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I recently acquired a low mileage '88 Spider Veloce. It's mostly been a California Car, but was back East for about 3 years. The owner in the East installed headers and a different CAT. When the owner I bought it from here in CA had it smogged, he had to remove the hearders and cat to restore it to our silly standards.
He included the headers/cat in the sale. I have two years until the next check, and was thinking of putting them back on.
My wife & I are now retired in N. Calif. and this car will just be our fun, backroads weekend car.
I cannot identify whose headers they are, but they seem well-made.
But will I notice THAT much of a difference? This car already runs sooooo much better than my twp prior spiders!
I am conflicted between installing...or putting 'em on eBay.
 

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I believe that the difference is about 10 HP. Alfa used a very restrictive exhaust manifold from 1975 to about 1990 in order to reduce NOx emissions. Prior to 75 the limit was 10 times higher and I think that they were able to install a decent manifold again when they switched to a 3 way catalytic converter on the S4 cars. Many other manufacturers used more complex EGR systems to achieve the same ends.
 

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Just to give you my experience. On my previous two 105's, both coupes fitted with 2 ltr engines, I fitted the "GTA" type manifold & system.
I thought they were ok, but didn't have anything to compare them with.
My current car is a '63 Giulia Ti Super Replica, fitted with a fairly standard fresh 2 litre, and an original cast manifold and standard 2 litre system.
All I did was match the manifold to the head, and the thing breathes better & revs more freely than either of the other two.
I won't ever buy another Alfa fancy exhaust manifold & system if I'm under 160 bhp.

Steve
 

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I believe that the difference is about 10 HP. Alfa used a very restrictive exhaust manifold from 1975 to about 1990 in order to reduce NOx emissions. Prior to 75 the limit was 10 times higher and I think that they were able to install a decent manifold again when they switched to a 3 way catalytic converter on the S4 cars. Many other manufacturers used more complex EGR systems to achieve the same ends.
1990 is when the Motronic system came out. Alfa went back to the 2 piece euro style cast iron header like the 1974 and earlier cars.
 

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Richard Jemison
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Discussion Starter #9
"1990 is when the Motronic system came out. Alfa went back to the 2 piece euro style cast iron header like the 1974 and earlier cars."

"Yep, that`s when the severe restriction in the exhaust was cast into the exhaust port just outward of the seat/bowl in the area of the guide. In fact it started about 1989 when the motronic head design still utilized the L-Jet FI."

I am trying my best to see how these responses directly address my question, but logic fails me. Someone help me out....
 

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You should notice the difference if they are well designed headers. IAP sold some with the Tube welded at 90 degrees to the flange and they did not flow very well. If yours look like the primary is at an angle to the flange then they are probably decent ones. I would at least give them a try and see if you like them.
 

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Posting a picture of the ones you have would help.
 

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Richard Jemison
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Headers

Headers of any sort will offer little without a properly constructed header back, low back pressure exh sys.

You have Alfa`s weakest performing Boulevard cruiser. They stopped being sport cars about 1975 with more weight and body reinforcements, emission device choked engines and comfort do-dads.

Likely your `88 is making only 85HP at the rear wheels.
A 10 HP gain with headers and exhaust system would be a noticeable improvement. BUT, you`re in California, and the State forbids such callous disregard for their already fully polluted atmosphere.
 

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But Mad North-Northwest
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You would have to be asleep to not notice a 10 HP gain on a 110 HP motor.
 

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But Mad North-Northwest
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A header change on an '88 isn't going to get you 10HP. The Motronic 2-liter only had ~10HP more than the L-Jet, and that was with a reasonably decent 4-into-2 cast manifold, higher lift cams, more ignition advance, higher compression pistons, and using higher octane gas. Just slapping tube headers on an L-jet car isn't going to do much at all.

I mean, if I were in the same position as Lawrence and lived in a state where I could use the headers I'd slap them on for whatever benefit they have. But having to swap them out every couple years for CA smog? For a couple HP? Fugghetaboutit.
 

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Headers give you a better take off. No top end. Exhaust also provides just the same. For example I have 2 GTV-6's one with headers and one with Euro Down Pipes and I'll take the Euro Down Pipes with the original case iron manifolds any day. What a sound and just as fast.
 

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Shankle's catalog shows dyno data for his headers versus the very restrictive manifolds that were used from 75 on and the improvement is more than 10 HP. The output of Alfa Nord motors dropped dramatically from 74 to 75 and that was largely due to the exhaust manifold. Alfa deliberately strangled the exhaust and the incomplete scavenging enabled them to get the NOx numbers down. The same restrictive manifold was used on the L-Jet cars with the same results. Dyno data proves the loss of power when scavenging is compromised.
 

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Discussion Starter #18
Here are the headers in question. They were in the trunk when I bought it. Any idea whose they are?
BTW...I am not nearly as interested in the peak HP as much as I am what it will do to the torque curve.
Remember: "Horsepower sells motors...
Torque wins races"
 

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Alfasrule: short pipes from the exhaust port to the point where they join causes interference between cylinders and the pressure from one cylinder inhibits the scavenging of the other cylinders. This gets worse as rpm increases and the whole manifold becomes pressurized. Alfa did that on purpose to lower NOx emissions. The two piece manifold that was used on Nord engines prior to 1975 had individual primaries that are long enough that the cylinders do not interfere up to the power rpm of stock motors but they are restrictive at higher rpm. That is why Alfa designed tubular headers for the GTA. Low down power is of little consequence to race engines but they all have headers.
CSC headers enable V6 engines to make more power. They are one of the reasons that my GTV6 makes 214 HP at the wheels - over 250 at the flywheel.
 
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