Gu Patrol exhaust tuning

Submitted: Sunday, Jan 06, 2008 at 19:08
ThreadID: 53179 Views:1544 Replies:4 FollowUps:6
This Thread has been Archived
Gday all the gu 4.2 tdi seems to lack power on take off and in the sand
although once shes wound up goes very well keep the revs over 2000 rpm and turbo working well i couldnt be happier
my research tells me a 3 inch exhaust will fix this
but some adjustments of the fuel pump and turbo are req
my question is can any one tell my what these adjustments are
or should we be not such a tight **** and pay some one to tune her after the new exhaust goes on
and can anyone recomend somewhere in the pilbara to do it
Cheers Barn
Back Expand Un-Read 0 Moderator

Reply By: Member - Mick O (VIC) - Sunday, Jan 06, 2008 at 19:26

Sunday, Jan 06, 2008 at 19:26

Post a question here on the Patrol Forum. Someone will know the answer for sure.

Cheers. Mick
''We knew from the experience of well-known travelers that the
trip would doubtless be attended with much hardship.''
Richard Maurice - 1903

Lifetime Member
My Profile  My Blog  Send Message

AnswerID: 280123

Follow Up By: Truckster (Vic) - Sunday, Jan 06, 2008 at 23:14

Sunday, Jan 06, 2008 at 23:14
or ask here and get the info..
or search here and find numerous threads on the same subject.
FollowupID: 544395

Reply By: Trevor R (QLD) - Sunday, Jan 06, 2008 at 22:01

Sunday, Jan 06, 2008 at 22:01
Hi Barn,

Try a couple of archive posts for info, 48656 & 47644. Wayne (in these posts) has done a bit of work on his 4.2 in your neck of the woods. Don't know if he got anyone to do the tuning or if he done it himself but next time you see him post, give him a follow up and I am sure he will offers his words of wisdom. OR!!! become a member and Member Message him directly without the wait LOL!!! If you have trouble finding these old posts let me know and I will post a direct link for you.

Enjoying the silly season in your part of the world?

AnswerID: 280171

Follow Up By: barney rubble - Sunday, Jan 06, 2008 at 23:35

Sunday, Jan 06, 2008 at 23:35
yeh yeh alright ive done it ok had 12 mths of lurking now ive paid for the membership ok haha
guess i was waiting for a reason oh yer and i am a tight****
Cheers for the archive posts too Barn
FollowupID: 544399

Follow Up By: Trevor R (QLD) - Monday, Jan 07, 2008 at 21:13

Monday, Jan 07, 2008 at 21:13
Good onya Barn, welcome to the members lounge hehehehe.

I will MM Wayne and alert him to this post to get his contacts on here for you while you await the members logon details LOL!!

See you at the members bar one day soon LOL!!!
FollowupID: 544567

Reply By: Skinnydog - Monday, Jan 07, 2008 at 00:56

Monday, Jan 07, 2008 at 00:56
Been in the pibara 15 years & all I can recomend is a drive to Perth, however if your near Hedland catch up with Paul from Battery sales & service as he has modded his Patrol, in Perth of course
AnswerID: 280204

Reply By: Member - Coyote (QLD) - Monday, Jan 07, 2008 at 13:01

Monday, Jan 07, 2008 at 13:01
I have a 4.2 TD GUIV and a 3" exhaust (mandrell bent) fitted. I had it done shortly after buying it new so it's hard to 'compare" but I really don't think it has made all that much difference.. certainly not all that much difference t o it's perfromance around town etc that I could pick up in the 10000k's or so I did before I had it fitted.. Maybe I'm missing something. It was re'tuned after the exhaust was fitted too.
AnswerID: 280259

Follow Up By: Trevor R (QLD) - Monday, Jan 07, 2008 at 21:06

Monday, Jan 07, 2008 at 21:06
Dear Coyote,

Not trying to minimise your opinion because some people validly do have this opinion of the old 4.2 slugs, but I am curious if you had the dump pipe fitted as well as the 3" exhaust. If not, here may be the problem. This dump pipe in standard is quite small compared to the aftermarket jobs and the difference is quite noticable when you drive an unmodified side by side against my worked 4.2 Patrol. I have a dyno printout on my rig pics to give you an idea but essentially I am almost 100% over factory settings and I have been running like this for miles. I currently have 340 000km on the clock and mine was worked on for the first time, pre delivery when brand new so longevity is a non-issue in my opinion.

If you are in Brisbane, Mike Vine turbo's will set you straight and fix any lack of performance issues you have with the 4.2 so long as you understand it is a workhorse and not a racehorse.

Best regards,
FollowupID: 544560

Follow Up By: Member - Coyote (QLD) - Tuesday, Jan 08, 2008 at 09:54

Tuesday, Jan 08, 2008 at 09:54
Thanks Trevor, I am now in Brisbane.. I had the 3" exhaust system fitted in Adelaide early on and I got Dyno rpint outs et and there wa sonly a marginal improvement. I accpet that if there is more improvement to be had it is out of my ignorance in not asking them to do further tuning etc.. addmittedly, I rushed it as I wasn't even iun the statte when my wife dropped the car off and then she picked up inthe arvo and they gave her the rpint outs. they told her a list of stuff they had done and I accpeted it on face value. Thecar now has 70k on it and I drive it like a workhorse not a race horse. I will take up your suggestion and tget the guys you mentioned to check it out and see if there is something I'm missing.. Thanks for the tips...
FollowupID: 544659

Follow Up By: Member - JohnR (Vic)&Kath - Tuesday, Jan 08, 2008 at 16:50

Tuesday, Jan 08, 2008 at 16:50
Coyote, you didn't answer the question as to the dump pipe which is the pipe at the back of the GU turbo. It is extraordinarily restrictive on the 4.2 at about 1.7" diameter. A 3" dump pipe takes a heap more gas out of the turbo.

Mine with a 3" dump pipe gave a 16% improvement in the 0-100kph time. Without a dyno, it was the only way I could quantify the improvement. It made a hell of a difference to the drivability.
FollowupID: 544699

Sponsored Links