Forced induction, Macs vs. Kooks?!?!?!
04-02-2006, 06:44 PM
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Forced induction, Macs vs. Kooks?!?!?! So i am running forced induction again and was wondering how much HP i am losing with my macs!
I hear there is only about 8 Horsepower being robbed from me with the macs over the Kooks, but i am hearing it from a really unreliable source. I was wondering if anyone had stepped up from macs and made more HP numbers. I guess it dosnt necessarily have to be Kooks, but kooks are wonderful headers and i want them LOL.
I posted this here because i guess it is considered a bolt on with the headers and all, PLEASE help before i go spending a GRAND on headers and then see only 5 horse power LOL
Thanks a bunch,
Dan
I hear there is only about 8 Horsepower being robbed from me with the macs over the Kooks, but i am hearing it from a really unreliable source. I was wondering if anyone had stepped up from macs and made more HP numbers. I guess it dosnt necessarily have to be Kooks, but kooks are wonderful headers and i want them LOL.
I posted this here because i guess it is considered a bolt on with the headers and all, PLEASE help before i go spending a GRAND on headers and then see only 5 horse power LOL
Thanks a bunch,
Dan
04-03-2006, 03:54 AM
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with a blower and the mids i would think you're gonna lose a lot more than 8whp compared to with LT's.
if you don't wanna spend a G on headers, theres quite a few more options...my pacesetters were $400 coated, there not stainless but hey, they weren't a grand either
if you don't wanna spend a G on headers, theres quite a few more options...my pacesetters were $400 coated, there not stainless but hey, they weren't a grand either
04-03-2006, 05:10 AM
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Good header design is all about scavenging, this promotes a 5 process in the combustion cycle. Essentially the scavenging affect can contribute upto 80% of the intake velocity into the combustion chamber. The longer the primaries the better the torque is in the lower rpms and as OHV engines generally rev at fairly low rpms they tend to offer the most gains. Mid length headers would work better at higher rpms, hence many people running wild cams and mids tend to make good PEAK numbers (although the below the line numbers may not be quite so good).
Shorties require the highest rpms in order to scavenge correctly, I've seen reports of 10,000rpm and above as being their optimum operational rpm range. Hence why they offer little to nothing in performance terms for the LS1.
However!
Once you introduce a supercharger this all changes. This is because the intake air is forced into the eninge at a constant above atmospehric pressure, this eliminates the 5 process in the conbustion cycle. Flow then becomes more important than scavenging ability, flow will be determined by primary pipe diameter and not length.
So IMO I doubt you'll see any real benefit going to LT's, however the possibility always exists. Tuning of the exhuast pressure wave is probably the biggest factor though.
Personally if you want more power with FI, just add more boost. If need be build an engine that has an appropriate CR and is strong enough. A good blower cam and maybe even heads would be my choice over swapping mids to LT's.
But hay each to their own.
Hope this helps, and if my explanation is slightly sketchy I apologise but I'm working from memory.
Shorties require the highest rpms in order to scavenge correctly, I've seen reports of 10,000rpm and above as being their optimum operational rpm range. Hence why they offer little to nothing in performance terms for the LS1.
However!
Once you introduce a supercharger this all changes. This is because the intake air is forced into the eninge at a constant above atmospehric pressure, this eliminates the 5 process in the conbustion cycle. Flow then becomes more important than scavenging ability, flow will be determined by primary pipe diameter and not length.
So IMO I doubt you'll see any real benefit going to LT's, however the possibility always exists. Tuning of the exhuast pressure wave is probably the biggest factor though.
Personally if you want more power with FI, just add more boost. If need be build an engine that has an appropriate CR and is strong enough. A good blower cam and maybe even heads would be my choice over swapping mids to LT's.
But hay each to their own.
Hope this helps, and if my explanation is slightly sketchy I apologise but I'm working from memory.
04-03-2006, 12:00 PM
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Originally Posted by 300bhp/ton
Good header design is all about scavenging, this promotes a 5 process in the combustion cycle. Essentially the scavenging affect can contribute upto 80% of the intake velocity into the combustion chamber. The longer the primaries the better the torque is in the lower rpms and as OHV engines generally rev at fairly low rpms they tend to offer the most gains. Mid length headers would work better at higher rpms, hence many people running wild cams and mids tend to make good PEAK numbers (although the below the line numbers may not be quite so good).
Shorties require the highest rpms in order to scavenge correctly, I've seen reports of 10,000rpm and above as being their optimum operational rpm range. Hence why they offer little to nothing in performance terms for the LS1.
However!
Once you introduce a supercharger this all changes. This is because the intake air is forced into the eninge at a constant above atmospehric pressure, this eliminates the 5 process in the conbustion cycle. Flow then becomes more important than scavenging ability, flow will be determined by primary pipe diameter and not length.
So IMO I doubt you'll see any real benefit going to LT's, however the possibility always exists. Tuning of the exhuast pressure wave is probably the biggest factor though.
Personally if you want more power with FI, just add more boost. If need be build an engine that has an appropriate CR and is strong enough. A good blower cam and maybe even heads would be my choice over swapping mids to LT's.
But hay each to their own.
Hope this helps, and if my explanation is slightly sketchy I apologise but I'm working from memory.
Shorties require the highest rpms in order to scavenge correctly, I've seen reports of 10,000rpm and above as being their optimum operational rpm range. Hence why they offer little to nothing in performance terms for the LS1.
However!
Once you introduce a supercharger this all changes. This is because the intake air is forced into the eninge at a constant above atmospehric pressure, this eliminates the 5 process in the conbustion cycle. Flow then becomes more important than scavenging ability, flow will be determined by primary pipe diameter and not length.
So IMO I doubt you'll see any real benefit going to LT's, however the possibility always exists. Tuning of the exhuast pressure wave is probably the biggest factor though.
Personally if you want more power with FI, just add more boost. If need be build an engine that has an appropriate CR and is strong enough. A good blower cam and maybe even heads would be my choice over swapping mids to LT's.
But hay each to their own.
Hope this helps, and if my explanation is slightly sketchy I apologise but I'm working from memory.
WOW! I think my I.Q. just went up 20 points LOL! That was some good stuff. I think i will just buy a set of heads or something. Thanks alot.
Dan
