15-17 intake manifold improvements?

[Meanbgreen]

Following, information either way sounds good

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[1MeanZ]

Once you have tuned your engine to suit the '18 mani on a 17 Coyote, you dont notice the near negligible loss of torque.

What you do notice is the extra oomph you get when pushing the car hard around tight and twisty roads and out on the track. Thats where the 18 comes into its own

I don't see how this is possible. 25hp and 25ftlbs is a lot, and the Gen 2 intake dominates from 3000 to 6000rpm. See the below graph. I'm considering the Gen 3 and the GT350 intake to be near identical in performance, also see attached graph. I also don't see Ford Performance leaving 25hp on the table that a tuner can scoop up. So the notion that I'd put a Gen 3 intake or a GT350 intake on my car and gain or even match the mid range power of PP2 is false in my opinion.

Lots of people get caught up in bigger or more RPM is always better, but I don't think that's the case on a street car. Drag car is a different story.

 

[TeamDenno]

I don't see how this is possible. 25hp and 25ftlbs is a lot, and the Gen 2 intake dominates from 3000 to 6000rpm. See the below graph. I'm considering the Gen 3 and the GT350 intake to be near identical in performance, also see attached graph. I also don't see Ford Performance leaving 25hp on the table that a tuner can scoop up. So the notion that I'd put a Gen 3 intake or a GT350 intake on my car and gain or even match the mid range power of PP2 is false in my opinion.

Lots of people get caught up in bigger or more RPM is always better, but I don't think that's the case on a street car. Drag car is a different story.

Because as pretty as graphs are... when you go out and drive in the real world, the low down rpm power/torque on the non tuned 17 vs a tuned 18 is not noticeable when you have your foot planted onto the pedal.

On the 6MT, having driven several hundred of KM's last weekend, mainly not on freeway driving, I am stating the driver experience. You dont notice the lack of low rpm torque. Mostly becuase non freeway driving you are sitting higher in the rev range, and pushing the car a little harder than you would driving round town. I didnt notice the lack of low rev torque or power.

What I did notice was on the freeway, on an uphill section in cruise, I did have to drop from 5th from 6th where normally the car would be good for 6th gear.

 

[WildHorse]

Gen 2 intake dominates from 3000 to 6000rpm

Yep. Nothing beats the gen 2 intake below 6500. Myself shifting a close ratio D3, with 3.31's @ 7100 is killer. I ain't worried about other shifting at 400 rpm higher. I'll tell yah right now from what I've seen. A 15-17 MT82 / 3.31 geared car is much quicker than a 18+ with the same.

 

[Andrew@Lethal]

Anyone that's looked at the power curves of the stock 15-17 manifold vs the '18+ or GT350 manifolds can see that the 15-17 intake is better until 6500rpm. I think the ideal scenario for many of us with street cars would be to find a way to port the 15-17 manifold to get another 500+rpm out of it. If you could get the 15-17 manifold to make equal power to the 18 manifold at 7000 rpm but still make more power down low that would be the win-win in my opinion.

So the question is, does anyone know in detail the shortcoming of the 15-17 manifold? Is it runner length too long? Can it be ported? I've looked everywhere and I can't find anything on modifying a 15-17 manifold, everyone dumps them for the 18+ or GT350. If anyone has a 15-17 manifold they want rid of, PM me and I'll pay shipping. I'd like to try to modify one and see what happens...

There's been quite a bit of R&D on this. The 18+ manifold is the best flowing and when you port it there are even more gains to be had. The 15-17 manifolds nobody really ports but yes it can be done.

 

[1MeanZ]

There's been quite a bit of R&D on this.

There has been? Do tell because I can't find anything pertaining to the 15-17 manifold. Again, I'm not disputing the 18+ manifold flowing better at high rpm if that's what you're referring to. I want to know the port lengths and volumes, and comparative flow numbers of the 15-17 vs others. I'd also like to better understand what people are porting on the 18+ manifolds. Is it all centered around matching the inlet of the cylinder head I assume? I have a nearly new '16 manifold I have procured for this exercise, and while there is some small clean up I could do, i'd be shocked if it added more than 1-2hp.

 

[WildHorse]

The 15-17 manifolds nobody really ports but yes it can be done.

I'll be porting mine this winter. And here's the key.. I have a flow bench to verify. I bet the gains will be from 3000-7500, just like a 18+ intake. 25 years of experience talking.

 

[Whitewalkers550]

im really curious to see numbers on the 15-17 vs 18+

 

[Grimreaper]

I doubt there is enough plastic that can be removed to match the my18 mani volume. Really really doubt that. The my18 runners are huge compared to the my15-17 mani. The porting I've seen is typically clean up/smoothing The sonic welding from the plastic parts leaves nasty seames with overlaps etc.. think of putting an oil pan on the block with too much sealant. It bulges into the openings.

If you could get enough to carry the curve to 7500rpm that would be outstanding. Just don't see it being there physically. These manis have several pieces making up each runner. Some times the alignment allows more plastic removal than in others before you start pushing the thickness of the walls or ending up with a funky corner/ transition/flat spot.

No harm in trying. Parts cheap enough. Measure the volume before and after too

 

[Strokerswild]

The cross section of the '18+ runners is much more significant. It was readily apparent when I was messing around creating my mounts to fit the '15-'17 intake cover to the '18 manifold. The earlier intake cover barely fits over the runners. I ended up selling my '18 setup though, as I just don't drive my car hard enough in general (or race) to reap the benefit. Not to mention I'm gunning to order a GT500 next year and want a quick return to stock.

I'd still be interested in seeing numbers for a ported Gen 2 and dyno results.

 

[WildHorse]

he cross section of the '18+ runners is much more significant

Cross section isn't everything. Under the curve is where it's at. Peak for peak will be about the same.

 

[Strokerswild]

Cross section isn't everything. Under the curve is where it's at. Peak for peak will be about the same.

Correct, another reason I left my stock intake on my '15. My Lund flex fuel tune with it is ample.

 

[Dapepper9]

Thread revival!

Couple things:
1. How's testing going for those of ya'll doing it?
2. This test over at the svtperformance site isn't quite what you're looking for in terms of information but it's interesting nonetheless and the chart at the end has some pretty good info.

Myself, I don't have a mustang but instead an F150 with the coyote. Truck is a 2015 SuperCrew that's also 4wd with 3.31 gears. My local track is 1/8 mile and the truck is a daily. I've come to the conclusion that running manifolds for higher rpm isn't my best option. My 2012 I had previously for example was .2 quicker in the 1/8 with a ported 11-14 mustang intake than it was with an 18gt/boss/edelbrock setup. Granted, those have crap cams but I think I'll notice the same with the '15 being that I have 3.31 gears.

Basically I'm kind of doing a little bench racing right now on which manifold would offer me best results in the 1/8 while being a solid fun daily. The truck murders up to 5000 but I can't find where anybody has ported one like has been discussed here or pulled one higher. I'm curious if the 15-17gt, especially once ported, would fall in between something like an 18gt and a stock manifold and give me a little of both worlds. I also have the usual other bolt-ons as well, CAI and catted LTHs with ported tb in the works.

 

[gameovergt]

I've been running the 18 mani for a lil bit now. No loss in sotp feel down low. With the Circle D 5c in the car really rips! I sold my '16 intake to a club member with an f150. He loves it. Someone bite the bullet & have a 15-17 ported/tested.

 

[1MeanZ]

I'll be porting mine this winter. And here's the key.. I have a flow bench to verify. I bet the gains will be from 3000-7500, just like a 18+ intake. 25 years of experience talking.

I have access to a flow bench as well. It's a Superflow unit for doing cylinder heads, we will likely need to do something with some tooling to get it to work with these intake manifolds. I bought a nearly 0 mile used intake from a '16 GT. I've looked it over pretty good and other than a few of the seams where the plastic parts are joined, I don't see where there is much to port. I'm curious to see where you spend your time porting. That said here is my plan.

I'd like to try and get a baseline flow number for the intake in stock form, then clean up the seams and try it again. Outside that, I'm kind of stumped. To really get serious, I'd need to start cutting an intake apart and see whats going on where the runners meet the plenum. There are rumors of 15-17 manifolds cracking, so I don't want to cut up my perfect virgin spare manifold because I may need it some day.

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