Patrol Pics



Freeflow pipe diameter on a 4.5

Engines and Engine Systems

Freeflow pipe diameter on a 4.5

Postby Zantus » 24 Nov 2012 05:33

My Patrol has 270K on the clock and it still has the factory exhaust and catalytic converter.

It' time to do a freeflow system and let her breath properly, but the question is, what diameter pipe should it be and why?
Zantus
Senior Member
Senior Member
 
Posts: 151
Joined: 30 Apr 2009 14:50
Has thanked: 3 times
Been thanked: 5 times
Full Name: Barto de Koning
Nickname: Zantus
Home Town: Port Elizabeth
Current 4x4: '01 4.5 GU & '91 4.2D GQ
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby Tinus lotz » 24 Nov 2012 07:14

I do belief that cats on patrols came out. Only on some s.x models but I might be wrong if you have a cat and you remove it you have to make a plan to con the lamda censor to keep every thing happy I will keep manifold and put 50 or 63 to the back
It works well with 2 big boxes
Keep in mind the under bonnet temps when u remove mainifolds
:thumbup:
User avatar
Tinus lotz
Moderator
Patrolman 1000+
Patrolman 1000+
 
Posts: 6334
Joined: 29 Aug 2010 13:07
Has thanked: 419 times
Been thanked: 214 times
Full Name: Tinus lotz
Nickname: Tinus lotz
Home Town: Centurion
Current 4x4: Nissan patrol 4.8 GRX 2005

Toyota 2.7 legend 35 LWB 4X4
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby Peter Connan » 24 Nov 2012 08:21

Zantus, do you truly have a Cat on your Patrol? I have looked at several much newer cars (up to 2003/2004 4.8's) that did not have cats?

Anyway, to answer your question, I believe that the experts say that the pipe needs to be smaller for the first section, then open taward the back. There is an old post here somewhere with a more complete explanation, but as a shortcut send Frans Fourie (Tour de Frans) a PM.
Mag ons ons kenniskry met lekkerkry aanhoukry.
User avatar
Peter Connan
Moderator
Patrolman 1000+
Patrolman 1000+
 
Posts: 4722
Joined: 10 Sep 2010 07:21
Location: Kempton Park
Has thanked: 144 times
Been thanked: 200 times
Full Name: Peter Connan
Nickname: Piet
Home Town: Kempton Park
Current 4x4: 1996 Patrol 4.2SGL
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby marakasmalan » 24 Nov 2012 10:23

Hello,

Yes, Peter, the pipe needs to be smaller closer to the manifold as a certain level of "backpressure" is required for the engine. Towards the rear it can open up to provide less resistance to flow. I personally do not like to tamper too much with the factory set-up, as they take a lot of factors into account when doing these specifications, and when you alter this you alter the pressures and flow rates in the combustion process. Hence it is possible to create more power, by enabling it to combust more fuel and placing the whole process outside the design specifications - which can be detrimental to the engine in the long run.

As for the cat, if there is a cat, you need to replace the lambda sensor with a resistor. messure the amperes and meassure the voltage as well as the voltage drop over the sensor on this circuit when the engine is hot and running smoothly. Get the clever guys to calculate the resistor value. Ideal would be to set it up so that these values can be monitored in the vehicle so you can monitor the effect under different conditions. It is trail and error to a certain degree so try to obtain information from somebidy who did this already.

Back in 2006 we hacked the ECU code for a OM 501 LA-541 engine and we were quite surprised to see where the lamba value was parsed to. Though we did not bother too much about this, it affected or was fed to the inlet/turbo pressures, the fuel management (mixture adjustment, and injection pressure managment) routine and the retarder routines also aquired this value. What exactly it did we did not know, but it was not a value that was simply monitored, these units actually used it as input, with lots of other values, to create output.

This was in Europe and a Euro-5 complaint engine, so emissions were critical.

regards
User avatar
marakasmalan
Senior Member
Senior Member
 
Posts: 360
Joined: 20 Oct 2010 17:22
Has thanked: 4 times
Been thanked: 17 times
Full Name: Marnus Malan
Nickname: marakasmalan
Home Town: Kempton Park
Current 4x4: '94 Patrol SGL
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby Kagiso II » 24 Nov 2012 17:21

Hond se maaaaamie -- julle kan hirri nuwe frgggn tegnologie maar HOU -- Lam daar, lam hier, e-gee-tee, en dan alles on sensuur ook nog, alewag gesensor met noggge sensor om elke hoek en draai, en boonop hoor ik nou van katte wat nesmaak inni exhozzt .. se mur - Gee my 'n ou-skool V8 .. klaar gelag.
Don't bring God down to your level of faith ... bring your faith up to His level!
User avatar
Kagiso II
Patrolman 1000+
Patrolman 1000+
 
Posts: 3372
Joined: 10 Jun 2009 16:58
Location: Benoni and wherever the Outreach takes me.
Has thanked: 178 times
Been thanked: 77 times
Full Name: Mac Mc Menamin
Nickname: Oom Mac [Uncle Mac] [Uncle] [Oompie] Kagiso
Home Town: BrentwoodPark, Benoni
Current 4x4: 1982 Datsun Safari 2,8 aka LOBO; [1,300,000 Km verby !]
'99 PATROL 4,2 diesel.
2012 Jimny [SWAMBO se Kantoor-toe]
Home Language: AFRIKAANS

Re: Freeflow pipe diameter on a 4.5

Postby SJC » 18 Apr 2016 07:49

What would be the ideal freeflow setup for a 4.5? wrt,pipe diameter, number of boxes?
User avatar
SJC
Patrolman 1000+
Patrolman 1000+
 
Posts: 2332
Joined: 23 Nov 2014 14:20
Has thanked: 56 times
Been thanked: 94 times
Full Name: SJC
Nickname: Fanus
Home Town: Lowveld
Current 4x4: 4.2TD Pickup & 4500 GRX
Home Language: Afrikaans/English

Re: Freeflow pipe diameter on a 4.5

Postby Michael » 18 Apr 2016 14:25

I dont belive in the back preasure thing and belive that there is only one engine that requires back preasure......and thats a 2 stroke engine.

Any other engine performs better the fater you cab get the old air out and the fresh air in. More back preasure means less wxhaust gas will actually get out of the combustion chamber which in return will give you less oxygen when air needs to enter the engine.

Motor manufacturers focus allot on emmissions so they will gladly secrifice performance to get better emmission readings.

One thing is sure, when you install a freeflow exhaust the engine will run more on the lean side, so its best to dyno it asap as a Patrol engine running lean can lead to burnt valves. :mytwocents:
"The Just shall live by Faith" Rom1:17

Check out my build here My Patrol
And my engine rebuild here mostly engine related stuff
User avatar
Michael
Moderator
Patrolman 1000+
Patrolman 1000+
 
Posts: 2204
Joined: 05 Mar 2014 14:39
Location: Centurion, PTA
Has thanked: 97 times
Been thanked: 186 times
Full Name: Michael
Nickname: Steyn
Home Town: Centurion
Current 4x4: Patrol GU 4.2 Turbo Diesel
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby jonathan » 18 Apr 2016 15:13

Fanus hieronder is raad wat ek by Frans gekry het 'n paar jaar terug vir my 4.5. Ek het die kompleel stelsel opsie gedoen en ek was baie happy! Selfs my swaer wat 'n cruiser man is het opgemerk hoe baie torque op lae revs die patrol gehad het :lol:

" 'n Kompleet stelsel. Gaan vir 63mm. met 2 silencers. Maak die front pipe 50mm tot by eerste box, die box maak jy 63mm. Voltooi die sisteem met 63mm.
n Halwe freeflow. Gooi die agterbox uit en sit n 400mm lank 63mm box in, voltooi die res met 63mm.
Indien jou kar 63mm op het, werk net die boxse. Dit alles natuurlik as die pypwerk nog in n goeie toestand is.
Die 50mm pyp voor die eerste box gee meer torque op lae rpm, en boet geen krag in op hoe rpm nie.
As jy hou van n crisp klank, maak al die boxe "centre to centre" MAW jy moet regdeur die box kan kyk."
User avatar
jonathan
Senior Member
Senior Member
 
Posts: 230
Joined: 20 Aug 2012 16:24
Has thanked: 3 times
Been thanked: 18 times
Full Name: Jonathan Venter
Nickname: jonathan
Home Town: Jacobsbaai
Current 4x4: 2005 4.8 GRX
Home Language: Afrikaans

Re: Freeflow pipe diameter on a 4.5

Postby David M » 18 Apr 2016 15:27

Remember that on the 4.5 if you go the branch manifold route with the freeflow you must ceramic coat the branch or your under bonnet temperatures go through the roof.

A couple of the guys here including myself have been very happy with Abel from Viper's branch and freeflow.
There are still places out there!!!! - Daniel Goz - The "Tapam" movie
User avatar
David M
Patrolman
Patrolman
 
Posts: 693
Joined: 12 Nov 2013 15:13
Location: Midrand
Has thanked: 16 times
Been thanked: 59 times
Full Name: David Marais
Nickname: David Marais
Home Town: Midrand
Current 4x4: 1998 4.5 GL Patrol
2006 4.2 Td Bakkie (SWAMBO's) - The "Firetruck"
Home Language: English

Re: Freeflow pipe diameter on a 4.5

Postby BulDog » 22 Apr 2016 11:56

How's it guys
I read this post quick and I'd just like to add my 2cents. I might be wrong but I seriously remember reading some where once that on a petrol car the exhaust is the other way round. With that I mean that the exhaust starts out wider/bigger and then slightly narrows towards the end. The reasoning behind this was that as the exhaust gasses leave the manifold they are hot and heat has a high expansion value ie more volume. Then as it goes down the pipe it cools slightly and contracts taking up a lesser volume/space in the pipe.
What this means is that it causes a type of vacuum and by so doing helps suck the gas out the pipe and engine faster.
Ill try look it up where I saw it.
BulDog
Junior Member
Junior Member
 
Posts: 17
Joined: 23 Jan 2015 13:46
Has thanked: 0 time
Been thanked: 2 times
Full Name: Niel Herselman
Nickname: Nielas
Home Town: Sterkstroom
Current 4x4: Nissan
Patrol
4.2 TDI
Pick up
Home Language: English


Return to 09. Engines

Who is online

Users browsing this forum: No registered users and 2 guests