ksu-chewie

iTrader: (14)

I just got done installing my Greddy SMIC, so I took my car for a road test. I got the car up to operating temperature, then went to the high way. 3rd gear @ 35 mph and floored it.
Car started to speed up, boost lvl on PFC commander was .7-.8 kg/cm^2. Got up to about 60 mph, and my knock was really bad. At one point I heard the knock so I got off the gas.

Would a greddy smic cause me to need a new tune, or was my tune already bad and just now noticing it? I'm kind of worried to drive the car at the moment because I know knock is not a good thing.

jpar196

what was the peak knock reading on the PFC?

ksu-chewie

iTrader: (14)

How do you get it to display a number? I just have the black bar going across the screen...in which case it was at least 3/4.

Montego

iTrader: (1)

not on a good tune it should not.

from an ait perpective a better ic simulates a colder day. this only applies if you are boosting at the same level. meaning taking account the different pressure drop from the new ic

arghx

iTrader: (3)

press the up key after a run. the bar will turn into a number. you can also log with a Datalogit.

And yes, changing the intercooler can affect your tune. Theoretically it shouldn't matter that much but IAT sensors and aftermarket computers are fickle things.

ksu-chewie

iTrader: (14)

Ok, I'll think about taking the car to work tomorrow and getting a knock # after a boost run.

I don't have a datalogit it yet, but it's on my list. Maybe I shoulda got a datalogit before smic.

adam c

iTrader: (2)

Not only will your new intercooler give cooler temperatures, it will increase flow. Increased flow means more air, which means a leaner fuel mixture.

I would be very hesitant to run high boost at high rpm if I were you. Get a good tuner, and do it soon.

arghx

iTrader: (3)

Is this the base PFC calibration or was it previously tuned?

You said you physically heard it detonating. In that case I would NOT get on it to see the knock reading. You are only risking engine damage then. If you heard marbles in a can, a tink or thunk sound then the smart thing to do is to lay off it.

Since you don't have a wideband either you're limited at what you can do. You can throw fuel at it with the Commander but that's about it.



See https://www.rx7club.com/showpost.php...23&postcount=4

thewird

iTrader: (8)

A bigger/better intercooler may affect your tune. Not because your AIT's are now cooler, but because it is more efficient and can flow more at the same boost level as you have opened up a restriction. It may be fine, it may be not, but don't just assume its perfectly fine.

In my experience with knocking, it has always sounded like one of those automated sprinklers on steroids. At least that's how I picture it when I hear it.

thewird

ksu-chewie

iTrader: (14)

It was supposed to be tuned by KD rotary, but the previous owner coud have changed it afterwards. The problem I have regarding tuning, is all the local shops I've called don't know jack about FD's or PowerFC's. 1 shop I talked to said yes we can tune it, but you hould buy X EMS instead...which makes me think they don't really know how to use the powerFC. So I think I'm going to have to learn how to tune this car. So I know that at some point I need to get a datalogit and a wideband.

Looking at mine here are the settings you listed:

8000 100
7000 100
6000 100
5000 100
4000 100
3000 100
2000 100
1000 87.8


1.0V 100
1.5V 100
2.0V 100
2.5V 100
3.0V 100
3.5V 101.9
4.0V 102.3
4.5V 103.1

ksu-chewie

iTrader: (14)

I drove my FD to work this morning. After making the changes that arghx linked to, here are some #'s. I drove it as safely as I could (gradually increasing wot / rpms). I didn't hear any knocking this time but I also didn't redline it.

max rpm: 6092
max boost: .84 kg/cm^2 = (11.9 PSI) I never saw it go this high before, better intercooler perhaps?
max water temp: 89* C
max knock: 48 (How bad is that?)

jpar196

Ive been told anything under 60 knock reading is safe, somebody correct me if Im wrong ?

thanks


regards,

thewird

iTrader: (8)

^ That is not true at all. The knock sensor can't be used to know if your safe or not as its pretty useless most of the time. If your knock sensor isn't picking up noise, I'd say anything under 10 is safe but its not something you can just use to know if its safe or not.

thewird

ksu-chewie

iTrader: (14)

bought a datalogit and wideband yesterday, so that should help diagnose.

ksu-chewie

iTrader: (14)

Another twist...
Before putting in the greddy smic, I never saw my commander show boost higher than .7 kg/cm^2. I haven't made any changes to my boost settings yet on my commander:

So it seems that the greddy is just flowing better than the stock unit causing a little lean. So I'm going to try to turn downt the boost a little to see if that makes it a little safer.

thewird

iTrader: (8)

Smart choice.

thewird

ksu-chewie

iTrader: (14)

contrary to my forum name (which I need to put in a req to change), I am trying to be smart and safe with this car.