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Discussion Starter · #1 ·
Tuning Idle right now and was wondering how lean I can go
Seems pretty smooth at about 16:1-17:1
15:1 just smells really rich
How much timing should I run?
500-1000 rpm
240cc stock injectors
Na build.
Thanks
 

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93 Civic HB SI
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What wideband are you using? How can you confirm calibration? If 15:1 smells rich, what is your basis for comparison? An exhaust leak upstream from the sensor pulling in false air would make readings appear leaner than they really are.

What is your background in tuning? What platform are you using to tune with?

Holy questions man, we need more information lol. Advice on tuning anything is not something that can be offered with no context.
 

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lean idle tuning becomes a hunting headache with the tach bouncing because ECU is trying to lean things out and timing tables are trying to adjust because of varying MAP signal.

Thats just with a stock cam, and in something lumpy and you'll be bald in a weekend trying to figure it out.

+5-6 degrees at the dizzy and let the OEM ecu figure it out on stock tables. Yes, I ran 21-22 BTDC.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Depending on the head casting and cam/valvetrain you are using, compression differences, displacement, ect it can go as low as 20:1 afr and as high as 26°btdc, or as high as 14.6:1 afr and as low as 16°btdc, every setup is different, have you fired it up stock tune to see if it idles?
 

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Buy and utilize a vacuum gauge. Find the factory value for idle vacuum, and make it the goal. If you cannot find the factory value, shoot for 15-25 inches (in-Hg)
 

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Discussion Starter · #7 ·
I smoothed it out, was a alot of adjusting. I got every gauge you could have in my space ship of a civic. Problem I'm having is some kind of enrichment setting, when I start it when it's cold it dumps fuel and hardly runs.
Where do I adjust this, I'm using chrome.
 

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Not sure how you missed the coolant temperature enrichment setting. But it is in there, possibly worded differently.

There is a table that scales fuel enrichment based on coolant temp, due to needing more fuel when cold.
 
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Discussion Starter · #9 ·
Hey transzex, I've read some forms on mpg builds. Seen you in alot of them.
I'm building a d16 bottom end with pm6 pistons, will come out close to 11:1
I will be runing a y5 head on that motor. It's going into my daily witch is a 97 HX
So it has a dx/HX trans same ratios.
My question is could I benefit in mpg by switching to a ex trans. I'm in Florida so it's relatively flat, I do alot of driving, hwy and town. I have a vx trans, but have read it will take me out of a good rpm torque range and the motor will bog/ increase load. My intentions are to drive 75-80mph on hwy. Not trying to set records but I want to just drive it conservatively and get 40mpg. Right now with my tune im doing about 37mpg when I'm driving normal.
About 31-32 mpg when I'm being a jackass.

Oh btw pcv wasn't hooked to vaccum so that helped alot with the smell and oil burning lol car was turbod for a little bit. So she's been abused. That's why I'm building this other motor, litterly have hardly any money it. Paid like $40 for a good bottom end. About $100 in gaskets and machine work. $80 in pistons. Any how what you think.
Trying to make an efficient d series. Do you recommend I use y8 intake or the y5 with egr. Same intake desighn but one has egr. I got every damn D series intake.
Would the y5 head be beneficial becuase I can port one of my z6 heads or a y8 head and slap her on there. The y5 as you know is the roller cam so I know there's some energy conservation. If I run the ex trans hwy speed will probably be like 3200-3400 should I set the vtec higher and stay out of the y5's vtec to maintain velocity. Or keep it set to 3000. Right now hwy speed is about 2900-3100 doing 70-80mph. Running stock HX wheels 185/60/14s
No power steering. I'm in Florida so got to have ac that slaps, still suffering tho lol it's fuckin hot

-thanks
 

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Discussion Starter · #10 ·
Ok thanks bro, I think I did see that I'll look for it.

Oh also side note from my previous comment.
I'm cruising 70mph
7-10 inhg 2900ish
Runing bout 15:1 15.5:1
 

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DX and HX do NOT share transmission gearing. Very different from the driver's seat. I am speaking on how it feels, not mechanically, as internally, they are nearly identical. (forgot to add this prior to edit)

You want the lower gearing (longer) because the Y5 headwork, camshaft, and the ecu that generally runs it will focus on low and midrange rpm torque.

The entire point of fuel efficiency is maximizing torque from the engine side. aero of course helps, but getting those rpms stabilized and a bit lower help the most. With a focus on low rev torque, comes a penalty of high rev power.

Either you have a differnt 5th gear, or your final drive is not correct.


With 185/60/14 tires, the HX will be at 2700 revs at 70mph. The EX trans will be at approx 3100 revs. a DX trans will sit at 2950 revs


Finals
HX - 3.7
DX - 4.058
EX - 4.25

HX trans is just a DX trans with the lower final.

EX trans is 2nd and 3rd gears shortened up slightly and of course the 4.25 final.


Id source an EX trans and throw in a HX final so you have low speed drivability improvements. The extra mechanical torque will allow getting up to speed easier. honda should have done this form the get go, but they probably did not want the HX to be as drivable around town as the EX. (just a GUESS)


You can have custom gears made if you really wanna string out 5th, which would be very usable with the extra compression.

Check out the zeals calculator in my sig link. It has a trans section upper right that I am using right now.
 
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If you adjust timing a little bit ot advanced, and run 91 or higher octane fuel, you can slightly lean up that fuel mixture at cruising speeds. The D16Y5 head will tolerate as high as 17:1 AFR when temps are proepr, the fuel isnt trying to detonate, and you have very clean injectors that are properly atomizing the air.

Even slightly dirty injectors will feel like they are firing correctly, but things like lean burning tunes will still be harmful to the engine.
 
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Setting up a warm air intake will help atomize the mixture on its own, such as sourcing the air from above the exhaust manifold. Note this will play with your tune's actual AFR limits, as too hot is quite easy to get.

You can settle for sucking in air from in front of the radiator (front as seen looking down. Not fresh air side. Fan side is the ticket), that way by the time it is starting to really heatsoak the intake, the engine is warmed up and up to operating temp, and fuel enrichment tables are not as active.

Make sure the intake air sensor sees actual temps of the air flow (dont have it dangling out in the open away form heat) YOu can watch your ignition timing to see this effect.

A slower car is not always one that is struggling either. I have learned a LOT about honda's take on fuel efficiency owning my 2001 Honda Insight with its very specific focus on fuel mileage.
 
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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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You might look into the b7 intake manifold and a cam gear to advance the cam timing a couple degrees, the manifold will need port matched to maintain atomization. The b7 intake focus is on building low to mid range torque, that along with a cam advance of 2-3 degrees, and tri y header like the pacesetter torque step will build torque much faster and smoother, it would even pull the vx gearing happily. It should be noted that intake tube diameter/length and exhaust tubing size/muffler choice are important in maintaining velocity on the intake side and laminar flow on the exhaust side, both of which effect lower engine speeds and how and where the torque is made.
 

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The d15b7 camgear will not help at all with timing. its the same,
 
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Wasnt saying use a b7 gear, guess I should have said adjustable cam gear, oops.
 

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'93 / '95 Del Sol Si - '95 DX Coupe - '98 Civic Hatch - '00 Accord EX F23 Manual
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I used Crome for a long time. Even with all the issues in the coding. When you get used to the "weirdness", there are a lot of things you can do with it.

There were a few things I found with idle. One was setting the idle and having it constantly be switching cells. Due to slight RPM fluctuations or whatever. I try to adjust the idle so that it remains in the same cell. If it can't, there is some tweaking you can do to the RPMs / Vaccuum / Fuel to get it to even out and quit jumping around.

Also - There is more than one idle setting area. Depending on which Basemap version and version of Crome you are using.

Crome's timing is not what is seems either. A lot of people set the dizzy to 15 or 16 degrees and tune. With Crome, I don't do that. I subtract timing on the tables from about 1200-1500 RPMs on up. So 42.75 degrees would be brought down to, say, 36.25 degrees. Then I physically advance the dizzy five degrees. After I started doing things like this, my previous idle issues vanished.

I've been using Crome almost exclusively since getting into ECU tuning. And have learned about a lot of the weirdness that Crome offers. And how to get around it. Mainly because I like using underdog stuff when I can. But with Honda Tuning Suite getting the previous bugs worked out, I'm going to be leaving Crome World in the next few days.

Just trying to add this information to older posts to give possible solutions.
 

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Discussion Starter · #18 ·
Yea I feel that I recently switch to HTS
I do like it, but the learning curve is a bit more difficult.
So far with my experience my tune with chrome runs better and is easily adjusted.
My eg is running a HTS tune and I'm still working out the small adjustments. I haven't quite figured out the limiter settings yet, I'm a little scared to play with it lol.
I jumped timing on my ek hitting a crazy 2 step, but I think that's my fault I put the belt on to loose about a year ago and have been beating the shit out of it. Turbo/na for a year.
 
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