vetteguy75

Just how good are the Ram's horn exhaust system? I figure the engineers in Detroit had to take the performance of the exhaust system into consideration when they built the Corvette. Are full headers really that much better? What advantages does long tube headers have over the stock Ram's horns? Inquiring minds want to know....

mar

The question might be better stated: "How bad are they...?" they are probably ok for 98% of the uses they are seeing out there.

bucky-katt

after milling a few thousandths off the mating surfaces on mine, they bolted up with no sealant and not a single leak. no blown header or collector gaskets to worry about. headers arent necessary for most street driven cars.

HamadUP

I don't know how good they are, but I heard that they flow much better than the other stock sb manifolds.

3rd_Vette

They are just fine unless you care to go one step further and find a set of SHORTY GM Headers that were STOCK on the LG4 Calif 1980 and the 81 Vette.. Just so happens I have a nice set sitting on the shelf! They are a direct bolt on where the cast ram horns are.. Complete with the A.I.R tubes intact.. Chevy put them on the LG4 to help boost the HP in 1980 on the LG4 motor.. If I had to have a smog pump on my 1979 L48, i would install them, but my car is exempt, not to mention I live in Oregon and NOTHING requires a smog inspection here!

bucky-katt

are those still available as a repro or oem part? sounds like they might be the trick. i could mill off the bungs for the A.I.R. tubes and fill the holes with weld.

3rd_Vette

They have been discontinued for 25 years! Another GM mistake.. I searched forever to find an extra set for my 80 and finally scored 2 set's. One on Ebay. Now, I have sold my 80 and one set is still collecting dust on my shelf. They are VERY RARE..
I sold one set a month ago and still have one left. This set has one broken stud, but is an easy fix.

jb78L-82

The ramhorns are OK but any header is an improvement over them but as others have stated they are probably OK for most people if you are not interested in maximizing the HP potential of your engine, regardless of how much HP the engine currently has.

As noted above, another GM mistake discountinuing the 80-81 (not sure if the 82's had them) tubular exhaust manifold above. These manifolds above look almost exactly like my McJack's shorty headers that I have on my 78 L-82 except my primaries look slightly larger-I paid $495 for my ceramic coated shorties since I wanted a shorty header that would hook directly up to the stock type duals and had the same dimensions of the OEM ramhorns in a shorty header. I have always been aware of the 80-81 shorties from GM but opted for the McJacks due to the slightly larger primaries, ceramic coating, and air tube issues (don't need or want them, but obviously easy to plug).

So do the shorties help with power over the ramhorns-Yes, in the mid to high RPM range-3,500-6,000 RPM-no change down low. Another example, I replaced the tubular exhaust manifolds (they are Ford's version of the manifolds above) on my 1994 Mustang GT with BBK shorties that are very similiar to the OEM Ford manifold but have larger primaries than the OEM tubular exhaust manifolds. So in this case, going from OEM tubular to aftermarket shorties-any difference? Again, yes. No other changes to the exhaust on the mustang other than the BBK shorty header swap. The exhaust sound immediately was louder (more airflow). Alittle loss of low end grunt but, again, a pickup in HP in the mid and especially the high RPM where the 5.0 liter previously really fell on its face.

Lastly, the only real difference between a 78, 79, 80 L-82 was some slight exhaust changes-better mufflers in 79 versus 78 (220 HP to 225HP) and very slight changes in the exhaust configuration and the tubular exhaust manifolds from 79-80 (225 HP versus 230HP). I figure my Mcjack's shorties are worth about 10 HP on their own, maybe 15 HP with a complete high flow exhaust. Just my 2 cents based on my experiences!

redwingvette

Covette Fever Mag did an article about building an L-48 motor to add 150HP back in 1996. The point of the article was to build the motor but keep it looking totally stock on the outside. Anyway, when they were done they put the motor on a engine dyno and ran it with both headers and the stock exhaust system. They only gained 3HP with the headers. The motor made top HP at around 5500rpm's. I have the article still if anyone would like to see it.

daanbc

redwingvette, sent ya a pm on that.

jb78L-82

I have been getting Corvette Fever (now called Vette) since the early 80's so I am sure that I saw that article. Unfortunately, there are other articles that contradict this one so who knows who is right. Were the full length headers versus the ramhorns tested with a full exhaust versus no exhaust? It appears that they were not hooked up to a full exhaust system since the engine went from build to dyno after a 20 minute breakin. There will definitely be a big difference in HP gains if both were tested with a full exhaust versus open headers/ramhorns. However, I agree and figured out a long time ago with my 73 Nova SS that long tube headers are just not worth the trouble, road and engine clearance issues, lack of any big gains in performance on the street, thus my preference for shorties on the 78 vette and mustang GT.

The article confirms my comments above about the 80 L-82 with shorty headers having about 5 more HP than the 79 L-82 with ramhorns. I think the consensus in the motor world is that some type of header will help your engine. I have real world experience with not one but 2 examples of shorties on V8's.

You may want to read this about headers and why most high performance cars use them. I can assure you that engine/car manufacturers would not go through the expense and trouble of designing and fitting headers on engines if there was no benefit on the street.

http://www.sandersonheaders.com/Lets-Get-Technical.html

mrvette

IMO, the problem with rams horns is the stupid spark plug routing, that stock vette under the engine layout flat sux.....no way around it, clearing a orange glowing rams horn exhaust is not easy....I did it with my initial TPI conversion on the L48 in my '72....so with a good closed loop system, they get hot, and in the two years there seemed to be some strance checkering on the iron surfaces....dunno what that meant, really....

but I switched to headers....Schoenfeld #151 which clear everything fine, but you maybe need some ceramic boots on the plugs...

those headers ran me 150 bux...but that was over 8 years ago too....

The owner there told me that as soon as you cap any exhaust with a long pipe, much less a muffler of ANY type, you have lost the effect from the header.....that much makes total sense to me.....

so it's a matter of style and convenience....

Imo Apita

Brzezinski Racing makes a stock looking cast ported Ram Horn.
He's even mentioned in one of Vizard's books:

http://www.castheads.com/corvette_systems.php

Taijutsu

I couldn't help but notice that the heads were stock w/big valves, and the intake was a performer. Not much performance potential there!
They did improve the flow and the HP/TQ. Now if they added some aftermarket heads and an AG to take advantage of the bigger cam, I'm sure the headers would help more. JMHO
I have wanted to see a back to back on a strong engine "Over 400 HP".

R

jb78L-82

Those cast iron manifolds are very cool and a great alternative to shorties. I might have considered them over the Mcjacks if I had known that they existed at the time although the McJacks really are a work of art! The Brzezinski cast iron ported manifolds are not cheap either at about $400 for a set-4-8 HP gain over stock ram horns which again confirms my suspicion about McJacks giving me around 10 HP! Thanx for that link since I learned something new on this thread.

bucky-katt

i've just found that Patriot Exhaust Products makes a mid-length header that fits the C-3 small block cars. theyre shown in the ad as for the tri-five chevies but under application theyre stated as fitting the C-3 vettes, both manual and automatic, power and manual steering. the mid length headers give you the power increase of a long-tube but without the ground clearance hassles. they have the standard 3 bolt collector flanges. the mid-length headers have been really popular with the modern performance car people. i can tell you that i got another 15hp at the wheels over the equal length shorties i had on my mustang when it had the 408 (351w) windsor motor in it. gains would likely be less for a real street driven car but theyre only around 300 dolllars for the ceramic coated ones. i may end up going that route with an x-pipe and an Allens chambered exhaust for my 78. it got me pretty excited to see the mid length headers for these cars, they really ARE worth the money, i'd have them over long tubes any day.


http://www.summitracing.com/parts/PT...TE&prefilter=1

Darrell's 68

Interesting thread, I would have thought I would see a bigger hp benefit from full length headers vs ram horns.

bucky-katt

only at higher rpms, with a loss or torque down low unless you have nice small primaries.

Solid LT1

My 72 LT-1 ran 12.60@113MPH with a set of ported 2.5" rams horns, next year with Hooker Super Comp headers 12.28@117MPH at same track no other changes but exhaust. Spent a lot of time on those manifolds and broke $90 worth of carbide burrs porting them. I offered them to a friend of mine for $400 but he bought Chinese copies, I now have found a new home for them on my wife's Vette (they are a family heirloom)

Sigforty

It really depends on cam sizing and valve sizing. Those two help determine the exhaust optimal sizing and where the exhaust pulse would want to exit. I think if you get a good cam designed to work with the manifolds the results would not be as big of an improvement when switching to headers. Now on the other hand if you had a cam that wants more exhaust volume and bigger runners it could very well see a big improvement switching to headers.