Thread: Headers or stock manifolds POLL

Jesus Christmas guys
Let's take a vote


here is strong proof stock manifolds make the most power.
403hp/468tq on stock manifolds 2.6 pulley l67
Dyno video
https://youtu.be/dQw4w9WgXcQ

http://www.grandprixforums.net/threa...first-fast-car

I like turtles and headers.

LOL

I voted for headers. My buddy's turtle bit my toe when I was younger, so **** those things XD

BUT

Someone vote for manifold so we can see what color it is?

Let's ask a vague question, or no question at all. Let's also provide no information so we are able to grab the suckered vote influenced by the media and popularity.

Sounds a lot like an election recently.

c'mon turtle people... let's hear from all of you!! Make America Testudinata Again.

What an overly generalized poll.... Most people who have been around a while will know that you don't gain enough from headers to make a difference.

Here's what it comes down to:
8.5:1 compression ratio - Stock manifolds are fine
9.4:1 compression ratio with a blower - get some Headers

Is 4 horsepower worth $200-1000? That's the difference between a mildly built GTP on stock manifolds vs headers.

Headers is NOT about power gain. It is about flow. They are a supporting mod.

What are you supporting in a GTP with headers that stock manifolds cannot support? NOTHING!

This whole flow thing is where people get mixed up... You want to keep exhaust velocity. Only turbo cars should be free flowing.

The more air you put in, the more air you have to get out.

So if I added a blower to my silveardo I should keep my stock exhaust manifolds and loose 50+ rwhp?

Sounds like an awesome idea.

Like said the reason to open the exhaust up is to allow for more airflow and help prevent knock. It's been proven even on stock vehicle that it will remove some knock retard with more exhaust flow. That is a better solution than removing even more timing and increasing EGT's and cylinder temps.

Originally Posted by stealthee

The more air you put in, the more air you have to get out.

I think you're failing to recognize how inefficient M90s are. Or did we start a new conversation about stroker motors?

Originally Posted by Fivefingerdeathpunch

So if I added a blower to my silveardo I should keep my stock exhaust manifolds and loose 50+ rwhp?

Sounds like an awesome idea.

Like said the reason to open the exhaust up is to allow for more airflow and help prevent knock. It's been proven even on stock vehicle that it will remove some knock retard with more exhaust flow. That is a better solution than removing even more timing and increasing EGT's and cylinder temps.

Weird how the whole N/A compression with a supercharger thing was already covered... That's a completely different ballgame.

95% of people with a supercharged 3800 will not ever outflow the stock manifolds.

Originally Posted by Fivefingerdeathpunch

So if I added a blower to my silveardo I should keep my stock exhaust manifolds and loose 50+ rwhp?

Sounds like an awesome idea.

Like said the reason to open the exhaust up is to allow for more airflow and help prevent knock. It's been proven even on stock vehicle that it will remove some knock retard with more exhaust flow. That is a better solution than removing even more timing and increasing EGT's and cylinder temps.

Many do keep stock manifolds. Also, a set of headers on a ls style motor with forced induction will not pick up anywhere close to 50whp. Typical gains are 2-3%, if that.

Also, where is this proof that headers reduce knock? Because I've seen nothing of the sort.

Originally Posted by GTPpower

Many do keep stock manifolds. Also, a set of headers on a ls style motor with forced induction will not pick up anywhere close to 50whp. Typical gains are 2-3%, if that.

Also, where is this proof that headers reduce knock? Because I've seen nothing of the sort.

If adding headers to a supercharged LS engine only added 2-3% something is wrong with the vehicle/tune. Headers and tune only on a GEN 3 or 4 V8 can add 10-20whp easy in the upper rpms. Then add a blower and the power to gained is even more. It's been proven that there is even a difference between 1 3/4th headers and 1 7/8th headers too. So only gaining 2-3% with a header install is not right, that's like saying I was at 400hp and payed $500 for headers and now have 410HP. The larger primarys and longer runners are what help increase HP/Torque.

Do people keep stock manifolds, yes but they are limiting their power output by quiet a bit. Many keep them for sound and emissions reasons.

Ask just the majority of the people that added headers or did a 3in downpipe/plog combo, the amount of knock is reduced because of a free flowing exhaust.

Originally Posted by Fivefingerdeathpunch

If adding headers to a supercharged LS engine only added 2-3% something is wrong with the vehicle/tune. Headers and tune only on a GEN 3 or 4 V8 can add 10-20whp easy in the upper rpms. Then add a blower and the power to gained is even more. It's been proven that there is even a difference between 1 3/4th headers and 1 7/8th headers too. So only gaining 2-3% with a header install is not right, that's like saying I was at 400hp and payed $500 for headers and now have 410HP. The larger primarys and longer runners are what help increase HP/Torque.

Do people keep stock manifolds, yes but they are limiting their power output by quiet a bit. Many keep them for sound and emissions reasons.

Ask just the majority of the people that added headers or did a 3in downpipe/plog combo, the amount of knock is reduced because of a free flowing exhaust.

No. Forced induction motors do not show gains with headers like NA does. You cannot compare a na ls1 vs one with a blower. They are nothing alike. Do some research. You will find that 700whp cars pick up 2-3% when switching from stock manifolds to headers. Take a look into the cobra world...very very few will run headers.

Originally Posted by GTPpower

No. Forced induction motors do not show gains with headers like NA does. You cannot compare a na ls1 vs one with a blower. They are nothing alike. Do some research. You will find that 700whp cars pick up 2-3% when switching from stock manifolds to headers. Take a look into the cobra world...very very few will run headers.

Now you're bringing in a whole different world of cars here.

My example is still correct. If you supercharged a 5.3 block that made 300hp and now makes 400hp at the tire because of the blower on stock manifolds. Then you added headers, you'd be retarded to think you'd only gain 10hp or 2.5% because of better exhaust flow.

Are there applications where something may not gain as much power, sure I guess but the way you are saying it is that NOTHING can ever gain more than 10hp because someone added headers to a supercharged LS.

I've done plenty of reading on the subject.


Did I exaaggerereate my 50rwhp gain, yes but there can still be a gain better than 2-3. Blown applications on a LS may not be as picky but in many cases than gain can still be rather good.

I want someone to just slap a 3.0 pulley on stock car and tell me the exhaust flows great, I'd like to see the destruction.

Even with tuning and no other mods and junk 91 octane you'd be running like 5-10º of timing total at full throttle, that sounds great for power and all that just to keep the knock from destroying a piston.