Sensing Detonation?

[GNDAN]

Soon (When snow hits) I will be out testing/tuning on a Boondocker kit I installed on my 600 IQ CFI. My question is how do I go upon telling if I am running into detonation on not?

I have done a TON of tuning on turbo 4 stroke cars and typically I use knock sensor input to tell if I am detonating or not to know if the tune is safe.

I am reading that at 0-3000' boost should be around 4PSI. Knowing that every sled/application is different, I would like to know if I am at a safe boost on pump gas but I am unsure of how to tell if it is detonating or not.

How do you guys judge a "Safe" tune when you are tuning?

Thanks, Dan

 

[wakerider]

Your sled should have a built in "DET" sensor at least all the carbed 600's newer then 04 did.

 

[GNDAN]

Yes it does. But what I am asking is how do I know if its sensing detonation? I would rather not rely on the sensor to try and stop detonation everytime AFTER it happends, I'd like to have a "safe" tune.

, Dan

 

[GNDAN]

Nobody watches for detonation when tuning? Just take other peoples word for it and run what they say?

,Dan

 

[jwentzer]

How do you guys judge a "Safe" tune when you are tuning?

Plug color, wash, AFR gauge and EGt's are a good starting point in tuning. I would never rely soley on the Det sensor as some are more sensitive than others.

Typically, det sensors are sensitive enough to where they detect the det prior to it causing damage. NOT ALWAYS, is it this way....referring back to some sensors are too sensitive and some aren't sensitive enough.

Keep in mind a bolt or any other object vibrating can possibly cause your det sensor to go off. Examples are some airboxes hitting/vibrating against the bulkhead can send a vibration strong enough to cause the det sensor to go off.

"Soft Det" usually just throws a code/light/something on your display screen depending on which sled/model you have.

"Hard Det" typically retards your sled and will only allow you to reach a certain throttle position or rpm. This can usually be reset by turning off your sled and restarting it. A really high-rpm spike will also give you this same result.

Always start with extra fuel and slowly take fuel away. Keep and eye on your gauges, if you don't have gauges, you shouldn't have a turbo.


If you are concerned about your PSI at sea-level, start with a gallon or two of race gas or av fuel in your tank. This can add a little protection while you get it tuned in. Every sled acts differently like you mentioned, the only way for you to know if your sled will be safe at a certain setting is for YOU to tune it. Don't rely on someone elses word.

 

[Boyko]

Your best bet is to run good fuel, lots of guys running av gas, 4psi is just a small tease of what boost does.

 

[GNDAN]

Great, this is the info I'm looking for. I have a Innovate WB02 on the sled and the EGT's will be next. It looks like I will have to look into piston wash to familiarize myself it what I am looking for as well as a little more detail on reading 2 stroke plugs, though I have heard for a good reading you have to cut the plug apart to see the lower part of the ceramic?

I emptied the fuel tank out and will be filling it with 100% CAM2 110 Octane leaded fuel to start with. I will start fat on fuel as I do when starting on any turbo setup I tune.

I have been looking into the 2.5 gallon fuel cans for the track extension. If I were mixing 50/50 or even 30/70 110 to 91 fuel would I possibly be able to go up to 6PSI with no intercooler? This would make the trail riding with better fuel more probable as I would have an extra 5 to 7.5 gallons worth of fuel with me then.

Thanks, Dan

 

[jwentzer]

If I were mixing 50/50 or even 30/70 110 to 91 fuel would I possibly be able to go up to 6PSI with no intercooler?

You should be fine with 6 psi and no intercooler. I run 10 to 12 psi on my boosted Pro with no intercooler. This is with 50/50 and at 10K plus in elevation. I know of people who ride at 1800' elevation with 8 to 10 psi on 50/50 and no intercooler.