So basically you're running headers and an intake... Go ahead and put a 3.4 pulley on it. Hopefully it won't have much detonation. That being said, it took me an entire ported top end and p-log to be mostly KR free on a 3.4 pulley.

SCAN SCAN SCAN, or you're gonna blow it up.

 

Ouch. All cars are different I guess, all it took for mine was headers and intake as well. I'm assuming maybe you had it differently since you had to swap a SC in it?

 

No, I got a knock lobster of a motor. It's not uncommon for L67's to have 5* or more KR being 100% stock. If/when my engine blows up, I'll build another one the same way I built this one, and the results will vary.

 

A scanner will work fine also, the downside with scanning it now is that it is pretty cold out relatively speaking, so you'd have to scan it again in the early summer. Some of these mornings have been in the high 40s/low 50s down by me. The amount of KR you see can be a good bit different when we get back to 110* summer heat. If you happen to start off with 4 or 5 degrees of KR on the smaller pulley now, you could end up with pretty ugly KR in the summer that will make the car a total dog. There is certainly a sweet spot for timing, and if you're pulling too much off the stock timing tables, the power starts to drop off pretty quick.


I would like to offer an alternative to the aero force gauge that is somewhat similarly priced. You could think about picking up a used DHP Powrtuner. It can scan and allow you to tune, and used ones can be had for under $200. Obviously you won't be able to monitor gauges 24/7 like a gauge can, but it nice to be able to actually do something about the KR instead of just knowing it is there.

 

Glad i'm reading, i assumed you'd have more kr in winter with more boost due to colder weather. I'm hoping to drop to 3.4" pulley in the spring so all the knowledge i get is good lol.

 

Temperature in the cylinder is what causes the knock / KR. That's why people can run a smaller pulley after adding an intercooler- the cooler air is more dense, but you shift your starting temperature down drastically which shifts temperatures down across the cycle. It's hard to explain without diagrams of what is going on in the cylinder though.

 

Whats the process for measuring the KR? I have a scanner do I then just as safe as I can find an empty road and get on it?

 

What kind of scanner do you have? You need something that reads kr. I use either my aeroforce gauge or hp tuners with a lap top hooked up to monitor mine.

Once you are monitoring it, roll into the throttle more and more until wot. If you see no kr your fine, if you see more than 2° kr back out of the throttle and tune it more

 

If you post what scanner you have, maybe someone who has that scanner can post the exact method with the one you've got.

Basically, you need to get it to the screen that displays live engine sensor data. Scroll through the options until you find KR or knock sensor. Then have it log or display that data.

As for actually seeing what the values are, you'll need to drive around in high load conditions to see when you get it and what the peak values are. You should make sure you approximate the range of your worst operating conditions.

At a minimum, I would try to launch it from a dead stop (since youre interested in 1/4 mile racing), I would try WOT from a roll at highway speed, and I would try WOT on any local hills/inclines (if you have any that you would normally drive on).

If those all show no KR, you should be good to go. Just keep in mind, the cold mornings out here are 80+ degrees cooler than the dead of summer. So I'd definitely check during the day to minimize the delta, and would recheck in the summer just to make sure youre still good to go with whatever new mods you add.

 

Just get on it when you safely can, while keeping an eye on the gauge. Aeroforce is very popular and works well. Not very easy to watch a laptop whilst going WOT. If you're in a hilly/mountainous area, just go uphill and put your foot into it. Part throttle KR and all that good jazz. Hope for 0* knock though, for sure.