turbo conversion kits on a 2.8 diesel toyota

Submitted: Monday, Nov 24, 2003 at 22:22
ThreadID: 8727 Views:20268 Replies:5 FollowUps:2
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can anyone give me any info on turboing a 1994 4 runner 2.8 diesel 200,000k's
i am considering towing a 16ft single axle caravan (1300kg) will it do it easy or would it put too much strain on the motor and drive train, also would it be an advantage also to intercool it i would appreciate any constructive opinions

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Reply By: Meggs - Tuesday, Nov 25, 2003 at 10:07

Tuesday, Nov 25, 2003 at 10:07
Try the technical section of the overlander site as there are a few Hilux experts there.
AnswerID: 38343

Reply By: get_me_outa_here2003 - Tuesday, Nov 25, 2003 at 11:48

Tuesday, Nov 25, 2003 at 11:48
G'day, here's my two bob worth...
I turbo'd my 2.8 Hilux as soon as the new car warranty ran out in '92. Best thing I ever did !!! It's now 11 years later and just under 300,000 K's and motor hasn't missed a beat. As long as the motor has been looked after (read clean, brandname fuel, clean filters & oil change EVERY 5000KM, with good oil !!), then all should be well, it's still a baby !! The turbo won't turn it into a V8, but will give you at least 1 gear better up any hill, and slightly better fuel economy (when taking it easy). Towing the caravan means you'll be working the car hard, but won't break it. Cruising on the speed limit is not too hard. Be prepared to be patient up the hills !! The trick is to know the rev's. Don't rev too hard, let the lowdown torque do the work. I tow a camper which weighs at least 1000kg, and find that down changes are not done until 2200RPM, with up changes at between 3000-3500. 3500RPM is about as high as you want to rev at any time. The drive train seems to handle the work OK, although I have broken diff pinion gears, but I don't think this is related to the turbo (long story). My gearbox is starting to become a little growly, especially in third, but it's still a long way off before I'll have to touch it. Clutches may be your only drama. Standard clutches won't last, they simply aren't strong enough. I've been using a "heavy duty" replacement clutch (brand name escapes me) from my reputable local auto parts store, for about 150000km, with absolutely no problem. The pedal pressure is about the same, just starts at higher position (not even the ex complained !!). The clutch takeup and feel are about the same. The intercooler would be a good idea as the car does seem to lose a bit of power when working hard on hot days. It definitely runs better on cooler days.

Overheating could be a problem. I find that the engine does have a tendency to run VERY warm when working hard on hot days. Never boiled or had to actually stop, but I have had to turn off air-con and slow down on really hot days. Intercooler wouldn't help this.

Look for a turbo that is water cooled, not just oil cooled. A Garrett T2.5 is very good. You want a system which has lots of boost down low (at least 7psi at 2000RPM). Pressure will actually rise at higher RPM (mine goes to 13PSI @ 3500). Disconnect any wastegate. Diesels are very different to petrol motors. For a petrol, too much boost means too lean a mixture, means too hot, means motor goes (expensively) bang. More boost in a diesel means more air, means leaner mixture, which means runs cooler, which means better !! As the fuel flow rate is fixed in HiLuxes (due to mechanical injection and no computers), there is no chance of the motor self destructing due to "overboosting".

The bigger, reputable companies all seem to do a good job, but it does take a little talent to get the injector pump tuning right. Be wary of anybody who simply "cranks up the pump until it blows smoke and then backs off a little". There seems to be a bit more to it, to get it right.

Bored or lost yet ??? Sorry, I get carried away !! There's more to the story, but the short version is: do it, you won't regret it !!!

AnswerID: 38350

Follow Up By: wizzer - Wednesday, Nov 26, 2003 at 17:57

Wednesday, Nov 26, 2003 at 17:57

I was curious about the disconnecting wastegate comment. Do you mean remove the pipe from it or block the pipe up or something else?

Has anyone else done this.

FollowupID: 28563

Follow Up By: Tonksy - Wednesday, Nov 26, 2003 at 19:32

Wednesday, Nov 26, 2003 at 19:32
Hey Dave,

I have a 98 Td Rodeo with aftermarket intercooler. With the factory turbo only putting out about 5psi, am I gonna cause damage at all by adding a boost controller and adjusting to 10psi or near about? Or should I be adding more diesel and monitoring with a pyro.
FollowupID: 28573

Reply By: howesy - Tuesday, Nov 25, 2003 at 19:36

Tuesday, Nov 25, 2003 at 19:36
Previous response is giving you the right advice. (i have a aftermarket turbo on mine)
Pay particular attention to his advice on the injector pump. Most installers say you only need to turn up the fuel but this is crap. Put an extra 500 aside and get your pump pulled off and stripped and cleaned and when they put it back together they add a prcentage to all the specs. not just the fuel.. it's the only way t do it properly
AnswerID: 38431

Reply By: get_me_outa_here2003 - Thursday, Nov 27, 2003 at 10:00

Thursday, Nov 27, 2003 at 10:00
The wastegate is a pressure driven valve. When the turbo is really pumping, the pressure builds to the (designed) point where the valve begins to open. This is done by opening an exhaust bypass gate. Instead of the exhaust gasses driving the turbine (and making the boost pressure), the exhaust gasses are directed straight out the exhaust pipe, hence less drive to the turbine, less boost pressure. In a petrol engine, uncontrolled boost can lead to spectacular, albeit inconvenient problems.

Diesels are different. The more boost, the better.

To disable, you simply block the small air hose from the turbine to the valve. You need to block the line so that pressurised air does not escape (waste !!!) and also block the valve side to stop any crap getting into the valve. The valve itself is usually located on the side of the turbine and has a lever, actuating rod and a pressure actuator (a cylinder about 2-3 cm long, about 2-3 cm in diameter, with the rod at one end and small air hose fitting at the other).

It is advisable to use a pyrometer (a type of temperature gauge), to monitor exhaust gas temperature. This will tell you whether the temps are getting too high which means the fuel/air mixture is too rich (lots of power, just not for very long....bang !!!!). High exhaust temps are the result of either too much fuel for a given boost pressure, or a problem with air flow resulting in reduced pressure (dirty air filter, bad or restricted air plumbing, badly designed snorkels etc)

Remember this applies to conventional, mechanical diesels, not the computer controlled, electronic injected types. Tinkering with these can be hazardous to the hip pocket !!

AnswerID: 38654

Reply By: get_me_outa_here2003 - Thursday, Nov 27, 2003 at 10:15

Thursday, Nov 27, 2003 at 10:15

I haven't heard of a "boost controller". The only thing you can do to the turbo directly is control any wastegate. If that is disabled, then boost pressure is not restricted. There are limits as to what a particular turbine can produce. If the most the turbo can produce is 5psi, then that's about it. If the wastegate is disabled and the turbo then makes 7 or 8 psi, then head for a good diesel tuning expert and get the pump re-calibrated to suit and enjoy the extra performance !!

As I said before, this is assuming there's no nasty electronics interfering anywhere!!

AnswerID: 38655

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