Stock Exhaust Manifold vs Shorty Headers +++ WHICH TUNER?

tjm73 said:

The day of cheap and easy "dirty" increases of power is winding down. The sun is setting on that. While not as cheap, the good news is we can make bucket loads of power and still be clean these days.

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Yup! Throw that CARB legal blower on there and melt some rubber..legally? Except for the the traffic laws... lol
Or wait 25 years before modding...hehehe

Juice said:

The short answer is, no computer modification, no check engine light. So shorties are overlooked by inspection.

Once they start checking for tunes installed, we are screwed. Funny thing is, it is actually legal to make some modification to the tune under some circumstance. SCT is the only company right now that is emission legal, as long as the end user keeps the OBD/emission stuff unaltered.

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Shorty headers aren't a problem because the stock mid-pipe and cats can be retained, and a tune isn't a problem as long as the functionality of the O2 sensors and other emissions monitoring systems remains enabled.
The days of cheap and easy "dirty" increases of power are indeed winding down, but only because engines are becoming so efficient that manufacturers are leaving less under the table.

About 7 or 8 years ago, around the time the 5.0 DOHC arrived, I told a friend of mine that cars are soon going to be like motorcycles. We were discussing his old 2001 GSXR1000 at the time. He looked at me a bit puzzled. So I explained my thought better. We are fast approaching the point where making tweaks and changes to factory engines is near fruitless. Major improvements will require unnatural aspiration or seriously expensive complete rebuilds that most people will not be able to stomach. It'll be mufflers for sound and call it a day, or a turbo/supercharger and call it a day. Just like modern motorcycles. They are so capable and powerful you don't need to modify them much anymore. Think about the refinement level that delivers 460-480hp from 302 cubic inches. It's hard to really improve on that.

And yet ppl stil put turbos on Hayabusas. 'cause 160 at the wheel is so 'lame'. roflmao

I've been following ths post and I am also considering shorties for my 07 NA GT. It has a 91 octane tune and SLP 1 Axlebacks the rest of the exhaust is stock. What will shorties do for me, any more power or just a deeper growl ? Sorry don't want to highjack anyones thread its just a question on the same topic. Thanks

Monkeyporn said:

I've been following this post and I am also considering shorties for my 07 NA GT. It has a 91 octane tune and SLP 1 Axlebacks the rest of the exhaust is stock. What will shorties do for me, any more power or just a deeper growl ? Sorry don't want to hijack anyone's thread its just a question on the same topic. Thanks

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Your answer is in post #37.
I have a pair of JBA replica shorty headers that I haven't yet found the time to get installed.

Monkeyporn said:

I've been following ths post and I am also considering shorties for my 07 NA GT. It has a 91 octane tune and SLP 1 Axlebacks the rest of the exhaust is stock. What will shorties do for me, any more power or just a deeper growl ? Sorry don't wantot highjack anyones thread its just a question on the same topic. Thanks

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Your answer can also be found on post #25.

Dino Dino Bambino said:

Your answer is in post #37.
I have a pair of JBA replica shorty headers that I haven't yet found the time to get installed.

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I was wondering if you'd installed those by now...………………………………. You know you wanna so go on & get dirty!

The Covid-19 lockdown certainly delayed things so I only took care of essential maintenance items during that period. It's an itch that I'm certainly going to scratch at some point.

I had titanium ceramic coated JBA LT's installed on my 2010 (with M90 blower) years ago..along with the 62mm tb, and a VMP 94 tune. Difference was night and day. With the blower on 2 blocks from the driveway, lift the hood, and I can push down on any of the 8 primaries with my fingers..and hold em there. Everything else under the hood will take your fingerprints off.

With the LT's coated both inside and out, I have this theory that the internal gases are hotter. On paper, the hotter the exhaust gases are, the faster they will flow, which might just add to the total effect. The JBA LT's are longer than kooks. More tq down lower, but still loads at the top end. It wasn't some subtle difference either..it was blatantly obvious, pulls like a mofo. Plan B was to just use a smaller blower pulley.
But the LT's work good, whether in blower or NA mode. Most of the time I'm not into boost, so they were a good, albeit expensive, investment.

I’ve been running Kooks headers for 10 years. Normally aspirated and now with the blower. I chose them for there reputation of quality. The mistake I made was not planning for the heat they radiate. Should have had them coated or at least wrapped them last time I had them off.

Anyone that uses the search function on this forum would easily find that shorty headers and bama tunes are a waste of time unless you want to run rich, sputter or blow your shit up


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I can't help but wonder if extrude honing the stock manifolds could help with a turbo setup to decrease backpressure pre-turbine.
I'm probably better off trying to fit a 3 1/2" or 4" downpipe rather than worrying about anything pre-turbine though.

The iron manifolds would be better at holding heat in for the turbo.

Midlife Crises said:

The iron manifolds would be better at holding heat in for the turbo.

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The extrude hone process takes the iron manifold and pushes an abrasive media through it to remove casting flash and has some ability to round sharp corners. It is still the same manifold.
It was quite popular before CNC machines were common as it could reach areas in cylinder heads and exhaust and intake manifolds that were not possible to reach with conventional porting methods. On long runner aluminum manifolds it was capable of enlarging the cross section of the runners and leave a nice smooth wall on the runner as well.

Extrude hone is expensive. Hellaexpensive. It was almost a grand to port an intake 15-20 years ago.

I'd question it's value on anything but an all out race car and at that point you'd build custom manifolds anyway.

This car made 850 whp through stock manifolds. EDIT: sorry 950whp. The manifolds are not going to be the place to spend money.

http://www.mustangandfords.com/feat...d-mustang-lx-bringing-home-the-canadian-bacon

A problem with pumping abrasive through a manifold for porting is it cuts metal from the wrong places. Example would be, on a sweeping bend material is removed from the outside of the curve where the highest flow is. When porting by hand or CNC material would be removed from the inside of the curve to even the flow through the entire area which will allow more total flow through the port.

Midlife Crises said:

I’ve been running Kooks headers for 10 years. Normally aspirated and now with the blower. I chose them for there reputation of quality. The mistake I made was not planning for the heat they radiate. Should have had them coated or at least wrapped them last time I had them off.

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I had my Kooks coated and they still run hot as hell.


FWIW, I did an unscientific experiment to show difference between LT`s and stock 05 manifold for anybody who is interested.

Laga said:

I had my Kooks coated and they still run hot as hell.


FWIW, I did an unscientific experiment to show difference between LT`s and stock 05 manifold for anybody who is interested.

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There is ceramic...and then there is ceramic. Cook top stoves are sometimes ceramic coated..and the heat from the 4 x burners sails right on through. Natural gas hot water tanks, the high eff types, use a 2-3" diam, spiral wound, copper tube for the exhaust. They are ceramic coated, both inside and out. Heat from the inside..passes right through both ceramic coatings... heating the water. I suspect if the ceramic layer is thick enough, it will severely restrict heat conduction.

If it's just a paper thin coating, it won't retain heat.

You’re right. I think the place that did mine did a poor job. You can see the scratches on the headers in the video. ( the result of a 3 YO grandson helping, LOL) Would do it differently if I had the chance.