liquid nitrous stream just re-condense it back to liquid? If used with a pro injection type set-up, would it work better to fire atomised fuel closer to the valve where the nitrous stream would be more gaseous in the case of the above happening?
On another line of thinking, I'm considering using nitrogen over nitrous to control nitrous pressure. As controlling bottle pressure on a motorcycle by heating has its limitations on a motorcycle owing to battery capacity. This weekend saw us sitting in the pairing lanes for over an hour waiting for an oil down to be cleared by which time we had lost all gas pressure owing to the air temp being around 14 degree C (57 f). Now if i put a shot of nitrogen on top of the gas, the bottle will maintain its pressure at that temp no problems, BUT, does the nitrogen dilute the nitrous at all? I mean i know it will when you get to the bottom and only gaseous nitrous left, but does it absorb into the liquid nitrous, and if so does it do it enough to require re-jetting, or can it be dealt with by running at slightly higher pressure?
Sorry if it seems im constantly asking questions, i dont expect you to know all the answers, but am just thinking out loud and welcome yours and anybody elses opinions

Cheers
Steve

Hi Steve,well this is a very deep question and one that i have been working on for 5 years or better with many ideas and some solutions and many many questions still that no one knows for sure...and in no way am i knocking anyone person or company but this is a very gray to dark area as i said.Placement of fuel nozzles have many effects for differant apps. Closest to valve isnt a good one..for fuel to burn it needs to be vaporised so many things are needed for this to happen..Higher pressure from a open end line or nitrous nozzels wont cause atomazation either .Fuel has to atomize before it can vaporise.Since bikes dont usally have a very long runners and usally a very high RPM range I would place the fuel side at the top of carb mouth to give it time to break down and absorb and atomize as much as possable so it can then vaporise eaiser..EFI is great for turbos and superchargers but has yet to yield any performance gain in nitrous engines over carbs. to date in Pro Mod. I am not sure in bikes as i dont really follow bikes other then those here on the board...

My ideas and remidies I wont state or go into here for reasons I would hope you understand.

Nitrogen boosting has been done for many years and does not effect the nitrous it self at all. the amount you use to raise pressure is determend by the temp outside and the temp of your bottle..Also will effect your refills as it will cause rapid pressure increses when refilling unless it all removed and on a small 2.5 even turning upside down wont remove it...i have tried and still had enough remain that it caused refilling issues causing high pressure on large bottles.So in a small bottle like yours you could dump it all. Also i am unsure how much you use in a pass but if you your replacing area for the gas....Its something used with extreme catioun also because of this...if left in a bottle thats not got a SPRV it could rise so much in heat to cause blow offs to go..tuned at a heated pressure say of 1000 which is around 98f i think you would have to adjust the tune up . If like your race day you boosted your bottle at 60f and boosted to 1000 your going to be running super lean...my advise is especialy there and your temps are usally cooler then hotter jet it for the average day...meaning your fuel...then you wont have to heat as high.. Trev has done alot with boosting using nitrogen...Tought me the basics in it also....I choose not to boost at this time though..I would if i was you have several bottles as i am sure you do and go back when its getting close and replace it with a fresh warm one...to many things to already add to the equation...
These are my opinions and not anyone elses...some may have other ideas on some of what I have stated...

One other thing Steve is I am not sure if your bike is started by a aux. box or all is self contained but if you carried a battery cart with you to the lanes you could have a 2nd battery for a bottle warmer that you could keep wrapped in the bike with a quick connect electric connector....just a thought as things like this I think will be eaiser for weekend racing...

Modern diesel injection and newer petrol cars that inject into the engine CC are injected at pressures ranging in the 20,000 to 35,000 PSI area and injected in very small amounts thru the cylce...Even older mech. deisel injected at 30,000 psi or better. Many are working on self ignition petrol engines and do some of things above...Certanly if you want to try and make your own injector its something i think you would enjoy doing and researching but you need good test procedures. I am in no way ever going to say not to try but its not that easy to just bolt something on and not test and measure it all correctly as this could do some serious damage.

Unfortunatel, in our class, the bike has to self start, hence the issues with battery capacity. We have tried the aux power supply this weekend, and although far from ideal with some work it can be improved upon. I think a possible solution with the addition of a couple more bottles, would be to have a thermostaticall controlled water tank to store the bottles in at a constant temp. Fit the bottle when called up, then use a heater to maintain pressure rather than using the heater to bring it up from cold, because being such a popular class, we have less time between eliminators than most, because they need to bring the class size down quicker so all the semis and finals are run together.
Or alternatively use a nitrogen boost to make the pressure, this is appealing purely because we dont have the availability of electricity in the pits at all venues, and carrying a bottle of nitrogen in the van is no real hardship.
The only real answer i can give ya in regards to jetting to a lower pressure is that on race day with our climate, the conditions can change so much hour to hour, and you dont always get time to mess about changing jets etc, we can get a 2nd call within 45 mins of our last run. This time is important to get the engine cool again being basically an overbored air cooled motor, so testing of jetting during this time would be far from ideal. Along with that we use this time to check the bike over, cure any oil leaks, drain catch tanks etc and if necessary, strip and rebuild clutch plus any other functions we as humans require lol.
Purely because of time issues ive been tempted to switch to turbo on numerous occassions, but i really want to make the bike work on gas and get some consistency first, if nothing else, im very obstinate like that, ive chosen a path and will stick to it untill ive achieved what it was i wanted to achieve. So for now the gas stays as does the old air cooled monster. Unfortunately my ambition to get one of these old dogs to run with the big boys running consistent 7.5's i now realise is ten years too late as sourcing parts is already becoming an issue, so sooner rather than later i will have to make the switch to modern, and with that comes a whole new set of issues. Most modern kit now run nikasil lined bores, which from people ive spoken to, doesnt tolerate high doses of nitrous very well, but seems to have no issues running boost. Possibly something to do with the higher ignition temps of nitrous or possibly something more on a chemical level, i dont know.
Steve

Hi Steve,by no means was i sugesting to go turbo . I understand about cooling a waterless motor and even one that was made for water. i took are motor a filled the heads so it was solid and i actually had better more even cyl. temps and cooled much better between runs. With the fans i ad it cooled down within 30 mins easily after a pass. now I messuerd from the oil temp as it never got any hotter then 200 on the hottest 100 F days here in the summer. It was down to ambient within 30 mins usally 40 tops...I never liked getting the oil cooler then 120 as i usally warmed it before we went to the lanes.

If you go with boosting you will have to jet for it...having multiples and water is the best way i feel. I refilled my bottels after each pass but I only ran 4 to 5 lbs in each bottle anyway and then they hit the water at 110F usally got me to 1200 PSI....then when we did open the bottels it went down 100lbs then a purge and motor purged and it was right @1050 where I had it flowed for...

I cant see with the right fans on that engine with your climate it taking long to cool..you can even pull the plugs and run filterd leaf blower thru your exhust up thru the engine as a suggestion...I saw another racer do this is why i say it....i never had the need as i say it cooled off very well.

Hi,
No i never took it as you advocating turbo use, its just something ive considered myself in more recent years. In fact, i am in the process of modding an old gsxr to EFI and turbo, but the race bike will remain gas for the forseable future.
Using fans is not something ive seen done here and hadnt even considered it, so some usefull info there, shame we just weighed a load of big high volume fans in at the scrappy a couple of weeks ago. DOH!!
Water vs N boost i will look in to more over the next few weeks, and could depend on whether a suitable regulator can be found to keep consistant pressures, otherwise, like you say, we would end up having to rejet every time. I had considered running an N boost system on the bike, but it gives away enough weight advantage to it now without adding any more, and again its something else drainig electrical power, to which there is a limit before ignition and nitrous start getting robbed.

Steve

Thats all cool Steve,I had a blow thru turbo on my street Harley...9psi boost and it was wicked quick..quick enough I couldnt keep up with the shifts..lol it also for 600' gave every bikeon the street a scare that made them wonder how this 2 cyl was running away including a Busa...


You know the idea of the NiSi liners si something I have looked into and looking more at the newer spray in thats Ford is doing and also sold right too Nissan for there R TT motor...

The fans will work and your motor is smaller then mine so it should cool down rather easy..plus it was designed for air cooling as mine wasnt....I also helped a friend who hurt the drivers side head and we had a main brg problem so we threw are solid head on his motor and he went the exact 4.13 again...i also got to read his computer and all his numbers before he hurt it were the same with this head and thats running 3 nozzels per cyl. I love the easy tear downs and assembly without the water also....

well i guess a few bikers out there need a scare like that from time to time lol. My old 7/12 streetfighter used to be a good tool for the job as well, completely scruffy, looked like it shouldnt go over 50mph, weighed next to nothing, and went like the proverbial up to around 140, where lack of fairing and any real horse power caused it to run out of legs, but, hell it was fun!!

Steve

Steve it is funny how you can cobbel some parts together and have something thats off the wall and shouldnt run and just amaze everyone,then looking at it from the other side you try your best with all the best parts and making things fit better going with known combos. and lose it when it wont even fall out of a tree...

I think this could be a thread in itself titled what you built that shouldnt run...lolol I bet there would everything from tricycles to electric cars to the Nitro Fuel model cars that screamed across the school yard as a kid....

Lol, i hear ya. I have a bike now (my race spare) that has all the right bits, yet for some reason will not do a decent 60ft, seems way down on power, yet my race bike, which we know has the wrong cams, has too much power off the line.... Hohum. Will check the cam timing out on the spare before it goes out again, but i know everything else is 100% spot on.
Going back to fuels, how do you know what octane rating your engine needs prior to running it. Is there some kind of formula for working it out or is it just try one fuel and see how it runs? I guess once you've built a few engines it becomes instinctive to know what it needs. Just wondering as there are lots of different fuels out there, and they arent cheap, so it could become a very expensive learning curve untill ya get it right.
Cheers
Steve

Hi Steve, I dont know of any formula thats out but thats doesnt mean there isnt one. I do know the common mistake made by all including me has been to get the highest MON not RON but thats wrong all together.Knowing your true cpmpression ratio and I mean dynamic is important. Having way to much octane can cause detonation from unburned fuel thats remains alot like running to rich and when I say rich I mean excesive...

I would only run whats needed but we tend to think more is better and I am looking the other way now. I will say that 25 years ago on a street car i had that ran a true 10.50 thru the exhust and a true road tire with 340ci and 3300lbs i ran regular was 89 RON with nitrous. It didnt have any compression because of a mess up with the pistons and the machine shop..they were below deck an aditional 1.5mm which with the cam I ran it was less then 8to1 and put this thing at 120lbs cranking and It would only run 12.30's on motor but hit the plate and BANG and never hurt anything and ran at least 30 bottles before I sold it...Now 25 years ago if you could run a 10. andthing on the street and this was my daily driver also but anyway you had something...
Now yes nitrous does add cyl. pressure but the cooling effects to a point and especially WON products would help with the needed higher octane i think of course depending on your tune up.Combustion chambers and ally vs steel heads and blocks,cams are other things needed to take into consideration.
Call me crazy but there is another thing to look at and that is the class Fatty runs as I look at it here in the states also and there limited on the fuel they can run so this is something that backs up what I am saying i think...

Steve i found a leading carb man here that has a nice sight and has worked with the leading teams in all types of motor sports and he races single cyl.carts but the 100,000.00 equipment hey way prevy to use with these leading manufactures in Drag racing from N/A to Nitrous was cool reading but it follows exactly what i was saying about EGT's and O2 sensors

Enjoy....

The A, B, C's of EGT's and Oxygen Sensors

As most of you know we have a video out that explains the proper use of E.G.T. (Exhaust Gas Temperature) information and how to properly use the information this type of sensor supplies. But we still receive calls from misinformed racers about the use or potential misuse of this data.

Since onboard data-logging systems are now becoming pretty mainstream most people are under the impression that they can bolt these systems on and burned pistons, detonation, and incorrect jetting are a thing of the past. Not true.

EGT and Oxygen sensors are wonderful inventions, but they are not an end all be all of tuning. Here's why.

Every engine has a thermal signature. Meaning it will create "A" amount of combustion heat, it will burn "B" amount of fuel in a given span of time and it will expel "C" amount of unburned or currently burning gases.

"A" is "in the chamber" combustion. Allow me to explain. One of the teams I work with has a system that actually measures the combustion temperature. This is an "in the chamber" reading not and "in the pipe" reading and you can directly correlate chamber efficiency, fuel distillation curve selection and even cylinder head temperature to assist you in burning all the fuel "in the chamber" as opposed to a residual burn. Its really quite an eye opener and it really taught our company a lot about droplet size and fuel preparation.

"B" is the amount of fuel required to match up fuel and air to get proper combustion. Now everyone knows that 14.7:1 is stoic, but this is not a perfect world. Piston tops and intake to exhaust scavenging percentages will alter the required air to fuel ratio for proper operation. Now don't panic, just because your engine requires .8 more of an air to fuel ratio or EGT's that are 100 degrees lower than your buddy's car is not a bad thing. Some engines make excellent power with lots of fuel and although they may seem to be wasting it, you can't deny proven on track performance. For example: We have a particular carburetor design that makes no more power on the dyno, but for some reason its very quick on the racetrack. When the fuel curve is altered to supply what the engine builder deems is a proper air to fuel ratio, the vehicle slows down. So there are no set rules and EGT and Oxygen sensors have to thought of as base-lining or reference tools. Remember that statement.

"C" is the amount of residual unburned or currently burning gases that are expelled into the exhaust pipe. One of the nitrous teams that tests for our company currently has EGT numbers in the 1760 degree range. You may think that's high and that sure seems excessive, but it's a World Record holding tune-up and you don't deny that. The engine gets torn down regularly and to quote the racer "Its so nice inside this engine, I could even reuse the bearings if I wanted to". So don't panic if you're seeing real high EGT numbers. Oftentimes its residual fuel burning and if you roll some ignition timing into it to get it to burn in the chamber, you could end up hurting parts.

Oftentimes an Oxygen sensor will show you a cylinder that requires more air to fuel ratio than its opposing cylinder or even its direct neighbor. Let the cylinder have the fuel. Don't get caught in a numbers game. The same thing goes for EGT data. If your engine performs better with higher or lower numbers than someone else's, look at the A,B,C's and you can probably pretty accurately determine what's different from your combination than his/hers.

Also remember, when mounting EGTs or Oxygen sensors symmetry is VERY important. An EGT sensor mounted on the bottom of a header pipe will typically record data 100 degrees lower than the same sensor mounted on the top of the pipe. If you're using a single oxygen sensor, remember a misfiring cylinder will exhibit an over-rich condition and you may think less fuel is required (or it may even exhibit an exceptionally lean reading as a result of fresh air being pumped into the header from the misfiring cylinder) so don't forget to look at everything when you're tuning.

When you open the hood there is a lot of stuff under there and something as simple as a fluctuating fuel pressure regulator can create surging and just plain unusable data. That's when the real tuner earns his pay. EGTs and Oxygen sensors are tools that can lie to you, but they're great for educating you on what to look for, so pull that header off or pull out that sparkplug when the car is running good. Get a good look and remember what you see. Sparkplugs and header pipes are harder to read but they rarely tell a lie.

Thanks for reading. Have a great season everyone.



Copyright © 1999-2002 Pro Systems
Engineered and Maintained by Michael Ray

Hi Johnny,
Very interesting read there and some well made points

Not been on for a while as work/business/family pressures on my time recently, no doubt something we've all had to cope with in the past.

Anyway, now collecting parts for new fuelling system, and clutch issues being resolved so hopefully we can start making some serious numbers by end of season ready for next year. Spent some time with a friend who runs comp/pro stock suzukis and learnt a lot recently, so plenty to look at and work on. As with most things in life, you just cant beat experience!!

I will be moving to a fuel rail type set-up with a variable fuel pressure reg, to ease fuelling adjustments. Got to mod my fuel tank first for fuel return the rest will follow. Should be ready to order some x-fires soon as well to replace the NOS foggers and switch to nylon tubing. I also have to get some exhaust bosses made for AFR sensor for individual cylinder sensing and hopefully should then see some really improved ET's. Am hoping to have system up and running for the Extreme Performance Bike weekend in October to get some base settings for next year.

Now knowing what the cause of the clutch issues has been, should see this bike running near index without gas, so hopefully, the RWYB time at the october event will see us very close to the 8's if not in the 8's

Steve