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Does anyone have the port areas for the stock 4.8/5.3/6.0 truck intake manifold? I found a old LS1 article where the engineer mentioned the port taper which I calculated about a 1.5 degree taper angle, but not sure if that's in the heads or the intake runner or both? Also not sure if its the same between a LS1 and the truck engines. Also if anyone knows the stock exhaust manifold sizes too I could use those.
I may just have to take my intake off and measure it, not sure if its worth it to try to pull the exhaust manifolds given how rusted everything is, I can't even get the flange nuts off the studs.
I have a stock intake manifold and stock exhaust manifolds I can measure when I get some free time.
put some eBay 1”7/8 headers and a y pipe on the Tahoe today and retuned it this evening. Needed somewhere around 8-10% more fuel at wide open and it was able to take 4 more degrees of timing over the stock exhaust manifolds without any knock count. Also it sounds way better. I should have taken a video of it with the stock manifolds and cats to compare to it but I spaced it. Next thing I’m gonna try is the 615-183x manifold I got for it. I need to figure out how to mount the map sensor on it and Shave it first. If it doesn’t make any more power I’ll take it off and throw it on my shelf or post it for sale but I got it for cheap on a eBay auction so it’s worth the shot for the learning experience.
What is the total advance you're now running? I've been sneaking up little by little and now at 27* total. I'm sure I can get a degree or two more but I'll get a random KR at a steady cruise rpm/tps. I'm sure it's false knock cause it's not the typical stair step you usually see on the scanners "time/graph" layout. Plus I've used Boostane for higher octane and see no difference. I guess I need to lower the sensors sensitivity then add another degree or two.
I have a stock intake manifold and stock exhaust manifolds I can measure when I get some free time.
put some eBay 1”7/8 headers and a y pipe on the Tahoe today and retuned it this evening. Needed somewhere around 8-10% more fuel at wide open and it was able to take 4 more degrees of timing over the stock exhaust manifolds without any knock count. Also it sounds way better. I should have taken a video of it with the stock manifolds and cats to compare to it but I spaced it. Next thing I’m gonna try is the 615-183x manifold I got for it. I need to figure out how to mount the map sensor on it and Shave it first. If it doesn’t make any more power I’ll take it off and throw it on my shelf or post it for sale but I got it for cheap on a eBay auction so it’s worth the shot for the learning experience.
That manifold is the doorman OE replacement for the TBSS/NNBS truck intake correct?
I used the dynomation iterator to try to back calculate the intake dimensions assuming GM tuned the intake to peak at the peak torque at 4000 rpms. I put everything else to stock LQ9 6.0 specs. It gave a surprising result at 525 ft-lbs at just under 4000 rpms. This is stock heads, stock cam, stock compression, just optimized intake dimensions. You can also see how HP drops off very early as well.
I am hoping to get all the correct dimensions so I can create a setup that will bring the most out of stock or nearly stock/ported components. For example, if I put 706 5.3 heads on my LQ9 and thinner gaskets to try to bump the compression and optimize it for E85. This way I can just optimize the setup with the cam specs and not have to spend so much money.
What is the total advance you're now running? I've been sneaking up little by little and now at 27* total. I'm sure I can get a degree or two more but I'll get a random KR at a steady cruise rpm/tps. I'm sure it's false knock cause it's not the typical stair step you usually see on the scanners "time/graph" layout. Plus I've used Boostane for higher octane and see no difference. I guess I need to lower the sensors sensitivity then add another degree or two.
24-26 at full throttle. Be careful with cruising knock count, it is a real thing and it could totally not be the knock sensors reading wrong. I’m tuning Honda’s I’ve seen too much low load timing kill rod bearings.
24-26 at full throttle. Be careful with cruising knock count, it is a real thing and it could totally not be the knock sensors reading wrong. I’m tuning Honda’s I’ve seen too much low load timing kill rod bearings.
It's like a random KR blip then gone. It never happens with TPS changes or transmission shifts nor any wot events. I've boosted the octane to 103+ and killed the spark to 5* and it still shows up. In the retard histogram I'll see at the most 0.6 of timing pulled during a KR event. I set the knock sensitivity tables back to factory settings when I did the heads that upped static to 11.4 out of an abundance for safety.
Got some new headlights for the Tahoe yesterday. They had one broken tab where the adjuster attaches but it was easily fixed with some Jb weld and feels stronger then it did before. I was reading reviews on these headlights and people were saying that’s a common problem. The seller said they would give me a partial refund. Also got my hd grill in the mail yesterday. Can’t decide on what to have painted on it or if I should leave it unpainted. Might have to fit it to see what looks best first. Also started shaving the z71 sideskirts I picked up. Already painted the front and rear caps with sem trim black and they came out looking awesome. I’m cutting filler pieces to fit from a spare z71 skirt I got at the junk yard then Jb welding them in place and using a little filler once they are cured to smooth them out then they will be painted with sem trim black as well.
Last edited by T-RevMotorsports; 10-27-2020 at 11:53 PM.
Waiting for a link to those gorgeous headlights my round eyed brethren! Looking super clean!
I like those style of headlights too. First saw them a few months back when FreddyLSX installed a set with matching corners on his Silverado. His have the extra LED that makes a "U" shape instead of an "L". I have a set in my wish list for my GMC.
Shows the lights on at the 3:10 mark in the video.
10-23-2020, 05:41 PM
