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...

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]

Originally Posted by 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.

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.

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]

Originally Posted by 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.

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]

Originally Posted by 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 ?

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.