Today I brought my car in to get tuned on the dyno at 12 psi ever since I installed an inlinepro headgasket and str cam gears. My fuel setup is 8:1 fmu / vafc / 310cc / intank fuel pump. Well I was getting my hopes up that I could run higher boost now and make more hp, but it turned out when the mechanic was tuning it on the dyno, my car was already running lean at only 7 psi with the vafc maxed out at rich settings. That meant if I turned up the boost any higher, my car would be running dangerously lean. But we turned up the boost to 10 anyways just to see if I would be ok (since the fmu is suppose to supply more fuel) or run even more lean, and in fact my ratio was even worse 20:1. What confuses me is that I don't understand how I can already be running lean only at 7 psi and not to mention that my car has a LOWER COMPRESSION when other people with higher compression and the same fuel setup can boost 10-12 lbs. with no problems. Can anyone help me with a way to solve this problem...I dont really want to dish out a grand for hondata right now. Im just having a bad day today...

 

Maybe your intank is not raising the fuel pressure high enough. Did you check how high your Fuel pressure was going? Try an inline pump.

 

Here is my dyno graph. This is with inlinepro headgasket, str cam gears...compression lowered to 8.4:1 @ 7lbs.

 

I agree. I would never run an FMU with ONLY an intank pump. Definetly get an INLINE pump to keep up with the outrageous fuel pressures created by the FMU.

Then just save up for Hondata or aem, which I am sure you already know.

 

Man, you need an inline pump to properly operate any FMU with any calibration disk. Not flaming but people just dont seem to understand this, we go over this at least once a week. Well at least you know now.


Rob

 

I got a vafc/4:1fmu/walbro 255 hp (no inline) and it works just fine with 500 cc RC's

I'd recommend going to larger injectors if youre not ready for standalones.

 

I always get mixed answers about inline and intank...on honda-tech people say inline is better, but when I go to shops around town, all the mechanics say an intank will do the job. It drives me crazy.

 

You need an inline to build the high pressure the FMU needs in order to keep you from leaning out. An intank can only put out 60-80psi max. They're good e for volume, not pressure.

 

I have no probs with the 4:1 and the bigger injectors.

If your a/f ratio is too lean then I think the need for the inline speaks for itself.

 

yup, you need an inline, and i would think about some 450s. btw, are you bringing in vtec at 4k? you're losing lots of power there.

 

i got 440cc 5:1 fmu inline pump

you need a inline fuel pump

 

you do not need an inline to support 10-12 lbs of boost with your set up. something is not right. i ran a 255 intank, 440 injectors and 12:1 fmu and ran super super rich. 310's and a 8:1 should be fine at 10 lbs. surely all you people don't think he's running lean with the 310's, 8:1, and intank. whatever it is its not the capabilities of an intank pump. maybe the pump itself isn't working properly, set up incorrectly, or something else is off. i've seen an intank support over 500 hsp for a whole season.


[Modified by jinxproof99, 8:04 PM 10/9/2002]

 

I went to the same people as you except I had a hondata. They told me I needed bigger injectors or a pump. They only had injectors on hand so I bought some 440's.
I'm running stock pump and stock FPR with a hondata and everything turned out fine.

 

my opinion on this is that you do not need an fmu/ inline pump/ ect. ...
that is too much pressure on the fuel system. not only that but im most
cases fuel is forced through injectors that are not made to flow that much.
rising the fuel pressure should be a last resort option when more fuel is needed.
the right way to do it is bigger injectors, intake pump to feed enough fuel, and
some type of tuning/vafc/hondata to add more fuel.

something to think about: if your car is turbo'd, a greater volume of air is forced into the cylinders, therefore, a greater volume of fuel must be added to compensate. more fuel flowing through the injectors means more volume. now if you have fuel pressures exceeding 90/100psi, that does not mean you are getting adequate flow. THE HIGHER THE PRESSURE, THE LOWER THE FLOW RATE, THE LOWER THE FLOW RATE, THE LESS VOLUME.
i'm sure youve all seen the page on hondata's site about this, if not check it out.

 

If the case is that something is wrong with my car, how would I go about to detect what the problem is. I do not have enough experience myself in order to seek out the causes that are making my car run so poorly. I have no clue what I'm going to do, hondata is just too darn expensive...I know its the best way, but I'm sick of putting in so much money into my car.

 

come on jinxproof99 i know you know your **** and all but you had 12:1 with 440cc and nice big 255 intank so of course you ran super rich

this guy is trying to run 310cc's with no inline fuel pump thats just like trying to run stock injectors 12:1 with no inline pump

come on you guys should know better you have to have an inline pump with 310cc's if you had 440cc's or 550cc's it would be a different story

 

everyone here prolly knows a lot more shiet than i do... -i just wanted to comment that you might think it was a bad day for you at the dyno but at least you found out you were running lean... and that's something that you're going to take care of or figure out before raising the boost...

 

20:1 is like holy sh*t lean. thats pretty bad man. You need an inline pump in there. I ran my car once at the track when my inline pump came ungrounded, I was trapping 74mph in the 1/8 on 4psi. THen I turned it up to 7 and ran 73mph. hooked up the inline w/ 8psi and trapped 82. listen to us. this is honda-tech. we are always right.

 

i was taking into account when he said intank, he didn't mean "stock pump" if he had a 255, 8:1 fmu, and 310's, i would think he could run 10 lbs of boost. what i really was getting at was you do not need a large inline pump(aeromotive, paxton, etc..) to run 10 lbs of boost.

 

yes its 255 walbaro intank pump.

 

Something is wrong. when I had the greddy kit in its purest form (blue box and 310's) with no aftermarket pump or fpr I was running SUPER rich.


[Modified by Aeka GSR, 6:35 PM 10/9/2002]

 

you could try 370 injectors if your going to stay at those boost levels. any reason you chose 8.4:1 compression??

what was your fuel pressure at idle??


[Modified by jinxproof99, 9:36 PM 10/9/2002]

 

I would agree that something is definately wrong. I used to run a 255 Walbro pump, 8:1 FMU disk, RC310's, and 7psi. I ran extremely rich with this setup.

 

Well now that you have learned what following their advice gets you........

 

Actually the compression is whatever the inlinepro headgasket lowers it to and I'm assuming my compression is around 8.4-9. And I dont have a fuel pressure gauge so I do not know what my fuel pressure is at idle. You think I should just go for an inline pump to see how it turns out or get 450cc and try out the vafc hack (if possible)?


[Modified by NHB Fighter, 7:28 PM 10/9/2002]