How did you learn how to tune?
 

Found out I can't PM another member until I reach 10 posts so I'll post my question to y8s in this public forum:

y8s,

Sorry to have to bother you but I've noticed that you are pretty knowledgeable with the Hydra ECU with your posts on the Hydra forum and your mechanical knowledge in general here and on m.net and was wondering if I could pick your brain for a few minutes?

Like you, I have a Hydra. I've learned to manipulate some of the main screens within the software but not the point where I feel comfortable entirely. Jeremy at FM has guided me through most of the tuning but only to the extent of "Upload this map to the Hydra, run it on auto-tune and get back to me with a log of a 1,2,3 gear pull and a 4th gear pull along with your auto-tuned map". He sends it back and says he modified the timing and smoothed out the fuel map and to upload it and repeat. This obviously doesn't allow me to learn how or why he did what he did. I just don't want to feel like I have to rely on him to tune my car as I still have tip-in knock and a surge (very slight bucking) at cruising speed.

Recently, Jeremy sent us an email to re-calibrate the wide-band O2 while the car is running so I 'll be performing that soon. I can manually tune idle fine but it's the "smoothing" of the fuel past 1500RPM after auto-tuning that I'm having problems with...I just don't know what to look for or what to modify.

From what I gather, if I have a high point and the surrounding cells are low, I simply lower the high and raise the low to make the transistion between cells "smoother".

Regarding timing, when do I fool with that? When I see knock? If I don't see knock do I raise it until it does knock then back off? When I datalog and run through the gears and I see a knock spike, how do I quell that? Do I increase fuel or pull timing? If my A/F is rich in spots, can I lower this to try and increase power and would I have to worry about EGTs? How about tweaking the VVT? What do you tune when it gets cold

Basically, I want to know how to tune and was wondering how you learned? Is there a book you read that you could suggest?

Respectfully, Dan Bachman

This is a really great book for beginners as well as experienced tuners. It will help you grasp a lot of concepts. I highly reccomend it. http://www.amazon.com/Modify-Managem...e=UTF8&s=books

Also check out www.EFI101.com

Hey mate,

I know this was meant to be a private message but if you could post the answers to your questions back here then we can all benefit!

Cheers

I've got that book at home and it has a chapter on tuning which runs through a typical tuning session, but it doesn't really give any theory behind WHY you need to do what they say. Can you recommend anything that covers this stuff?

This forum might be of use too:

http://www.msefi.com/viewforum.php?f=31

Cheers

Check out the efi101 site. They have classes that travel the globe teaching you how to tune and to understand why you did what you did.. From what I have read almost everyone who attends says its the best money they ever spent on their car.

I thought EFI101 wasn't worth the money, BUT I did have a guy who was teaching it for his first time and was not very organized (over head slides contradicted class booklet, a few "oh yeah uhh ignore that" moments, etc), AND some asshole know-it-all who kept inturrupting the instructor with boring war stories. Your results may vary. If you really don't know much, then anything is worth it. I do not have the book WOT posted, looks good though!

i dont know nothin bout no tuning. actually I'm still learning.

i just know the basics, but dont have a TON of experience. you know, enough to be dangerous.

so i do it like this:
start with a solid baseline. ask around, someone has already made one I guarantee. dont do work that's been done already. FM gives us all base maps so that's a good place to start... and EMS systems all want the same basic info. AFR, spark advance, etc. it can be ported from one machine to the next. solid baselines.

tune light load fuel first. the last thing you want to do is blow your motor while it's green. use the baseline to get the car running and find a solid idle (10 degrees, 14.7 AFR). then see how it drives with all the enrichments turned off. remember what they were as a baseline. get your OFF boost fuel dialed in roughly. this will give you a general idea how the car uses fuel. you can smooth out the map and make some predictions as to how it might run ON boost.

smooth out the map and extrapolate. you can use the above data to get some ideas about fuel usage in regions of increasing boost. still, I'd keep it conservative and only go up a few psi at a time to dial it in. let the car autotune or dig through the datalogs (make sure to avoid spots where enrichments are triggered--no steep MAP or TPS lines). repeat this step a few times and see how your map is starting to look. it'll probably resemble the baseline but with somewhat more contour across the rev range as the ECU dials in the mixture.

Fiddle with timing. once you have your fuel maps dialed in, you can experiment with timing. You dont *have* to since FM and others have done lots of work on this over the years and the base maps you find are likely to be 95% good. plus you usually want a dyno around to get it nailed. BUT if you have time and lots of donuts riding shotgun for the cops... find a flat, straight, long (and high speed limit) section of road (onramps work GREAT for 2nd or 3rd gear pulls) and datalog in one gear from as slow as you can go to redline. make slight changes to timing and see if your power increases or decreases. an EGT gauge is good here too. you want timing that maximizes power and keeps EGTs in check.

You can also use timing to improve drivability, but that's more than I'll go into here.

re-tune your fuel maps. after you make timing changes, re-tune your fuel maps. the car will respond differently with different timing so these need to be redone. timing and fuel changes are somewhat interactive so you may want to go back and forth a few times.

Enrichments! these are a royal pain sometimes. partly because Hydra doesn't give a lot of specifics on how they work, but also because you can really affect drivability in big ways with small changes. You really can't mess with these without datalogs. Once you have a dialed fuel map, take some new datalogs of you driving around town and doing runs through the gears.

You'll notice that the car may go super lean or super rich as the TPS goes from 0 to 100 or MAP increases quickly. You can set enrichments for both. It's generally not a bad idea to err on the slightly rich side but not by much. You want the car to maintain the proper AFR for the zone it jumps to but it's best if it approaches it from the safe side (rich) instead of risking a lean spot and potential damage. In short: if you mash the gas and the AFR cell you jump to is 12:1, set the enrichments to provide around 11.8:1 while the O2 feedback and/or map table catches up. Be careful though or the feedback loop will pull too much fuel and it'll rebound lean on you.

The only way to do these is trial and error. You can TRY calculating the right percentage based on what the datalogs say, but I've found it's rarely accurate. it is a fair starting point though.

In our next issue... specific answers to your questions! ;)

Hi Dan,

best to do it in the forum in case others are curious too, right?
pretty much. remember also that autotune isn't perfect. it samples the AFR and adds what it thinks you need. periodically you should do a "reality check" and turn off autotune and just datalog different areas of the map (again, watch the enrichments aren't making changes for you).

the FM timing map is pretty solid. i feel it's a little aggressive for the 01-05 cars, but that may just be my car. leave it alone unless you DO see knock. If you see knock, you might want to pull a degree or two depending on where it is. Above atmospheric (0psi or 100kpa), advance drops off as boost increases. here you can pull a degree and have a significant impact on knock in some cases. if you're pulling more than 3-4 you may have other problems.

off-boost (below 0psi/100kpa) is another story. timing generally doesn't have as big an impact because it's not directly related to peak power and EGT since it's considered lower load (load meaning throttle position or total mass airflow into the engine--and thus horsepower produced). these sites DO have an impact on cruise EGT which can be significant though. Typically that region is around 30-70 kpa and 3000-5000 rpm. try to leave those where they are in the base map. everything else can be adjusted (SLIGHTLY) to affect drivability. but you probably dont need to.

as for AFRs... well, try to maintain the recommended AFR for a given load/rpm. FM's defaults are fine and conservative enough that you wont hurt anything by keeping them. If, as you asked, it is rich in spots, let the autotune take care of it or adjust it yourself based on datalogs. when the AFR stays pretty consistent, you can leave it alone. If you have to add fuel beyond what they recommend, then you may have other problems.

As for VVT, nobody seems to have an answer to that yet. All I know is my car surged like an SOB when there was VVT advance (taller map points) below 90 kpa (100mmhg). Set that to -12.5 for every cell from there LEFT and your surging should go away. either that or unplug the VVT connector on the top front of the engine at the oil control valve.

when it's cold, you can tune the cold start enrichment as well as the cranking enrichment (I think). above freezing these have much less effect. FM should have as good an idea as anyone what with the snow up in vail pass near them. and since jeremy likes to hit the slopes.....

umm a book... no i learned by not having another car to drive. :)

hopefully this helps some. just remember to make small changes (3-5% or less) when you don't know for sure. see how the car responds. it'll guide you.

Matt

I'l let you know when I figure it out. I have never tuned with the aid of a dyno, but the Miata will go on one this spring after I get the IC in and build an exhaust. Looking forward to it.

So what is considered to be a safe EGT range and a number to absolutely not go over?

What aids would you consider to be essential for tuning? Obviously wideband O2, but EGT, fuel pressure?

EGT helps. Open ears. Reading plugs. A dyno really lets you get dialed though and see what is working and what doesn't.

EGT is just another reality check, really. Once you get your timing and fuel dialed in, it'll corroborate your tuning. If you find you're backing off on timing to squelch knock, the EGT will tell you when you've gone too far.

I use mine primarily for cruise.

Matt

Can you guys datalog? That IMO is the key. Drive around focusing on a certain area, then sit back at the pc and look at what's going on. Looking at the data on the screen really puts things into a more comprehensible form. My process for tuning boost is two part. Go out at lunch and make a logged power run after warming up the car. Then that night bring the log file over, make adjustments and do it again the next opportunity. Top that off with lots of research through various forums and the rest is just education through experience. - rob

Matt and other nice folks,

Thank you very much for taking the time to write this up. This is exactly what I needed to get me started. I have this book marked and this is now my cheat sheet for my tuning.

May I get you folks to look at this attached screenshot of a 4th gear pull from the other day? I'm really concerned with the knock spike at graph point 27.5. What should I do there? I'm thinking it's too lean?

http://img465.imageshack.us/img465/2...b101606iu7.jpg

...and it sounds like I should be investing in some guages. An EGT and a A/F meter...but especially an EGT. Where will the probe/sensor have to be inserted?

Dan, can you repost that graph but leave out C Temp, Vac, DC%, and A Temp but add in ignition advance?

AFR looks good, but I'd like to see what your timing is doing. Have you done a few runs and seen that spike on all of them? It may not be knock since it's only about 3X stronger than the normal engine noise. As I understand it, knock spikes would look much bigger. Can you *hear* it?

Matt

Hey that book "How to tune and modify Engine management"

It is crap. I bought it and was completely disappointed with it. Lol the thing goes through all sorts of systems and tells what they can do, but ...

... They never say anything about the most important thing: HOW.

Let me sum it up for you in a sentence or two: "Engine management systems vary greatly, so make sure the one you choose will work for your application and will have the features you need to get the result you are after. You can control a twin turbo with a motec."

I can't hear that particular knock. I have throttle tip-in pinging at low load but not up this high. I'm not too worried about that right now. I'm doing 80+ on a two-lane country back road with the top down. This is definitely where a dyno comes in handy huh? I need to ride around with a stethoscope too...but it'll look too weird. I'll post a 1-2-3 pull with the same parameters. I can forward you .cvs files if that helps but I wouldn’t want to impose and looks like other’s are interested so I should keep this public.

I really appreciate your time on this. Too bad you live so far away.

4th gear pull:

http://img357.imageshack.us/img357/9...b101606iz7.jpg

1-2-3 gear pull:

http://img456.imageshack.us/img456/2...b101606nb1.jpg

Another 4th gear pull from a few days prior:

http://img490.imageshack.us/img490/4...b100906rh4.jpg

I don't see that 5500 knock in your other logs. One means for detecting noise is to make DLs to rev limit w/o going into boost. Whatever shows up in your knock log is noise and it makes a good reference to future boosted logs when knock does show up. - rob

Good to know. Thank you. Any particular gear you do this in?

...see? I didn't know that there could be "noise" in the mix. I just figured that there was a spike and it didn't look normal and therefore I should be worried. I didn't know what real knock "looked" like.

Any one have a datalog of real knock?

actually real knock looks very similar to what is seen in your log- it's just that your spike is so small. My logs are loaded with noise- but it's more or less a linear increase. Then at 7k I get a huge spike- but running the car in 3rd, out of boost up to 7300 I got the same spike. So it's something that only rattles at 7k. I've also got to find a better mounting spot for my sensor. Using the adapter plates for the engine swap has eliminated the recommended location. I have learned that the further away from the front the better. Apparently all those pulleys make a lot of noise which the sensor picks up. Moving the sensor back cut the noise in half. The next thing are my lifters- which are in bad in shape. Such is the case with most JDM engines- sounds like a few of them never pump up. And that seems to get the sensor excited to. All this said, your knock line looks very clean. And like I said, I don't see that knock occuring in your other logs. So it's most like some kind of noise. Repeatability is also key in detecting knock... though not good for the engine. But if you make at least two runs in your log, you can then reference them to eachother, so if you do see anything suspicious you have something to go back on to reference and back it up- or not. - rob

there is a really good tuning shop in the DFW area, and for $350 max, it will make more power safely, and with a near perfect cold start in about 2 hours (cold start may take longer). I'm just going to drop the cash, and be done with it, and know its safe.

I'd rather learn to tune the car to 90% of it's potential than have someone else tune it to 99%. What happens when you need to tweak the tune? Spend more money on having someone else tune it? Take that $350 an invest in dyno time learning to tune it yourself. The original poster is doing exactly the right thing in trying to figure it out for himself rather than relying on FM to do it for him.

This is a great thread guys! I especially like the idea about seperating actual knock from ambient engine noise.

Jay

That's exactly what I'm doing. I was intimidated at first, but like anything, the more time you spend on it the better you get. And with all the right sensors/gauges/data it's hard to make any stupid tuning mistakes. I've gotten my fuel map fairly well tuned and have now started tweaking the IGN map. Another nice thing about DLL is the power graph. It's good for measuring the before and after of tuning changes. I've also got to get the EBC up and running- but that appears to be a wiring issue. Then I'll head to the dyno and let my expert tuner pal take over.

Havent boosted high enough to see knock yet, sorry...

but a knock sensor is basically a microphone for engine noises. it responds to high frequencies of knock but since it's a wideband mic, it'll hear whatever noises the engine makes. a rattle here, a vibration there... etc.

If I had new miatas like you guys, I probably would have so many rattles. ;)

Fuel Map
 

May I get you to look at this fuel map screenshot and give me ideas on what to change? When I'm in boost, I feel hesitation at points to redline.

http://img242.imageshack.us/img242/8251/fuelleftpj4.jpghttp://img174.imageshack.us/img174/5...elrightjj8.jpg
http://img179.imageshack.us/img179/3081/fuelmaplb9.jpg

it's not so simple. you have to look at your datalogs and see where AFR is off-target and then make the changes.

Sorry. I meant may I get you to look at the spreadsheet to give me an idea of what you would change to "smooth" it out? I just thought that doing this may make my car feel smoother...but I found out that my IC piping had come apart after installing new engine mounts.

it might make it a little smoother. Just try to eliminate the steep transitions. better to err on adding a little than subtracting a little. if you have to go up or down more than 5%, try adjusting the adjacent cells.

best way to find out how close it is is to do a datalog with autotune off and see how it reads.

great info guys, keep it up. I'm learning to tune a TEC3, but the basic info is the same.