Ported Gen 4 vs Stock Gen 5 Intake

[ViperC]

I know there are several threads comparing Gen 4 and Gen 5 intakes, but have there actually been any direct comparisons between a ported Gen 4 and a stock Gen 5 intake? I've seen stock vs stock. I know BBG and Dan Cragin, as well as a few others, port Gen 4 intakes. What does the dyno say?

[IndyRon]

There is some data out there from a while back. The consensus is that a max ported Gen 4 intake flows slightly better than the Gen 5 intake. Both make similar power numbers with the Gen 5 having a few advantages: 1) Less weight (10-12lbs up top), 2) Less heatsoak being composite, 3) Making more midrange torque and power compared to Gen 4 due to the longer runners and intake design.

[Fulltilt]

Dumb question - I've wanted to put a Gen 5 intake manifold on a Gen 3 engine but I'm sure it wouldn't work.

[13COBRA]

Dumb question - I've wanted to put a Gen 5 intake manifold on a Gen 3 engine but I'm sure it wouldn't work.

Correct.

You could do a hybrid package and put it on..but it'd be heads, etc.

[ViperC]

There is some data out there from a while back. The consensus is that a max ported Gen 4 intake flows slightly better than the Gen 5 intake. Both make similar power numbers with the Gen 5 having a few advantages: 1) Less weight (10-12lbs up top), 2) Less heatsoak being composite, 3) Making more midrange torque and power compared to Gen 4 due to the longer runners and intake design.

I wonder what the mid-range difference would be? I know stock vs stock its pretty significant. But I have seen ported vs stock gen 4 and the ported picked up quite well everywhere and especially up top. I personally prefer the looks of the Gen 4.

[J TNT]

If memory serves me correctly a Ported Gen 4 Intake picked up 15 to 18 HP .

[Steve M]

This post was as conclusive as I could ever find: https://driveviper.com/forums/threads/6364-Gen-5-to-Gen-4-Intake-Manifold-install-Thanks-Doug-Shelby?p=93548&viewfull=1#post93548

For the lazy:


We just finished installing another Gen 5 intake on a Gen 4. Advantages being more power and less heat soak. The new manifold produced 5 more peak hp than our ported Gen 4 manifold and the power was more consistant with multiple pulls.

Although I'm sure a few Viper owners have done both in the past, no one really had conclusive data to suggest one was better than the other. Back in the day when I had to decide, I found that porting my Gen 4 intake was more expensive than just getting a Gen 5 intake. The lower weight and better thermal properties were worth the downgrade in the looks department to me, and I haven't looked back since. I do still have my old Gen 4 intake, but don't have $1k+ burning a hole in my pocket at the moment to have it ported so I could do some testing of my own at the drag strip.

I don't think you could go wrong either way, but it seems most just do the Gen 5 intake manifold these days for naturally aspirated builds...it's pretty proven at this point. I think the Gen 4 intake manifold only comes back into the mix when looking at doing forced induction, but that's orders of magnitude more expensive than what my broke ass can afford.

[Steve M]

Good info in this thread as well: https://driveviper.com/forums/threads/4665-Porting-Gen-IV-intake

[Steve M]

Sorry for the multiple posts, but I've been re-reading many old threads both here and on the VCA forums. There's definitely some good info out there, but you have to dig for it these days since most folks that posted in those threads have long since moved on to other platforms.

Either way, the biggest concern with porting anything is the skill of the person doing the work. It seemed like Dan Cragin (quoted above) did a lot of testing of his ported Gen 4 intake manifolds. Two quotes stuck out to me from two different threads over at the VCA forums.

First is this one (source: https://www.viperclub.org/vca/threads/gen-iv-ported-intakes.641423/#post-2910537)


We spent quite a bit of development time on our Gen 4 intake manifold porting. We have tried many differing configurations, including welding up runner areas and changing port alignment. All this has been tested on the dyno. The final results has been very repeatable and proven. I think what makes this modification work is all the testing we did. About 3 pounds of material is removed to get the flow where we want it. Our intakes are labor intensive and include many changes.

3 pounds is a lot of aluminum, and indicates a very labor intensive process.

The second quote backs up the first, with a few more details (source: https://www.viperclub.org/vca/threads/ported-intake-gen-4.652885/page-2#post-3095308):


We did quite a bit of testing on the Gen 4 manifolds, we tried numerous things including welding, reshaping the ports and shortening the runner length. We dyno tested all these options and found a point of diminishing returns. There was a point were we gained hp and lost torque. The biggest changes where in the inlet of the port, realigning the ports and changing the port volume. Of the 36 manifolds we did, We saw hp gains from 12-24hp with the high number most likely an anomoley. With the stock valve size and rocker ratio we saw another 25hp from porting the heads. Small increases in compression gave another 10hp but required 93 octane fuel min.

So they tested 36 manifolds, which is about as large of a sample size as you'd ever hope to get.

Why post this? I think it lends some additional credibility when Dan says:


The new [Gen 5] manifold produced 5 more peak hp than our ported Gen 4 manifold and the power was more consistant with multiple pulls.

Obviously 5 HP isn't all that much of a difference between a stock Gen 5 intake manifold and a ported Gen 4, and is likely within the error bounds of your typical chassis dyno.

I guess the question then becomes this: who is still around that ports these intake manifolds, and has a proven track record? Dan Cragin just retired, so he's out of the game...not sure who that leaves. Arrow racing used to port them, as did Bad Boyzz Garage. Not sure if either still do. I'm also not sure I'd want some rando with a grinder going to town on a very expensive piece of aluminum that may or may not know what they are doing. You don't have that variable with the Gen 5 intake manifold.

[ViperC]

Good info in this thread as well: https://driveviper.com/forums/threads/4665-Porting-Gen-IV-intake

Thanks for all the digging you did. I had never seen those posts. If I had I probably wouldn't have made this thread. Dan put a lot of R&D into porting the Gen 4 intake, that's for sure!

[TrackAire]

Gen 5 probably flows a tad better, but damn the Gen 4 aluminum manifold looks beastly when you pop the hood.

[LATAMUD]

Dumb question - I've wanted to put a Gen 5 intake manifold on a Gen 3 engine but I'm sure it wouldn't work.

You would need Gen4/5 heads on the Gen3 otherwise the runners do not line up with the Gen3 heads intake ports.

[Viper Specialty]

This has been a point of opinion for quite some time. Performance wise, the G4 ported is very, very similar to G5. Strength wise [Forced Induction] the G4 manifold is the clear winner. In the looks department, subjective of course, but G4 is the clear winner for me.

I guess it comes down to what is most important to you. Personally, I prefer the G4 as it looks better, and can be disassembled, modified, and cleaned. As time goes on, I am sure that billet and/or CF G4 components will end up being produced. The G5 "is what it is"... take it or leave it in that regard.

[VIPER BAZ UK]

I agree with Dan Lesser
Gen 4 looks so much better but that being said a CF Gen 4 intake would be so cool....