How Many Degrees Before Detonation? MPG Problems

rcj

Member
Hey CI crew. Im going to get straight and to the point. I did a b20b high comp. non vtec swap in my 94 dc2. Everything went smoothly. Dad and i put it in no problem. Bypassed and merged the crank and cam angle sensors at the ecu. I still have a p75 obd2 ecu with obd2 dizzy i swapped out from parts geek.com. Everything is on time and was on TDC. When the dizzy was put at TDC i really didnt have pull or usable traffic torque. I decided to advance it by 1 degree which i believe it counter clockwise. I put marks on the dizzy and housing for TDC, anyways after the advance she pulls like i champ and actually climbs through revs like no tomorrow. My question is that how far advanced can it be before detonation? Also i think my MPG is suffering because once i fill up (job is 30is Miles away) go to my job and come back home im already sitting on 3 quarter of a tank. and last week i went to Atlanta on a full tank and made it back home with like 1/8 of a tank left. Is this solely because of me advancing the dizzy 1 degree or is there something more technical? Again always thanks for you guys' help! :D
 

Muckman

Not a M0derator
Then you know that you cant make tuning changes without some way to measure the effect (dyno, trap speed, G force meter). You also cant expect someone to know the very limit of detonation on your engine as it depends on many many factors. Its something you need to test on each engine in a controlled environment.

You may be able to get away with 1* of advancement because the stock Ecu is detuned to make it safe. However I don't think your "butt dyno" can feel the difference from 1* of advancement.

If you are experiencing poor mpg then look at regular maintenance not simply distributor orientation. You'd be surprised how much power you lose from old ignition parts, dirty fuel filter, dirty oil, dirty air filter, even years of carbon build up on valves. Give a full tune up. And if you still want to street tune, get a reprogrammable engine management solution and a GTECH.
 


rcj

Member
Muckman said:
Then you know that you cant make tuning changes without some way to measure the effect (dyno, trap speed, G force meter). You also cant expect someone to know the very limit of detonation on your engine as it depends on many many factors. Its something you need to test on each engine in a controlled environment.

You may be able to get away with 1* of advancement because the stock Ecu is detuned to make it safe. However I don't think your "butt dyno" can feel the difference from 1* of advancement.

If you are experiencing poor mpg then look at regular maintenance not simply distributor orientation. You'd be surprised how much power you lose from old ignition parts, dirty fuel filter, dirty oil, dirty air filter, even years of carbon build up on valves. Give a full tune up. And if you still want to street tune, get a reprogrammable engine management solution and a GTECH.
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Yeah I understand I'm gone have to eventually put her on a dyno and get an official basemap to know what to work with. I was asking did the 1* affect anything else besides PowerBar Cuz I did recognize my gas mileage started to suck. As for the ignition parts everything is brand new. Ngk plugs and wires and a new starter. as far as EMS. I've been looking at AEM or Megan quiet.
 

95B18BTurbo

New Member
Go with a proper S300, Neptune, or Crome. Don't waste your time with anything else as it's not worth it at all.
 


rcj

Member
95B18BTurbo said:
Go with a proper S300, Neptune, or Crome. Don't waste your time with anything else as it's not worth it at all.
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Imma invest in Neptune. I heard about crime as well but I'm quite skeptic on that. Could I chip my obd2? But I know it involves soldering
 

Muckman

Not a M0derator
No, there are no OBD2 tuning solutions for Honda on the market, only piggy backs.
You have to go with a chipped OBD1 ecu. Crome, Hondata, Neptune etc
AEM EMS and Megasquirt are more involved stand alone systems. Certainly more complexity and cost than you need.

Put the distributor back to 16* BTDC and run a tank of gas through it. Thats the only way to test if its affecting gas mileage. 1* is probably not enough to make any significant difference but tuning isn't about guessing.
 

rcj

Member
Muckman said:
No, there are no OBD2 tuning solutions for Honda on the market, only piggy backs.
You have to go with a chipped OBD1 ecu. Crome, Hondata, Neptune etc
AEM EMS and Megasquirt are more involved stand alone systems. Certainly more complexity and cost than you need.

Put the distributor back to 16* BTDC and run a tank of gas through it. Thats the only way to test if its affecting gas mileage. 1* is probably not enough to make any significant difference but tuning isn't about guessing.
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Ok i get itt but my question now is do i have to commit to a heavy tune on a basically Stock motor? only things added was my Blox Intake Manny, HAP Throttle body , CAI and DC 4-2-1 Full exhaust from my old b18. I didnt even put in my AEM adjustable cam gears. i might sell them. Also when you say 16* BTDC thats basically stock Dizzy position isnt it? i appreciate all the extra knowledge on EMS's and ECU suggestions.
 

Muckman

Not a M0derator
No, you dont NEED a tune because its basically a stock motor like you said, but you'll be missing out on 10~15hp from those upgrades.
What you need is more fuel with all those breathing upgrades, not timing.
Adjustable cam gears are useless. Do you even have cams?

And yes 16* is stock dist timing. Put it back to 16, and test to see if your mpg improves.
 

rcj

Member
Muckman said:
No, you dont NEED a tune because its basically a stock motor like you said, but you'll be missing out on 10~15hp from those upgrades.
What you need is more fuel with all those breathing upgrades, not timing.
Adjustable cam gears are useless. Do you even have cams?

And yes 16* is stock dist timing. Put it back to 16, and test to see if your mpg improves.
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Ok just making sure on that one. And I have an AEM sport fuel rail and I forgot what cc injectors. Idk how to measure them. And another fuel pump with B&N fuel filter and pressure regulator. And no I don't have aftermarket cams in either. Because I didn't move them over from my b18. Only thing sitting out are my cams and cam gears
 

Muckman

Not a M0derator
wow so you have all these fuel mods too and you're running on a stock Ecu? Hey do you think those unknown CC injectors might have something to do with your poor mpg?

You didnt mention this until post 12?! ugh
:smackself
 

rcj

Member
Muckman said:
wow so you have all these fuel mods too and you're running on a stock Ecu? Hey do you think those unknown CC injectors might have something to do with your poor mpg?

You didnt mention this until post 12?! ugh
:smackself
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I apologize sir. And yeah that could be a possibility as well. Also I use premium gas cuz the comp. Is 9.6:1 which I think is low comp in Honda eyes
 

Nick_C78

New Member
Why in gods name would you run different injectors without a tune. swap back to stock fuel system and I bet the mpg fixes itself like magic.
 
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