Power FC and 1000cc+ injectors?

[SuicidnS13]

Does anyone here have experience in running/tuning the power fc with large injectors? Thinking of an E85 setup as its pretty common around here in Las Vegas and cheap. Ive searched and found conflicting answers. Some people say the power fc is limited upto 740's, and others say there is no limit.

Discuss-

[jspaeth]

Does anyone here have experience in running/tuning the power fc with large injectors? Thinking of an E85 setup as its pretty common around here in Las Vegas and cheap. Ive searched and found conflicting answers. Some people say the power fc is limited upto 740's, and others say there is no limit.

Discuss-


Why would there be a limit?

If you don't have access to the full maps (i.e. you DON'T have datalogit), then you can only scale the injectors.

If you have access to the full tables, you can put in whatever on-times you want, directly in the tables.


I have a friend who runs 1000cc injectors in an RB26 Skyline with a PFC.


Is it harder to tune? Possibly, but it is not technically "unallowed" or "infeasible".

[rc1honda]

Does anyone here have experience in running/tuning the power fc with large injectors? Thinking of an E85 setup as its pretty common around here in Las Vegas and cheap. Ive searched and found conflicting answers. Some people say the power fc is limited upto 740's, and others say there is no limit.

Discuss-

I have a PFC with 850cc injectors. The PFC is able to run any size injector. All you have to do is correct for injector size and lag time.

You go to the setting menu on the PFC and go to INJ and make your corrections. You use the stock injector size as the base. So in case of a SR20 370 is the base.

To work out new INJECTOR correction and latency;

Old SIZE / New Size = Correction
New Latency - Old Latency = Latency Correction

John plans to install 600cc injectors into his RB26 VL Turbo. The following figure's are used;

444 / 600 = 0.74 * 100 = 74.0%
0.81 - 0.77 = +0.04 msec

So he would enter 74% for correction and 0.04 as new latency

So if the 1000cc injectors are going in a SR. The correction would be 370/1000x100 or 37%. You would enter in this correction for each cylinder. Then the next probelm is finding the lag or latency time for the injectors.

The above example is for a RB26 latency, so the latency time for the SR stock 370cc injectors is different. Latency is the lag time. The only problem i had with injector correction is finding the right lag times. Bosch and MSD hold that information as proprietary and you will need a subpena to get it out of them. Ask me how i know.

So go with a injector company like RC engineering that will freely give you the lag times for the new injectors. Happy tuning.

Also here is link with a lot of helpful information about the PFC. If you have one you need to bookmark this link now.
http://www.paulr33.com/powerfc-faq/powerfc-faq.htm

PS, after going through all the problems i had with my PFC i highly suggest NOT BUYING A PFC. The PFC can do the job yes. But there are so many better options available now. Haltech, AEM, Megasquirt, all offer way better and more modern software and hardware.
A lot of people argue the price of these EMS's, but after all is said and done you will spend just as much for PFC to get tuned properly as you would for the other EMS's that are by far superior to the PFC.

[jspaeth]

I have a PFC with 850cc injectors. The PFC is able to run any size injector. All you have to do is correct for injector size and lag time.

You go to the setting menu on the PFC and go to INJ and make your corrections. You use the stock injector size as the base. So in case of a SR20 370 is the base.

To work out new INJECTOR correction and latency;

Old SIZE / New Size = Correction
New Latency - Old Latency = Latency Correction

John plans to install 600cc injectors into his RB26 VL Turbo. The following figure's are used;

444 / 600 = 0.74 * 100 = 74.0%
0.81 - 0.77 = +0.04 msec

So he would enter 74% for correction and 0.04 as new latency

So if the 1000cc injectors are going in a SR. The correction would be 370/1000x100 or 37%. You would enter in this correction for each cylinder. Then the next probelm is finding the lag or latency time for the injectors.

The above example is for a RB26 latency, so the latency time for the SR stock 370cc injectors is different. Latency is the lag time. The only problem i had with injector correction is finding the right lag times. Bosch and MSD hold that information as proprietary and you will need a subpena to get it out of them. Ask me how i know.

So go with a injector company like RC engineering that will freely give you the lag times for the new injectors. Happy tuning.

Also here is link with a lot of helpful information about the PFC. If you have one you need to bookmark this link now.
Apexi PowerFC FAQ (http://www.paulr33.com/powerfc-faq/powerfc-faq.htm)

PS, after going through all the problems i had with my PFC i highly suggest NOT BUYING A PFC. The PFC can do the job yes. But there are so many better options available now. Haltech, AEM, Megasquirt, all offer way better and more modern software and hardware.
A lot of people argue the price of these EMS's, but after all is said and done you will spend just as much for PFC to get tuned properly as you would for the other EMS's that are by far superior to the PFC.


Basically, what this guy said is correct.

However, in practice, let's say you go from a 333 cc injector up to a 1000 cc.


Simply scaling the injector times by a factor of 1/3 can get you CLOSE, but it is never going to get you close enough to run the car under boost safely.

What I am saying is, the injector scaling is good to "ball park" it, but if you make a drastic change from 370--->1000 and think you can just keep the same map, you will most likely find that a lot more tuning is required.