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-   -   Doug Thorley Headers (http://www.jeepforum.com/forum/f310/doug-thorley-headers-736956/)

ShootgunSchmid 03-23-2009 07:23 PM

Doug Thorley Headers
 
How many of you are running this header on the 4.0L in the WJ?
I am looking at getting one from Nick. Want to make sure that It holds up with out issue. And the number increase if able.

Nick: i just had to ask, I want to make sure, But once i get installed whats already ordered, I will probaly get one. I am going to help by brother-in-law out. By getting his jeep lifted. first.

Nick, Thanks for the quick responses and your help.

Eric

StrokedWJ 03-23-2009 08:06 PM

I'm interested too. I replaced everything behind the headers and would like to know what kind of gain they would give since they're the most expensive part of the exhaust system.

Kolak 03-23-2009 08:22 PM

There's no better constructed header on the market than the Thorley for the I6 -

It's 13 gauge stainless steel with 1/2 laser cut flanges -

The header is ceramic coated inside and out for excellent heat rejection -

Lifetime warranty -


If your 1999 WJ doesn't have precats we can use their Tri-Y header, otherwise Thorley also makes a split-style header for use with the precats.

StrokedWJ 03-23-2009 10:46 PM

Nick, do you know if anyone's dyno tested the 4.0L headers to see what kind of gain they give? Is there any benefit to the tri-y vs. the split style? I thought I read somewhere that the split style gave better torque #'s at lower RPM's but I could be making that up...

CrazyWalnut13 03-23-2009 10:55 PM

Quote:

Originally Posted by YHC2000WJ (Post 6861233)
Nick, do you know if anyone's dyno tested the 4.0L headers to see what kind of gain they give? Is there any benefit to the tri-y vs. the split style? I thought I read somewhere that the split style gave better torque #'s at lower RPM's but I could be making that up...

150whp 178lbfttq


post #15658 here:
http://www.jeepforum.com/forum/showt...dyno&page=1044

it's a ZJ with the 4.0 and 235/75/15 tires and 3.55 gears. Don't know about any other performance mods, he doesn't have any listed in his profile.


I know it's not a WJ 4.0, but it should be pretty close.


Edit: whoops, thought you were asking for dyno #s for the 4.0, reading>me

xJoshxx 03-23-2009 11:21 PM

Quote:

Originally Posted by CrazyWalnut13 (Post 6861304)
150whp 178lbfttq


post #15658 here:
http://www.jeepforum.com/forum/showt...dyno&page=1044

it's a ZJ with the 4.0 and 235/75/15 tires and 3.55 gears. Don't know about any other performance mods, he doesn't have any listed in his profile.


I know it's not a WJ 4.0, but it should be pretty close.


Edit: whoops, thought you were asking for dyno #s for the 4.0, reading>me

Isnt there a Stock HP difference Between the Older 4.0 and the new Powertec 4.0L? Stock says 195bhp other guy had his 4.0 Wj dyno'd stock and it was at 170 with bigger tires and gears.

rm2001wj 03-24-2009 09:42 AM

Tire size and gears don't matter on the dyno; the results are the same no matter what those numbers are. It's on the road that they matter.

Chatham036 03-24-2009 10:21 AM

Quote:

Originally Posted by rm2001wj (Post 6863506)
Tire size and gears don't matter on the dyno; the results are the same no matter what those numbers are. It's on the road that they matter.

i am going to have to disagree with that one.

when referring to vehicle weight i agree.

but tire size is a differnt story.

rm2001wj 03-24-2009 10:56 AM

Quote:

Originally Posted by Chatham036 (Post 6863754)
i am going to have to disagree with that one.

when referring to vehicle weight i agree.

but tire size is a differnt story.

Disagree if you want to, but you are diasgreeing with a fact, not an opinion.

ShootgunSchmid 03-24-2009 12:30 PM

Well if i do order one for mine i will have it dynoed, Then post numbers. Mind you with the ammount of miles i have on it. I think they might be low. I will wait till my programmer comes in from Nick before i dyno. I will ask the shop what factors affect dyno numbers beside the weather and elevation.

Eric.

StrokedWJ 03-24-2009 02:44 PM

Quote:

Originally Posted by rm2001wj (Post 6863953)
Disagree if you want to, but you are diasgreeing with a fact, not an opinion.

So you're saying that a jeep with the 4.0, 28" tires, and stock 3.55 gears would produce the same dyno numbers at the wheels as a 4.0 with 33" tires and the stock 3.55 gears? I don't see how thats possible, there has to be some parasitic loss due to the increased tire size.

ShootgunSchmid 03-24-2009 04:50 PM

I will ask for you. Till then can we all agree to disagree on this, yes.:tea:

rm2001wj 03-24-2009 07:04 PM

Quote:

Originally Posted by YHC2000WJ (Post 6865551)
So you're saying that a jeep with the 4.0, 28" tires, and stock 3.55 gears would produce the same dyno numbers at the wheels as a 4.0 with 33" tires and the stock 3.55 gears? I don't see how thats possible, there has to be some parasitic loss due to the increased tire size.

You are right, larger tires (with their larger weight) will reduce the wheel torque/hp numbers. :oops:

nashmd454 03-24-2009 07:27 PM

Quote:

Originally Posted by rm2001wj (Post 6867515)
You are right, larger tires (with their larger weight) will reduce the wheel torque/hp numbers. :oops:

wow....I thought I would never see this day...but you were wrong and yet still admitted it. Good for you Bro....


I for one do not have Thorley headers but can offer proof by seat of the pants gain and not dyno gains (I have bought alot through Kolak) that there is a considerable increase....not supercharger or turbo on Nos increase...but an increase. I have yet to Dyno mine...and yet mine stock says 235 from the factory (5.2...I am sure at the crank) and yet I am sure I am at 300 at the wheels with my mods.

nashmd454 03-24-2009 07:28 PM

I apologize...I really never commented your topic....anything you get from Kolak will absolutely be of your best interest.

Hey Nick...will that help on my new heads mods prices...:rofl::rofl:


The time now is 02:51 AM.

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