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ARH Race Manifolds 1-7/8 x 3" direct fit for 392/Hellcats.

6862 Views 29 Replies 11 Participants Last post by vortecd, Sep 13, 2020

JauntyBishop

Discussion Starter · Jun 13, 2020

10

Last week, I spoke with Nick the owner of ARH (American Racing Headers) and decided to purchase their direct replacement stainless "race manifolds" designed for the 392 and Hellcat variants. Figured the General Discussion area would get more traffic views to show these off since I haven't seen much info about them from 3rd parties.

I didnt want to go with Long tubes, but I did want the larger 1-7/8 primaries with 3" collector. For reference, The stock manifolds are 1-5/8 x 2.75 and expand to 3" before the catalyst.

Seeing how the factory manifolds work pretty well for a stock piece, ARH designed these 1-7/8 manifolds to optimize the factory setup since the 392 and hellcat were designed with a short primary, jacketed manifold. ARH claimed 14-15whp on stock tune, but I'll be doing my own testing and most likely installing them myself to save cost overall. That, and curious to see how the overall power band is effected vs a LTs on the 392 using stock cam profile.
(I'm well aware of the shorty vs long tube, makes more power etc. I wanted a different option for my setup.)

These will be installed on my 2019 Charger 392, which has mmx catless mids, carven 3" Xpipe, and Vibrant 1142 with Carven tips. Stock tuning, hellcat box.

*1-7/8 primaries x 3" collector with merge spike,
* 304 Stainless, 50 State legal, and will work with factory and aftermarket midpipes
*3/8 flange, hand ported inside, tig welded, etc.
Part # DOD-15178300SH

My first time owning a product from ARH and their quality is top notch.

These are a great option as a replacement manifold for those who want a 1-7/8 primary tube and retain the use of stock cats, or already have catless aftermarket midpipes. Gain a some extra power, without worry of potential ground clearance issue of long tubes, and the cost overall is cheaper this route, especially for those who want to maintain the 50 state legal. These would've been awesome to have from the factory.

Enjoy!

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JauntyBishop

Discussion Starter · #2 · Jun 13, 2020

4

Below are some pics showing a visual reference of the ARH manifolds attached to my old stock 392 midpipes.

ARH manifold collector outlet LEFT vs 392 stock catalyst midpipe inlet RIGHT

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JauntyBishop

Discussion Starter · #3 · Jun 13, 2020

Lastly, here is the youtube video from ARH explaining the basic design and comparison of the stock 392/hellcat exhaust manifolds.

Reactions: 4

Taxinator

· #4 · Jun 13, 2020

Looks great...eagerly waiting for your review.

Reactions: 2

hpindy

· #5 · Jun 13, 2020

Those are very nice and a great idea for those who don`t want to go the long tube route. Please keep us posted on your results.

Reactions: 1

Kotta390

· #6 · Jun 13, 2020

Subd

1885

· #7 · Jun 13, 2020

subd

JauntyBishop

Discussion Starter · #8 · Jun 14, 2020

Those of you who have installed long tubes, its probably safe to say these ARH manifolds are still gonna be a pita to install or do you think less of a hassle since you're not dealing with more space constraints from having an extra four 15"+ of tubing per side, as well as weight?

1885

· #9 · Jun 14, 2020

JauntyBishop said:
Those of you who have installed long tubes, its probably safe to say these ARH manifolds are still gonna be a pita to install or do you think less of a hassle since you're not dealing with more space constraints from having an extra four 15"+ of tubing per side, as well as weight?

Good question I want to know also.

Reactions: 1

JauntyBishop

Discussion Starter · #10 · Jun 14, 2020

hpindy said:
Those are very nice and a great idea for those who don`t want to go the long tube route. Please keep us posted on your results.

Agreed, one of the main reasons I went with them aside from the 1-7/8 x 3 design is that they work with factory or aftermarket mids. I already have mmx/sw catless mids. Also, not worrying about ground clearance scraping those $1200+ headers against the ground. I've heard that ARH LTs hang the lowest out of the LTs.

People claim LT arent worth the money for the little power gain, and stick with factory manifolds. So my thinking is why not use an optimized replacement manifold being the 392 and 6.2 were designed within those OEM SRT manifolds.

hpindy

· #11 · Jun 14, 2020

JauntyBishop said:
Agreed, one of the main reasons I went with them aside from the 1-7/8 x 3 design is that they work with factory or aftermarket mids. I already have mmx/sw catless mids. Also, not worrying about ground clearance scraping those $1200+ headers against the ground. I've heard that ARH LTs hang the lowest out of the LTs.

People claim LT arent worth the money for the little power gain, and stick with factory manifolds. So my thinking is why not use an optimized replacement manifold being the 392 and 6.2 were designed within those OEM SRT manifolds.

The factory manifolds are well designed for factory engines but as some point they will not be efficient any more .

Sent from my BBF100-2 using Tapatalk

Reactions: 2

JauntyBishop

Discussion Starter · #12 · Jun 14, 2020

This is a widebody 2020 392. He does before and after same day dyno tests of stock, then Hooker shorty replacement headers that are 1-7/8 x 3, then JLT series 2. All on stock tuning.

The Hookers picked up 12-14whp thru the curve using stock midpipes.

For reference below this Janetty tuning vid with the 392 6spd challenger added Longtubes and midpipes with tuning picked up 20whp/20wtq thru the curve.

I understand this is apple's to oranges being different cars and dyno, however there is enough data out there to support common gains with LT gains.

So it's possible on a stock engine that the ARH manifolds with a tune could be equal or within a few whp as long tubes.

Now once the camshaft/displacement increase and other components are changed then long tubes should be considered.

Glad there are multiple options out there for us to choose.

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JauntyBishop

Discussion Starter · #13 · Jun 14, 2020

I measured the primary tubes on the ARH manifolds. From the flange to inside the collector.
Pass side cylinders primary length (ARH)
#2- 17"
#4- 13"
#6- 9"
#8- 7"

The driver side is roughly an inch longer per primary.

Also, from where the primary tubes converge inside the collector around the merge spike to the ball/socket outlet is 4". (This isnt added into the measurements above).

Beast707

· #14 · Jun 14, 2020

Sub'd

vortecd

· #15 · Jun 14, 2020

Dyno numbers are cool and all but actual track times matter more to me. From what I have done with my Daytona and with my '13 mustang there isn't much there. I picked up more just doing the cat deletes alone then what the headers added. Close to 15 hp with the deletes and about 10 hp with the long tube headers. My best readings before and after with my '13 mustang with full exhaust was 40 hp. At the track it picked up about nothing. I was able to go a tenth quicker, was down 1 mph but I also put light weight wheels on it loosing 70 lbs. Ran another time after that with same results in good DA. I was thinking 3-4 tenths, nope.

There are others thinks to spend money on that will make your car go faster

JauntyBishop

Discussion Starter · #16 · Jun 18, 2020

Point being , is there potential for the ARH manifolds coupled with catless mids (mmx/sw or equivalent) to produce similar power/track times, as the same vehicle with LTs and catless? I think that is what most are wanting to see, aside from the fact of having a larger 1-7/8 header option designed to retain factory catalyst.

Also, i'm only intersted in the outcome using the stock cam profile since the majority of people will typically stop after the full bolt ons with the 392 since the next step is a huge jump in $$$, and at that point, most will upgrade to a Hellcat anyways.

Either way, i'll share my findings when I have the results.

hpindy

· #17 · Jun 18, 2020

JauntyBishop said:
Point being , is there potential for the ARH manifolds coupled with catless mids (mmx/sw or equivalent) to produce similar power/track times, as the same vehicle with LTs and catless? I think that is what most are wanting to see, aside from the fact of having a larger 1-7/8 header option designed to retain factory catalyst.

Also, i'm only intersted in the outcome using the stock cam profile since the majority of people will typically stop after the full bolt ons with the 392 since the next step is a huge jump in $$$, and at that point, most will upgrade to a Hellcat anyways.

Either way, i'll share my findings when I have the results.

Shorty or mid length will not compare to a proper set of long tubes on a properly built motor . But they will be better then stock after a certain point.

Sent from my BBF100-2 using Tapatalk

Enigma

· #18 · Jun 18, 2020

Me personally, I appreciate you sharing your findings on the replacements with us. It's refreshing to see any genuine results from someone who isn't trying to sell a product. People forget that any one add-on should be part of a systematic upgrade of the entire vehicle for a specific purpose. No one product (except nitrous or more boost) is going to make a huge difference. No header, short/long/mid is going to make the car much faster, no cam is going to do it, not even a cnc head is going to make a huge difference. But a well designed, well thought out, purposeful package comprised of individual parts will make huge gains. Even if done in stages.........exhaust here, pulley/tune/injectors there.......and so on........that's where big gains come from. I don't expect huge results just from a little larger primary tube, but I'll be following along for the results like everyone else to see them and get an idea of whether or not these would be worth including into some kind of total package. Like you, I wouldn't want long tubes either, as I just don't want to take this car that far down the rabbit hole. But these mids look like a great compromise.

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JauntyBishop

Discussion Starter · #19 · Jun 18, 2020

Plus, I'm well aware that a "proper" built header is going to outperform these off the shelf headers on a "built" engine. It's the combination as we all know.

Personally, if my budget allowed I'd have the engine built to whatever my NA intended goal was, then submit the build form that Burns Stainless offers as a starting point.

Then have Calvin Elston build my header package and call it a day.

I wish I had the budget to directly compare on my vehicle these ARH manifolds and a set of their LT. Guess when all is said and done I'd like to run against someone with equivalent mods that has LTs and catless with preferably the same tuner.

Be interesting feedback nonetheless.

Glad this is post is seeing some open minded feedback though.

JauntyBishop

Discussion Starter · #20 · Jun 18, 2020 (Edited)

I also will have to see if i still have access to Larry Meaux Pipemax software.

You input the factory 392 engine specs and it will spit out primary length, diameter, steps, collector length, and diameter for 4:1 or a 4-2-1 setups.

If I still have the access key I'll input stock 392 specs and share the build data.

Below is an EXAMPLE of what inputs and data the software provides.

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