Kooks 1 5/8 headers before and after

[Jumpmaster2015]

Finally grew a pair and picked up some long tube headers!! They are not yet installed at the time of this thread as I just bought a set from @beefcake today. I should have them installed immediately after they arrive. Beefcake was amazing to work with, thanks a lot and he definitely has the best prices on the internet hands down. This is going to be an all motor full bolt on 2014 coyote once these headers are installed. I went with the Kooks 1 5/8 long tubes per Shaun's recommendation. I am hoping the smaller primaries allow me to pick up some much wanted low end power.

Mod List:
Ported Cobra Jet Intake Manifold
SCJ oval monoblade TB
FRPP CJ CAI
L&M Intake Only Camshafts
Ford Racing Exhaust Cams (Ford says they are prototype 11mm/290dur per grind numbers)
LU47 Injectors/AED E85 flexfuel tune
1 5/8 Kooks longtubes with off road H, 3" exhaust
Ford Racing Sport 4.5" axlebacks


This is my last engine modification, so the goal is to hopefully see how restrictive these stock manifolds really are. I am pretty sure I am retiring this build and either buying a GT500 or building a race car after this, but it sure has been fun! This 5.0 should be a pretty stout daily driver. I will post results onto this thread, but wanted to post it now to chat about during the next couple of weeks.

 

[gt5.0coyote]

Very nice! If you don't mind me asking, you don't think the 1 5/8 headers will be restrictive in the upper rpms where the CJ mani shines?

 

[Riddick]

How big are the factory manifolds? AED has put the R&D into these cars and they know what works. What was the cost difference between the 1/5/8 and the 1/3/4?

You will like the Kooks, I recently purchased 1/3/4 ones and the fit is fantastic. I am not a fan of the locking style fastners they use but the quality of the headers is great. After reading on here everyone recommended using factory studs and factory gaskets. Looking forward to reading about the results. Id guess you will pick up 15-20 hp from the headers and CJ porting.

 

[Jumpmaster2015]

Very nice! If you don't mind me asking, you don't think the 1 5/8 headers will be restrictive in the upper rpms where the CJ mani shines?

I thought about it, a lot, and I already have a lot of power in the upper rpms with the manifold and camshafts. I would love to pick up some responsiveness with the car in the lower portion of the power band.

Plus, I really liked Shaun's "bigger is not always better" primary discussion thread from a couple years ago. It was a deciding factor for me when making this purchase.

https://www.svtperformance.com/forums/threads/long-tube-headers-which-primary-size-is-best.1065263/

 

[Jumpmaster2015]

How big are the factory manifolds? AED has put the R&D into these cars and they know what works. What was the cost difference between the 1/5/8 and the 1/3/4?

You will like the Kooks, I recently purchased 1/3/4 ones and the fit is fantastic. I am not a fan of the locking style fastners they use but the quality of the headers is great. After reading on here everyone recommended using factory studs and factory gaskets. Looking forward to reading about the results. Id guess you will pick up 15-20 hp from the headers and CJ porting.

I shopped around between every popular internet supplier (AM, LMR, Beefcake, CJ pony parts, etc) and there was usually no price differences between the primary sizes. I think there might have been like 40-50 bucks at one of the sites. I am not sure of the factory manifold sizes, but I am confident these are going to flow a lot better just from looking at pictures lol.

 

[gt5.0coyote]

I thought about it, a lot, and I already have a lot of power in the upper rpms with the manifold and camshafts. I would love to pick up some responsiveness in the car in the lower portion of the power band.

Plus, I really liked Shaun's "bigger is not always better" primary discussion thread from a couple years ago. It was a deciding factor for me when making this purchase.

https://www.svtperformance.com/forums/threads/long-tube-headers-which-primary-size-is-best.1065263/

I can understand what you are saying. I read through his thread also a while back. It was interesting. Good luck!

 

[oldbones]

Header picks up the midrange a lot on these cars. Plus the American sound that comes out of the tailpipes is amazing!!!

 

[Jumpmaster2015]

Header picks up the midrange a lot on these cars. Plus the American sound that comes out of the tailpipes is amazing!!!

Honestly, after adding the camshafts I have a dead zone where the car falls on its face if throttle is applied between 3-4k RPM. That is not heard of happening from the intake cams, so I am guessing it is from the exhaust cams. Hoping that adding the headers improves this feeling!

 

[WhiTriCobra]

I went with 1 5/8's and it's plenty. Felt better low and mid range gains.

 

[sur_real1]

I'll be going kooks on my build as well. Maybe a different size due to my direction, but hands down, they are amazing quality. Can't wait to hear your thoughts!

 

[Jumpmaster2015]

I'll be going kooks on my build as well. Maybe a different size due to my direction, but hands down, they are amazing quality. Can't wait to hear your thoughts!

Yeah I dont see myself sitting on the hardware for too long, TMS is doing the work since im still living on an army base but am not a mechanic anymore. This whole install is a retirement present to myself lol.

 

[corepwn]

When I still had the blower I picked up a set of the 1 7/8s kooks LTs and mid pipe, the quality and fitment was great.

 

[Jumpmaster2015]

Has anyone had any problems with waiting on parts lately? I heard the industry is backed up at the moment with racing season in full swing. I am still waiting on the headers to ship, not a huge deal, just wondering if anyone else is having the same luck

 

[sur_real1]

If you'd be willing to step up to a 1 3/4, American muscle has them available http://www.americanmuscle.com/kooks-longtube-headers-2011.html to ship on Monday with free shipping.

 

[Jumpmaster2015]

If you'd be willing to step up to a 1 3/4, American muscle has them available http://www.americanmuscle.com/kooks-longtube-headers-2011.html to ship on Monday with free shipping.

I already paid for the 1 5/8 from Beefcake, who did not have them in stock.

 

[sur_real1]

Well, maybe 1 5/8's are either so popular they are hard to keep in stock, OR Kooks has de-prioritized their production because they aren't so popular. Either way, good luck with your wait and install.

 

[Riddick]

Has anyone had any problems with waiting on parts lately? I heard the industry is backed up at the moment with racing season in full swing. I am still waiting on the headers to ship, not a huge deal, just wondering if anyone else is having the same luck

Have you reached out to your vendor to ensure the order was placed? When I ordered mine, I had them on my door step within a week. I honestly dont think it matters whether its racing season or not from a shop like Kooks. They have made many many sets of headers and I'm sure they can produce these at will.

 

[Jumpmaster2015]

Have you reached out to your vendor to ensure the order was placed? When I ordered mine, I had them on my door step within a week. I honestly dont think it matters whether its racing season or not from a shop like Kooks. They have made many many sets of headers and I'm sure they can produce these at will.

Yeah I talked to terry, and sent kooks an email over the weekend to see if they are backed up. Beefcake says exhaust can take 5-10 business days to ship if they do not have it in stock, and I hit that threshold on Thursday. Probably going to sit on it for another day or two.

 

[Jumpmaster2015]

1 5/8 seems to be a pain to find. A few places like AM had 1 3/4 in stock, but only beefcake and vmp could get a hold of 1 5/8. I found out today that the holdup is on kooks end, getting frustrated with their shipping process at the moment. Shaun had good things to say about 1 5/8, so im hoping the juice is worth the squeeze lol

 

[SixPak]

Don't recall hearing any quality or performance complaints from people who have installed Kooks. The same cannot be said for too many others. I know my BBK's were and absolute PIA to install, but the results made it worth while. But,...if I were to do it all over again....well, nevermind.
I think you made a good decision. Be sure and post up your impressions good or bad.