A New Easy Way To Really Dial In A Tune?

FastDriver

My dad had a bra
SN Certified Technician
Sep 5, 2001
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I'm really talking about how a tuner decides what to do next, not so much the programming or specific tuning software a guy is using. As a basis, a tuner is trying to do 2 things: 1. maximize power, and 2. an even bigger priority in most circumstances is to keep the motor safe. Essentially, the goal for a race car is to lean the AFR and advance the timing to MBT the limit of detonation, which can usually be seen on a dyno or by improved results at a track. For a street car, the goal may be to stay away from detonation altogether. These two goals are not, despite popular opinion, the same goals.

So the old way before dynos, widebands, datalogging, etc... was to get a motor running smooth on a safe rich low timing tune and take it for a blast down the strip. Dial the fuel/air mixture by changing carbs/jets/carb fine-tuning until you're not getting any faster, then start dialing in the timing advance. We all know how to listen for knock, and some of us still know how to pull the plugs and read the subtle indicators of what's happening in each of the cylinders. Little, by little, your car gets faster, and the tune gets better.

Along comes the dyno that significantly shortens this procedure and removes driver inconsistency as a variable. It has it's own disadvantages like not having proper load as if the car were actually driving on the street accelerating its own mass, etc... But the major advantage here is a document showing how much power the car is making at every point in the RPM band. Suddenly, you can more accurately fine-tune specific parts of the band. You can see power drops associated with too much detonation. Let's not forget the biggest disadvantage with a dyno: money! A pretty reasonable $75 dollars an hour means that most backyard guys are only going to pay for a WOT tune and we'll try to work out any major driveability kinks either on our own or with a street tune.

Next come the widebands and dataloggers that DIYers could afford. Suddenly, the DIYers can see the AFRs across not only the RPM band at WOT but even at partial loads and idle. We know, as a rule, NA AFRs will range from 14.7:1 at idle and very light throttle (or leaner if your motor likes it), 14:1 to 13:1 at part throttle, and around 13:1-12.5:1 at wide-open throttle. Boosted AFR targets are normally the same as naturally aspirated engines outside of boost, but with boost we run a lot more rich to leave extra fuel in the chamber for cooling and preventing lean spots reducing detonation. We usually shoot for 11:1 to 12:1. So.... awesome. With widebands, we can get pretty close to optimum AFRs.

But how do we do timing? We're basically stuck to the old-fashioned method of advancing timing slowly and listening for detonation, reading plugs, etc... This is really problematic, though. My car is so loud I'm never going to hear it. Reading plugs, is time consuming because it requires you to literally shut the car off at a given load/rpm and the plugs tell you what was going on in only the few seconds before shut down. Pull all 8 plugs at every RPM and load? Not so feasible, but again doing this once or twice at particular points will get you in the ballpark. Want to tune the timing on the dyno? You'll more easily find MBT (Most brake torque, or max brake torque, most best timing ;) or whatever), but that doesn't mean you're safe. It just means that under those load conditions, at that temp/humidity you made the most power. This also typically happens after a bit of detonation too. So, we get somewhere in the neighborhood and then we pull 2-3 degrees back out of the tables to pull us out of detonation and to account for moderate changes in the weather.

Man!....With so many variables, this :poo: is getting complex.... we're adding extra dimensions of complexity. So far, I've only scratched the surface. RPM, load (MAP or MAF typically), fuel, spark, IATs, engine temps, EGTs, tip-in. You don't really get an appreciation for the complexity until you try going through the tune on a stock EEC IV from almost 20 years ago. God knows what the factory is doing now. The stand-alones are simpler, but then again you're never going to invest the time, expertise, resources, and money that the factory engineers could into your car's tune.

Now, I'm sure we've all heard about knock sensors in factory cars to protect the motors from poor gas, an unexpected problem, etc... But if this is reliable, the tuning help would be awesome! Now you could tune with relative confidence you're going to be safe and at the same time, you'll be able to see if you push the car over the edge. I personally don't want to be at MBT. I want to be out of detonation, even though a little detonation is supposedly ok. If you can use this thing to actually see what's going on in each cylinder and you can tune individual cylinders on the street/track as a DIYer, this is the holy grail. As an extra measure of security it's nice, but as a tuning tool it could be amazing! The pessimist in me is sure it's too good to be true, but I'm very interested in pursuing this if it's reliable.

Effective knock sensors that retard timing on individual cylinders and allow for datalogging would be amazeballs! Then you will quickly be able to see where to add/remove timing to get to what I would consider optimal: the most timing and least fuel possible prior to detonation. I would probably still factor in an extra degree or 2 across the board, in case this system failed AND some other factor would push the motor dangerously toward detonation. As an engineer, I like a double-redundant system. I also like how easy it seems it would be to be able to easily and efficiently see/know that I've properly tuned all the way across the RPM band. There are probably plenty of them in the aftermarket, but this is the one I've been reading about:

http://www.jandssafeguard.com/NewUniversal/UniversalVersion.html

I hope it works for my motor with with the MSD digital 7+. If it's as good as I hope, then tuning should be a breeze and it should be safe.
 
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Not really sure. Read $300 for the box on one of the forums, but didn't read a forum newer than 2011, yet. I just wanted to flesh out my tuning understanding and see if these boxes work worth a damn, first.
 
I did a little bit of research on this unit a few months ago., and it's probably something I will go with as well. I really like the idea of having a knock sensor on the car. You can never have too much data to look at. Like you said, hearing knock is sometimes easier said than done, and tuning for it is much harder. I'm glad you're giving this unit a try. Be sure to let us know how it works for you. I'm excited to hear what you think about it.
 
Fellas, the more I read about this thing, the more I'm hooked. I just wanted to post what I think is a more accurate price tag: about $650. If you're building a $2k motor, I wouldn't go for it, but if you're building a $10k motor, it's both cheap insurance and also a way to get the most out of your tune. Hell, if it gives you the confidence to tune it yourself, then you essentially just paid for it with the dyno time and will probably get a better result, too.
 
I can agree with most of you "ranting" ;) wit a few exceptions. The dyno I use is load bearing and has an eddy current brake. This truly simulates load as if the car was being driven down the track/street. We can load the dyno so heavy that even a 1500ho motor will labor trying to spin the rollers. We also always always always read plugs. Almost ever dyno pull or pass down the track results in atleast 2 plugs coming out of the lean cylinders to be read. Lets say the motor responds well to a little more timing but the heat mark on the plug strap isn't where I want it to be, time to back it off. I could never hear detonation in my motor or get a know sensor to work with it so pulling the plugs to read them is the best viable option. As for just getting a wot tune at most places, that I definitely the case. My buddy that does all of the tuning for me gets a lot of cars that were tuned that way. He winds up retuning them for wot and drive ability. More time is spent working out the drive ability and cold start stuff than wot pulls. Sure 1 hour a few wot pulls and you can be done, but who wants to deal with a car that runs like crap cold or bucks going down the road. How many of us only drive at wot? Honestly to tune it right you need 3 hours. The car needs to sit to cool off and the drive ability needs to be a huge consideration.

I'm curious to see how you make out in tuning this thing and would love to see the results!
 
I agree with everything you said. I wasn't thinking about the loading dynos, just the inertial ones. Anyway, I'm pretty excited about this thing. If it works with my stuff, I'll go for it. I've read 30-40 reviews on this thing and every one of them was positive.
 
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Fastdriver...

I read through (skimmed) some of the things on that website and thought to ask... Where's a best place to mount the sensor on a Windsor motor?

Some cars have EECs that are intended for knock sensors but came without them because of misinterpreted noised from the engine that messed with the sensor's ability to detect knock (mostly factory boosted cars).

I tell ya that one thing that really caught my eye was the gauge that you can get with this system. Knock detection readings on top and AFR on the bottom. That's pretty badass.
 
Fastdriver...

I read through (skimmed) some of the things on that website and thought to ask... Where's a best place to mount the sensor on a Windsor motor?

It's a concern of mine, as well. I found this from Hot Rod magazine online: "The 5.0L block has a blind hole on the block's bellhousing flange behind the intake manifold that accepts a knock sensor (used stock on some Ford 5.0L V-8 trucks)."

My follow-up question is whether Dart Iron Eagle blocks also have this hole.

http://www.hotrod.com/pitstop/hrdp_1101_tech_questions_and_answers/viewall.html

Some cars have EECs that are intended for knock sensors but came without them because of misinterpreted noised from the engine that messed with the sensor's ability to detect knock (mostly factory boosted cars).

I tell ya that one thing that really caught my eye was the gauge that you can get with this system. Knock detection readings on top and AFR on the bottom. That's pretty badass.

Yep, I'm not sure if I'll use the AFR function because I already have that through the Racepak dash, but who knows... maybe I'll do both and have a backup, or maybe I'll prefer the reading on this gauge. In the end, there are 3 really nice things about this system: 1. Security, 2. Datalogging capability, 3. visual alert that something is amiss. Pretty sweet! I've got the link to his site save in my favorites, so I've apparently seen this before. It must have been before I started learning to tune, because I don't remember it at all.

Now, another really sweet capability of this system is its ability to pull timing on individual cylinders. With a cam-synch, I'll have that capability with my BS3, but you could just throw this thing on a motor with a stock EEC, push the timing up, let it retard timing on the "lean" cylinders and you end up with more power out of the other cylinders. Pretty cool! I wasn't interested in getting a cam-synch for the BS3 before, because I figured I'd never have a practical way to really tune individual cylinders. This system's going to change that. I'm sure I sound like an advertisement for the company, but if it'll do what everyone says it will, I'm going to love learning to tune without the worry of blowing S@#$ up!
 
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HRM said:
The 5.0L Mustang engines have no factory knock sensor. Again, since you want to push things to the limit, consider adding a J&S Electronics Safeguard individual cylinder knock control system. This device is compatible with the factory computer. The 5.0L block has a blind hole on the block's bellhousing flange behind the intake manifold that accepts a knock sensor (used stock on some Ford 5.0L V-8 trucks).

Ohhhhhhh.... I had not heard of this before!
 
My Dart block does not have the threaded blind hole you are talking about, granted that is a 351 block, I would imagine the 302 is similar.

As far as individual cylinder timing, that gets really tricky, especially without an EGT gauge for every cylinder. You could read each and every plug but that process is super tedious. I run a cam sync (modified msd distirbutor) with my XFI 2.0 so I can run it sequential instead of batchfire. I do not however play with the individual cylinder timing at all. If I had a nitrous car I would consider it but I can't argue with the results I've had already.

I wasn't really talking about batchfire vs. sequential. That has to do with injector timing.

Are you saying you still wouldn't mess with individual cylinder ignition timing even if you could see which cylinders knocked first? I can't imagine why you wouldn't want to retard timing on those cylinders and advance timing on the others until you started to see even knock across the board.

EGTs should theoretically be an indicator of detonation, and you'll know with a given engine that you're close to MBT at that engine's target temperature. If you can achieve the same conclusion from a single knock sensor that monitors every cylinder, why wouldn't you? In an ideal world, we'd be measuring AFR, and EGTs for each cylinder. Since that's obviously not practical, I'd argue that a knock sensor is the most practical alternative.

Would measuring EGTs at each collector be helpful in tuning? Another problem, is that you would have to learn a lot to apply EGTs to tuning at different loads. At cruise, I assume EGTs will be different than at WOT. With a knock sensor, it's either knocking or it isn't.

I know I'm talking out of my inexperienced ass, but I do so to be corrected if I have a lack of knowledge or am off in my reasoning.
 
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I couldn't get the image to come up here, but if you go to google images and search for "302 SBF knock sensor" you'll see a pic with a red arrow pointing to it on a stock looking 302.

Wait a minute... here's a different one:
file.php?6,file=2847,in_body_attachment=1
 
My Dart block does not have the threaded blind hole you are talking about, granted that is a 351 block, I would imagine the 302 is similar.

As far as individual cylinder timing, that gets really tricky, especially without an EGT gauge for every cylinder. You could read each and every plug but that process is super tedious. I run a cam sync (modified msd distirbutor) with my XFI 2.0 so I can run it sequential instead of batchfire. I do not however play with the individual cylinder timing at all. If I had a nitrous car I would consider it but I can't argue with the results I've had already.

I would be in the same boat as you, I think. I have a Dart Sportsman and that probably doesn't mimic that recess either. The search continues though. I'm rather intrigued by the idea of this thing.
 
My Dart block does not have the threaded blind hole you are talking about, granted that is a 351 block, I would imagine the 302 is similar.

As far as individual cylinder timing, that gets really tricky, especially without an EGT gauge for every cylinder. You could read each and every plug but that process is super tedious. I run a cam sync (modified msd distirbutor) with my XFI 2.0 so I can run it sequential instead of batchfire. I do not however play with the individual cylinder timing at all. If I had a nitrous car I would consider it but I can't argue with the results I've had already.

I wasn't really talking about batchfire vs. sequential. That has to do with injector timing.
Are you saying you still wouldn't mess with individual cylinder ignition timing even if you could see which cylinders knocked first? I can't imagine why you wouldn't want to retard timing on those cylinders and advance timing on the others until you started to see even knock across the board.

EGTs should theoretically be an indicator of detonation, and you'll know with a given engine that you're close to MBT at that engine's target temperature. If you can achieve the same conclusion from a single knock sensor that monitors every cylinder, why wouldn't you? In an ideal world, we'd be measuring AFR, and EGTs for each cylinder. Since that's obviously not practical, I'd argue that a knock sensor is the most practical alternative.

Would measuring EGTs at each collector be helpful in tuning? Another problem, is that you would have to learn a lot to apply EGTs to tuning at different loads. At cruise, I assume EGTs will be different than at WOT. With a knock sensor, it's either knocking or it isn't.
I know I'm talking out of my inexperienced ass, but I do so to be corrected if I have a lack of knowledge or am off in my reasoning.
 
Ok, so I've researched the EGT question. It looks like the right way to go is never in the collectors, and that the preferred solution is to place a single EGT sensor in the primary of leanest cylinder.

An observation: the idea of a "leanest cylinder" is a strange answer if you have a standalone. My BS3, for example, can adjust fuel injector timing in sequential mode. However, I don't know if it can adjust pulsewidth/duty cycle on individual cylinders. I hope it can, because then the cylinder with less air would just have a reduced injection. Likewise, leaner cylinders with more air would get an increased injection. I wonder if a cylinder with less air/fuel at the same AFR at WOT would yield the same EGT as the other cylinders... Further, I wonder if it will make still make MBT at the same EGT as the others.

With a set amount of timing and fuel across all cylinders, this knock sensor should indicate which one is lean because it will knock first. Then, ideally you'd be able to increase fuel to that cylinder. If not, you could retard the timing. If you don't have those capabilities, you can rely on the J&S box to pull timing for you, which I wouldn't like. Similarly, you could plug your EGT into that primary and confirm that the EGTs were higher, due to the lean condition. If you can't add fuel to that cylinder, retarding the timing should actually increase EGTs further.

Another reason I like the idea of having an EGT and knock sensor is that they would give you the opportunity to do tuning diagnostics. When the wideband O2 sensor starts to go bad and indicates an excessively lean or rich condition but the EGT and knock sensors don't indicate a change, that would be an indication that it's just time to replace the O2. Likewise, if you're allowing EGO corrections and an inaccurate wideband O2 leads the motor to make excessive trim corrections to maintain an AFR, you should see a change in the EGTs, and possibly engine knock.

Man, this stuff is exciting! :nice: :burnout: :trip:
 
I think you are diving much farther into this than required. As you have stated, never run egt's in the collector, always in the primary tubes. I personally see no benefit to one egt and would opt for all 8 if you decide to go that route. The thought of individual cylinder tuning is a very daunting task. You can with most stand alone dfi's that run in sequential adjust fuel and timing on a per cylinder basis. This is tricky, different plenum designs typically lead to different cylinders receiving more air or less air than others. With a carburated setup where the fuel is atomized with the intake air the same general fuel/air mixture is distributed to each cylinder. With an injected setup varying amounts of air are fed to different cylinders due to flow inside the plenum while typically the same amount of fuel is fed to each cylinder. This is where the benefit to individual correction can be realized and typically the only benefit is seen at WOT. With out EGT's you must rely on reading the spark plugs and make small corrections to your individual cylinders for a base tune up and if you do any sort of adaptive corrections based on AFR they must be global corrections to the maps. Honestly I doubt I will ever do individual cylinder corrections with mine. If I was class racing and needed every last ounce of power from my combination than yes I would go down this road. I personally can't afford to have my stuff on KILL all the time running ragged edge amounts of timing and lean AFR's. I prefer to keep things on the safe side and that is why I run one timing map and one fuel map for everything. When we pull plugs we check 5 & 7 because they seem to be the leanest two on my combo for whatever reason. All in all running the same map for everything there are only small variations in the way the plugs read. Almost all of them read the heat mark in the same spot on the strap.
As far as a knock sensor goes, I don't see this being a very successful device in a high horsepower application. There is a lot going on inside on an engine that makes a lot of horse power. I remember years ago fighting with some of the GM stuff we played with, while showing no signs of detonation we would have knock sensors pulling the timing down from whatever was going on inside the engine. I personally feel rather than re inventing the wheel here, we stick to a good a/f gauge and some old fashioned reading the plugs. I like to stick to the KISS(Keep it Simple Stupid) principal to the best of my ability on everything I build.
As far as the O2's going bad, we have a limit set to the amount of correction that the wideband can control. I know the tune up is good and depending on elevation/weather there will always be a small correction in the tune up. If the correction begins to go to far one way it will be limited. I think my correction is limited to 4% currently. I get an alarm in the laptop dashboard if the correction is trying to go past that. Had it happen earlier this year, was calling for 11% which wound up being a bad sensor.