68 340 Exhaust Manifolds vs TTi Shorty headers

[a-bodyguy]

I agree. And it makes the motor in the manifold test absolutely meek.

are the high 10 low 11s a-body engines meek running 340 logs manifolds stock intake and carbs on 7 inch tires?
you dont need headers to be fast
ive had long tubes on my 1st 6 small block a bodys
last 2 68 70 340 logs
are they worth 800 on a mild small block nope
Do they help yes and mpg yes are they a pita 100%
can you run 10s 11s without headers yes

 

[DionR]

are the high 10 low 11s a-body engines meek running 340 logs manifolds stock intake and carbs on 7 inch tires?

My comments was only related to the 300hp crate motor used in the manifold test and that it was more than just mild. That's the only motor my comment was pointed at.

 

[Inertia]

I just know after installing true "tuned" equal length headers for decades, then working on, and installing shorties with that goofy head pipe, - I can't help but wonder why, what does it achieve?
The shorties reverse flow direction a coupla times, certainly not equal length, certainly not tuned, no "scavenging".
So my question is why.
You can get equal length tuned long tubes that DONT drag on the ground for a $100ish more than the shorties, and get something of value that's efficient, effective .
This - " there's more room " - keeps being repeated . . . . . - For what ? ?
It's not like you gotta remove the headers every oil change.
Mine have been on a decade .
The long tubes give so much better/easier access to plugs, don't burn plug wires, and actually work for other "bigger intake, displacement" additions you may want later.
There is just sooo many thousands of $$$$ thrown at heads, cams, pistons, machining, porting, intake, carburetor.
Thousands ! !
And then wimp out at headers, - cuz there's more room, blahh !

Good luck

 

[toolmanmike]

17 hp 20 lb ft long tubes vs the chit 340 logs
upgraded the 72 340 to 2.02s bowl work no cam specs made power until 5800 torque 4300

See my post #28

 

[a-bodyguy]

My comments was only related to the 300hp crate motor used in the manifold test and that it was more than just mild. That's the only motor my comment was pointed at.

My 1st comment was to toolmanmike only and then you quoted me
there is a stroked 318 390 cid 235@50 525 lift thru 340 logs 425 hp 440 torque

 

[Dart Frog]

The more air you need to move either through higher RPMs or increased cubic inches exhaust restrictions become more noticeable. There's been many tests over the years and show a progressive increase from 340 HP exhaust to shorty headers to a good full length header. I know that when I pulled off my HP manifolds and went to a good header it was one of the biggest seat in the pants improvements . when combined with a big Cam and higher gear ratio it just allowed the motor to twist up faster. Now I will say that the HP manifolds were combined with full length two and a quarter tail pipes with the typical pinch at the head pipe as it navigates the torsion bar it was definitely room for improvement there.

 

[DionR]

My 1st comment was to toolmanmike only and then you quoted me
there is a stroked 318 390 cid 235@50 525 lift thru 340 logs 425 hp 440 torque

But the quote of mine you responded to isn't a response to you at all. I might have quoted you earlier, but it isn't related to your response to me that I then responded to.

You quoted me:

Which was a response to something I said to 273.

That had nothing to do with what could be done with manifolds. You inserted yourself into that sub-thread in this post, I didn't drag you in. Just to be clear.

 

[toolmanmike]

I had a 73 340 Challenger back in the late 70's. I had some fun with it out at the local drag strip. It wasn't overly fast (9.75's in the 1/8th) but it was fun and pretty consistent. I won a lot of trophies with it. I thought why not put a set of headers on it. We had a set of Mickey Thompson Try Y's that needed to go so I put them on. It didn't go any faster than with the stock 73 manifolds. Through the full exhaust or opened up. It just made more noise.

 

[Dart Frog]

There has been many tests over the years comparing 340 HP manifolds and shorty headers versus good long tubes with the results in the same order. The more cubic inches or the higher the RPM the bigger the discrepancy. I know that when I removed my HP manifolds and went to a good long tube header it was a very noticeable improvement. When you increase the cam that's increasing the power band RPM range you just need to move more air basically the same as increasing the cubic inches combined with a high set of rear end gears the motor needs to expel the exhaust quickly to take advantage of those upgrades. I will say that my stock manifolds were accompanied by the two and a quarter inch factory pipes and it definitely crimped as it navigated the torsion bars so there was room for improvement there.

 

[DionR]

My 1st comment was to toolmanmike only and then you quoted me
there is a stroked 318 390 cid 235@50 525 lift thru 340 logs 425 hp 440 torque

I should add that I don't have a dog in the fight over whether 340 manifolds work or not. My only complaint with pointing people to the HR magazine test is that it generally results in someone saying the 340 manifolds are only worth a couple of HP over 318 manifolds so they are junk.

If the point of referencing the test is to say that they showed steady improvements as they moved up the list, great. But too many are quick to see only what the HP improvements were and assume that's all they are worth while ignoring that the rest of the combo feeds into it. If they don't have the same stock 5.9 motor, their results will be different and unknown. Maybe you can ratio it and extrapolate the data, but it's still only a guess. And most aren't doing that, they are just saying "they are only worth 4hp so don't waste your time".

 

[a-bodyguy]

Its already been done
compared 340 manifolds shorty and long tubes
as recall they were about the same as the stock 340s maybe 5hp up top down low the same
think 273 posted the vid

Installing Exhaust Headers Into 300hp Crate Engine - Exhaust Blowout ​

Read on as we dyno test our installed exhaust headers and exhaust manifolds into our Mopar Performance 300hp crate engine. Read on for more details along with photos only in Mopar Muscle Magazine

www.hotrod.com



6hp 5lb ft of torque

And as I argued here, that is a completely pointless test for anyone that has a cam in their motor bigger than a 2BBL cam. And I'm not so sure a late 60's 2BBL isn't actually bigger than the stock 5.9 Magnum cam.

You can't use that test to validate anything unless you are running the same motor. Even the best headers only made 16hp more than the 318 manifolds. For that, why spend $1K for TTI's when cast off 318 manifolds are almost as good?

The way this test is references, seems like people are wasting their money putting headers on their 408's.

That test is worthless to anyone not running a stock 5.9 Magnum or maybe a stock 2BBL 360 out of a van. People need to stop pointing to it as the Holy Grail of exhaust tests.



Here you go
you say you have no dog in the fight still not sure they work
they are members here running high 10s low 11s thats not working?

 

[DionR]

Here you go
you say you have no dog in the fight still not sure they work
they are members here running high 10s low 11s thats not working?

Read it again. I didn't say the manifolds don't work, but I did say the cam in the motor was too small. Several times.

Let me try and say it again a different way. The cam is the bottleneck in that test so the results can't be used to say anything about how good or bad the manifolds are. The results say the 340 manifolds are good for only 4hp over the 318 manifolds and 1hp over the 360 manifolds. I am arguing that because of the small cam in the motor, those results shouldn't be taken to mean that the 340 manifolds don't amount to much. I think that with a real cam, the 340 manifolds would show a much larger increase. But it's just a guess because no one knows since the motor wasn't tested with a cam with actual lobes. Is that more clear?

I'm not saying 340 manifolds don't work. I'm not commenting on the manifolds at all. I am simply saying that the magazine test shouldn't be applied to every situation where manifolds are brought up because the test is flawed. Sure, with a stock 5.9 Magnum it is a slam dunk to apply it. But for the 90% other situations, it is only a vague idea at best.

 

[a-bodyguy]

Read it again. I didn't say the manifolds don't work, but I did say the cam in the motor was too small. Several times.

Let me try and say it again a different way. The cam is the bottleneck in that test so the results can't be used to say anything about how good or bad the manifolds are. The results say the 340 manifolds are good for only 4hp over the 318 manifolds and 1hp over the 360 manifolds. I am arguing that because of the small cam in the motor, those results shouldn't be taken to mean that the 340 manifolds don't amount to much. I think that with a real cam, the 340 manifolds would show a much larger increase. But it's just a guess because no one knows since the motor wasn't tested with a cam with actual lobes. Is that more clear?

I'm not saying 340 manifolds don't work. I'm not commenting on the manifolds at all. I am simply saying that the magazine test shouldn't be applied to every situation where manifolds are brought up because the test is flawed. Sure, with a stock 5.9 Magnum it is a slam dunk to apply it. But for the 90% other situations, it is only a vague idea at best.

Other tests with bigger cam235@50 dont add much more
the heads and the stock chit carb are the choke point not the 340 manifolds thermoquad excluded
you can run a big cam and make the manifolds work by adding exhaust duration and lsa
so much for the cam being the choke point
thats how they run low 11s with logs
tunning

 

[340sFastback]

Stock 340 exhaust pipes have severe pinch driver side by torsion bar, stock 340 tail pipes small and crush bent, stock 340 chrome tips have what 1 5/8 inner diameter. Put a full TTI mandrel bent 2 1/2 full exhaust and 2 1/2 inlet chrome tips and 340 manifolds. Then compare same exhaust to headers.

Usually the comparison is manifolds with choke exhaust choke chrome tips compared to headers with full 2 1/2 mandrel bend pipes big inlet tips. Thats not a fair comparison at all.

Some of this subjective where ppl like 340 manifolds, others like headers. Doesn't matter what anyone says, some ppl like what they like for lots of different reasons.

Lower hp engines have lower exhaust flow needs then say a stroker with ported heads and big cam. So how much headers improve is highly dependent on the engine.

 

[Wvbuzzmaster]

I have real world feedback to provide on TTI shorty headers as I installed them in my 340 Duster with 727. I used the TTI head pipes and their full 2.5” H pipe dual exhaust. I paid up and bought the ceramic coated version so they would always look good, and they did up until I cleaned fingerprints off them before running, and ran the car to break in the new lifters. Within a week of the car sitting in the garage the coating on the headers appeared to rust…. Therefore looking crappy… ugh. But before that I had issues with header fitment, mainly passenger side. TTI says it fits with the oil filter direct mounted to the block, which is true… if you use a short oil filter and wish to pull the header to change said oil filter. Since I had no 90 degree factory adapter and everyone wanted $100 for a rusty one at the time I did an oil filter relocation kit instead. So then on to the full exhaust, which I had to cut and modify to remove the offset that pushed the exhaust into wanting the same real estate as the original floors… ugh. Drivers side… I am running manual steering box and had column shift, and bought the TTI Z bar, which has fully length adjustable linkage… so between it and the original trans linkage being adjustable and the throw of the shifter, plus drilling additional hole in the TTI Z bar I never could get the gears to line up on the column indicator thru the full sweep… so I went out and bought a floor shifter to shift my automatic by cable. I didn’t even complain about the oversized muffler hangers that don’t have the right angle or fit how described, so I went out and bought cheaper clamp on strap hangers for the mufflers. At the back I used TTI frame hangers. Still to this day the tips are not lined up after yet more tweaking of the pipes. Does it sound good, yes. Does it look good, better than rusty Headman Headers. Fit is ok, but nothing to write home about. If I were to do it again I would save the money and avoid TTI. I don’t know what I would go with instead. Always heard TTI was the best, and one should pay for the best… I’d like to see second best I guess…

This was my personal experience and I never called TTI with my problems, as I didn’t want to waste time waiting for their solution. It seemed clear, cut and weld… the headers fit as they said and to return this stuff would kill in shipping cost, so instead of going to war… I went to work modifying things to work…

Entire project I learned one thing, nothing advertised to fit ever fits, and everything advertised as universal fit was way easier to work with because it wasn’t supposed to fit, so no expectations of that fitting, but it did…

I am still running the TTI shorties and full exhaust, no complaints now except due to the modifications required I have exhaust leaks I need to revisit but until then, the windows are always down anyway.

 

[Kern Dog]

OR some people are never happy and choose to complain about everything....

 

[autoxcuda]

Stock 340 exhaust pipes have severe pinch driver side by torsion bar, stock 340 tail pipes small and crush bent, stock 340 chrome tips have what 1 5/8 inner diameter. Put a full TTI mandrel bent 2 1/2 full exhaust and 2 1/2 inlet chrome tips and 340 manifolds. Then compare same exhaust to headers.

Usually the comparison is manifolds with choke exhaust choke chrome tips compared to headers with full 2 1/2 mandrel bend pipes big inlet tips. Thats not a fair comparison at all.

Some of this subjective where ppl like 340 manifolds, others like headers. Doesn't matter what anyone says, some ppl like what they like for lots of different reasons.

Lower hp engines have lower exhaust flow needs then say a stroker with ported heads and big cam. So how much headers improve is highly dependent on the engine.

I thought the magazine test was on an engine dyno.

They don't run full exhaust on engine dyno's typically. And I'm sure they didn't run OE nos headpipes cut to fit a dyno.

 

[Super-Cuda]

I have real world feedback to provide on TTI shorty headers as I installed them in my 340 Duster with 727. I used the TTI head pipes and their full 2.5” H pipe dual exhaust. I paid up and bought the ceramic coated version so they would always look good, and they did up until I cleaned fingerprints off them before running, and ran the car to break in the new lifters. Within a week of the car sitting in the garage the coating on the headers appeared to rust…. Therefore looking crappy… ugh. But before that I had issues with header fitment, mainly passenger side. TTI says it fits with the oil filter direct mounted to the block, which is true… if you use a short oil filter and wish to pull the header to change said oil filter. Since I had no 90 degree factory adapter and everyone wanted $100 for a rusty one at the time I did an oil filter relocation kit instead. So then on to the full exhaust, which I had to cut and modify to remove the offset that pushed the exhaust into wanting the same real estate as the original floors… ugh. Drivers side… I am running manual steering box and had column shift, and bought the TTI Z bar, which has fully length adjustable linkage… so between it and the original trans linkage being adjustable and the throw of the shifter, plus drilling additional hole in the TTI Z bar I never could get the gears to line up on the column indicator thru the full sweep… so I went out and bought a floor shifter to shift my automatic by cable. I didn’t even complain about the oversized muffler hangers that don’t have the right angle or fit how described, so I went out and bought cheaper clamp on strap hangers for the mufflers. At the back I used TTI frame hangers. Still to this day the tips are not lined up after yet more tweaking of the pipes. Does it sound good, yes. Does it look good, better than rusty Headman Headers. Fit is ok, but nothing to write home about. If I were to do it again I would save the money and avoid TTI. I don’t know what I would go with instead. Always heard TTI was the best, and one should pay for the best… I’d like to see second best I guess…

This was my personal experience and I never called TTI with my problems, as I didn’t want to waste time waiting for their solution. It seemed clear, cut and weld… the headers fit as they said and to return this stuff would kill in shipping cost, so instead of going to war… I went to work modifying things to work…

Entire project I learned one thing, nothing advertised to fit ever fits, and everything advertised as universal fit was way easier to work with because it wasn’t supposed to fit, so no expectations of that fitting, but it did…

I am still running the TTI shorties and full exhaust, no complaints now except due to the modifications required I have exhaust leaks I need to revisit but until then, the windows are always down anyway.

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.

 

[Inertia]

It's really, really hard to have installed so many sets of headers on all breeds, have lotsa folk just return to our shop with a **** faced grin, laffing about how much seat of the pants power they feel they gained.
It continues to be interesting that serious dudes come back time after time showing time slips 2-3/10s quicker at the track by the bolt on.
When I install headers, I do much more tuning, plug change, perhaps jet and timing changes, and these dudes come back with time slips 3 - 4/10s quicker.
That's the real life improvements I've seen over dozens of sets and dozens of years.

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.

I bet it's waayyy more than 6 or 8 hp .

 

[toolmanmike]

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

I bet it's waayyy more than 6 or 8 hp .

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

 

[toolmanmike]

It's really, really hard to have installed so many sets of headers on all breeds, have lotsa folk just return to our shop with a **** faced grin, laffing about how much seat of the pants power they feel they gained.
It continues to be interesting that serious dudes come back time after time showing time slips 2-3/10s quicker at the track by the bolt on.
When I install headers, I do much more tuning, plug change, perhaps jet and timing changes, and these dudes come back with time slips 3 - 4/10s quicker.
That's the real life improvements I've seen over dozens of sets and dozens of years.

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

I bet it's waayyy more than 6 or 8 hp .

Way more than 6-8. Probably more like 25-30.

 

[TF360]

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!

 

[a-bodyguy]

It's really, really hard to have installed so many sets of headers on all breeds, have lotsa folk just return to our shop with a **** faced grin, laffing about how much seat of the pants power they feel they gained.
It continues to be interesting that serious dudes come back time after time showing time slips 2-3/10s quicker at the track by the bolt on.
When I install headers, I do much more tuning, plug change, perhaps jet and timing changes, and these dudes come back with time slips 3 - 4/10s quicker.
That's the real life improvements I've seen over dozens of sets and dozens of years.

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

I bet it's waayyy more than 6 or 8 hp .

Thats been done as well but iam not digging it up
fully built 340 heads huge cam 1 7/8 headers power band 4k and up logs lost 50 hp not really a streetable engine
392 408 416 good build 425 plus hp more torque 25 30 hp
stock 340 6 to 10 hp
could they change the cam specs and have less loss aka exhaust duration and lsa yes
you build around what logs like ift works
you build around what headers like it works
stockish 340 with logs and nitrous will suck the paint of most builds

 

[Inertia]

Way more than 6-8. Probably more like 25-30.

Agreed.
But most folk seem to feel the max gain of the headers is 6 or 8 hp

 

[toolmanmike]

Agreed.
But most folk seem to feel the max gain of the headers is 6 or 8 hp

On a stock or mildly modded 318, yes. But, they didn't start with much power.