Background on Problem:
So I have Precision 1000's and Hondata S200. I was orginally tuned to like 57% DC on the last turbo and it made 372whp. All I did was run that tune for a few months (boosted it like 5 times maybe since the turbo seals were shot) and then upgraded to the T3 60-1 turbo and retuned. I noticed when tweaking the tune that my DC's were at 99% at 323whp. So I stopped and waiting until the tuner arrived and asked him if he had any idea why. Soooo when he gets there, we're going at it (I pointed this out before hand) and at 365whp, the supposed DC was at 122% hahaha.

Steps Taken:
I replaced my Walboro 255 low pressure with a new high pressure thinking that this might be the culprit (losing flow while still maintaining pressure). I will be going to the dyno tomorrow to tweak it myself again and then retuning next week for 25psi.

Questions:
Can injectors even get to 122% without commiting suicide first? Could there just be something wrong with the program/tune that wasn't switched right i.e. the re-calibrating for bigger injectors got f-ed up or something? Just a little confused at to what could have changed from then until now unless it was the old pump starting to go bad. The rest of the tune is the exact same and hasn't change. A/F's at idle and cruising are right where they originally were. It just seems like it wants "supposedly" alot more fuel under boost. I didn't know if I could be getting false DC readings from Hondata simply because my fuel system is definitely enough for well over 500whp. Could a clogged AEM fuel filter be the culprit that would cause only boosted areas to need more fuel?

It's not like it won't make more power...it will, but the valves in the boosted areas are outrageously high. I'm talking like valves of 3000+

Only bad thing I can think of is that (one) time the gas went to one side in the tank and my motor didn't like that too much haha. I shut the car off before it could do any damage, but I did see the boost gauge going on up to like 15-20psi...when my foot was OFF the pedal??? Explain that if you can also haha.

Fuel Setup:
- Walboro 255 hp
- Precision 1000's
- AEM fuel filter
- Aeromotive Compact EFI regulator (at 50psi at idle)
- -6 feed line from filter to rail
- -6 return from rail to stock line

Non-Vtec Map:


Vtec Map:



Modified by AF-P Dunc at 9:52 PM 10/19/2006

 

What was static fuel pressure on your old fuel pump and what is the static fuel pressure on your new fuel pump?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrecisionH23a &raquo;</TD></TR><TR><TD CLASS="quote">What was static fuel pressure on your old fuel pump and what is the static fuel pressure on your new fuel pump?</TD></TR></TABLE>

The old low pressure walboro was 50psi and then 60 under WOT. The new high pressure walboro is like 52psi (basically just slightly higher pressure) at idle. I haven't looked what what it would be at WOT yet, but I would assume like 62-65psi.

 

Wide open throttle doesn't matter.... static is what matters.

Fuel pressure will increase 1psi per 1psi of boost.

 

Just looked at the last turbo's tune. The highest value in vtec was 1700. Now it's basically double...but it's 4 less psi and like 50 less whp haha.

I'll know more tomorrow when I get on the dyno and do some tweaking myself. Also, how long do the AEM filters usually last you think? Can a stock one handle 300-500whp? I would assume it could, so I might replace the filter tomorrow just to see.

Could injectors actually take a true 122% for the 10 pulls we did tune it without locking open or shut?

 

The highest I've seen duty cycle read in hondata has been 101%. That's just my experience.

By the way... it's not good to go that high, lol.

 

haha yea no kidding. I was a little worried, but mechanically everything seems to be fine so it just seems like maybe it's an issue with the program maybe. I've got good fuel pressure, it keeps making power when I add boost, etc. Plus I'd assume if an injector really saw 122% it would kill itself....and if it didn't then that would say ALOT about Precisions Well I guess Hondata can read more than 101 cause the highest I've seen now is 122.

 

i would like to know also, having the same problems

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg:R &raquo;</TD></TR><TR><TD CLASS="quote">i would like to know also, having the same problems</TD></TR></TABLE>

Oh really? That's good to know I am not the only one. Is your setup acting like it's mechanically alright...and more than enough to support current power output?

 

fuel setup: 255lph, 1000cc, new fuel filter, pressure set at 45psi in idle. i could only dyno my car to 400hp@16psi due to hondata showing that my injectors were at high 80's to low 90's. can resister box be any problem to this?? ran hondata s100b and s200b and still the same problem. im thinking it could be the tuner hondata program.

 

I would definately like more info on this problem as well just for future reference.

 

I believe hondata reads a little high on the duty cycle. My buddy's 1000's were at like 60% duty cycle on 10 psi of boost with a b16, now we all know a b16 is not a thirsty motor with that tiny stroke.

Stock resistors work to some degree, an injector driver gives you ALOT more injector. It controlls the injectors 100% better and will lower your duty cycles alot. Currently on 16 psi with a t67 ive got about 42% duty cycle with an aem injector driver and 1000cc rc injectors with a base of 54 psi

i think 100% duty on hondata is more like 80or90 but you should be using 90% duty on a 1000cc injector for 325whp with 50 base. 1000cc injectors will give you a good 600whp. sounds liek a bad resistor or something electrical or that pump. no way a 1000cc should be that muhc used up on 320whp 550 yeah but not 320

 

your multipliers and scaling are probably wack.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote">your multipliers and scaling are probably wack.</TD></TR></TABLE>

exactly what i was going to say, you arent actually at 122% duty cycle, thats a calculated value in the program, like mase said check the multipliers

 

duty cycles doesnt mean **** in the program just add fuel till it doesnt richen up any more and thats when you know you have maxed out the injectors

 

Well just got back home from the dyno (and just working outside installing a new steering wheel haha ) Anyways, the multiplier is .251. I just used the calulator tool to get that number.

So for the good news:
Right off the bat my DC's were much lower. They were at 105% and the A/F wasn't even on the chart (richer than 10.0) due to the new fuel pump haha. Sooo after a few pulls and such, I got the A/F back to 11.8 and then the DC's were at 90-94%. So that's pretty comforting that I gained like 30% back just by going with a new walboro high pressure pump. I'm also going to replace the fuel filter just to see what that does. Plus, I figure I can still bump up the base pressure to like 60 instead and bring the DC down even more that way.

How would I go about calculating the <U>true</U> DC without using what Hondata tells me?

Thanks for all the input so far guys

 

there is no point in raising your base pressure, the injectors are fine up to around 600whp, you arent anywhere near their max duty cycle. The program is wrong, those are just numbers

 

1. never trust hondata duty cycle, I've seen it up to 130% on a stock b16 with 440s. But I think with 1000s, it would be around .24

2. I've had this exact same thing happen to me last year. Changed out turbos and injectors and boom, instantly out of injector. I replaced pumps too and had no change. The end result...Dead paxton fuel pressure regulator. instead of pressure increasing with boost, it held stagnant. so instead of fuel pressure rising, it head static. So either get an electric fuel pressure gauge or some other way to look at fuel pressure under boost.

changing the fuel filter is always a good start too

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by seen4ever &raquo;</TD></TR><TR><TD CLASS="quote"> ...Changed out turbos and injectors and boom, instantly out of injector. So either get an electric fuel pressure gauge or some other way to look at fuel pressure under boost. </TD></TR></TABLE>

Yea that's exactly what has happened. It was at like 57% on the last tune, and all I did was put a new/bigger turbo on. The pressure is cool though. I have a gauge mounted to the fuel rail and it rises to like ~60 when boosting.

 

did you use the calculator for the fuel trim? if its not configured properly the injector duration will not work. anyway, if it afr doest follow anymor when u richen the program, then u've reached maximum duty cycle.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mase &raquo;</TD></TR><TR><TD CLASS="quote">your multipliers and scaling are probably wack.</TD></TR></TABLE>

this is within the hondata program right? so i should tell him to check if it is on the right spot??

 

Follow this link to the new thread that has updated information from today's dyno session ---&gt; https://honda-tech.com/zero...16877