kpt4321

Hello there Honda guys!

I have a fairly simple question:

At what point, for those of you with turbo'd motors (B16, B18, H22, whatever), do you begin to see knock? I would like to know in terms of boost, but I *also* need a bunch of other relevant information, listed below:

-What Motor?
-Compressor wheel?
-Intercooler?
-Compression?
-Injector Size / Fuel Pressure?
-Approximate flow of fuel under full boost at WOT?
-Wideband O2 value / A/F ratio (if applicable)?
-Maximum Timing Advance at WOT?

This is aimed at stock-blocked cars, but if you are not stock-blocked, please just list the mods you do have.

Thank you!

DIRep972

iTrader: (1)

this is a hard question cause hondas can't just "see" knock. Its not like a DSM where u can just crank the boost until the ECU saves ur ***. Most of us on here tune our cars conservatively and are nowhere near the knock threshold. Usually when a honda motor sees detonation its already too late.

LsTurbo91

-What Motor?
b16

-Compressor wheel?
to4e 50trim

-Intercooler?
umm, yes? heh

-Compression?
10.2

-Injector Size / Fuel Pressure?
750cc / 41psi

-Approximate flow of fuel under full boost at WOT?
6-7ms, dont have my map avail.

-Wideband O2 value / A/F ratio (if applicable)?
11.8-12.1:1

-Maximum Timing Advance at WOT?
24deg

This was on 91 octane @ 11psi, started knocking at 9,10,11. Set back to 20deg max timing.

LsTurbo91

this is true, most guys here dont wanna use aftermarket units, the stock unit is pretty much unusable in boost situations. They just run really safe and cross there fingers hehe.

DIRep972

iTrader: (1)

LSturbo91 has a J&S knock sensor just fyi. he doesn't have to wait for audible knock like most of us would if we were trying to push the limits.

kpt4321

LSturbo: any reason as to why you're running such huge injectors if they're at less than 50% duty cycle at higher rpm's?

I realize that you guys cannot see knock, that is why I put up this post. I'm looking for the "safe" range to run a turbo'd B18A, but I don't just want numbers people pulled outta their butts. I'm looking for real-world info, ya know?

Anyone else who can chime in, I appreciate it!

The car I am working on will probably have a JS Safeguard eventually, too, but until then we're going to be tuning with a wideband O2. I'm thinking about 7-8 pounds of boost, and a A/F ratio around 11:1. We'll have to see what happens.

Also: on a stock ecu'd car with the distributor in the normal position, what kind of timing do you see at WOT? (I need an estimate of how much base timing to pull out for the car to run well).

Thanks guys.

FritzInTN

I've yet to run across a review of this. The closest I've come is 'turbopanda' on the board stating that his integra had one, however this comes from a kid who has gone through a fair share of motors. Everytime I bring it up either in a post or IM he ignores me when I inquire why it didnt save his motor. What exactly goes on when it detects a knock?

tony1

Unfortunately knock doesn't happen at a certain boost level. It can happen at 4psi or 45psi. Knock is simply a measurement of detonation and the level at which it is seen is all dependent on tuning.

DIRep972

iTrader: (1)

Well I have an LS turbo so maybe i can help.

9.2:1 compression.
550cc inj. @ around 60% duty cylce w/ 45psi base fuel pressure
a/f 12:1ish
total timing around 22 degrees
13lbs of boost
57 trim T04e intercooled.
no detonation on 93 octane.

LsTurbo91

Sorry I'm way off, its been 6months since i've pulled up my maps heh. My fuel pulse was 10.76 @ 12lbs with a LS, so that would be around 66% duty cyle @ 7400rpm.

I had 450's before and was pretty much maxing out at 10lbs, 45psi rail pressure about 80-90% duty cycle. So I decided to get these

Its about 28deg, according to my base maps provided with the program.

kpt4321

Yes, I realize that. It is for that reason that I asked for ALL other relevant mods, in order to get an estimate of what fuel flow / charge temps / boost pressures would be more likely to create knock.