Gen III BBC 0411 Swap Almost Complete - KNOCK SENSORS

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Danspeed1
Posts: 9
Joined: Tue Jul 04, 2017 8:07 am
Location: Orange County, NY

Gen III BBC 0411 Swap Almost Complete - KNOCK SENSORS

Post by Danspeed1 »

Hello,

I haven't been on here in a little while but I just wanted to update you guys on my project and ask a few knock sensor related questions I can't seem to find the info for anywhere else.

https://ls1tech.com/forums/conversions- ... velle.html

If you are interested in taking a closer look at the build most of the information is in the link above. Project got totally out of control.

Anyway here's where I am at :

I have a 0411 PO1 from a 2001 5.3 Vortec Truck. I have a PSI harness for a 2002 Silverado installed on my Gen III (1972) Big Block with a 24x reluctor installed on the front of the motor, and a 1x cam trigger installed in place of the distributor. The vehicle is setup for multiport fuel injection with individual coils. I already burned a 2002 Chevy Suburban 5.3 with Flex Fuel file to my 0411 ECU. The reason I chose this file is because I wanted the flex fuel option (I am running a sensor on my return fuel line). I changed the firing order in the tune file. Not sure if this is going to work but we are going to find out this week when we fire it up. My current dilemma is what to do about the knock sensors. I really need them to function correctly as I plan on tuning this thing on the edge. Using the tune file I am using I can't figure out if it is smarter to use the vortec 5.3 knock sensors or the vortec 7400 sensors from an older model. I am concerned about resonance and if/how the sensors will pick up actual knock. I don't have a good understanding of how knock sensors pickup harmonics and I can't be sure knock will transmit in a 454 the same way it will in a Vortec 5.3. I know many of you have done Vortec 7400 454 0411 swaps on this site. I also know many of you use the 5.7L tune files from the earlier trucks. I am hoping someone has stepped up to the new tune file and has a solution for me. Safety is my main concern.

Thanks,

Dan

Speeder
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Joined: Fri Apr 30, 1999 9:12 pm
Location: 2015 Tahoe 2WD 5.3L 6L80E, 2008 Colorado work beater, 2003 Dodge Dakota pro-touring project

Post by Speeder »

Since nobody else has responded, I'll recommend trying the 5.3 knock sensors in the 7.4L stock location. Start conservatively with the tune. Take WOT and part throttle data logs with the knock sensor performance and timing tables. Using these, you can adjust timing to allow you to run the ragged edge on 87 octane. Ideally, you will be looking to get 0 to 1 degree of knock retard coming in across the band. Once 87 is tuned, you can use this as a basis to start the 93 tune. Do the same thing, only with 93 octane in the tank. Not sure on the ethanol part, I have a flexfuel vehicle but haven't tried tuning it yet.

On the E85, you'll need to make sure your fuel pump, lines and injectors are all E85 compatible. You will also want the sensor in the fuel that sends the feedback so the computer can tell what the ethanol level is.

Danspeed1
Posts: 9
Joined: Tue Jul 04, 2017 8:07 am
Location: Orange County, NY

Post by Danspeed1 »

Thanks for the reply. I might give that a shot, hope it works. I installed an ethanol content sensor so I should be all set there.

Thanks,
Dan

orange ss
Posts: 218
Joined: Thu Aug 30, 2007 1:12 pm
Location: Emory, Tx

Post by orange ss »

KS operation is more about placement and block material, GM moved the KS back to the side of the block at one point from the lifter valley, maybe look over one those tunes and see if you can correlate to yours

Hog
Posts: 5037
Joined: Tue Dec 11, 2001 4:00 pm
Location: 1997 Chev ECSB L31 350 1997 GMC Sierra SLE RCSB, Ontario

Post by Hog »

You also have to use the correct sensor be it the resonance style or flat response style.

peace
Hog

Danspeed1
Posts: 9
Joined: Tue Jul 04, 2017 8:07 am
Location: Orange County, NY

Update

Post by Danspeed1 »

Well, after literally weeks of reading and attempting to digest all this information about knock sensors I've come to a conclusion based on something that I learned using hptuners. Initially I plan to use the 454 knock sensors because they made the most sense. Upon taking a look at the tune file for the vortec 7400 I realize there's actually no knock sensor tables that are accessible within that tune file, be it they don't exist or hptuners just didn't add them because there was no demand. I had this posted on a couple other fourms as well. A few people recommended using the 454 sensors with the 5.7 l knock sensor information. I had trouble digesting that because the blocks are so different so although the information was readily available I decided not to go in that direction either. After using the AC Delco interchange manual online I found that the 454 knock sensors are specific to the 454 engine and the 6.5 turbo diesel. That means they were never used in any other engine application. With that said somebody recommended I take a look at the 8100 knock sensors. In theory the vortec 8100 is a 454 block bored out and stroked to 8.1L. The tables directly correlates to the tables on the 5.3 L tune file I'm using, and the 8100 also used an 0411 ECU. I was able to move the tables over to the 5.3 tune file and so long as the thread pitch is the same on the vortec 8100 knock sensors I think this will work the best. I ordered two and I will post back how they work.

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