Outer Limits 4x4 Board

how much boost is it safe to run in my td42t i have a high flowed turbo and a 3 inch mandel exhaust with no muffer am currently running 15 psi

im running 16psi with 3 inch exhuast without a cooler or fuel/boost compensator with 35's on and havent blown the motor in my gq yet

Hey mate,

Measure your inlet temps that will be a good indication of how much boost you can run. The more efficient your turbo the lower the inlet temps. Go beyond the efficiency and the turbo produces more heat then the extra boost will give powers.

With a good intercooler you can see 80-100 degrees drop from one side to the other.

Cheers Heath.

The motor can handle 22psi without any hassles, chances are you turbo won't (as Heath said) There is no point running extra boost if all the turbo is doing is heating things up. If you want to increase boost first thing is an EGT gauge so you know what is happening. Then you can gradually increase boost and fuel untill you get to a desired performane and EGT and you'll know when the motor is going to go bang! If you want big HP then you need a bigger turbo. Garret T3 / T04 hybrid or similar (ball bearing if you've got the money) is a good starting point but it all depends on what you want.

How much boost will a std turbo off a 4.2 gu safely push

DR Frankenstine wrote:How much boost will a std turbo off a 4.2 gu safely push

10-12 psi should be kewl

Ive got an aftermarket dynamic turbo kit i think when dynoed with 33's on it made 150hp atw but it definatly needs a fuel/boost compensator bit smokey smokey

i have a egt gauge fitted in the dump pipe and have had the factory turbo high flowed ( larger compessor wheel ,compessor housing flowed) the truck was dynoed and boost and fuel adjusted .im still using the standard intercooller and piping i dont know how hot the air temp is but it didnt run hot on the dyno. im not chasing more power i just dont want an engine or turbo failure in the middle of the dessert or somewhere else inconveneant .thank you for your input

Keep your EGT to below 500 and you'll be fine forever

Im running 12 pound through a dynoglide turbo setup (looks very similar to a R33 skyline turbo sizing and my EGT maxes at about 450 on a long hard pull in 4th gear (tassie has lots of hills) and mine hasnt given me any grief.

My 2c anyways,

Simon.

running 16psi and ive only had the egt upto about 550 doing hill climbs but apart from that just cruising it sits on about 200 mite need to go a bigger turbo to get rid of some of that heat

sld86 wrote:running 16psi and ive only had the egt upto about 550 doing hill climbs but apart from that just cruising it sits on about 200 mite need to go a bigger turbo to get rid of some of that heat

unless they happen to have a crap turbo you would be better off fitting an intercooler.

i gather its best to go a top mount i/c whats the best size for them

What is the better intercooler setup?Top mount or Front mount.What are the benifets and downfalls of either.

if you do alot of mud top mount or water air is more beneficial however for around town or non mud activity and when i mean mud i mean bog holes over the bonnet go a front mount.

Front mounts are generally alot cheaper to setup i mean u can buy a second hand factory top mount but its no wear near as good as a front mount for air flow.

Saying that if you get a decent top mount cooler development it would be good also..

I'm going a front mount in my GU, with 4" snorkle larger airbox extractor manifold and roller turbo so as soon its done will let u know how I go.

i just fitted a top mount to my td42 and i did notice improved power and way better economy on the hwy but i did lose about 3 to 4 psi at the intake manifold , it was prior to intercooler 15 psi now i can only get about 12 max even if i wind up the fuel pressure my egt did drop by about 100 deg also i was wondering if i put a bigger pipe from the cooler to intake would this reduce the back pressure enough to boost my psi or should i look somewhere else it is currently 2 1/4 from turbo through to manifold

i think if you front mount it you are putting extra strain on the cooling system plus you get a bit more turbo lag through the extra piping

im running gu td42 with 3" exhaust, boost compensator, 18psi, cranked up the fuel, egt max towing 600 degrees, 95 kw and 450 torque at rear wheels. Well balanced for fuel use and power and temps.
Cheers

how costly is it to go a top mount on the 4.2d and how expensive has it been to get a boost compensator

More accurate detail is standard top mount intercooler, standard turbo, boost control added and the standard compensator was tuned while on the dyno. He backed off the off boost fuel as it was fuelling up like a bastard.The diesel tech dida great job.

rvh96 wrote:how much boost is it safe to run in my td42t i have a high flowed turbo and a 3 inch mandel exhaust with no muffer am currently running 15 psi

hey mate,

been told by a number of people dont go more than 15psi if you want realiabilty they can do upto 20psi but they wont last long see it done before.

if you want more power your in the same situation as me and you will need better intercooler larger turbo air and most likely a snorkle

it is the pistons u need to worry about with high boost temp and strength as the crank and rods are dorped forged steel but good news is droped forged pistons are only $1500 as for how much boost well how long is that bit of string. ive had 25 psi in mine and it has 550000 kms still going . aznd inter coolers well whats the car for high speed top mount is ok but low speed think water to air is better just my tow bobs worth hope it helps