Kook's Headers Dyno Results!!

So Logan,
I guess you'll have a used 1-5/8" set for sale before too long... When you put the supercharger on you'll naturally need the bigger ones!
 
Mike, mine will be on within the next two weeks (although I said that a few weeks ag too... hmmm...). We'll have to meet up somewhere and you can check these bad boys out. There's no reason to hook up those 2" pipes to these monsters. You can use everything from the stock mufflers back. A custom cat / x-pipe is neccessary to run between the collecotrs and mufflers.
 
Part of the reason the exhaust is actually making power is because the stock exhaust is just plain restrictive. All you need to do is look at the dyno graph. The stock exhaust gives up the crapper after 5200rpm.

So just adapting the header to the stock, restrictive exhaust system may net you a couple horse, but no flow no where near what a full aftermarket custom job does.

If you want quiet, use the 18" magnaflows instead of the 14's I use... The 18's are ALOT quieter than mine.
 
John, As efficientcy increases so should fuel mileage. If an engine requires less effort to move the same weight, it should be more fuel efficient. Obviously this may not apply to engines that have had their air/fuel ratio altered. Of course most of us have a tendency to alter our driving habits when we introduce headers to our cars. There's something about the installation of headers that makes us want to drive the bee jeesus out of it until we get it out of our system. Unfortunately these new found driving habits, as much fun as they are, have a tendency of taking our fuel mileage and sending it into the toilet. Regardless of that, if all else is equal, Kooks headers will increase HP and torque and should give you a tick or two increase in fuel mileage. Nick "Kook's Headers"
 
Nick is right, my mileage has increased...I'm getting roughly another .9-1.0 mpg on average...

So there ya have it, a mod that pays for itself!! :D Or at least, that's what you can tell the wife... :)
 
Header write-ip

Hey Logan!

Do you have that write-up for the header install done yet? I just got the x-pipe and hi-flow cats from Kooks yesterday and the headers are not far behind.

Thanks!
 
Logan, Did you opt for the entire Kooks system, headers, x-pipe, convertors etc? The numbers you gave are truely outstanding as it seems this DOHC motor really needs to breathe. Thanks for sharing the dyno results.

MarauderHI
2004 Merc Marauder Red in the 50th state


Logan said:
Wow!

I just got back from doing the post-dyno on my car with the Kook's exhaust on and was so excited I just can't contain myself!

Wow! (It bears repeating)

The only caveat I have to mention is that my car has a 3000rpm stall in it, so getting number much below 4000rpm is near impossible on a dyno. BUT, I can tell you, the newly available amount of power and torque down low launches my car like you wouldn't believe out of the hole.

That being said, my car prior to the header install, was making 256.3rwhp and 278.6rwtq.

My car, post header install is now making....

285.7rwhp and 293.5rwtq!!

That's peak, 29hp and 15tq!!

What's important to examine is that although the peak numbers are high, there are even higher spreads in the torque and power bands throughout the curve. There's almost a 50hp spread on power at 6000rpm!!!

All in all, what a kick ass investment!!
 
In the event Logan is busy or offline...


I am pretty sure he did what most of us have done, and that is purchase the ENTIRE Kooks kit which includes Headers, cats, h-pipe, and optional magnaflow mufflers.

And yes, the numbers are REAL!
 
Kooks

Logan said:
Wow!

I just got back from doing the post-dyno on my car with the Kook's exhaust on and was so excited I just can't contain myself!

Wow! (It bears repeating)

The only caveat I have to mention is that my car has a 3000rpm stall in it, so getting number much below 4000rpm is near impossible on a dyno. BUT, I can tell you, the newly available amount of power and torque down low launches my car like you wouldn't believe out of the hole.

That being said, my car prior to the header install, was making 256.3rwhp and 278.6rwtq.

My car, post header install is now making....



285.7rwhp and 293.5rwtq!!

That's peak, 29hp and 15tq!!

What's important to examine is that although the peak numbers are high, there are even higher spreads in the torque and power bands throughout the curve. There's almost a 50hp spread on power at 6000rpm!!!

All in all, what a kick ass investment!!
Hi, I'm close to going the kooks full system route. Couple questions: Did you do the 1 3/4 or 1 5/8 diameter pipes and is there an exhaust drone at speed (80mph) ? I've go the 4.10's, Lidio chip and CAI. I'm in New Jersey and can drive to Kooks in LI for a local install. Thanks, Stan
 
Go For It!!!

Yamaha said:
Hi, I'm close to going the kooks full system route. Couple questions: Did you do the 1 3/4 or 1 5/8 diameter pipes and is there an exhaust drone at speed (80mph) ? I've go the 4.10's, Lidio chip and CAI. I'm in New Jersey and can drive to Kooks in LI for a local install. Thanks, Stan
I just got my 4:10 's last week; with the Lidio chip, CAI, and the Kook's full system. It is a pleasant sounding exhaust, I don't notice any drone. You won't be sorry. Go for the larger pipes, let it breathe!
Note: you may need to get dynoed and the A/F ratio adjusted, I didn't notice it after the Kook's, but I did after the JLT CAI install. Lidio said that it was about 13.7-13.8, instead of about 13.0.

Ken
 
The cars that have had a mild drone, it tends to dissipate after 1000 miles or so after the new mufflers get broken in a bit. My headers were 1 5/8's...
 
I have the Kooks and was hoping to go there for a "local install," too. Nick was my rep and made it all sound like going there for the install was ok. I also asked him to let me know prior to his finalizing the order and shipping so that I could make sure that I had the cash in my account.

The next thing I knew the headers were delivered and I was being told by Nick that they were "too busy" to do a local install. I'll leave open that Nick could have forgotten but I have been in sales and marketing a long time and am inclined to think that not forgetting stuff like that is part of the job.

I am happy with the product. I, personally, feel that they have a little too much drone but I also am in love with the HP gains and the comments that others make about the exhaust note.

There has been an occasional contact problem which I noticed by seeing light scratches in the Jet coating on one of the pipes. Again, not a major issue. Stuff like this is sort of to be expected from aftermarket parts; expecially in a set up where it is all so very tight.

I was mostly happy with the service. The only thing that I disliked was that I was overpromised and underdelivered with reference to the local install and pre credit card charge phone call.

I mean NO disprespect to anyone, especially a club sponsor and especially to not to Nick but I feel it is necessary to say how I felt I was treated for the sake of others who might be planning to drive to LI for an install. Please don't flame me for thinking about fellow club members.

Best,

Dan
 
Last edited:
Logan said:
Wow!

I just got back from doing the post-dyno on my car with the Kook's exhaust on and was so excited I just can't contain myself!

Wow! (It bears repeating)

The only caveat I have to mention is that my car has a 3000rpm stall in it, so getting number much below 4000rpm is near impossible on a dyno. BUT, I can tell you, the newly available amount of power and torque down low launches my car like you wouldn't believe out of the hole.

That being said, my car prior to the header install, was making 256.3rwhp and 278.6rwtq.

My car, post header install is now making....

285.7rwhp and 293.5rwtq!!

That's peak, 29hp and 15tq!!

What's important to examine is that although the peak numbers are high, there are even higher spreads in the torque and power bands throughout the curve. There's almost a 50hp spread on power at 6000rpm!!!

All in all, what a kick ass investment!!

Logan, if you don't mind me asking, around how much did it cost you

to have the Kooks sytem installed? I need to have mine installed but

I am scared to ask for an estimate. :( Thank you.
 
Count on 10 hours labor x whatever the shop rate is... The guy I work with is $40/hr... At a dealership, it's typically $75/hr...
 
I paid $450 to a fellow that builds race cars from scratch. He did it in 5 hours, said it was relatively easy, particularly since I gave him all the install notes from our members here. BillyG has quite a writeup around here somewhere explaining every possible Marauder issue that could happen. The little things like a mis-aligned steering wheel shaft can wreak havok on an otherwise uneventfull install if unknown.;)
 
Back
Top