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View Full Version : the headers are going on


Dave B.
08-17-2005, 09:30 PM
got a set of BBKs the chrome looking ceramic coated ones, and an X mid without cats,,,,,,so with a 2.76 pulley, accufab, mac cold air, whats this thing going to feel like? and most of all, going from a magnaflow catback and X pipe, whats it going to sound like compaired to the other?? :bounce:

InfamousSVT
08-17-2005, 10:15 PM
It'll sound wicked and really good IMO.........as for power, you will probably gain around 20rwhp+ through out the powerband!

Dave B.
08-17-2005, 10:31 PM
20 RWHP across the band??? are you SH*&t*#& ME??

I have avoided putting headers on from the very begining as I had several people over the two years iv had the car, one guy was George from rpmoutlet, told me if I put long tube headers on it would be like throwing an anchor out as far as bottom end torque goes,

Now you must understand that I do not ever go to the track, its a daily driver for me, and its the around town bottom end that I like, I just put 4:10's in about two months ago, I wish I would have paid more to get a mid pipe with cats, I really dont like that raspy sound Im affraid its going to have

with the Magnaflow catback and X pipe, the car has an exotic, V-12 sound to it, very tight Euro/Italian high end sports car type sound, Im affraid thats all going away now it is not?

InfamousSVT
08-17-2005, 10:36 PM
I'm talking a 20rwhp gain throughout the entire power curve. It'll defenitely help keep the engine cooler by getting some of the hot air out and help the Supercharger breathe. The sound will remain exotic due to the cat-back, but it'll be louder, way louder! I actually like the O/R pipes on mine. Good luck and let us know how you like it!:thumbsup:

Dave B.
08-17-2005, 10:48 PM
did you notice a bottom end drop in grunt torque? if not, is there a chance you did loose some but because its louder it sounded like it gained at the bottom? or did you have it on a dyno? thanks

kilroy
08-18-2005, 12:36 AM
did you notice a bottom end drop in grunt torque? if not, is there a chance you did loose some but because its louder it sounded like it gained at the bottom? or did you have it on a dyno? thanks Dave, My former neighbor bought those same headers & O/R H-pipe with Borla stinger-like mufflers dumped. I've heard no car that sounds better - but... He was always +.1-.4 & 2-3mph slower than me with just catted bassani & stingers. His 2.80 to my 2.85. When I drove his car at one of our local cruise-ins it was obvious why & I think George was right. Boat anchor loss of low-end torque. Note where your boost needle is now. You'll lose some boost & its associated torque. If you leave the cats on that - it should feel better than my neighbors ride. My neighbor LOVED the top end though...
If your plans are to go big with boost, then I'd do it... all the big guns run them.

Dave B.
08-18-2005, 12:42 AM
Now I just had a 2.76 pulley put on as i had to get rid of the 2.80 as the belt was not riding on it right when I went to the Billetflow pulley set,

is what your telling me that im going to loose bottom torque bad but that as the power band RPM rises, im going to gain all thru the band? Im going to gain somewhere am I not? thing is, have you ever looked at the exhaust holes in the stock manafold vs the header ports? theres a hugh differance in hole sizes

kilroy
08-18-2005, 12:52 AM
Dave, My former neighbor bought those same headers & O/R H-pipe with Borla stinger-like mufflers dumped. I've heard no car that sounds better - but... OK, it sounded ProStock in volume & quality. Definately bad-a$$. H-pipe, not X on his setup...

I was on the fence for over a year on the subject. Jim D'Amore has advised me of the same about big boost & when to use headers. I had Bassani mid-lengths before I had purchased the Terminator - I was so stoked to do headers... until I read some threads that gave me reason to pause. Having driven my neighbors car I'm happy with my decision. If you do it, post up before/after dyno numbers & that wicked sound byte. ProStock, I tell ya...:eek:

kilroy
08-18-2005, 01:01 AM
thing is, have you ever looked at the exhaust holes in the stock manafold vs the header ports? theres a hugh differance in hole sizesRestriction = boost (loosely) if you lessen the restriction your boost #s drop but in theory you flow more. This is what I do not understand: if you flow more air/fuel you should make more power. But what happens to the torque on our motors without some backpressure is a mystery to me. Call Jim D'Amore up... he can better explain it.

On N/A cars you bolt on LTs & instantly make 25rwhp & similar TQ... not so with Termintors - in lower boost configurations.

ausie
08-20-2005, 09:16 AM
I believe the loss of torque is due to the lower compression ratio when compared to the same motor that is N/A. 8.5:1 as compared to 10:1. Also the cam profile is designed for a specific back pressure and has a longer duration than most of the other 4.6L motors. In my opinion, either replace the cams or increase the boost or both. The increased scavaging of the LT header will suck out the fuel/air mixture since it is under boost as compared to the N/A motor which relies on the piston to draw air in. LT headers will create a low pressure vaccum (scavage) to allow for more air/fuel to enter the combustion chamber but under boost most of it gets pushed out. Sure LT headers can be a good thing since they allow for more exhaust gasses to be removed from the combustion chamber, but combining that with a supercharger and a different cam profile may make a huge difference.