68 340 Exhaust Manifolds vs TTi Shorty headers

[a-bodyguy]

I remember "back in the day" you would take your car to an exhaust shop and have them put your pipes on with either Headers or Factory Manifolds. The quality was terrible, and after they finished bending your 2 1/4 pipe over the Rear End, your pipe diameter was like 1 7/8 -terrible. Amazing what we have today with TTI, Dougs, Pipes etc. They are so sweet!

Back in the day you could get the 440 tail pipes as i recall they were 2 1/4 i bought those

 

[DionR]

What I'd like to see is one of these engines 408(?), all the goodies/tuned, do a Dyno and/or timeslips, THEN TAKE OFF THE HEADERS AND PUT ON MANIFOLDS/SHORTIES, - AND SEE HOW POWER/TIME THEY LOSE.

That would be a much more informative test than the old Hot Rod manifold test. Add the 318 manifolds and do the whole thing, too.

Just takes a BluePrint engine, a stack of manifolds and headers and some dyno time. Maybe someone should reach out to Holdener and see if he can pull some strings and get it done.

 

[a-bodyguy]

That would be a much more informative test than the old Hot Rod manifold test. Add the 318 manifolds and do the whole thing, too.

Just takes a BluePrint engine, a stack of manifolds and headers and some dyno time. Maybe someone should reach out to Holdener and see if he can pull some strings and get it done

That would be a much more informative test than the old Hot Rod manifold test. Add the 318 manifolds and do the whole thing, too.

Just takes a BluePrint engine, a stack of manifolds and headers and some dyno time. Maybe someone should reach out to Holdener and see if he can pull some strings and get it done.

Its been done 15 or 20 times over the last 25 yrs
you are beating a dead horse

 

[Super-Cuda]

Here's a pic of the 2.5 Adapter pipes TTi supplied with my shortie headers.

Very well made, fit is excellent with no dimpling or hammering required.

Easy install when done according to TTi instructions.

 

[Inertia]

Its been done 15 or 20 times over the last 25 yrs
you are beating a dead horse

I'd really appreciate a link to one, never seen stock manifold as the last test, after all the other improvements stepping up, then choking it with a stock exhaust manifold.
TIA .

 

[Inertia]

Another aspect overlooked with long tubes is just fuel mileage.
Headers make the engine more efficient, you need less gas pedal to drive, accelerate.
I wonder if there is any test of a daily drivers fuel consumption before/after headers.
Just normal driving.
If you consider your fuel saving daily with gas @ $5.00 a gallon, I wonder how long it'd take to "pay for the cost of headers", or the difference in type of headers, thru fuel saving.
Just musing . . .

 

[273]

That would be an interesting flip side to the testing of a basic stock 318 with manifolds, shorties, and then headers.

There's 2 dyno's of a stock 2bbl 318 (dyno trim) that I know of, but they only tested them with headers and made about 190 hp each, how much less with manifolds hard to say but I imagine would be around 10 or so hp less.

 

[Inertia]

There's 2 dyno's of a stock 2bbl 318 (dyno trim) that I know of, but they only tested them with headers and made about 190 hp each, how much less with manifolds hard to say but I imagine would be around 10 or so hp less.

That's kinda the "general guess" that's repeated thread after thread .
I would think a percentage would be more accurate to allow for engine size, hence the problem.
Hemi or 6 cyl, lol

 

[273]

That's kinda the "general guess" that's repeated thread after thread .

Most of this **** is a guess, unless you do your own manifold header shootout on your exact combo in car, it's varying degrees of guesstimation.

All we can do is take the few examples of various manifold vs short vs long vs diameter and make best guess. And as much as DoinR say the test is invalid it pretty much resembles what's happing with the other test out there, would it be better on a more built engine sure.

The 427-443hp LS I posted #41, 4.8l with heads and cam made manifolds 427hp, shorties 433hp and long tube cheap and expensive 443hp. Make what you will from it.

 

[DionR]

And as much as DoinR say the test is invalid it pretty much resembles what's happing with the other test out there

It's not that the test that is invalid, it's the application. What bothers me is when people point to that test and say things like "340 manifolds are only worth 6hp over 318 manifolds" without factoring in differences in the builds. That's what I rail against.

Absolutely, the test reflects what other tests have show with a steady improvement for the most part. Nothing wrong with the test there.

Use a ratio or something, but don't say this test reflects the actual HP difference on a completely different motor.

 

[Wvbuzzmaster]

Not my experience at all .

I bought the same system as you, including X-Pipe ,down pipes , shortie ceramic coated headers, hangers and the stainless steel tips I got from Accurate exhaust products as suggested by TTi.

A call to TTi would have saved you a lot of headaches as that's what people advised me to do so I did.

Extremely helpful!

One major suggestion by TTi was to mock up the complete exhaust system on the floor before installing it.

I did this and boy-oh-boy am I glad I did!

Its so much easier to adjust the ends of the pipes so they slip together easier on the floor than when its mounted under the car.

Also, they advised to mount everything under the car and leave the clamps loose while adjusting tip location as clamps are tightened.

7 years since installed and system looks new and performs very well, no leaks.

TTi for me from now on.

Glad your experience was better. You bought the X pipe kit and I bought the H pipe kit. No amount of mock up on the floor would reveal the interference of the pipes with the car floor, or any other adjustments required to fit the car (I had it mocked up). The kit did not work out of the box, so I modified it to fit… (cut the offsets out of the pipes to get it away from the floor). But to have the ceramic headers tarnish after the first use (break in of cam and lifters) was the bigger disappointment because I read the warnings and cleaned any oils and fingerprints off before staring the engine the first time. I am not saying never again on TTI but I will not be quick to just “buy once cry once” with their products… that was not my experience.

 

[RT Dude]

In August reproductions will be out $850 Steve ivester

Is there a release date on the reproduction manifolds?

 

[Duster360LA]

Just a note on TTI shorties. I am putting a set in my 74 Duster (360 with a Tremec TKX) and am making mods to my zbar and clutch fork to get enough room for the DS adapter pipe to fit between the clutch linkage an torsion bar. Had to get a short clutch fork in the hope that it provides needed clearance.

 

[WymanV]

My 340 didn't come with any manifolds so when it came to exhaust I opted for the TTI shorties since either option was going to be pricey and I'll go with the performance bump (and sound) of headers. It's a 4 speed car and the fit of the extender was a little tight on the left side but it was certainly doable.

And totally worth it

 

[toolmanmike]

My 340 didn't come with any manifolds so when it came to exhaust I opted for the TTI shorties since either option was going to be pricey and I'll go with the performance bump (and sound) of headers. It's a 4 speed car and the fit of the extender was a little tight on the left side but it was certainly doable.

And totally worth it

View attachment 1716444250View attachment 1716444252

I changed my mind about shorties. The early ones were pretty universal and only worked on trucks and street rods. Those look like they fit quite nice.

 

[Super-Cuda]

Glad your experience was better. You bought the X pipe kit and I bought the H pipe kit. No amount of mock up on the floor would reveal the interference of the pipes with the car floor, or any other adjustments required to fit the car (I had it mocked up). The kit did not work out of the box, so I modified it to fit… (cut the offsets out of the pipes to get it away from the floor). But to have the ceramic headers tarnish after the first use (break in of cam and lifters) was the bigger disappointment because I read the warnings and cleaned any oils and fingerprints off before staring the engine the first time. I am not saying never again on TTI but I will not be quick to just “buy once cry once” with their products… that was not my experience.

What I was referring to by mocking up on the floor was to ensure the pipes slip together easily. I had to open up the ends a little in order to get more "wiggle room " once the pipes were in place. No issues after doing this getting everything properly aligned.

Also, what did TTi say about the tarnishing?

I have 8000 miles on mine and they look like they day they were installed.

 

[jrc4y4]

What I was referring to by mocking up on the floor was to ensure the pipes slip together easily. I had to open up the ends a little in order to get more "wiggle room " once the pipes were in place. No issues after doing this getting everything properly aligned.

Also, what did TTi say about the tarnishing?

I have 8000 miles on mine and they look like they day they were installed.

Yeah I’m curious too. That looks how mine went after the VHT came off. With coated headers I’d be pretty upset.