header options and performance gains...

fiatmonkey

fiatmonkey

Tim Hoover
:hmm:

Hi,

I have had many discussions on just what is the best performance style header for an X.

I hear that a 4-2-1 is better for low end while 4 - 1 is better for high end. I know there is a lot of wiggle and of course engine mods come into the picture however for a modest to near stock engine? And could there be a header/exhaust system that sort of meets in the middle? For example a LONG header system like Vick's could be a compromise?
X19%20nickle%20header.jpg


Curious what others think.

-T.
 
Well...

A header is part of a package. It will help over stock exhaust but cam timing, intake manifold and upgrades over stock to fuel delivery all make the package. Over stock, maybe you will gain a few HP and some higher RPM. You still need the other items mentioned above. You will see more HP gains in changing the camshaft and or increasing fuel delivery than what Headers will give you. Increased compression is also be a bigger gain than just headers. In my car it was the last part of the package, 4 into 1 that sees higher rpm's and shorter time in getting to the high RPM power band.

TonyK.

Grimsby Ontario Canada.
 
My setup.

34 DMTR Carb
Ported head and intake runners.
37/75 Faza cam

My exhaust is a stock 74 4-2-1

DSC_2396.jpg


I still need to do some carb tweaking but so far the it pulls nicely from 3-7k
 
you should read my thread on dyno results with our new header system. We documented peak 10% hp and 15% torque gains with a completely stock motor, but nearly 15%hp and 20% torque gains in the upper rpm range where the stock curves fall off dramatically. Our stepper design eliminates the need for long tube headers, so our system has great ground clearance.
And those gains were with a catalyst in place, and it fits ac equipped cars
 
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Well, any way you look at it...

That header sure looks purrrty!
I'm thinking about Allison's header as my first choice down the road, but that one surely would be a close second!
But, I also agree with TonyK's thoughts about pushing the performance envelope by porting the top end first.

This doesn't discount what you've got there by any stretch. It's a great addition no matter what. Thanks for posting!

Bling-bling!!
 
I ordered one of Allison's headers ceramic coated - since I'm doing the head & a cam, I just couldn't see putting a cast manifold back on. Looking forward to the performance improvements!
 
Getting rid of the stock single outlet exhaust manifold, even on a totally stock motor, will make a noticeable difference to the output.

While some aftermarket headers are definitely more for "show", and others are made more for "go", the stock twin out manifold has most of the go for a fraction of the cost...

I've said it before, but looks like I need to say it again...

128 coupe 1300cc euro spec has 75hp
128 rally 1300cc euro spec has 67hp

Both engines are basically the same, same cam, same CR, same carb, same capacity, same inlet manifold, same ports, same valve sizes ... (you get the picture)

They are the same EXCEPT for one thing... the exhaust manifold.

The 128 coupe uses a twin out manifold and associated twin pipe front downpipe.
128 rally uses a single outlet manifold and associated single front pipe.

If you change you X19 from a single outlet manifold and frontpipe to a twin outlet manifold and dual front pipe it changes the engine, letting it rev easier, and harder.

I've changed the manifold (for female customers) who were tired of the single ball fitting working loose and sounding like a tractor... they all noticed a considerable improvement in performance, and this is from women drivers!!

So find a manifold from a (for you in the USA) from a 1974 or even a Yugo, and have a front pipe fabricated from a Yugo front pipe to fit your existing system, it's the cheapest HP you'll ever get.

1500 twin out exhaust manifolds are a little better in the port size than the 1300 twin out types, theres a guy on ebay selling new euro 1500 manifolds at the moment, freight from Germany is probably a bit of a killer though...http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=370401575177&ssPageName=STRK:MEWAX:IT .. no connection to seller, just posting for reference.

SteveC
 
I also have to agree there is an immediately noticeable difference. My car is bone stock and I feel the car pull and rev out better.

Perhaps the HP to H/W seems low to some but I can say that a DIY'er with a little experience, could do an exhaust/header install if they have something bolt on or close and see the gains within minutes of install. Although with engine mods you will see a greater level of performance gains, Installing a new cam, ported head would take more skill IMHO. Not saying one over the other as they do compliment each other but perhaps for some if an exhaust upgrade will get you 3-5 HP(?) or in Steve's example 8HP and you don't want to monkey with the rest of the engine then why not?

Thanks,
-T.
 
ceramic coat

what ever you buy before you install. we had to take ours out and jet hot it to keep temp down. costs a few bucks
 
here are pics of our new header and system with ceramic coating. The flanges are now cnc machined. The entire system with a catalyst only weighs 25 lbs, without the cat just under 20 lbs.








 
Nice!

Thanks for the pics - I was assuming mine would be white like the pic you had previously - that looks much more purdy! :grin:
 
It's a beauty for sure...

So, as pictured, (looks complete!) How much for the package?
 
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