Re: HFS-4 Q&A, application for your engine...
 

this might help you down the road. the chrysler crossfire srt-6 and the mercedes slk32 are brothers under the skin. heres the complete service manual
http://www.majormotorshotrods.com/_d...ice_Manual.pdf

Re: HFS-4 Q&A, application for your engine...
 

Hi Richard,

Just thinking things through and I have a question or two.

The first one is are you saying there is a 5V power supply available from the controller to power the MAP? If so can the MAP feed the input of both the controller and an LM-2 dataloger at the same time?

Do you think it is possible to take a setup that is tuned to run safely and effectively on 93 octane and use the HFS-4 to basically run 87 octane and use the water meth to make up the octane differnce? I ask as it seems the spread between 87 octane and 93 octane here has spread from the old 20 cent premium to more like 50 cents a gallon.

Just thinking out loud.

Thanks,
Dave

Re: HFS-4 Q&A, application for your engine...
 

Hello Dave,

1. There is a 5V supply on ther grey RJ48 connector but it is not normally accessible because we use a 8-core cable instead of 10-core cable. This is to protect against excessive current drawn by an external device abd affect the performance of the controller. There is only 10mA available before the 5V regulator warms up too much. If you want to access this source, a 10-core cable has to be crimped into the 10-way RJ48 plug. Let me know if you want us to supply this with the system.

2. This is a good use of water/mthhanol injection. It is more commoin for the system to replace race fuel with pump fuel. I cannot see any reason why this can't be achieved. The HFS-4 is well equipped to do this job, tracking fuel flow from medium load to high. I would say yes.

Re: HFS-4 Q&A, application for your engine...
 

Hi Richard,

I'm been searching for info on whether hfs-3 can read my new RC injectors, which is peak-and-hold low impedance. If not, can I just trigger by boost instead?

Thank you,
Jess

Re: HFS-4 Q&A, application for your engine...
 

Hello Jess,

Yes it can. You need to use the green harness (HFS3-v2 only).

The red wire of the grey harness goes to a +12V@pre-crank key position.

Re: HFS-4 Q&A, application for your engine...
 

Hi Richard,

Thanks for your info.

Jess

Re: HFS-4 Q&A, application for your engine...
 

Thanks for the great info and encouraging words on my goals. I think I will build a seperate 5v supply as no sense in taxing the controller if 10mA heats it up.

Thanks,
Dave

Re: HFS-4 Q&A, application for your engine...
 

How much current does the MAP sensor draw? They rarely draws more them 2-3mA. The 5V is mainly used for reference purposes.

Which MAP sensor do you have in mind?

Re: HFS-4 Q&A, application for your engine...
 

Either one of the GM 3bar MAP's or the one sold by Inovative for use with their LM-2 data logger. I want the data logger to share the pressure readings with the HFS-4 so that it can track the boost and the controller can use it to help regulate the injection flow. I can ask what the current draw is on their MAP and find out.

Thanks,
Dave

Re: HFS-4 Q&A, application for your engine...
 

There is a flow sensor 0-5V output on the HFS-4 you can data log (blue wire of the green connector).