View Poll Results: What is the best option for my driving goals.
Buy Package Headers (i.e. evo etc.)
6
16.22%
Buy Custom Headers
2
5.41%
Port Stock Headers
21
56.76%
Leave Them Alone.
8
21.62%
Voters: 37. You may not vote on this poll
Headers....Again!!!!
#16
08-04-2007, 12:00 AM
Join Date: Jul 2006
Location: ga
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Originally Posted by 9Eleven
Dude, I don't claim to be an expert, these are my simple observations from installing different mods on my car and learning as I go. I think the biggest boost lag culprit is back pressure, which would be air getting through the cats, since the first thing that reduces the turbo fins spinning are the cats. Although no backpressure is bad; less is good. I believe you need a little backpressure for the turbos to load giving you low end torque. A good exhaust did wonders when added to my flash.
Headers are pre-turbo (air going in). I don't really believe that the air going into the turbo (k16 or 24's) from the headers is a problem; it's the air going out. The stock headers can handle it, even if you install a bigger intake, which I'm still not convinced will add any more power. Our power is all related to boost, how much and how fast. I really don't believe that an intake and a set of headers will make that much of a difference to justify the expense and installation. What is the true horsepower gain for cars under 600 fwhp when you add an intake and headers, 7 to 10 hp; and at what speed? Are the power gains at the rpm levels that you can use?
If I only get that additional hp at 150 mph and above, is it truely hp that I can use and feel on a daily basis? To me, it's not worth the 2 to 4 grand for that little of a gain at speeds I only hit occasionally (absent the law). Unless you bump it up to 700 fwhp, IMHO you're squandering cash better spent on suspension, tires, brakes, etc.
Now, if your going for big power (700 fwhp and up), then all bets are off. Again let me say, this is coming from a guy who is just going on what he has observed in the last 2 years, it isn't gospel, just my recent discoveries. There are guys on this forum that have gone much, much, farther and have spent a lot more cash that probably know better than I.
Headers are pre-turbo (air going in). I don't really believe that the air going into the turbo (k16 or 24's) from the headers is a problem; it's the air going out. The stock headers can handle it, even if you install a bigger intake, which I'm still not convinced will add any more power. Our power is all related to boost, how much and how fast. I really don't believe that an intake and a set of headers will make that much of a difference to justify the expense and installation. What is the true horsepower gain for cars under 600 fwhp when you add an intake and headers, 7 to 10 hp; and at what speed? Are the power gains at the rpm levels that you can use?
If I only get that additional hp at 150 mph and above, is it truely hp that I can use and feel on a daily basis? To me, it's not worth the 2 to 4 grand for that little of a gain at speeds I only hit occasionally (absent the law). Unless you bump it up to 700 fwhp, IMHO you're squandering cash better spent on suspension, tires, brakes, etc.
Now, if your going for big power (700 fwhp and up), then all bets are off. Again let me say, this is coming from a guy who is just going on what he has observed in the last 2 years, it isn't gospel, just my recent discoveries. There are guys on this forum that have gone much, much, farther and have spent a lot more cash that probably know better than I.
#17
08-04-2007, 12:02 AM
Join Date: Jul 2006
Location: ga
Posts: 8,934
Rep Power: 550
Originally Posted by jcb-memphis
I think custom, well done ones will make a difference...but for me my hard earned money has a few other places to go for now.
It is an area that seems to have a lot of BS around the edges...if you will. When it comes time, I plan to have my tuner guide me.
Stock for now...once big power...something else, perhaps just a port if not a new model not yet on the market that is really good....
I say "DITTO" to Woodster's perspective. I don't have them on my car now.
JB
It is an area that seems to have a lot of BS around the edges...if you will. When it comes time, I plan to have my tuner guide me.
Stock for now...once big power...something else, perhaps just a port if not a new model not yet on the market that is really good....
I say "DITTO" to Woodster's perspective. I don't have them on my car now.
JB
#18
08-04-2007, 12:47 AM
On any turbo car, and especially one with turbos as small as the 996, the turbo/turbine will be choke point, or source of backpressure.
The factory headers would have to be absolutely horrible to be leaving anything on the table with "streetable" turbos.
Also, fwiw, turbos do not need any backpressure post turbine. The less the better. (as in, a relatively short, open bell post turbine would be ideal).
The factory headers would have to be absolutely horrible to be leaving anything on the table with "streetable" turbos.
Also, fwiw, turbos do not need any backpressure post turbine. The less the better. (as in, a relatively short, open bell post turbine would be ideal).
#19
08-04-2007, 08:02 AM
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Join Date: Jan 2006
Location: MPLS, MN USA
Age: 63
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Sidenote:
My K24 Headers (not EVOMS brand-theirs are better quality),
required Todd Knighton to de-burr the inside of them, make the flanges straight (so they would not leak) and minor "porting". Had I known that
I would have him make me custom ones that bolt up to the GT30's
and be done with it.
MK
My K24 Headers (not EVOMS brand-theirs are better quality),
required Todd Knighton to de-burr the inside of them, make the flanges straight (so they would not leak) and minor "porting". Had I known that
I would have him make me custom ones that bolt up to the GT30's
and be done with it.
MK
#20
08-04-2007, 08:24 AM
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Join Date: Aug 2005
Location: Melbourne Beach, Fl
Age: 61
Posts: 1,477
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Originally Posted by heavychevy
What intake are you reffering to? I'm talking about a (drop motor to install )custom intake. More air into the motor is always good from the restrictive stock intakes and should not affect backpressure. This is just a guess though, feel free to correct me.
I agree with with most of your observation. I believe that the only time that you would need a custom intake is if you are upgrading your turbos. IMHO, the stock intake is more than capable when you are using k16's or k24's.
I've read some threads where some forum members went to straight pipes (little or no backpressure) and actually lost power.
What intake are you reffering to? I'm talking about a (drop motor to install )custom intake. More air into the motor is always good from the restrictive stock intakes and should not affect backpressure. This is just a guess though, feel free to correct me.
I agree with with most of your observation. I believe that the only time that you would need a custom intake is if you are upgrading your turbos. IMHO, the stock intake is more than capable when you are using k16's or k24's.
Originally Posted by INTMD8
Also, fwiw, turbos do not need any backpressure post turbine. The less the better. (as in, a relatively short, open bell post turbine would be ideal).
Last edited by 9Eleven; 08-04-2007 at 08:47 AM.
#21
08-04-2007, 08:47 AM
Join Date: Jul 2006
Location: ga
Posts: 8,934
Rep Power: 550
Originally Posted by 9Eleven
Originally Posted by heavychevy
What intake are you reffering to? I'm talking about a (drop motor to install )custom intake. More air into the motor is always good from the restrictive stock intakes and should not affect backpressure. This is just a guess though, feel free to correct me.
I agree with with most of your observation. I believe that the only time that you would need a custom intake is if you are upgrading your turbos. IMHO, the stock intake is more than capable when you are using k16 or k24's.
What intake are you reffering to? I'm talking about a (drop motor to install )custom intake. More air into the motor is always good from the restrictive stock intakes and should not affect backpressure. This is just a guess though, feel free to correct me.
I agree with with most of your observation. I believe that the only time that you would need a custom intake is if you are upgrading your turbos. IMHO, the stock intake is more than capable when you are using k16 or k24's.
Ok but remember my goals, and that is to decrease lag and to help with throttle response, not neccessarily for power, what do you think about that?
#22
08-04-2007, 08:54 AM
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Location: Melbourne Beach, Fl
Age: 61
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Bro, throttle response and lag are due to exit gas, not intake. As long as the turbos have less backpressure they will spool up faster and the trottle response will increase. The air going in is plenty for a k16 or 24. The stock headers are more than capable of delivering enough air to the turbos. When I was looking at the whole set up the other night when I installed my exhaust it was pretty obvious to me and to my tuner. But as I wrote earlier, if you go bigger turbos, now you're talking a lot of changes.
Last edited by 9Eleven; 08-04-2007 at 02:14 PM.
#23
08-04-2007, 09:34 AM
Originally Posted by 9Eleven
Headers are pre-turbo (air going in). I don't really believe that the air going into the turbo (k16 or 24's) from the headers is a problem; it's the air going out. The stock headers can handle it, even if you install a bigger intake, which I'm still not convinced will add any more power. Our power is all related to boost, how much and how fast. I really don't believe that an intake and a set of headers will make that much of a difference to justify the expense and installation. What is the true horsepower gain for cars under 600 fwhp when you add an intake and headers, 7 to 10 hp; and at what speed? Are the power gains at the rpm levels that you can use?
#24
08-04-2007, 10:02 AM
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Join Date: Aug 2005
Location: Melbourne Beach, Fl
Age: 61
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Originally Posted by wross996TT
Just want to make sure this is just your opinion as you have no data to support any of it...only hearsay. You can't just look at one component and say it is responsible for "X"...the throttle response, lag, power are all a function of the entire system. Bringing cooler air into the turbos will help, reducing back pressure will help, tightening the wastgates will help (peventing premature venting), reducing the clearance between the blades and the housing will help...it just depends on the weakest component (limiting factor)....this is why you just can't look at dynos from different cars (and dynos for that matter) and make claims that will necessarily translate to yourcar. So given the right situation...the intake could be very beneficial (not just high hp)...get that cold air in...I think the consensus is that the headers are not at the top of the list for weak link. They are short (good) and adequate...by porting and polishing you just make the flow smoother through the headers. OH JMHO!
#25
08-04-2007, 11:04 AM
Originally Posted by kayman
When I talked to mike at evoms, he told me the stage 3 & 4 software is the same.
plus the price difference between the evoms stage 3 and 4 kit is equal to their k24 headers
yet they claim a 50 hp difference between the two... hmmm.....
plus the price difference between the evoms stage 3 and 4 kit is equal to their k24 headers
yet they claim a 50 hp difference between the two... hmmm.....
I don't believe EVOMS ever said their headers made 50 hp. They may have said their is a fifty hp difference between stage X and Y. You guys look at the parts list a jump to the conclusion that the only part difference is the headers and so the headers make 50 hp.
These guys, like others, make their money by not disclosing what the real differences are. Chances are the difference is something that anyone could "copy" at a very minor cost. Therefore, the info isn't going to be shared. Get the picture.
Back to the 50 ponies.......if you believe that just changing the headers (in this power range) provide this increase then I have an island that I would love to sell you.
Last edited by cjv; 08-04-2007 at 11:09 AM.
#26
08-04-2007, 11:22 AM
Originally Posted by cjv
You guys need to go back to the basics. Fuel is the only thing that makes power. Now think of any motor as the parts not being a restriction for the amount of fuel being used.
I don't believe EVOMS ever said their headers made 50 hp. They may have said their is a fifty hp difference between stage X and Y. You guys look at the parts list a jump to the conclusion that the only part difference is the headers and so the headers make 50 hp.
These guys, like others, make their money by not disclosing what the real differences are. Chances are the difference is something that anyone could "copy" at a very minor cost. Therefore, the info isn't going to be shared. Get the picture.
Back to the 50 ponies.......if you believe that just changing the headers (in this power range) provide this increase then I have an island that I would love to sell you.
I don't believe EVOMS ever said their headers made 50 hp. They may have said their is a fifty hp difference between stage X and Y. You guys look at the parts list a jump to the conclusion that the only part difference is the headers and so the headers make 50 hp.
These guys, like others, make their money by not disclosing what the real differences are. Chances are the difference is something that anyone could "copy" at a very minor cost. Therefore, the info isn't going to be shared. Get the picture.
Back to the 50 ponies.......if you believe that just changing the headers (in this power range) provide this increase then I have an island that I would love to sell you.
btw, here's a direct quote from their website:
"Power gains are increased by 17 HP and 20 Ft. TQ with no other modifications." thats listed in the descripton for the k24 headers.
If I were to buy both their stage 3 kit and stage 4 kit, the only difference in the package would be the inclusion of the headers in the stage 4. Yet they state that difference in hp gained between these two bolt-on kits is 50hp. So essentially what they are claiming is that without any other mods, the headers give you 17hp. And if you add them along with an exhaust, intake, flash and k24s, you'll somehow manage to get 50hp.
Yet based on everything I've read on the forums, nobody has felt or measured any power gains from headers alone. Has anyone called evoms out on this?
Last edited by kayman; 08-04-2007 at 11:24 AM.
#27
08-04-2007, 11:39 AM
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Join Date: Aug 2005
Location: Melbourne Beach, Fl
Age: 61
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Originally Posted by kayman
of course I don't believe their claims. I just find it really funny they are able to get away with it. Never said I bought into thier marketing hype.
btw, here's a direct quote from their website:
"Power gains are increased by 17 HP and 20 Ft. TQ with no other modifications." thats listed in the descripton for the k24 headers.
If I were to buy both their stage 3 kit and stage 4 kit, the only difference in the package would be the inclusion of the headers in the stage 4. Yet they state that difference in hp gained between these two bolt-on kits is 50hp. So essentially what they are claiming is that without any other mods, the headers give you 17hp. And if you add them along with an exhaust, intake, flash and k24s, you'll somehow manage to get 50hp.
Yet based on everything I've read on the forums, nobody has felt or measured any power gains from headers alone. Has anyone called evoms out on this?
btw, here's a direct quote from their website:
"Power gains are increased by 17 HP and 20 Ft. TQ with no other modifications." thats listed in the descripton for the k24 headers.
If I were to buy both their stage 3 kit and stage 4 kit, the only difference in the package would be the inclusion of the headers in the stage 4. Yet they state that difference in hp gained between these two bolt-on kits is 50hp. So essentially what they are claiming is that without any other mods, the headers give you 17hp. And if you add them along with an exhaust, intake, flash and k24s, you'll somehow manage to get 50hp.
Yet based on everything I've read on the forums, nobody has felt or measured any power gains from headers alone. Has anyone called evoms out on this?
Last edited by 9Eleven; 08-04-2007 at 11:47 AM.
#28
08-04-2007, 12:22 PM
In regards to headers on the 99x setup - the key to spooling up is pressure drop and velocity. Less back pressure behind the turbine will allow the wheel to spool faster. Open exhaust cannot be beaten for creating the biggest pressure differential across the turbine. However, if the turbo spools so quickly that the motor cannot increase the fuel trim to match, it is possible the AFR is becoming too lean and less than optimal power is being produced.
Now as far as velocity, the hotter the gasses, the higher velocity. If you run headers whose primary tubing is too large, too long, or allows more radiation of heat (stock manifolds are double walled) then the velocity will diminish and the turbine will not spool as quickly. I think a safe header will use the same size dia tubing as stock, be equal length, use an efficient merge collector (NASCAR style, Burns, etc) and have a thermal coating to keep the heat in.
Now as far as velocity, the hotter the gasses, the higher velocity. If you run headers whose primary tubing is too large, too long, or allows more radiation of heat (stock manifolds are double walled) then the velocity will diminish and the turbine will not spool as quickly. I think a safe header will use the same size dia tubing as stock, be equal length, use an efficient merge collector (NASCAR style, Burns, etc) and have a thermal coating to keep the heat in.
#29
08-04-2007, 12:46 PM
Originally Posted by kayman
of course I don't believe their claims. I just find it really funny they are able to get away with it. Never said I bought into thier marketing hype.
btw, here's a direct quote from their website:
"Power gains are increased by 17 HP and 20 Ft. TQ with no other modifications." thats listed in the descripton for the k24 headers.
If I were to buy both their stage 3 kit and stage 4 kit, the only difference in the package would be the inclusion of the headers in the stage 4. Yet they state that difference in hp gained between these two bolt-on kits is 50hp. So essentially what they are claiming is that without any other mods, the headers give you 17hp. And if you add them along with an exhaust, intake, flash and k24s, you'll somehow manage to get 50hp.
Yet based on everything I've read on the forums, nobody has felt or measured any power gains from headers alone. Has anyone called evoms out on this?
btw, here's a direct quote from their website:
"Power gains are increased by 17 HP and 20 Ft. TQ with no other modifications." thats listed in the descripton for the k24 headers.
If I were to buy both their stage 3 kit and stage 4 kit, the only difference in the package would be the inclusion of the headers in the stage 4. Yet they state that difference in hp gained between these two bolt-on kits is 50hp. So essentially what they are claiming is that without any other mods, the headers give you 17hp. And if you add them along with an exhaust, intake, flash and k24s, you'll somehow manage to get 50hp.
Yet based on everything I've read on the forums, nobody has felt or measured any power gains from headers alone. Has anyone called evoms out on this?
When we were conducting our tests years ago, the addition of headers by themselves leaned out the motor. Adding fuel brought the motor back into balance. As you know adding fuel added power. Without going back to the dyno runs memory says the gain was 12-15 hp by adding headers and adding fuel. Be aware that this number could vary depending where along the hp range the headers are added.
Last edited by cjv; 08-04-2007 at 01:24 PM.
#30
08-04-2007, 12:59 PM
Originally Posted by eclou
In regards to headers on the 99x setup - the key to spooling up is pressure drop and velocity. Less back pressure behind the turbine will allow the wheel to spool faster. Open exhaust cannot be beaten for creating the biggest pressure differential across the turbine. However, if the turbo spools so quickly that the motor cannot increase the fuel trim to match, it is possible the AFR is becoming too lean and less than optimal power is being produced.
Now as far as velocity, the hotter the gasses, the higher velocity. If you run headers whose primary tubing is too large, too long, or allows more radiation of heat (stock manifolds are double walled) then the velocity will diminish and the turbine will not spool as quickly. I think a safe header will use the same size dia tubing as stock, be equal length, use an efficient merge collector (NASCAR style, Burns, etc) and have a thermal coating to keep the heat in.
Now as far as velocity, the hotter the gasses, the higher velocity. If you run headers whose primary tubing is too large, too long, or allows more radiation of heat (stock manifolds are double walled) then the velocity will diminish and the turbine will not spool as quickly. I think a safe header will use the same size dia tubing as stock, be equal length, use an efficient merge collector (NASCAR style, Burns, etc) and have a thermal coating to keep the heat in.