LS 4.8 5.3 6.0 Porting 75mm Throttle Body

[@dragan3290]

I kept marking my butterfly with a sharpie in closed position. I'm gonna take a mm of the shaft either side or more. Nice tutorial. Cheers from Australia 🙂👍👍👍

[@coltonshimko799]

The easiest way I've found after porting a few throttle bodies is to get an extra throttle blade. Replace the blade and use your extra one as a stopper so you have 0 chance of hitting the sealing surface. I always enlarge the very front of the throttle body as much as possible also, to the point where it is almost knife edged. I grind the extra bit of bolt that pokes out the back off, and I also reduce the face of the bolts profile so they don't stick into the bore as much. (The bolts meaning the ones that hold the blade in place) As you said, I also get rid of the ridge in front of the blade and on a few of them I've smoothed out the ridge in the back. You may also want to look into grinding into the throttle stopper to allow the throttle blade to open fully to 90° also, the one that came on my LS1 was quite a ways off from actually being fully open. I personally always take a grinder to the coolant inlet and outlets to remove the pipes also, doesn't really do anything other than help my OCD lol

[@HeadFlowInc]

Colton Shimko Excellent tip using and extra throttle blade to use as a guide! I have some wish I’d seen this sooner, would have saved time. I’ll definitely check the opening angle to make sure it’s getting Fill WOT. Sop even on carburetors 👍 There’s nothing in the TB behind the blade, it’s straight smooth bore with a slight under cut at the edge. I heard of people beveling the transition on the back side but air doesn’t follow a bevel going down hill. I appreciate the help every little detail makes a difference! 👍

[@sizedsaturn7277]

Can you pls make a video I would appreciate it it alot

[@dragan3290]

Hi. Thanks for the quick reply! I love learning from American people! You guys have the best tools, best engines. My holden Commodore ecotec V6 3.8 litre is based on Buick engine. I found an awesome cold air box setup from you guys in the US. Insulate inside of my airbox! I did outside with a heat shield and Damn it's not a placebo effect when doing 80 km per hour and I give it a stab to the floor in the wet it spins until I back off. I scared the crap out of myself after putting a 25 mm manifold spacer And a 12 mm plenum spacer. I gave it a bit as usual in the wet around the corner and as opposed to a little drift. Lol it swung one way and luckily I caught it and swung the way. LMAO 😂😂😂. I'm slowly buying parts from mace engineering. But now porting the TB until I get a 69 mm and my ECU remapped! Sorry off topic. Thanks for the quick reply! Love your vids! Very informative! Nice to see sharing!👍👍👍

[@HeadFlowInc]

Be careful don’t remove material from the area the throttle blade seals or you’ll have a high uncontrollable idle. I’m always thrilled to hear from the people in Australia! JD

[@dragan3290]

@@HeadFlowInc I'm paranoid about that even if the Mark is still there. Lol. I'm taking it slow and steady. Thanks again.🙂

[@dragan3290]

@Waza G yeah I wanted to but the only one that will fit is of a 6.0 litre. LS throttle body and modifying to make it fit. Ecotec Is 63 mm. I need a boring bar. It's not rocket science.

[@dragan3290]

@@HeadFlowInc hey man. I fitted the throttle body all ported and polish. Knife edge on butterfly ( little one) took a little of the shaft because you have 3 mm either side. I took 1 mm of either side so it's still clamping up tight. Instant little extra! I thought nah!!!! But it was an experiment! So stuff it! Much happier. Asking my older brother if he would sell his boring bar? He told me to pee off! Lol cheers

[@dragan3290]

@Waza G btw holden 5 litre is 65 mm. 2 mm bigger than mine but mods to make it work.

[@mastertek383]

The modified tbi bodies have thinned throttle shafts along with bored out bores with larger blades. They turn them down and flatten them out.

[@HeadFlowInc]

Nubbins That would be awesome, remove the shaft and “Slab” cut it to reduce the profile. If you had a milling machine to cut a new precision bore to a larger size would be the way to go! That’s a lot of work when there’s inexpensive aftermarket options. Interesting information I appreciate it! 👍

[@marellerapinto9165]

What would happen if we blocked off the vacuum line that connected to the valve cover ? Should I or should I not ?

[@HeadFlowInc]

mark n michelle Jacinto I’ve done it, but it’s actually one extra way to reduce crankcase pressure same as the PCV setup. Many people with Turbos lust vent both valve covers to atmosphere, but running NA you may want to have a functioning way to reduce the crankcase pressure. I know my driver side OEM PCV setup needed a separator, but the line from the throttle body to passenger valve cover never showed any oil contamination. 🤔🤔🤔

[@mikasantos3774]

Nice job I like to work with what I got also everyone now days wants to buy parts to go fast.but if you have the know how you can turn stock parts into decent performance pieces with a little port work. happy thanksgiving

[@HeadFlowInc]

Mika Santos Happy Thanksgiving to you! Thanks!!! JD

[@nicholasdeangelis9143]

I think the oil is caused by the design of the valve cover which pulls oil that gets stuck in the baffle for the pcv on the drivers side. GM redesigned it or you csn mod i baffle with a few well placed holes. Everyone has a different way so use your best judgement. You will reduce oil consumption and smoking with the mod. Good vid man, i just leave mine stock though. Plenty of power as it is for me in my 5.3.

[@HeadFlowInc]

GM did redesign the PCV on the later valve covers, I hope it helped. I found out if you route the hose to the PCV vertical a few inches then to the vacuum source it helps the oil consumption using gravity. Currently after going Turbo I have no PCV instead I have open 5/8” hose from each valve cover going to a catch can. So far I haven’t had anything in the cam. JD

[@james10739]

Dollar tree is where its at you can get lye based oven cleaner for $1.25 and Walmart wants like $5 even for their brand plus La's totally awesome which is great i believe its pretty basic so if you sre soaking you should be careful with aluminum

[@permabulk1454]

That ridge I’m sure is to ensure an extremely proper seal. Idle and decel are a huge factor like you said… and the minute difference of power or Venturi velocity WITH the ridge (on a ported tb) vs without the ridge, is so small I wouldn’t even touch it if I were porting. Maybe a professional but not me lol that’s too risky for a proper idle

[@HeadFlowInc]

I agree! I ported 2 then decided it was cosmetic and stopped. Huge waste of time and money. JD

[@permabulk1454]

@@HeadFlowInc hell yea brother. I’ve been watching all your videos. I have a 2004 Pontiac GTO with almost the exact same throttle body but I believe my throttle cam is about an inch or less larger. Making it a little different torque band I’m assuming.. one for a truck one for a car haha. But yea man I really wanna port mine but I just don’t wanna fuck it up. Im mechanically inclined and have a dremel lol which bits would you recommend and also can you link the second video showing the follow up!?

[@HeadFlowInc]

@@permabulk1454 Flame or tree double cut for bulk removal then larger egg double cut smoothing then sanding cartridges. Depends how smooth you want to go. JD

[@permabulk1454]

@@HeadFlowInc bro awesome. Did you ever make a follow up video to this one? Would love to see your final product

[@james10739]

I would think the size would be based on the throttle blade size it might be like 75mm since its not straight but thats a good measurement regardless

[@HeadFlowInc]

I agree the blade size is the measurement. I’ve seen the stock truck listed as 75mm and 78mm. Smoothing and handwork the aluminum I think might make a very small amount of improvement and efficiency, but I think in the end, the maximum flow has to be determined by your blade size.

[@superc4308]

Happy thanksgiving

[@HeadFlowInc]

Cary Christian Have a Happy and Safe Thanksgiving!!! JD

[@coryperry3101]

I have found you can enlarge the bore to 77mm with the addition of a trailblazer throttle blade. Anything more and you exceed what you can bore the intake entry. You must add a small whole for idle air as found on the original blade.

[@HeadFlowInc]

LOOK I FIXED IT! Yeah, I don’t mess with throttle bodies anymore because it’s really cosmetic and you can buy a decent aftermarket unit cheap. Thanks for watching and the feedback I appreciate it! JD

[@jamest.5001]

Would a 86 or 92 mm throttle body fit the intake? Maybe with some help?

[@HeadFlowInc]

JAMES! Since the 70's Measure your opening on which ever intake you choose to run, as long as the opening into the plenum is equal to or larger than the Throttle Body you’re good! Thanks for watching and the feedback I appreciate it! JD

[@gregorykusiak5424]

You’re measuring the throttle body at much cooler than operating temp- did you ever measure with the hot coolant hoses attached on a running engine? You’re quibbling over less than a mm…that probably magically appears when it’s at operating temp

[@HeadFlowInc]

Unless the the throttle blade and opening are increased there’s no measurable improvement. I stopped offering this process on stock throttle bodies. Cosmetic change not worth the effort or cost. JD

[@familymann1956]

Why wouldn’t you just buy one of those cheap 90 mm throttle body’s and be done with it hell I was finding them for like 70$ and 102 mm not much more

[@HeadFlowInc]

Family Mann My TB on my Blazer is 100% stock unported. 😉👍