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Headers and Underdrive Pulleys
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=88&t=78411		 Page 1 of 1
Author:  huntb [ Wed Feb 26, 2014 6:04 pm ]
Post subject:  Headers and Underdrive Pulleys
I've seen the JBA (not Jeepin by Al) headers that are made for the KJ and was wondering if anyone knew if they would fit the KK. I'm 99% positive the exhaust ports are the same, but is there anything in the way?

I'm also wondering if anyone makes underdrive pulleys for the 3.7?

I work with a guy that knows his stuff (two NHRA racing titles) and he said those are two of the biggest things we could do for our KK to get back a little power. Along with replacing the muffler or entire exhaust system.
Author:  Gageraid [ Wed Feb 26, 2014 8:02 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
I've read quite a few things about headers for the 3.7L and would be curious to know to. The underdrive pulleys would be cool to know about, too.
Author:  tommudd [ Wed Feb 26, 2014 8:32 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
They only made headers for a short time, and that was 4-5 years ago so if there was still a set out there floating around it would be hard to find them. Plus unless you did some other work to the engine headers wouldn't help that much except maybe at WOT.
Author:  tjkj2002 [ Wed Feb 26, 2014 10:37 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
And you don't want under drive pulley's unless your just racing.Your battery and PS will suffer.
Author:  huntb [ Thu Feb 27, 2014 9:12 am ]
Post subject:  Re: Headers and Underdrive Pulleys
tjkj2002 wrote:
And you don't want under drive pulley's unless your just racing.Your battery and PS will suffer.


If I got an underdrive pulley, I would try to find an overdrive for the alternator. Not too worried about PS

Also, Tom, JBA still sells the headers here: http://www.jegs.com/i/JBA/578/1930SJS/10002/-1

They also come in stainless and titanium ceramic
Author:  tommudd [ Thu Feb 27, 2014 10:01 am ]
Post subject:  Re: Headers and Underdrive Pulleys
huntb wrote:
tjkj2002 wrote:
And you don't want under drive pulley's unless your just racing.Your battery and PS will suffer.


If I got an underdrive pulley, I would try to find an overdrive for the alternator. Not too worried about PS

Also, Tom, JBA still sells the headers here: http://www.jegs.com/i/JBA/578/1930SJS/10002/-1

They also come in stainless and titanium ceramic


You need the PS to turn at the right speed to provide the right amount of pressure as well so yes be worried.
Plus JBA doesn't "still" sell they must of started again. They had quit a few years back due to low demand, no use buying something if there is very little that it does for you in the end.
Author:  huntb [ Thu Feb 27, 2014 10:22 am ]
Post subject:  Re: Headers and Underdrive Pulleys
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428
Author:  Gageraid [ Thu Feb 27, 2014 2:42 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
huntb wrote:
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428


:goink: I'll have to do some more research. I have been looking for another engine mod... but there aren't any I know of. I will be trying the "Premium" Hypertech tune when it warms up again.
Author:  silverkk [ Thu Feb 27, 2014 3:44 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
I was thinking about the headers but idk about how much I need them lol
Author:  Cherrie 274 [ Thu Feb 27, 2014 3:54 pm ]
Post subject:  Headers and Underdrive Pulleys
silverkk wrote:
I was thinking about the headers but idk about how much I need them lol

Need is a state of mind!
I Had a Dodge V10 and I needed headers and dual exhaust.
Not for power or performance. Stock was good. But to try to make it sound like something other than a 6 cylinder Volare.
Go figure since then all have been 6 cylinder's.
Author:  tommudd [ Thu Feb 27, 2014 5:27 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
huntb wrote:
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428

NO Negative effects huh :ROTFL:
Ok you do realize that once someone bolts a product onto their vehicle it makes more power no matter if it does or not. VERY few people will ever say I just spent 500 bucks and guess what it didn't work.
Author:  huntb [ Thu Feb 27, 2014 6:07 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
tommudd wrote:
huntb wrote:
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428

NO Negative effects huh :ROTFL:
Ok you do realize that once someone bolts a product onto their vehicle it makes more power no matter if it does or not. VERY few people will ever say I just spent 500 bucks and guess what it didn't work.


Always a critic! Come on Tom, you've been around long enough to know that our crappy 3 into 1 headers are a junk design from the 70's. There is zero scavanging on the stock KK headers. The JBA headers may be shorties but they are better than noneies
Author:  tjkj2002 [ Thu Feb 27, 2014 6:16 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
huntb wrote:
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428

Will not work on a KJ/KK unless you have a bolt-on damper which the last time I checked all '10 and older are not a bolt-on pulley.What I'm talking about is a 2 piece pulley.

You don't gain anything but problems in a daily driver as your turning everything 25% slower,which includes the water pump.So less amps from the alternator,less PS pressure,and less cooling ability.I'll pass but go ahead to get your 0.10 extra mpg.
Author:  tommudd [ Thu Feb 27, 2014 7:16 pm ]
Post subject:  Re: Headers and Underdrive Pulleys
huntb wrote:
tommudd wrote:
huntb wrote:
Here is the underdrive pulley from ATI if anyone is interested. It's only a 25% UD reduction but it also weighs much less than stock. It is kind of pricey but I've heard great things for both performance and fuel economy. There is a company called ASP that used to make one but no longer does due to low sales volume but was about $100 cheaper than the ATI pulley. I have read several WK 3.7 success stories using the ATI pulley with no negative effects on battery or PS (I'm looking at you Tom and TJ :roll:). It wouldn't kill to try it if you have the funds. Gage, seeing how you're our resident hypermiler (oxymoron) and performance enthusiast (also an oxymoron) I think that you should be our test dummy. Here's the link over at Summit:

http://www.summitracing.com/parts/ati-918428

NO Negative effects huh :ROTFL:
Ok you do realize that once someone bolts a product onto their vehicle it makes more power no matter if it does or not. VERY few people will ever say I just spent 500 bucks and guess what it didn't work.


Always a critic! Come on Tom, you've been around long enough to know that our crappy 3 into 1 headers are a junk design from the 70's. There is zero scavanging on the stock KK headers. The JBA headers may be shorties but they are better than noneies


Critic?? Nope just real is all , tell it like it is.
And yes I am old(er) :wink: and have ran my share of headers on vehicles where I also did cams/intakes, carbs etc , where it made a huge difference in the end result. Had headers on both of my CJ5s with the 304s in them. Also had them on one of teh Cherokees but that was due to the exhaust manifolds always cracking, not for any performance gains. BUT in the 3.7s I can not see spending that much money for something that will give you back very little increase.
Author:  etflies1970 [ Fri Feb 28, 2014 1:51 pm ]
Post subject:  Headers and Underdrive Pulleys
There is no such thing as free power in an engine. It's a give or take and as stated above its cooling , power steering pressure and your alternator which all are very important. As you DD I would make sure my cooling system is operating at peak efficient not at 75%. Also when you get advice from a person who builds race cars just remembers the goal is a few runs a weekend and if your smart it comes and leaves on a trailer due to the fact it only meant to run only for a few min at peak power. I've been in the air-cooled vw scene for 15 years and have found that newtons law applies very well when you are modding a car or Jeep. Do what you want but Tom and TJ have it right. As for mileage you should of known what you were getting when you bought the liberty, there is nothing but changing your habits on the accelerator to get better MPG's
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