So I was ready to pull the trigger and order the FT550 and discovered they don't seem to have knock control anymore. It seems the older ECU's FT500/ FT400 had something called a knock meter than connected through the can bus. Seems that is NLA on the website and the manual makes no mention of connecting a knock sensor. It seems important since rotaries are so sensitive to knock, but then I read you have to induce knock to calibrate the knock control which also seems bad for a rotary. So my question is how important is it to have this or are there other safer/ better ways to prevent knock?

 

its not a deal breaker, but its old school.

 

Nah, not a deal breaker. There are certainly other reasons why I don't particularly like an FT for street cars though.

 

You've peaked my interests. Since my car is a street car I'm curious what those other reasons are. I already see they are mostly drag racing focused.

 

HP Academy has been pushing them, but I suppose it could be for financial considerations.

I thought knock control wasn’t any advantage in a rotary due to it not be tolerant to essentially any while a reciprocating engine is to some degree, but maybe I’m not up on the latest info/technology?

I was a bit confused about what specifically the “old school” reference was directed at?
.

 

having the ecu see a knock sensor is a pretty recent thing in the tuning world, and its nice to have. although people went fast without it....

 

I called Fueltech to ask if they had any plans to re-introduce knock control. They said not at this time. The reason he gave me was on high horsepower cars making thousands of hp and/ or using nitrous those engines create alot of noise that triggers the knock sensor when there isn't actually any knock so they took that feature out. I guess it makes sense since their primary market seems to be high hp drag cars. Seems it would be nice to leave in for us low hp street cars. I also was talking to a guy at work with one of the supercharged Mustang Cobras and he recalled his tuner turning is knock sensor off for that very reason. Anyway Fueltech's solution was to basically stay conservative and not get too aggressive on my timing and I should be ok with my goal of 350whp. He did recommend switching to E85, but since there's only one station within 10 miles of me with the next closest station being 30 miles away I don't view that as an option. The guy was very nice and reassuring I'd be ok without it( knock control) but he also has a product to sell as well. He did give me the number of a guy in Georgia that drag races rotaries and he pretty much said the same thing. and really seemed to like the Fueltech ECU.

That's what I've heard as well. I read somewhere on here once any knock could cause damage so by the time the knock sensor senses knock and pulls timing it could be too late. If that's true maybe knock control doesn't matter very much.

 

It's essentially what's been touched on already. FuelTech has a fairly specific focus and as such a lot of their feature sets and how the software is tailored is suited to drag racing to the detriment of other things. This isn't to say that it's a bad product and if someone can configure their hardware well enough to be civilized (I'm sure that there are setups and packages that'd be great with it) props but to me it's a little dumbed down and parametric when I'm building a car for clients and setting up transients/other weird things that people tend to want.

That said, I do really like using FTs for some of the carb'd race engines I build for E production/SCCA. Small package, very solid build and reliable triggering for ignition, no need for more gauges, reasonable datalogging.

 

yet the stock setup has a knock sensor.. you'll find that you can get a little knock in the low rpm, higher load areas when you're running a not rich mixture. the engine isn't making much power so it won't break anything right away.

what you need to avoid is knock when the engine is making power, you will hurt it there.