Aquamist

[APEX1]

Why buy an hfs-5 over a hfs-1 kit???

[APEX1]

Im just trying to get as much info as possible- cause Im calling Jack to buy today after work.

[dudical26]

the HFS-5 is progressive. The amount of meth/water it sprays will mirrors your injector duty cycle. This means that when the system first turns on only a very small amount will be injected and then as you use more fuel, more water/meth is injected. This is what progressive means.

The HFS-1 is not progressive; it is either full on or full off.

They both have the same failsafe technology, gauge readout, pump, etc...

The HFS-5 will be easier to tune and smoother in the delivery of meth.

The HFS-1 is mostly for people who want a very simple meth system but also want the added benefit of having a very high quality failsafe, and other kit components. In my opinion it makes more sense to get the HFS-5.

Or you can by the HFS-1 now and upgrade later for ~$275

[aqmist]

Thanks Alex. A little technical correction though. The HFS-5 is not progressive its linear to the flow of fuel. The HFS-5 uses the HSV (High Speed Valve) and the FIA2 to mirror you FIDC so that W/A injection is more or less a mirror of the fuel injection system = load is more accurately addressed with this system.

[Inprogress]

Sorry to bring this back up...

Seeing as how the HFS-1 is on/off, why would the tuning of the HFS-1 be more difficult?

[KevinD]

the turn on point where the methanol starts coming in causes a large change in the amount of gasoline that needs to be injected. its like instantly adding 20% more fuel, thus your injectors must inject about 20% less when the meth turns on. because tuning a car is done using lookup tables, this causes a problem where the table doesn't have the ability to fine tune a transition where the meth turns on (they only have so many fields where you can tune in the tables). you wind up having a lean spot before the meth turns on, or a rich spot immediately after. it takes quite a bit of work to balance the transition point.

[SlowCar]

the hfs-1 is just as predictable as the hfs-5. tuning is a breeze

[Inprogress]

Originally Posted by SlowCar

the hfs-1 is just as predictable as the hfs-5. tuning is a breeze

After Jestr tuned your car, did it have any rough spots like the one suggested it might have?


Abner, do you have any partial throttle or partial boost issues?

[SlowCar]

Originally Posted by Inprogress

After Jestr tuned your car, did it have any rough spots like the one suggested it might have?


Abner, do you have any partial throttle or partial boost issues?

there are a few, which can be tuned out - KevinD is helping me out with that.

partial throttle sometimes trigger the injection, not an issue at all

[DynoFlash]

Originally Posted by SlowCar

the hfs-1 is just as predictable as the hfs-5. tuning is a breeze

I agree - I have found the HFS-1 to be really easy to tune and a total delight

While the HFS - 4 is slightly smoother and easier to map - in the end the HFS-1 is a really neat kit and a total pleasure to work with

Al

[DynoFlash]

Originally Posted by SlowCar

there are a few, which can be tuned out - KevinD is helping me out with that.

partial throttle sometimes trigger the injection, not an issue at all

I have found that careful adjustment of the trigger can elminate a lot of issues with partial tps activation

[SlowCar]

Originally Posted by DynoFlash

I have found that careful adjustment of the trigger can elminate a lot of issues with partial tps activation

when i set up my system back in jan2007, i went with a boost trigger = 10psig. I was not sure of how things will work out then using idc trigger. The few hfs i have done since have been idc triggered and i like it better.

[deadbeatrec]

so far the HSF-1 is a high quality kit and i have had nothing but support from AL and Richard L with any issues i have had.