80 series exhaust size
Submitted: Sunday, Oct 29, 2006 at 23:50
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Member - Jiarna (NT)
Hi all
Some time ago I put a set of headers on the 1HZ, but ran out of $$ to replace the rest of the exhaust system. Has anyone out there got any useful suggestions about the best size to go for? I heard 3" is a bit of a tight fit.
Thanks
John
Hermannsburg NT
Reply By: alexk - Monday, Oct 30, 2006 at 09:50
Monday, Oct 30, 2006 at 09:50
John,
I don't have any personal experience here but have heard that 2.5" is the most common. Maybe a silly question but always wondered what will upgrading the diameter of the exhaust system give you in terms of power/toque and real off road performance, etc?
Cheers,
Alex
AnswerID:
201759
Follow Up By: Exploder - Monday, Oct 30, 2006 at 12:10
Monday, Oct 30, 2006 at 12:10
Allows the engine to breath better thus allowing it to produce slightly more toque and power.
Slightly more to it than that but that’s basically why.
As a example on a 5litre Windsor V8 buy simply adding a set of Tuned length Extractors and the rite exhaust you can pick up 15-20KW.
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Follow Up By: Member - Jiarna (NT) - Monday, Oct 30, 2006 at 13:49
Monday, Oct 30, 2006 at 13:49
Hi Alex
Probably not a lot of difference off-road, but maybe a few extra horses on the long stretches between the off-road fun bits.
Cheers
John
FollowupID:
461186
Reply By: madfisher - Monday, Oct 30, 2006 at 13:13
Monday, Oct 30, 2006 at 13:13
On a standard motor 2.5 in Should be best, go to big and you can lose power
Cheers Pete
AnswerID:
201791
Follow Up By: Member - Jiarna (NT) - Monday, Oct 30, 2006 at 13:51
Monday, Oct 30, 2006 at 13:51
Thanks Pete
I read on another post that I should change the muffler to a free-flow type, so it looks like 2.5" mandrel-bent system with a free-flow muffler is on the cards.
Cheers
John
FollowupID:
461188
Reply By: udm - Monday, Oct 30, 2006 at 21:21
Monday, Oct 30, 2006 at 21:21
You planning on turboing in the future??? If so, go for a 3inch mandrel now... I made up my 3" dump pipe and exhaust on saturday and cant believe the difference it has made...
Ulises
AnswerID:
201897
Follow Up By: Member - Jiarna (NT) - Monday, Oct 30, 2006 at 21:30
Monday, Oct 30, 2006 at 21:30
Good point udm. A turbo is on the wish list, but a very long way from the top at this point. I guess if the 3" system will fit OK, and work with the headers, then it might be the way to go. I'll have to decide if a turbo is likely or not - have to rebuild the engine first before that goes on!
Cheers
John
FollowupID:
461317
Reply By: Member - Glenn D (NSW) - Monday, Oct 30, 2006 at 23:37
Monday, Oct 30, 2006 at 23:37
OK , I need some help as
well ,
They say you need some back pressure on a normally aspirtated engine, but a free flow exaust on a turbo ( hense guys with twin 4 " systems ).
Whats the limit , Used to have a 3" single system on my V8 Commodore , seemed to go OK , you see a V8 Super Car and they have staight though pipes ?
Help Exaust Gurus !
Glenn.
AnswerID:
201946
Reply By: cruiserman1961 - Wednesday, Nov 01, 2006 at 21:50
Wednesday, Nov 01, 2006 at 21:50
Gooday mate,
you have to consider that a bigger pipe also poses the possibility of the motor consuming more oil. On hot days with a heavy workload the oilconsumption of an older engine can be quite a problem. My HZJ 80 has done 480000 km's now and doesn't use any oil with the standard system. It had a 3"system underneath when I bought it. The oil consumption then was approx. 1.5 ltrs over 5000 k's. I don't think that the bigger exhaust made that much of a difference but then I don't do any heavy towing either.
Cheers, Udo
AnswerID:
202383
Follow Up By: Member - Jiarna (NT) - Thursday, Nov 02, 2006 at 00:55
Thursday, Nov 02, 2006 at 00:55
Thanks Udo
I have 382K km on the clock, and don't use any oil between
services. Usually we are towing a trailer, and the weather is mostly hot, so I'll keep your experience in mind. Have to make my mind up sooner or later, and like most things for the 4WD, it's serious $$ to make changes so I don't want to make the wrong choice LOL.
Cheers
John
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