Can I use HFS-2 instead of HFS-3 for my 335i setup ?

[cstavaru]

Hello,

I want to install an Aquamist kit on my BMW 335i, which will be flashed with GIAC Stage 2 and Stage 2 Race maps (switchable). The Stage 2 map is designed for 91 octane US-spec (or 95 EU-spec) and the Stage 2 Race map is designed for race gas or 91 + meth. The Stage 2 Race map also has a "submap" for 93 octane (US-spec) or 98 (EU-spec) which is activated by the ECU based on the fuel quality.

I have to make a choice between HFS-2 and HFS-3. My question is, how important is a failsafe for my setup ? The GIAC flashes don't have a failsafe system so my only use of a failsafe would be to let go of the throttle if a problem is reported by the meth kit's failsafe system. If I always use at least 93 octane gas, will I need to worry about not having a failsafe ?

So what do you think ? Should I spend the additional money on the HFS-3 ? Right now I'm leaning towards the HFS-2...

[Howerton Engineering]

If you don't have a way of manipulating the timing and fueling via a Piggyback, then you can dump boost to wastegate pressure with the HFS-3.

These cars do tune themselves to an AFR with what I call the lambda map, so if the injection were to stop, the car would correct itself to some degree. The issue is how fast would this happen and would any damage occur in the transition. This and your right foot would be the failsafes with the HFS-2.

[maxman]

If you don't have a way of manipulating the timing and fueling via a Piggyback, then you can dump boost to wastegate pressure with the HFS-3.
These cars do tune themselves to an AFR with what I call the lambda map, so if the injection were to stop, the car would correct itself to some degree. The issue is how fast would this happen and would any damage occur in the transition. This and your right foot would be the failsafes with the HFS-2.

I have a 335i with the N54 engine with a Cobb flash tune and I'm looking for a water/meth system. As such, I'm trying to decide between the HFS-2 and HFS-3 sytems.
Could you please elaborate on how the HFS-3 can dump boost to wastegate pressure?

[Richard L]

The HFS-3 reads the meth flow after trigger. If the flow rate is outside the user specified window, the failsafe triggers.

Failsafe action will take place by the onboard relay: Cut one of the boost control valve (BCV) signal from the DME so it one turbo drops down to wastegate setting. In essence, the manifold will still hoovers above the wastegate setting. Alternatively the failsafe cuts the 12V supply to both BCV so both turbo is bypassed so boost pressure should drop donw to wastegate pressure.

I cannot say for certain how well this option works on the 335i because we have not tested this on the 335i. This is one of the options we will try out in the next few weeks. We are working on a few other options as we speak. It is imminent we will offer this to all 335i flash tune customers as soon as it is fully tested. At present, we cannot say too much.

This package will be offered by Jeff Howerton Engineering for the US marketm along side the bumper mounted bracket. I will ask him if he like to post some pictures of this bracket here. Jeff and I have been working on this 335i project for nearly 8 months. It will be a plug and play affair.

At present, until Cobb brings out a meth/race map on the stage 2, meths is only effective on bring the IAT down.

[maxman]

Thanks for the speedy reply.
Cobb is expected to bring out stage 2 at the end of summer which is tomorrow. Can only speculate on the real release and if/when stage 2 will have meth support but it will eventually come out.
Looking forward to the release of your N54 335i package (HFS-3) with the bumper mounting bracket..... will keep an eye on this forum for when it's released.... Any way you could offer a GB deal on it?

[Richard L]

Cobb will not bring out the meth map until they have fully tested the tune on meth/water system. Not sure if they will offer a race gas map first. I believe other non-cobb flash tune has already a s2 race gas map.

We are working independently on the failsafe regardless of any flash tune, I believe a meth/race map will be offered eventually given the positive effect of meth on the N54 platform.

It will be upto Jeff Howerton to initiate the GB as he designed and manufacture those wonderfully designed bracket. Give him a call.

http://www.aquamist.co.uk/forum/gallery/N54/7.jpg

[Howerton Engineering]

Here is a few pictures of the bracket. As Richard said, we are working on some great things with the controller to make for some interesting integration options with flash tunes.

[maxman]

Here is a few pictures of the bracket. As Richard said, we are working on some great things with the controller to make for some interesting integration options with flash tunes.

That sounds great. Any idea of when it might be available? Need any beta testers?

[Richard L]

When we are totally happy with the outcome of all the failsafe options, only then we will announce it.

The boost cut failsafe works anyway but wouild like to offer an alternative failsafe option. It does take a great deal of testing. Unfortunately I don't know any local 335i owner here, otherwise things will move a lot faster. Dallas is some 8000 miles from me. Thanks for offering.

Does your Cobb reset CEL automatically on every ignition key recycle ?

[maxman]

When we are totally happy with the outcome of all the failsafe options, only then we will announce it.
The boost cut failsafe works anyway but wouild like to offer an alternative failsafe option. It does take a great deal of testing. Unfortunately I don't know any local 335i owner here, otherwise things will move a lot faster. Dallas is some 8000 miles from me. Thanks for offering.

Does your Cobb reset CEL automatically on every ignition key recycle ?


Good question, however I don't know the answer to that.... I've been running Cobb for about 2 months and have never had the CEL come on. Cobb does have the ability to let you manually clear any codes that are thrown. I have read that it does automatically clear the CEL code thrown if one has catless downpipes installed.
I would be happy to have only the boost cut failsafe.

[Richard L]

I have spoken to Cobb on this, not in too many words, I believe CEL will automatically reset on key recyling on cobb tunes.

We have a few systems installed on flash tunes but does next to nothing on power. In order to take advantage on meth, one has to load in a meth map or race gas map. I have only started to look into the current offerings from varies flash tunes for the 335i. Until this is a reality, we cannot claim or expect any power improvement with our system.

Flash tune companies' main audiance is the daily driver group and not too adventurous on maxing out the performance on all fronts compared to piggy-back user. Until their audience demands more, they are not going to risk their low risk business model and reputation on a few people who are willing to take risks on their behalf.

What is your reason to opt for a flash tune rather a piggy back?

[maxman]

I picked a flash tune because of it's ease in removal, without any trace, as my car is still within the factory warranty. Yes I know piggybacks can be removed also but it take 20 minutes vs 5 minutes w/Cobb and without turning a screw.

Note: As of ~4:00pm CDT today Cobb released Stage 2 to the public. They did not release the race gas map.... yet. When they do, myself and quite a few others will be anxious to get it and give it a go. I will need meth to run this on any kind of daily or weekend basis.

[Richard L]

It is amazing how ease of installation swings the vote.

Things are looking up for the Cobb camp. I wonder how long it will take Cobb to be comfortable with the final stage 2 version. Only then, they will consider launching race or meth map. I think they are taking a very sensible approach.

I wonder if stage 2 is still targeting load.

[maxman]

Yes, from what I read they are still targeting load but with some "tweaks".

Q: Can I purchase an HFS-3 for my 335i N54 from you with the new bumper mount bracket now? Or do I have to wait?

Now with Cobb Stage 2 out pushing higher boost I really need to add meth/water injection and a progressive system based on boost level will be fine. I can always add a FSB later. What do you think?
NOTE: I will be using my WW tank and tap into that. It holds 1.5 gals and has a built in low lever warning.

[Richard L]

I suspect this is one simple way to improve the stage one map. If this is the case, I think cobb may have lifted the target boost than the OE intended and allow higher boost and slight timing advance. Will you be able to do a comparaison log between the stage1 and stage 2?

The HFS3-v2 has a few more features than you expect, I will outline a few:

1. It already has an 100% meth turbine base flow sensor included. No need to add FSB anytime.

2. It will automatically cut boost by interrupting one or two BCV should the system loose prime, no flow, over flow and power failure.

3. The system can ber configured to work as follows:
- Triggered by IDC, progressive with IDC %
- Triggered by Boost, progressive with IDC %
- Triggered by IDC, progressive with boost
- Triggered by Boost, progressive with boost
- Triggered by IDC, progressive with 70% IDC and 30% boost
- Triggered by Boost, progressive with 70% IDC and 30% boost.
etc , etc

4. The failsafe can be disabled if you want to run race only fuel when system is turned off

I believe tracking IDC% to mter meth flow is the most accurate and reliable way to represent true engine load,. This is because fuel flow is the results of thousands of engineering hours tweaking the fuel table based signals from multiple sensors. In fact all sensors. Tracking boost will only be progressive in a single dimension, regardless you are at 2000 or 7000RPM and gear positions. So, if you wish the system to track boost, you can. But I recommend trying the IDC first.

On the HFS3-v2/bracket purchase front. You can purchase it anytime along with the bumper bracket from Jeff Howerton, he has them in stock just hasn't got round promoting them yet.

[maxman]

I agree - IDC instead of boost is much better to use....however, where do I wire the IDC input from on my 335i?

[Richard L]

Here is the generic wiring diagram for the 335i


http://www.aquamist.co.uk/HFS3/BMW/H3v2-335i.gif

[maxman]

Excellent Richard! Just what was needed. Thanks.

I prefer to use your option 3a for controlling progressive meth flow:
"3. The system can be configured to work as follows:
- Triggered by IDC, progressive with IDC %"

I read the manual on the web site:
http://howertonengineering.com/manuals/
However, I do not see (may have missed it) where the user can pick this option of progressive with IDC%?

[Richard L]

The HFS-3 system is already set to triggered and progressive with IDC from factory.

The second jumper link (from left) is labelled as IDC (default). If you want the system to be triggered by boost. Move the jumper link to "MPS" (manifold pressure sensor).

Slightly further towards the right, The system can be set to either "progressive spray" or "on/off". Factiory default is set to prorgressive (PWM).

The system can also configured to communucate with the any piggybacks' failsafe, based on actual flow.

Does you have good logging capability with Cobb?

[maxman]

Yes, I've got real good logging capability with Cobb.
Yesterday afternoon I emailed Howerton engineering about the current status of the N54 testing and if I purchase an HFS3-v2 now (w/bumper bracket) could I upgrade/update it later when they finished the N54 testing. I'm sure they will respond soon.

I'm ready to move forward with this and use the IDC % as the injection trigger and to be progressive with IDC%.

[Richard L]

Once you have purchased and installed the system, I hope you can provide me with some good logs so that we can integrate our system more closely with cobb.

On eaim is to improve the failsafe capability to a more refined control instead of dropping the boost to wastegate setting. As far as I am aware from Cobb, they are running 19psi without meth so failsafe is not strictly necessary. It would be interested when they have decided to offer the meth map sometime in the future. By then we should have completed the more advanced failsafe stratagy.

Jeff has the capabilities of pre-configure the HFS-3 system for you in advance of delivery.

[maxman]

Richard, no problem providing logs after it's installed.

I received a return email from Jeff this am. He says they will hopefully be finished with the N54 testing by the end of next week. He offered to let me buy a "pre-production unit (without cetain failsafe and special features) then. We will not have manuals written and such, but it is not a difficult install."

Looking forward to getting one of these installed on my E93 335i.

[Richard L]

The standard unit comes with "boost cut" failsafe (which you can use if you want) and map switch output (not applicable to the N54). Jeff and I have been working on the N54 specific failsafe for a while.

Here is a link to the user manual to help you understand the system better.
http://www.aquamist.co.uk/HFS3/HFS3v2w1.pdf

[maxman]

The tag-team of Richard and Jeff get an A+ in my book.

Before I knew this I had already made the decision to go with the Aquamist system..... it was just a question of the HFS-2 or the HFS-3.

Q: I plan on using 2 jets for the W/M injection, one 0.4mm plus one 0.7mm to start with for a total flow of about 620cc/min, will I still need a restrictor? If so which one?

[Richard L]

Both Jeff and I believe in explaining how the system works first. At the same time acquiring information from the end user so that we can offer the most appropriate system for the application. It works well most of the time especially the user can supply good information.

The difference between H2 and H3 is the failsafe. If you are on the modification path, failsafe offers greater safe tuning potential

When you are calulating the total flow, allow 15-20% extra. It is not a good idea to put a ceiling on the flow because you can always reduce the flow electronically.

For the 335i, two 1mm jet is a norm. If you are running 0.4mm + 0.7mm, use the middle restrictor.