VTECSTYLE

It was dyno jet i believe. anyways If you increase fuel pressure to much it actually can get to the point where the injectors wont open. or they simply wont flow anymore. Also with increase FP u can heat up the injectors more which can cause them to fail, heat up the fuel to much and can damage the injectors. Solenoid like injectors work on ms and there consistently working. Ive flow about 40 some injectors and you 'll be amazed at what happens when u increase fp from 30 to 40 psi how different the spray pattern becomes, you do flow more. then also how drastic the change from 40 to say 60 psi can affect the overall flow and spray pattern it actually decreases flow and spray pattern. and at 72 psi i had some injectors not open at all

VTECSTYLE

Also if you read the first post correctly I stated that i am running the wrong EMS that makes a big difference. And if you have ever heard of MAP that is where i had my car tuned. Jordan has tuned his brother Joey s2000 and they made over 700 hp. With the right ecu I will see some better numbers

Gernby

No, the engine doesn't work harder at high altitudes. It just makes less power, and performs about like it would at part throttle at a lower altitude. Basically, it works LESS hard.

wadzii

my stock ap1 was hitting 100% duty by 8200 rpms with e85.

not only does it take more fuel to make the same power, but e85 likes to run at a richer lambda than gas.

VTECSTYLE

100% duty cycle is not good. e85 needs 33.3% more fuel. 85K but compared to 135k btu. sucks for people that live in higher altitudes

ap1_tot

This sounds very interesting. Does this mean that if for example you do a street tune on a car on higher altitude this would cause car to run like crap when you get to low lands? Something the same happened to me, as I had my greddy EMU tuned to a tuner that lived in a relatively high place (a mountain region here in the philippines)
all went well except that after the tune I went down to the city and I was misfiring all over the place during WOT.

also, can you tune e85 using piggybacks?

Gernby

If you do a good tune, it should be fine at any altitude. You might just wind up with a less flat AFR at WOT at the lower altitudes. It shouldn't make any difference at all during part throttle.

I don't see any reason why a piggy back wouldn't be usefull for E85 tuning, as long as it can ADD fuel (not like a VAFC).

Gernby

Since my stock injectors are running past 90% duty cycle, I'm considering raplacing them with larger ones. If I'm going to buy larger injectors, I figure I should get injectors that are big enough for whatever I might do in the future, like converting to e85, nitrous, or an SC. However, I'm concerned that my OEM fuel pump won't be able to keep up. Does anyone know if the DBW (returnless) fuel pump will be able to maintain adequate pressure for 675cc injectors? Since I'm not boosted, my duty cycles will be small with 675cc injectos, but it seems like that still might cause short dips in pressure even at idle.

wadzii

the fuel pump doesnt care what injectors you have. its about the volume you are flowing. you wont be flowing anymore by just changing injectors

if i remember right the stock pump is good to around 300 on the older cars, i dont imagine they put a smaller capacity pump in the car... the only way to know is send it off and have it tested. as far as i have seen no one has done that.

Gernby

I realize that the pump doesn't care about the injector size, and injector size won't change how much fuel I'm actually using with my current setup. However, IIRC, all the older Hondas I've had used an FPR and dampener on the fuel rail, and had a return line back to the tank. From what I've read about it, the dampener was there to reduce spikes and dips in the fuel pressure when the injectors opened and closed. I would expect this to be worse with larger injectors.

I haven't studied the fuel system on my '08 DBW S2000, so I have no idea where the FPR and dampener is on it. I assumed it was built into the pump.