Outer Limits 4x4 Board

Hey guys are Mav/Patrol 4.2ltr diesel and 4.2ltr petrol extractors a exact direct bolt on changeover or there nothing alike, what i mean is do diesel extractors fit and work well on the petrols or is there some sort of difference like..ie..exhaust port sizing bigger than 1 another,tuned lengths are different on both diesels and petrol..etc

The reason im asking is im buying a 2nd hand set of extractors from bogged's mate and there off his diesel 4.2 and i want to fit them to my petrol 4.2, bogged said he's not to sure but he thinks they(Petrol&Diesel) both use the same extractors, Just want to know as im getting a new exhaust fitted and dont want to buy the extractors if there not what i need.

Also does anybody out thats done extractors/exhaust on a 4.2petrol got any suggestions as to what diameter exhaust works best on a 4.2ltr petrol with extractors..ie..2 1/4..2 1/2..Thanks..MAV

hhmm.. theoretically they should be the same as the blocks are the same.
Google yourself senseless and see if they are the same part number??

When I put extractors on my 4.5 petrol GU the same part number was listed for the 4.2 diesal and petrol ...

go to the hm headers site.

I called Fast Fit Mufflers in Frankston today, and they said they are the same part # for Petrol and Diesel.

$485 new + fitting, Tim will take $200 for them.
He is in Frankston.

bogged wrote:I called Fast Fit Mufflers in Frankston today, and they said they are the same part # for Petrol and Diesel.

$485 new + fitting, Tim will take $200 for them.
He is in Frankston.

what brand are they? I put a set on my TB42 when the standard manifold sheared in half (!) and they were $330 fitted.

I have a set you can have for 180?
they are off a petrol motor.

Jes

Difference between diesel and petrol extractors is this:

Diesel setup for torque - so they will form up 6 into 3 into 1 to generate more back pressure for torque reasons.

Petrol will be 6 into 1 for free flowing top end(where teh power is!)

At least that the way Pacemaker make em - and the differemce on a diesel is good!!!

80diesel4play wrote:Difference between diesel and petrol extractors is this:

Diesel setup for torque - so they will form up 6 into 3 into 1 to generate more back pressure for torque reasons.

Petrol will be 6 into 1 for free flowing top end(where the power is!)

At least that the way Pacemaker make em - and the differemce on a diesel is good!!!

my petrol ones go 6 into 3 into 1..

One will give good bottom end,
the other top end.

On a petrol 4wd, you need bottom end, so go the 6-3-1.

Jes

Hmm im confused now,Jessie what brand are you extractors and how old are they.And Wendle where did you have your extractors fitted for $330 was it in melbourne.Mav

canberra.

Wendle wrote:what brand are they? I put a set on my TB42 when the standard manifold sheared in half (!) and they were $330 fitted.

Pacemakers, they are sort of a Silvery/Blue colour, not sure of much else cant remember, but yea thats the price he said yesterday on the phone... Sorta remember them being expensive, but didnt think that much, but was a while back.

Pacemakers are the only way to go, that's all we have ever used. You will pay a bit more for them though. We usually run them with a 2 1/2" exhaust, if you can afford it go mandrel 2 1/2".

now i'm confused?
why are pacemakers the only way to go?
Whats the wall thickness diferences?
and whats the HP and Power differences for this specific application?
Are they welded different?

You will find that different brand extractors work well with different applications, Its not because they spend hours on a dyno with a 4.2 patrol ( in this specific application), Its because the certain brand/type of extractor may have the bend in exactly the right spot and the merge collectors positioned better blah blah blah.

THEN again, even different engines of the same model react differently because of different accesories/ignition/timing/load and/or rest of the exhaust sytems...

there are many variables....

Jes

Aus4wd wrote:Pacemakers are the only way to go, that's all we have ever used. You will pay a bit more for them though. We usually run them with a 2 1/2" exhaust, if you can afford it go mandrel 2 1/2".

Theres a pic of mates ones forsale, they DO have the dirt still on em! They also come with the flex pipe...

Seeings diesel and petrol extractors are a direct bolt on change over wouldnt that also mean that you could bolt on a Turbo diesel exhaust manifold and turbocharger to a 4.2ltr petrol fairly easily.Just a thought but could you and how do you think it would work.Mav

pace maker are cheaper than hm headers. pacemaker dont come with a bolt up flange. 6 into 1 (tuned length) are not good for a street or low revving engine, except some efi eg ls1. tri y's are best all rounders

MAV-RIK wrote:Seeings diesel and petrol extractors are a direct bolt on change over wouldnt that also mean that you could bolt on a Turbo diesel exhaust manifold and turbocharger to a 4.2ltr petrol fairly easily.Just a thought but could you and how do you think it would work.Mav

That sounds quite a good idea - but the size of the turbo and the angle of the turbo vanes will be determined for the diesel's operating rev range and airflows not the petrol's.

Of course - you can find a better flowing t3 or whatever it is that will suit and save you making a custom exhaust.....

Otherwise you will get good bottom end, but choke your top end right off.

I thought the same thing Suzuki Viagra I was thinking the same thing of the turbo aswell, i mean the original turbo would be ok to run say like 5-7psi of boost and would liven up the petrol engine significantly and improve torque aswell and on such low boost it wouldnt require a high flowing fuel pump you could probly get away with running a mechanical factory pump or a small carter electric, you could also run the diesel intake manifold and re-route the piping to fit an intercooler in also.Anybody else got any idea's of how this would work.Mav