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nissan patrol st-l gu3 4.8
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Discussion Starter #1
Hey guys, I have an issue with my gu iv. From idle to about 17-1800 rpm i have about 3nm of torque. Will a diesel chip fix this? I have 3" exhaust, egr block, dawes set at 18. Im considering a conversion as its getting pretty annoying especially off road....
 

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While I'm sure the zd gurus will chime in but have you also got a needle valve?
 

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Discussion Starter #4
No needle valve. Want to get as much boost down low as possible. Reduction gears dont really solve the problem in 2wd n 4h.
 

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There is only so much you can do, its a small motor after all.

What tyre size are you running?

Cheers

Justin
 

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Discussion Starter #6
Im running 33" cooper stt. I'd love to drive one that has a chip to see the difference. Weighing up whether to do td42 conversion or waste money on zd30
 

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You are not doing your low down torque at the wheels any favours with that set up.

I would suggest that you change the diffs to 4.375s if you have the 4.1 diffs, that would bring you back to standard again. For a bigger improvement you could look into the 4.6 diffs which will allow you to run bigger tyres again without the sluggish feeling.

A chip will also make a difference to the low end torque but make sure that you have an exhaust gas temperature gauge installed before you go down that path.
 

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No needle valve. Want to get as much boost down low as possible. Reduction gears dont really solve the problem in 2wd n 4h.

Using 3rd instead of 4th is a lot cheaper than an engine swap. The ZD likes to rev so drive it like a 4cyl not a big 6 and keep the revs over 2000rpm.
 

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Discussion Starter #9
Yeah I have pyro n boost. Will increasing spool rate also better the low end torque? Say 10 psi at 1500? I think im getting around 6psi atm. With either a jdvm or hpf maf housing. And yeah have 4.1 diffs.
Also don't want to spend $$ on a chip if its gonna do jack squat to low end torque. Wish I could try one before buying. Would be great lol.
 

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Yeah try tweaking your needle valve to get a tad more boost earlier.
You can also look at a lift pump :)

The 33s won't be helping.
 

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Discussion Starter #11
I don't run a needle valve. Was thinking of tweaking the vnt screw. I have a lift pump I bought for my gq before it got knocked off. But what benefit would it give me down low?
 

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I don't run a needle valve. Was thinking of tweaking the vnt screw. I have a lift pump I bought for my gq before it got knocked off. But what benefit would it give me down low?
Putting a needle valve in and taking control of the turbo away from the ecu by bypassing the solenoid in the airbox has proven to increase performance. This way you can tune the spool up rate and bring boost on earlier. I'd do this before or at the same time as vnt adjustment especially as you are asking about down low performance.

Running a lift pump (after doing the fuel return bypass mod) presents a positive feed of fuel to the ip (instead of the negative suction vacuum it normally has) which not only takes the load off it (reducing fuel temp in the ip is a good thing) but it also allows the ip to deliver the fuel pressure on time. The lift pump seems to present 4 -6 psi of pressure at the filter. Great when priming after changing the fuel filter too!
Doing the fuel return bypass mod helps with fuel temps too (sending the hot fuel back to the fuel tank return line instead of straight back into the ip) and with a fuel lift pump it helps to circulate the fuel and prevent pressure when the engine isn't running.
 

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I've read through the forum that there's evidence that the 2 3/4" or even 2 1/2" exhaust will create more low down torque with the trade off of loosing out right power and torque at higher rpm.

Obviously with you already having a 3" its probably not worth the effort to buy another exhaust.

I recon go with what the other fellas say regarding the needle valve to get more air in early and then if you still need more then a chip will at least have more air to play with to keep things safer.

Cheers
 

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I've read through the forum that there's evidence that the 2 3/4" or even 2 1/2" exhaust will create more low down torque with the trade off of loosing out right power and torque at higher rpm.

Cheers

I don't think there is any "evidence"... there is some anecdotal opinion and some clever marketing by beaudesert but that's about it.
 

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Y2KGUII ZD Wgn
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I don't think there is any "evidence"... there is some anecdotal opinion and some clever marketing by beaudesert but that's about it.
I know one person who will disagree with you, he has a 2.5" and his torque comes in lower than mine, I have slightly more peak but not as low as his.

Beaudesert were not even making anything bigger than 2 3/4" for a DI some time back and may even still be, that in itself speaks volumes to me. They are in the business of making money, if a 3" system was going to make them lots I would think they would do it in a heartbeat.
 

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I know one person who will disagree with you, he has a 2.5" and his torque comes in lower than mine, I have slightly more peak but not as low as his.

Beaudesert were not even making anything bigger than 2 3/4" for a DI some time back and may even still be, that in itself speaks volumes to me. They are in the business of making money, if a 3" system was going to make them lots I would think they would do it in a heartbeat.

I'm not saying it does or doesn't work on the Di but I haven't seen the same car on the dyno back to back to make a clean comparison. We used to have a stock 2001 that out gunned a stock 2003 in a rolling drag race...same everything but it just came out of the factory quicker.

I think it's clever of beaudesert to market a product that no one else sells and play up the benefits of their exclusive product. If they made a 3" then they'd be no different to everyone else and couldn't justify a premium price.
 

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Remove the EGR blocking plate and see what happens for a little test run. The EGR is also for low end power to help force down the pistons to increase low end torque. catch 22 on these engines im afraid.
 

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Discussion Starter #18
I had it put on the dyno today and found that it's running really lean down low which is where my problem is. Is there a way to fix this without a chip. Got quote 1880 for unichip and apparently it can also tune out fuel/boost cut. Would rather save my money for a conversion....
 

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I had it put on the dyno today and found that it's running really lean down low which is where my problem is. Is there a way to fix this without a chip.
I think I know the answer to that, for a fraction of the cost (almost fish and chips price) :)

it has taken some time,throwing chit and kicking and screaming,and some yelling and a whole lotta limp when not appropriate.:headwall:

playing with max boost/needle and hand controllers ;) but Im not far off 1st/2nd/ 3rd snapping gears and frying rubber off at the lights all the way through like a 18 year old P plater.I dont condone this behaviour by the way but by heck the pooey gets sideways like no ones business.

Im not chipped either.

before you go and make your bank manager a part of your family ------->http://www.patrol4x4.com/forum/zd30-di-engine-3-litre-71/jaycar-digital-voltage-modifier-102192/
 

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Discussion Starter #20
I've been looking at the jdvm but I don't understand how it will be able to adjust voltage to add more fuel and not get limp mode... are they easy to set up and do they work by rpm vs voltage? Maf voltage seemed pretty linear with rpm so don't understand how its lean down low..
 
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