intakes

[Jackson1320]

if it gets 40 more torque over the gen2 gt manifold that's like 60-80 more torque over other manifolds

Sponsored

 

[K4fxd]

Yes, you can feel it.

I'm currently playing with the GT350 IM and am finding with CMCV's locked out and advancing the intake cam at part throttle I am gaining back the lost torque of the truck mani. After I lock down what I think is best I'll go back and retune the truck mani.

It's hard to give up the 7800 RPM sound. LOL

At NCM where I mostly track the 350 mani wins. We are at the end of the tracking season here so I will invest more time to the gen 3 truck mani.

 

[NGOT8R]

Yes, you can feel it.

I'm currently playing with the GT350 IM and am finding with CMCV's locked out and advancing the intake cam at part throttle I am gaining back the lost torque of the truck mani. After I lock down what I think is best I'll go back and retune the truck mani.

It's hard to give up the 7800 RPM sound. LOL

At NCM where I mostly track the 350 mani wins. We are at the end of the tracking season here so I will invest more time to the gen 3 truck mani.

Any plans to try porting your GT350 IM? How does your car run with the CMCVs locked out? Is it really a huge PITA to retune a car that has them locked out?

I just ordered lockouts for my Bullitt and will have to go through this process with Lund soon.

 

[NGOT8R]

I wish Extrude Hone could port composite IMs. I reached out to them about having mine done and they told me that the pressure used during the process is too much for composite IMs.

 

[Dapepper9]

I've ran Boss, 18, GT350 and Edelbrock. All stock and all ported. GT350 is my pick. Matches times of Boss, gives up no low-mid and installs/fits better. Boss and GT350 are both faster than an 18 if you want to track it or shift higher. 18 is only the "better" manifold if you want to keep lower shift points, 7400+ the Boss and GT350 are faster. Also have ran the 18 and gt350 both locked out and with functioning IMRCs. IMO, much less of a headache to just lock them out. Even in a heavy crewcab 6R truck it's virtually no different with or without them if you have a competent tuner.

One of my next projects might be opening the plenum of the gt350 and porting that, runners are already ported as it sits. Recent dyno testing from Billy Kessel showed that opening up the plenum and porting the runner inlets on an 18 brought the power up to match a race port boss, still falling off at 7400 where the Boss carried to 7900 but was worth like 30whp over standard ported 18

 

[K4fxd]

Any plans to try porting your GT350 IM

I hope to get it done over the winter.

How does your car run with the CMCVs locked out? Is it really a huge PITA to retune a car that has them locked out?

It runs fine. It took some time to get it right. It is not as easy as some say but any pro tuner should have this perfected.

One of my next projects might be opening the plenum of the gt350 and porting that, runners are already ported as it sits.

Who would you have do this?

 

[Dapepper9]

Who would you have do this?

I do my own porting so I’ll handle it. Did a race port boss and made a few mistakes on the reseal but I learned from that and have a much better method to go with now. After seeing Billy’s dyno testing, I’m quite hopeful it should be a nice gain.
Edit: snagged that dyno graph from his FB post. I misquoted his gains but still significant

 

[NGOT8R]

I do my own porting so I’ll handle it. Did a race port boss and made a few mistakes on the reseal but I learned from that and have a much better method to go with now. After seeing Billy’s dyno testing, I’m quite hopeful it should be a nice gain.
Edit: snagged that dyno graph from his FB post. I misquoted his gains but still significant

Now we’re talking here! I didn’t know it was possible to cut open and successfully reseal a composite intake manifold. IMO, that is the best way to access all areas. If you can, will you please share with us, the method for cutting and properly resealing an IM? Thanks

 

[NGOT8R]

Here’s a video that I found on YT, although it’s not a Coyote IM, it does give us a peek inside of one made of composite material.

 

[Dapepper9]

Now we’re talking here! I didn’t know it was possible to cut open and successfully reseal a composite intake manifold. IMO, that is the best way to access all areas. If you can, will you please share with us, the method for cutting and properly resealing an IM? Thanks

Well the problem I had when I did the boss was I removed the internal posts so they weren't an airflow obstruction. Problem was doing that eliminated a lot of rigidity in the top and the resulting flex made it start to separate in a spot. Luckily I found it while swapping the GT350 back in.

When I initially ported the 350 I had an issue with manufacturing consistency of the manifold where it chunked out in the seam of one of the runners. Decided then to try something people have been doing for years on cylinder heads, mixed the regular 2part JB Weld epoxy with shavings from the porting. Like I said, guys have been doing that for years with aluminum and iron heads which see much higher temps, fuel and expansion/contraction in the piece. Figured the composite manifold runs cooler, won't see fuel in that section and won't flex as much so I mixed the fine plastic shavings into the epoxy and pressed it in where the plastic chunked out. Built it up, let it cure for a day and hit again with the burr and rolls and blended it. That was like 20k miles ago and it still looks like the day I did it.

So my plan is to:
A. retain the plenum support posts, I may trim them but they'll stay in place for rigidity
B. Hot staples along the seams to more securely affix it than my previous attempt
C. 2 part JBWeld epoxy and shavings mix to seal the cut.

Will it work? Better than my previous attempt I'm confident but I can't speak on the longevity. Places like AFS and PurgatoryPorting and a few others do top removal race porting of Boss and CobraJet stuff and even raise the plenum volume when they do it sometimes. They use plastic spacers for that but I'm not 100% sure on how they're resealing/reinforcing them. I would recommend talking to those guys if you wish to try this rather than take my method.

 

[NGOT8R]

Well the problem I had when I did the boss was I removed the internal posts so they weren't an airflow obstruction. Problem was doing that eliminated a lot of rigidity in the top and the resulting flex made it start to separate in a spot. Luckily I found it while swapping the GT350 back in.

When I initially ported the 350 I had an issue with manufacturing consistency of the manifold where it chunked out in the seam of one of the runners. Decided then to try something people have been doing for years on cylinder heads, mixed the regular 2part JB Weld epoxy with shavings from the porting. Like I said, guys have been doing that for years with aluminum and iron heads which see much higher temps, fuel and expansion/contraction in the piece. Figured the composite manifold runs cooler, won't see fuel in that section and won't flex as much so I mixed the fine plastic shavings into the epoxy and pressed it in where the plastic chunked out. Built it up, let it cure for a day and hit again with the burr and rolls and blended it. That was like 20k miles ago and it still looks like the day I did it.

So my plan is to:
A. retain the plenum support posts, I may trim them but they'll stay in place for rigidity
B. Hot staples along the seams to more securely affix it than my previous attempt
C. 2 part JBWeld epoxy and shavings mix to seal the cut.

Will it work? Better than my previous attempt I'm confident but I can't speak on the longevity. Places like AFS and PurgatoryPorting and a few others do top removal race porting of Boss and CobraJet stuff and even raise the plenum volume when they do it sometimes. They use plastic spacers for that but I'm not 100% sure on how they're resealing/reinforcing them. I would recommend talking to those guys if you wish to try this rather than take my method.

Great info! I‘m not sure which way I want to go, but do know I would like the bump in power that porting is capable of providing. I just don’t want to get too into the weeds on it and spend money that is needed for other necessary repairs or upgrades.

I hope you will consider doing a detailed write up during your porting process.

 

[blue5.slow]

I do my own porting so I’ll handle it. Did a race port boss and made a few mistakes on the reseal but I learned from that and have a much better method to go with now. After seeing Billy’s dyno testing, I’m quite hopeful it should be a nice gain.
Edit: snagged that dyno graph from his FB post. I misquoted his gains but still significant

Never heard of cutting open the manifold. Do you mean you cut it open to port the inside and then reseal? Is this so that you can port the entire inside of the manifold rather than porting just the plenum and runners?

 

[Dapepper9]

Great info! I‘m not sure which way I want to go, but do knowI woukd like the bump in power that porting is capable of providing. I just don’t want to get too into the weeds on it and spend money that is needed for other necessary repairs or upgrades.

I hope you will consider doing a detailed write up during your porting process.

Personally my recommendation would be pick either the 18 or GT350 depending on whether you want to shift at 7-7400 or 7500+. Either works great with the basic porting, GT350 is worth about 10-15 more than 18 overall BUT will cost more. Boss is cheaper and works great too but there's engine lowering/new hood stuff or whatever with it. Mine is truck application so I don't have those problems but I do the "heavy brick" problem". Same concepts apply but numbers are less impressive. My permanent setup is going to be the Edelbrock that I couldn't get sold so I chopped it up, ported it, removed the strut brace drop and welded it back up. Also matched the inlet to my 90mm TB I picked up. Stock it matches an 18 pretty spot on so I'm hoping it's a little better than ported 18. I doubt it works as well as the gt350 but it's too expensive to not do something with and will work great if I do a procharger later on. The 350 I planned on selling but after seeing Billy's posts on FB I really want to experiment lol.

 

[Dapepper9]

Never heard of cutting open the manifold. Do you mean you cut it open to port the inside and then reseal? Is this so that you can port the entire inside of the manifold rather than porting just the plenum and runners?

This is one of Billy Kessel's photos. AFS and Purgatory do the same thing with Boss/CJ manifolds, just on the top.

One thing to think about too is with the 18 and 350 pieces, you'll never see the reseal job. You can make it look totally normal installed, grudge racer style

 

[NGOT8R]

Personally my recommendation would be pick either the 18 or GT350 depending on whether you want to shift at 7-7400 or 7500+. Either works great with the basic porting, GT350 is worth about 10-15 more than 18 overall BUT will cost more. Boss is cheaper and works great too but there's engine lowering/new hood stuff or whatever with it. Mine is truck application so I don't have those problems but I do the "heavy brick" problem". Same concepts apply but numbers are less impressive. My permanent setup is going to be the Edelbrock that I couldn't get sold so I chopped it up, ported it, removed the strut brace drop and welded it back up. Also matched the inlet to my 90mm TB I picked up. Stock it matches an 18 pretty spot on so I'm hoping it's a little better than ported 18. I doubt it works as well as the gt350 but it's too expensive to not do something with and will work great if I do a procharger later on. The 350 I planned on selling but after seeing Billy's posts on FB I really want to experiment lol.

My 2019 Bullitt came with a GT350 IM. I’ve never seen a 2015-2017 GT350 IM off of a car, therefore, I don’t know whether they are the same. Here are some pics to show what my Bullitt IM looks like.

Sponsored