Does anyone know how good the stock exhaust manifolds on our cars are good to? Does anyone know why replacing them with longtubes or tubular exhausts make them "seem" to respond better? Has anyone read any articles from lingenfelter or callaway? Here is why---its in the y-pipe!! The stock cast iron manifolds are good up to 450 horses; after that they flow like crap!! I spoke with Callaway and lingenfelter techies and they told me the supernatural and the modified vettes run STOCK manifolds into a custom catback only? I was told to replace the y-pipe and put a catback on unless I was pushing over 450 horses! I was going to go with headers but even in my years of experience with camaros I knew I could take that hundreds of dollars and invest it in places that make more of a bang for the buck like nitrous or a supercharger--look 1200 dollars for FLP headers that give you .3 off your et at the most compared to a 100 horse shot of N20 that knocks a possible 2 seconds off!! I will say your engine compartment does look nicer with a set of good headers but I want speed not looks. If you look at my pics in my sig you will see that ugly orange camaro that people laugh at until I run 10.3@127. My 1994 I will be keeping totally stock looking so people can come up to me like look at this stock appearing car adn I waste them in a heartbeat!! (I'm off topic) Before you dish out hundreds and thousands of dollars make sure you research very good what you plan on doing or buying and get every opinion and book possible!! Knowledge is power not a fat checkbook. The money I was going to spend on expensive headers will be spent in other areas UNTIL I get to 450 horses, then I go and buy those headers but then again at 450 horses I would need 1 3/4" and not 1 5/8"@650 dollars!! This is not a bash in the least, I hate seeing people fall victim to over rated hype since I see it all the time. Please no negs back at me sice I am educating people not bashing them

 

i always thought one of the main differences between corvette engines and the engine in the coinciding camaro was a slightly bigger cam and free-er flowing exhaust manifolds...

so i guess my question is, just becuase the corvette manifolds can "support" 450 hp, does that mean that the camaro style ones can?

another thought...even if they can "support" that much hp, you aren't honestly telling me that you'd lose ZERO hp up to 450ish by using stock manifolds and some miricle Ypipe? i'd be willing to bet that you'd lose a little, say 10-15hp...granted not alot (being generous), but definatly something i wouldn't mind having for an extra $500 worth of headers.

just my thoughts...but i think your interpretation of those "miricle ypipes" is a bit off skewed

 

I disagree. Too many people are seeing 30rwhp gains with headers. This may be true in Vettes, but not F-Bodies.

 

That's the key point here, isn't it? Certainly tube headers are effective at increasing the power production of an engine. If you measure every modification by the hp per dollar, then no doubt nitrous can exceed any other mod since a 250 hp setup costs the same as a 50, aside from the cost of the N2O itself. But headers do not accelerate wear the way most other engine modifications do, and they enhance the effects of other mods that improve the engine's airflow abilities (cams, port work, etc.).
If you are only measuring hp/dollar, how much more will it cost to get to that 450 NA hp point without headers? How much will you sacrifice in driveability because of a bigger cam?
As far as headers "seeming" to make cars more responsive, I noticed an obvious improvement in top end power when I installed mine. And they are only 1 5/8 shorties. I can only imagine that 1 3/4 pipes are an even more dramatic improvement.

 

grygst76

You've over looked one critical point. Since at least the 80's all Corvettes came with tubular exhaust headers not cast. They are very reminiscent of the classical Headman Headers. The ZO6 has titanium tubular headers. These headers flow every well and are one of the main reasons that Corvettes have higher stock hp ratings.

 

The Callaway Supernatural LT1 Camaro with a 383 also ran 13.1 in the 1/4 mile in Car And Driver Magazine in late 1993/early 1994.

Callaway sells 1 3/4" headers.

Sorry I don't buy the argument that the Y-pipe is the restriction. I've seen guys with 96 OBD II cars slap SLP headers on with the stock diameter y-pipe and gain 2-3 tenths.

 

the outlets on stock manifolds for the F-bodies can constrict to under 2" in diameter...I think you would have trouble getting to 450HP without forced induction or serious $heads and cam$. At that range your probably losing a good 50HP with the stock manifolds...

 

you guys misinterpreted me--I merely meant that even the vettes are running stock manifolds and there is no miracle y-pipe factor; the reason the headers are giving everyone "dramatic" increases in power is because they NEVER reuse the factory y-pipe do they? Think about it just for a second at least. The flp headers and hooker long tube headers increase power up high where you need it only at the track because the collector length is longer or shorter and I don't know how many of you spin your motors up high all day long just to see a 10 horsepower increase at 5500+. My case in point is most of us have our F-bodies as daily drivers and OCCASIONAL strip use; I don't know about most people but I would rather quickly beat someone on the street then slowly creep up on them because my power is up too high to play with every day right? In a second if I had the money I would go out and buy headers no doubt; but believe it or not it would only be for looks not because I would feel such a seat of the pants improvement because that is ridiculous; you can't feel 10 horses and I know because I drag my 76 a lot in the summer and one jet change yields me 15 horses but I cannot feel it! These cars are truly made to whip the pants off of street vehicles and to make it a drag vehicle is too expensive and then you will not want to drive it on the street. I used to drive the 76 on the street until I was sick and tired of "popcorning" and having to retighten my fenders all the time. What we want from our cars is torque because horsepower is how fast you hit the wall and torque is how hard!! I want to thank you guys so far for not bashing me and keeping an open mind because this is what I like about this site and sets it aprt from other ones!!

 

Its all an opinion, sure you could run a completely stock car with 150 shot of N20 but that car will last about 2 weeks if you are using that power to beat cars on the street every time. How many cars on the road do you need nitrous to beat with an Fbody anyway. With headers intake and catback you are good to beat any car on the road, except maybe a few, but theres also a few on the road that a 300 shot wouldnt help you with. Thats whats so cool about blowing or N/A horsepower, N/A even more, its there all the time, it doesnt hurt your engine, and you dont have to refill it for $40 or whatever it costs.

 

See sig. I have an aftermarket Y pipe and stock manifolds.

 

Blowing your motor in 2 weeks is not true thats called abuse. you can safely use 150 shots of nitrous anytime you want as long as you don't go lean; I did not mean strictly nitrous on a stock motor all the time because you will break things. N/A cars are great but remember anytime you make your motor higher revving or faster, you lose longevity regardless if its n/a or n2o.

 

your wrong however - 96-97 OBDII cars DO reuse the stock Y-pipe, and they still see fairly dramatic increases (not as much due to the OBDII Y-pipe design, but still enough to justify the cost).

I fail to see the point though? I spent $250 for my headers used, with a y-pipe...the Y-pipe itself from what I have seen is worth about 10hp, and I expect 20-30 from the header swap. I would say 10-20HP for $125 ($250 - what just a y-pipe would cost) @ .16 HP/$ is money WELL spent. Heck even a blower at $3500 for about 100 HP is .028 HP/$. Nitrous done correctly ($1100 for all the safety stuff) comes in at .13 hp/$. To match my used headers, a blower would have to give 560 additional HP!

If your talking $1300 for a set of headers, then the bang per buck value of course becomes much lower...but even brand new MAC shorties for $400 or so is worth it. (.075 HP/$) and the headers have an advantage of being worth more with the addition of more mods. Even a standard cat-back ($250 for a non stainless for about 15 HP) comes in at .060 HP/$

IMO headers are STILL one of the best mods that you can do for these cars.

 

If we are talking bang for the buck--possibly- I'm talking the most gains for the buck. 93-95 single cats do not feel much of an improvement due to dummy duals per say 96-up will since the 2- design is less restrictive

 

I love my HOOKERS!Yeah those stock manifolds dont look very restrictive,maybe I will put them back on with my 3 in.y-pipe and have more torque down low.

 

umm, well since bang for the buck = gains for the buck when your talking motor work I don't understand your comment.

The 96-97 Y-pipe may be less restrictive but the header designs are poorer because of the limited amount of space to work with, and they still see the gains. I know your probably aware of this, but the 96-97 design and the 93-95 design are both dummy duals...they both go into a y-pipe and they both go into a crossflow muffler.

Don't take this personally but I think you need to do some more research on this as some of your information is not quite accurate, I.E. dual cat designs gaining more from headers than single cat, or not seeing much gain from headers period. I don't know very many people at all that can say they didn't instantly notice when they put headers on, and those that didn't had something wrong with their car.