Regarding arh 1 3/4 for low rpm power.

[jolambright]

Hello,
I am no way an expert or a mechanic, I have just done research online like a lot of people about this but I am unable to determine this.

My car is basically just a DD 2012 5.0 that I plan on keeping the rest of my life. I do not go to the track and mostly baby it driving no higher than 2.5k rpm except for when passing people or just wanting to wot entering the freeway which is like once a day. I do enjoy driving it fast but I drive it easy a lot. I am planning on putting the 11:1 aluminator with billet pump gears in it soon with a Vortech V-3 hopefully to push it around 600rwhp and one thing I am concerned with is the headers.

I know I baby the car so most people will be wondering why do I want that much power if I won't use it a lot and I say for when I want to have fun or someone wants to race on the road next to me

From my research I have read that arh headers have the longest primary tubes which is supposed to give more power than any other header for overall performance. I am thinking that will pick the 1 3/4 with catted H pipe to give better scavenging with low rpm power.

Most dynos do not show rpm below 2.5k and I was curious if putting those on will rob me from the low end power that I was looking over the stock shorties that are a tri-y design. So I am wondering if there is anyone here that has those headers on and noticed how much of any difference from idle to 2.5k whether they think it is the same, less or more power. So if I am driving at 1.5k in fourth and/or 6th gear and I hit the gas how is the throttle response and power of the car. Compared to stock the same, less or more power at that rpm?

Thanks for any help!

 

[wildbillcody]

There shouldn't be a scavenging effect with WOT while running boost

 

[Unreal]

You won't notice any low end loss. In fact should gain some.

If I ever do headers on mine probably going to do the same thing. ARH makes the nicest headers around.

 

[jolambright]

There shouldn't be a scavenging effect with WOT while running boost

With a Centrifugal supercharger from what I read the boost doesn't really kick in till around 4k rpm. So if the primary size is small enough for the power when no boost has kicked it you will get the most low end power. I saw several people with 1 3/4 making 900 rwhp around so that is how I know I am good at making 600 with no problems. I just want the right size so I can also gain it down low as well and don't see less power when babying it. I almost wish arh made a 1 5/8 for the coyote.

Again I have never tested any of this and in no way shape an expert. Just read a lot online about how it works so I want to make sure I have the best of both worlds. I would rather lose like 10hp/torque at 7k rpm having smaller primary size than like the 1 7/8 and gain it at the low rpm's when I don't have the boost.

 

[travelers]

Before I put the 2.3 Whipple on the car (2011 GT), I installed the ARH 1 7/8" headers and had not noticeable low end torque loss. It also makes a difference on your tune. I kinda drive the car similar to the way you do. The coyote really likes to breath and it makes a big difference when you put headers and any kind of H or X pipe. I went with the OR H pipe and it's tuned to pass emissions. Also a big help with hitting the gas from low RPMs is your rear gears. I have 3.31 which you will need to down shift to make a more effective pass or acceleration. Now with the Whipple on, it's a different car altogether.

A friend of mine has the 3.73s in a '12 and he doesn't have to down shift as much but his is stock exhaust but with a CAI and tune.

You said about the oil pump gears, I pulled the cover off and installed the Ford Racing oil pump with billet gears AND an ATI balancer while I was down there. A little added insurance.

I hope this helps

 

[jolambright]

I thought a Whipple, which is a Twin Screw, gives power at low rpm anyway? And that Centrifugal does not.
Or am I incorrect?

 

[Department Of Boost]

At 550-600hp blown I wouldn't spend the money on headers. They are expensive, a PITA to put on and not needed. Spend that $1000 on something important, like intercooler upgrades.

 

[Unreal]

I thought a Whipple, which is a Twin Screw, gives power at low rpm anyway? And that Centrifugal does not.
Or am I incorrect?

Centris do add power everywhere, just not as much as a PD blower.

 

[07 Boss]

This is what I don't fully understand. If you want more power down low why don't we just press the gas pedal a little harder? I'm not talking about shifting later but just pressing the pedal down farther.

 

[Department Of Boost]

This is what I don't fully understand. If you want more power down low why don't we just press the gas pedal a little harder? I'm not talking about shifting later but just pressing the pedal down farther.

Ahhhh, but what if the foot is on the wood and it still doesn't accelerate as fast as you want it too?

 

[07 Boss]

Ahhhh, but what if the foot is on the wood and it still doesn't accelerate as fast as you want it too?

But the way the OP was talking about below 2500 rpms, he can't have his foot to the floor, no? I'm saying drive the car, don't let the car drive you. If you want power, downshift and go. Who floors it at 1500 in 4th, or whatever.

 

[Department Of Boost]

But the way the OP was talking about below 2500 rpms, he can't have his foot to the floor, no? I'm saying drive the car, don't let the car drive you. If you want power, downshift and go. Who floors it at 1500 in 4th, or whatever.

Gotcha, gotcha. I skimmed over the 2.5K part. Under 2.5K is for cruising on the freeway or getting to 3.5K.

That said we did all of our S550 data logs for Lund from 2500 in 3rd gear. Hold it at 2500 the go WOT. The PD blower still pulls like a train from that low.

If the OP wants torque put a PD blower on it and leave the exhaust stock (put mufflers on though). Something like this:

http://www.departmentofboost.com/vbull/forumdisplay.php?22-GT550-Manifold-amp-Supercharger-Kits-For-The-Coyote-Motor

 

[travelers]

Gotcha, gotcha. I skimmed over the 2.5K part. Under 2.5K is for cruising on the freeway or getting to 3.5K.

That said we did all of our S550 data logs for Lund from 2500 in 3rd gear. Hold it at 2500 the go WOT. The PD blower still pulls like a train from that low.

If the OP wants torque put a PD blower on it and leave the exhaust stock (put mufflers on though). Something like this:

http://www.departmentofboost.com/vb...ld-amp-Supercharger-Kits-For-The-Coyote-Motor

What he said. That's how I had to data log for Lund also. If you can loose the cats would be a help. Also talk to who you are going to tune the car.

 

[jolambright]

But the way the OP was talking about below 2500 rpms, he can't have his foot to the floor, no? I'm saying drive the car, don't let the car drive you. If you want power, downshift and go. Who floors it at 1500 in 4th, or whatever.

I don't always want to downshift to accelerate at a good speed if someone was in front of me driving slow and then got out of the way or I am just going from a stop sign or light. I do push the pedal to the floor but my question is about having the best exhaust to atleast keep the low end power or hopefully gain some for when I do that it will accelerate faster than stock at those rpm levels.

But since I spend most of my driving around like 1500-2500 I want it to gain power at that level while still having lots of power for wot.

 

[Department Of Boost]

I don't always want to downshift to accelerate at a good speed if someone was in front of me driving slow and then got out of the way or I am just going from a stop sign or light. I do push the pedal to the floor but my question is about having the best exhaust to atleast keep the low end power or hopefully gain some for when I do that it will accelerate faster than stock at those rpm levels.

But since I spend most of my driving around like 1500-2500 I want it to gain power at that level while still having lots of power for wot.

You won't get that with exhaust. You won't get that with anything NA.

 

[jolambright]

You won't get that with exhaust. You won't get that with anything NA.

So basically what your saying all I can do is put the vortech on, get a really good tune for all power bands and that is the best I am going to get for how I drive and no exhaust will improve that range that I drive mostly in?

 

[Department Of Boost]

So basically what your saying all I can do is put the vortech on, get a really good tune for all power bands and that is the best I am going to get for how I drive and no exhaust will improve that range that I drive mostly in?

A centri blower is the last blower you want for low RPM torque. You want a PD blower.

 

[jolambright]

Sadly I will not be able to put a PD blower on, going to use a CDC Shaker.
If it wasn't for that then I would be using one.
That is why I was looking at different places to add power down low. Since most people also put in aftermarket headers I am willing to put on the best when putting in the aluminator engine in 2-3 years but needed the right set for higher power in all ranges including low end.

 

[Department Of Boost]

Sadly I will not be able to put a PD blower on, going to use a CDC Shaker.
If it wasn't for that then I would be using one.
That is why I was looking at different places to add power down low. Since most people also put in aftermarket headers I am willing to put on the best when putting in the aluminator engine in 2-3 years but needed the right set for higher power in all ranges including low end.

Don't use a CDC shaker. Problem solved.

Go get a ride in a PD and centri car before you do anything. The difference is massive.

And no matter what you do I think LT headers are a waste. At least a waste considering what you want. My $.02.

 

[zeroescape]

Sounds like you need to buy a powerstroke instead of the aluminator lol