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Hagerty
Hagerty Employee

ECU and EFI 101: A beginner's guide to performance tuning | Hagerty Media

As he pulled into Toretto's Market & Cafe, Vince was disappointed with his '99 Nissan Maxima's performance after last night's street race. "Talk to me Jesse, this ain't working," he cried. "It's your fuel map!" said the scrawny cat as he climbed out of a modified '95 VW Jetta.
https://www.hagerty.com/media/maintenance-and-tech/ecu-and-efi-101-a-beginners-guide-to-performance-...
21 REPLIES 21
JimR
Instructor

I’m an aging boomer with little aptitude for the subject, but own a forced induction EFI (MAP system) car that I run a programmable stand-alone on. You might have to be old for the analogy, but I’ve found trying to decipher this subject can make it seem like I’m listening to a “Flintstones” phone conversation. So I lean heavily on the trusted pros.
I enjoyed the read and looking forward to “ECU and EFI 201. And  Phillip...take $10 out of Hagerty petty cash for your trouble. 😉

lohpilot
New Driver

I grew up tuning 60's and 70's Chevy's doing tune ups every 3,000 - 3,500 miles. Later, I had a 1981 Mazda RX-7 with the double timing and a tree-like distributor rotor. The only plus to that ritual was that everything was accessible. I do miss doing the fine tuning with everything being EFI and controlled by the ECU.
gpsuya
Intermediate Driver

Re: Instead of tearing apart a fuel-filled carburetor or having to futz with distributor weights, you could just “chip it” and quickly pick up some performance". Well, I for one much prefer doing the former.
JimR
Instructor

Good to know @gpsuya , but you missed the point of the article. On most any car built within the last 35 years or so,  you don’t have a carburetor OR a distributor. So your preference is irrelevant. 

gpsuya
Intermediate Driver

@JimR  Actually I didn't miss the point of the article at all. My thing is I'd rather buy an older car & play with it.

OldCarGuy300
New Driver

So, grew up on dual carbs, dual points. Still prefer but... I have played with my 2013 Sonic RS. Suspension, brakes, and making the "pump" more efficient. Have spent lots of time with the calibration. It's fun and therapy. Plus, as an A-B, it has dropped ~three seconds in 1/4 mile time. Very traction limited. Lots of grim time. This year run some track days on road courses to see how the chassis works.
tonyjustin
New Driver

I'm with gpsuya. Yes, you could argue modern tuning is more complicated than adjusting a carburetor, but there was much more to tuning back in the day than a simple carburetor adjustment. Today it sounds like all you have to do is read a screen, punch in a few buttons, and then head off for your next tattoo or piercing. No offense meant if computers, tattoos, or piercings are your thing. For me, there is some soul satisfying pleasure in figuring out cam specs, cam timing, compression ratio, ignition timing, and adjusting the old stuff. I own five cars and three motorcycles and it's about half and half as far as electronics vs. old school goes on those rides. I love 'em all.
bblhed
Detailer

Something missed here is the learning curve. Back when carburetors and points were common if you wanted to go faster you were either going to have to learn or spend to do so, probably both. This kept new drivers in slower cars and as their knowledge and skill with tools increased so did their driving skill. Now a 16 year old can go on the internet and add a bucket full of horsepower to a car before the lamination on their drivers license is cold. While I agree with the right to repair, I also believe it needs to be tempered with explaining to the drivers of tomorrow that it is not something to be taken lightly.
Tinkerah
Instructor

Kids today are more comfortable with this technology than I will ever be, and they'll learn about blowing up a motor with an ECU just as quickly as they learn about overclocking and roasting a CPU. Neither of which I know how to do.
stevecobb45
Detailer

Having had to deal with GM dealership service managers who didn't have a clue about fixing my new 83 Trans Am check engine light problem, I tried to educate myself on electronic engine management. Back then there was nothing aftermarket available for a resource. No code readers except for the dealers & finally I started seeing more & more information. With a paperclip I got the codes myself by shorting out two connections on the OBD 1 plug. The final straw was when I took the car back to the dealer in Louisville, KY, where I bought it & said fix it. I was off for two weeks on a business trip & when I returned to pick up my car, they handed me a bill for "cleaning the carburetor" which was not covered under warrantee. I paid it & on the way home the check engine light came on again. Emission equipment is guaranteed for 50,000 miles but they found a way to get rid of me & make some money to boot W/O fixing the problem. I didn't want to circumvent the emission controls but at this point it was using a lot of gas & it was running real rich. At a junkyard I got a carburetor & distributor from a 79 Z28 Camaro. Installed them in one afternoon & I was up & running. Better fuel economy & running much stronger & no more dealers. Sometimes there's a reason for dealers to go out of business.
F360Spider
Detailer

I have a 2001 Ferrari 360 with the Bosch Motronic M7 system. Lots of opportunities abound for changing the ECU mapping and all that. I wouldn't touch the ECU program with a ten meter cattle prod. The car is best left stock.

That said, there are lots of other opportunities to at least return a car to original specs without resorting to damning the ECU to eternal hell with a ECU tune. Bosch components have a lot of leeway between new condition and throwing trouble codes, in which time they can cause all sorts of havoc with power and smoothness. For common cars, it's a good idea to replace EVERY electrical box on the car when they reach about 15 years of age. For cars like the Ferrari 360, replacing a single box like a throttle body can cost as much as every single one on a Corvette or Porsche so the alternative to gang replacement is to test components to see what their state is.

I've been working on a testing suite for the 360 that can characterize the Bosch components and determine where they are on the failure curve. By replacing only the components that show degraded performance, returning the car to original specs can be a lot less expensive.

 

Here's a video I made a while ago of gen 0 of the tester for Bosch throttle bodies.

 

https://youtu.be/kPD8buqUzmQ

Newly developed device to check the health of Bosch series 0 280 750 XXX throttle bodies. Determine the lag, maximum amp draw and potentiometer variance.
Edwardsg
Pit Crew

A short video showing the changing of the map would show how the software can smooth out the map. Also interesting is dyno tuning - especially the large gains that can be made in a short time on a modified engine.
Stand-alone EFI systems are also available for old vehicles. They are self learning, but usually come with software / ability to tune. The big plus to computer tuning is how quickly you can return to an old tune should an incremental one not pan out. Unlike the carb or points / distributor recurve, where going back is not so simple.

SilentBoy741
Detailer

"With all that said, it’s extraordinarily unlikely that OEMs will ever build a fully hack-proof vehicle."
I'm pretty sure my '56 Oldsmobile's Rocket 324 V-8 has never been compromised...
Tinkerah
Instructor

Can't like this comment enough!
Maestro1
Advanced Driver

I maintain, and have the right, to repair my own cars, and i would never give that up to anyone else. Period. Obviously as the cars get more computerized, which I detest, there is more income for dealers service departments which I do not begrudge them provided their personnel are trained well in all the
nonsense and know what they are doing. My cars are all old. Not a lot of technology; I even try to stay away from digital dashboards. When any of them go sour, the repairs are straightforward and I'm back on the road again. And yes, I drive them all. And I tell their stories. It's what the Hobby is about.
TG
Advanced Driver

As much as folks claim to love it, digital hasn't really done the consumer any favors. I remember back in the day when you bought a stereo, it came with a double cassette deck for the express purpose of copying cassettes. Music goes digital, and all of a sudden this is a crime.

When I started driving in the 90s, I was broke and was driving cars from the 70s. They were great. you could swap just about anything into anything with a welder and a few butt-connectors. The big thing in my area at the time was putting small block chevies in Celicas. Imagine that now. I have a heavily digitized (by 90s standards) 90 cadillac, and I cringe any time there are problems with the electronic components, because replacements are made of unobtanium. I wonder what the car collector 20 years from now is going to do when all of the 20 year old cars have unresolvable electrical problems, and someone had the bright idea to put LS drivetrains in all of the 40 to 50 year old cars
Tinkerah
Instructor

If it helps, I can explain the rules of music (and most intellectual property): it's always been, and still is, legal to copy your material for your OWN use. Just illegal (and unethical) to share or sell it the copy. It wasn't as big a threat with analog since there was always some generational loss but once it became easy for consumers to copy their digital data the copies were every bit as accurate as the original. Ironic that the record companies freaked out about digital sharing after pushing us to invest in CDs.
JimR
Instructor

@TG  Not following your analogy. You could burn copies of CD’s all day long on most any Desk Top. I can buy, copy and share 20 songs cheaper than I could buy a LP back in the day...and half those LP songs I probably didn’t like, but had to take in order to get the ones I DID like. And it’s all perfectly legal. 

As for digital “favors”, with EFI I get more power out of WAY less displacement, the components last WAY longer. and I get WAY better economy. I’m not a tree hugger and given there’s no emissions testing in my state, a stand-alone ECU also allowed me to remove those trouble-prone emissions components without staring at CELs on my dash.  And all the while that particular car is still cleaner for the environment than most any carb’d car with points, and condensors, and distributor weights, and high lift/duration cams, and high octane fuels, and ignition amplification, and bigger carburetors with jet replacements. 
Now...do I dislike the old stuff? No! Each has their own place and charm. I love tinkering with my 50’s straight six.
But what some prefer has nothing to do with an article about how EFI works

It’s like seeing an article about the amenities at a Caribbean beach resort and using it as an opportunity to share that you’re afraid of the water because you never learned to swim...and don’t like sand anyway. 

TG
Advanced Driver

Granted my rant was a little off-topic.. but...

I suspect that what gives you more out of less with modern engines these days has more to do with tuned intakes, freer flowing exhausts, and engines that can tolerate 6000+ rpms sustained without splattering motor oil up your windshield, multi-speed overdrive transmissions - and yes to a certain extent the EFI

 

But on the other side of the coin, mu buddy bought a pretty wild tuner engine for his truck and was going on about what kind of tuning he would need to do to his computer to make it all work. My response was that if this were one of my older cars, all i would need is a bigger set of jets. exaggerated, but not by much

maybe my 74 isn't exactly the cleanest, most efficient car in the world, but i am not commuting 60 miles a day in it. i have a fairly modern fuel injected car for that task. but for having fun, tinkering, and modifying to some extent, older carbureted cars are lot easier to deal with... and as much as i rant about EFI, three out of five of mine are injected. 

JimR
Instructor

Edit

chrlsful
Advanced Driver

I missed the tuner world. My 'poverty' (read: need to self maintain an auto) came as a kid and now back again as an oldster. I missed the change from carb to puter'n efi. A big hole between '79 and 2010. aahahaha Yeah, as a person of means I could pay for another's skill, specialty tool & knowledge. Lota catchin up ta do. (well, there's abs and much more as well). I started w/a wide ban in the down pipe ( ford i6) a yr ago and may add hall effect dizzy or tfi and expand from there. But basically its "hybrid w/a upgrade plan"...