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105 Headers Comparison/shootout!

40K views 126 replies 32 participants last post by  Jerry Ehlers 
#1 · (Edited)
Window shopping for the best sounding headers:


1. Classic Alfa


Price: $722.40
Includes gasket: ?
Ceramic option: no
Notes:


2. Centerline


Price: $379.00 / $469.00 (ceramic option)
Includes gasket: yes(heavy duty)
Ceramic option: yes
Notes: claimed “10-15% increase in top end power”

3. Alfaholics


Price: $670.80
Includes gasket: no
Ceramic option: no
Notes:

4. Vickauto


Price: 299.00
Includes gasket: yes
Ceramic option: no
Notes: 1.5” OD tube and 2.0” OD collector

5. Spruell motorsports


Price: $889.00
Includes gasket: ?
Ceramic option: yes (included in price)
Notes: claimed 3-10 hp increase
“Tri-Y design”



Anyone know which one would sound the best? Perhaps the one with the largest diameter?


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#85 ·
180OUT and alfaparticle,

2 very interesting posts. I guess it all comes down to "the best overall compromise" makes the best racing car, and if making a dead even length exhaust system compromised something else or required ugly bends, then as your posts says "relax" and find a better solution :)

I think the best race cars are designed from a grip and handling perspective, but reality is many of us spend hours chasing hp ... I wonder if we spent those hours on handling, would we have a better race car? I think so, but its hard to chase handling improvements with a beer in one hand and your mates standing around your car ...
Pete
 
#86 ·
Perhaps this is the reason the common recommendation is to use the stock early two piece cast iron headers. Practical results do show that there is only tiny benefits at narrow rpm ranges that only sometimes are suitable for a specific track. The "casties" are much easier on heating the brake fluid and steering box.

In the early SCCA club racing days I did notice that most very fast cars used the cast iron ones, just adding larger pipes beyond their connections. Fancy "bundle-of-snakes" headers are more ego than effect, and a well hit apex exit will beat all of them every day. I agree that handling will beat small HP or Torque gains often. We've all seen that fresh tires run amazingly fast, and aren't even connected to the exhaust.

I love the look of the Darstan Headers (and other similar ones), but I do really know that they don't matter for an AX or TT car, and they do roast the engine bay every day on the street times.

Robert
 
#87 ·
From the Alfaholics site:

Superb quality, unrivalled on the market for quality, fit and performance! Primary & secondary lengths and bores optimised on the dyno. With this system fitted the engine will rev much freer with higher rev capability and in the region of 10BHP increase and 8lb/ft torque.
 
#88 ·
It is easy to get a gain of about 10 HP if the comparison is with the one piece manifold that was standard from 1975 to 1989. Fitting a two piece manifold from a pre '75 or a post 89 will achieve most of that. Headers with longer primaries will usually work better than the two piece manifold at higher rpm.
 
#91 ·
I thought the shankles were loud and you lost a little torque down low by the seat of the pants.

im not sure since it was never dynoed back to back with a stock 74 exhaust mani. it may be an illusion of losing low end just because the top end was noticeably stronger. from my experience top end motors dont feel as fast as they are and low end torquey motors feel fast though they might not be.


it wasnt as smooth as the stock mani since there was such a loud racket coming from the engine compartment. it was a worthwhile addition if one was looking for more performance and a lighter system. they used to be pretty affordable to just try out of curiosity
 
#92 ·
I think unless you building a race engine the stock cast exhaust works well, the money can be spent elsewhere, IMHO ...that said,its whatever blows your hair back ...
 
#94 ·
Looks like an overpriced Spruell hybrid to me, as was previously posted converting from the single to 2 piece cast manifold is the most beneficial and cheapest way to get alot of bang for the buck. they are cheap, and as stated IMHO unless you have a screamer race engine and need the weight loss-a waste on the street.
 
#95 ·
Looks like an overpriced Spruell hybrid to me
Those are some nice welds on stainless, though. It's very pretty.

[...] as was previously posted converting from the single to 2 piece cast manifold is the most beneficial and cheapest way to get alot of bang for the buck. they are cheap, and as stated IMHO unless you have a screamer race engine and need the weight loss-a waste on the street.
Hold it! I am sure they are the value option, but this is the point where we could use some objective data, like, ya know, dyno results.
 
#96 ·
Hold it! I am sure they are the value option, but this is the point where we could use some objective data, like, ya know, dyno results
.
Looks like a good project for someone who really wants an accurate number.:wink2:
The drop in performance when Alfa switched to the one piece manifold and the dyno results published by Shankle for his headers points to a difference of about 10 HP.
That is also backed up by theory - length of header tubes, speed of sound in the pipes, rpm.
 
#98 ·
The problem with objective data is it is rarely on YOUR motor. The best headers for you depends GREATLY on the exact specs of your motor and how you drive the car. Takes experimentation to get it right.

The stock (early) header is pretty good and doesn’t crack like a significant number of aftermarket ones.
 
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#104 ·
At the end of the day.... when god judges you, to tell the truth ....can you really differentiate the difference in a street drive?
 
#106 ·
According to the table for exhaust systems at 5000 rpm a '76 made 109 HP and a 77 made 118 HP. The exhaust manifold was the same. Where did the extra 9 HP come from?
What is interesting is that the 76 had cam LC's of 114. 114 and the 77 had 102, 102. My guess is the difference is cam timing and not exhaust system.
 
#109 ·
Truth be told it takes a real pro to translate 8-10 HP in competition performance. The trick here is anyone can spend money ...but to spend it wisely takes talent and a little experience. So speaking as a fool who did all this nonsense, 5,10,15 even 20 HP on your street car means squat, seek life elsewhere. I now put money into drivability, tuning suspensions, lightning flywheels that were designed for a family sedan, synchronizing first gears, lightening the gearbox rotating masses, better braking, well-done cosmetic enhancement...ah it's just an old near 70 guy thinking out loud..
 
#110 ·
My experience is that the best improvements come from the loose nut on the end of the steering wheel. And the track time and training that takes is a lot of fun as well. When I was racing, I always noted that my last few laps were always faster than the first ones, on any track.

Robert
 
#113 · (Edited)
I have twos sets not mounted on the car and another one mounted that I can't measure. To me it looks like the inside diameter of the tubing is about 38mm. However, there is some crude porting done that is very visible on my NOS set ... and indeed 1 and 2 have the 40mm dimension top to bottom on both sets. the side to side dimension on the used set is consistently 38mm and varies from 37 to 38mm on the other set. My money is that the apparently different size primaries are attributable to the porting of the flanges rather than due to differnt pipe diameters.
I measured the .o.d. of the primaries about 5in down from the curve. I'll be happy to do some more measuring if you want. BTW: I imported these headers about '73 or '74. The guy I bought them from was pretty well connected with Alfa so I think he maybe was buying direct, although at the time Alfa stil had stocking part numbers for the headers along with most other GTA and even TI Super specific stufff that could just be ordered at any dealer.

IMO 38mm works better on the street than 40mm or above and it may significantly lower the rpm when max torque comes in.

Re: some of the comments on drivability ... putting 1600 GTA headers with a 2 1/4" GTA exhaust on an otherwise very stock Giulia Super made a huge difference in bottom-end torque and drivability ... right up there with with close ratio box, lightweight flywheel and good shocks
Coming from someone who won his class in a TI Super against some respectablly fast competition in the '08 Carrera, I'd say this is a pretty solid observation. Your secret sauce works. >:)

Sadly the GTA headers require some modification to fit a 2 liter Alfa motor. Nonetheless, they are such a good design that I've wondered why none of the vendors haven't convinced their supplier to make authentic vintage-style GTA headers that will fit a 2 liter's taller block. I bought the Alfaholics exhaust for my Super because it was stainless and the headers were GTA style and the exhaust dia was 2 1/4" or 2 1/2". I'm very happy with the way it works with my version of John Trevey's "in the style of" version of your Rally motor.
 
#115 ·
Mechanical fans move little air when you need them most - when the motor is turning slowly. They move lots of air when the motor is turning fast but then you normally have high air speed. A good electric fan will move lots of air when the car is stuck in hot traffic and it will turn off when you are moving quickly and when you can the extra HP.
It should surprise no one that modern cars use electric fans.
 
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#117 ·
Talking about primary tube diameters, look at Giulietta Veloce headers, they are absolutely tiny, does smaller diameter add a performance gain in 1300 cc engines. Most suppliers claim their headers fit, 1300, 1600 1750 and 2000cc engines, and no doubt they fit, but is a larger bore primary overkill on a small displacement engine? I know in race engines a smaller engine might benefit from bigger diameter primaries, I suspect, at least at the time Alfa knew what they were doing with veloce headers. Just wondering.
 
#119 ·
Just as a side note for the original question regarding engine note.

I finally broke in my new borla muffler and the car sounds a lot better! Especially in 3rd gear!

I highly recommend people allow 300-500 break in miles on a new muffler before making any decisions regarding further modifications.
 
#121 ·
I have a set of original Shankle headers that are over 20 years old and have done 100k miles and despite the claims in the Ebay ad, they have not rusted. Mine are well made and I would recommend them. The 10 HP gain is compared to a stock one piece manifold.
 
#123 ·
Conedriver... your post #102 comparative table...fascinating, and eyebrow-raising for many, I'm sure.

I read the notes at the end of the page.....and I'm hooked, I'd like to see is the next page or pages which would appear to offer sage advice on filters....and maybe more besides.
If you have more, I'd like to see it, and I suspect others would too.
 
#125 ·
OK. It's a thread highjack, but here goes:

The U.S. Alfa club tech series for SPICA is a 170 page compilation of all of the newsletter articles from 1969 to 1993 as well as the factory SPICA manual, but is no longer available. Obviously I don't want to scan everything, but here are the pages for filters beyond what appears in my post #102.
 

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