Supercharging a GU Patrol

G'day Peter,

It's just not worth it. You can if you wish, but the differences in cost are the killer. Performance wise, the truck is a different proposition to a marine application. Marine engines tend to drone on for hours or days at constant rates. Not that this would worry a turbo, but supercharging is always slightly cooler in terms of performance. Remember, that you are compressing air here. With the compression of the air, you are heating it considerably!

I would suggest that the money spent on the turbo charger would be a better spend. That and an Intercooler.

I know a bloke who is an outback challenge competitor (read serious power hunter)and has a 4.2 PETROL patrol that has asupercharger on it and a huge intercooler c/w water spray. he has endless trouble trying to get someone to sort it including the original fitters so he can get it reliable. I'd be going the proven reliable route of turbo. I know what you mean about the superchargers potential low down and even spread of grunt but reliability is the prime criterea in a 4wd.

Im with you, I have the turbo, and next time IN going to go a supercharger.

You dont have AS many heat issues, you dont have turbo lag, if a turbo blows up, you get towed home, supercharger dies, you take the belt off and drive home.

They are HEAPS of $ but then so is a turbo with a good exhaust...

Wheres Chris, he has one, search the archives, he has a TD42 GQ with supercharger.

Hi all , Sprintex do a supercharger kit for the 4.2 diesel patrol. One of my farmer customers had one on a GQ and had no mechanical probs in nearly 3000,000 k's The vehicle had a very hard life in this time, with 'young blokes' driving it and was used for towing a boom sprayer in the paddock an operation that kills four wheel drives! It was a good advertisment for NISSAN,
Regards Ken.

Colin (do a search) has a supercharger on his TD42 (I have driven it).
Most impressive. Lots of grunt from idle up! Somebody near Beenleigh did it for him with a Commodore supercharger I recall. He reads this forum often I gather so maybe he'll reply with some costs etc.
However I went the turbo option all the same with mine.. as I had a friend who had one "spare"- as he was getting a new factory turbo GQ.
Cheers

HI peter, supercharging is not a good option for automotive diesel engines. a perfect example for this is that diesel engines have a heap of torque already and not too much top end. this is where turbo's come into it! i see that someone has said that with supercharging you are compressing air. that is true but you are also doing relatively the same thing with a turbo. turbo charging generates about a 30% increase in top end performance which is great but remember 30% more performance = 30% more heat and 30% more wear and tear. i guess my point is that i would still highly recomend a turbo over a supercharger for sure. even if it does wear out your engine quicker......

Hi all, i have a 92 GQ 4.2 diesal i have fitted a supercharger and i couldnt be happier, walks all over a turbo except in very high revs which i dont need to work at. American diesals in the 2nd war were super charged as were a lot of air craft there only down fall then was that the machining and metals where not up to the job, different nowadays with better tecnology.Mine is of a commodore and puts out 8psi at idle and all through the rev range, most of my driving on and of the road is done at between 1000 to 2000 revs, the tourqe is unbeleivable, around town i put it in 5th and drive around at 1000revs just like driving an auto. I fitted mine at about 230000ks and have done 50 to 60000ks since then and have had no problems at all, as for price it works out at about the same price as an intercooled turbo, other benefits are that you can also fit extractors which enhance the S/C. As for noise not a problem i do get a whistle but its not annoying. The mob that fitted mine is at Slacks Creek, they are On Track 4wd ph 32902533. I have heard people fitting them to cruisers and having the harmonic balancer let go and take out the radiator, whether thats all tojo donks im not sure. Put this set up in soft sand and they love it no more doing high revs to keep going, and as for towing they really come into thir own gives so much more rev range to work with. My set up cost me $5500 with 12 mths warranty. If i had the choice again i would deffinatly go the S/C. Col

Hi Peter, I'm mechanical engineer and what you are asking about I had as a subject in university. Both systems will give you heaps of power and torque, not only in the dyno figures but in terms of responsiveness and seat of the pants feeling. If you purchase either kit from a serious manufactures they will both be as reliable and will probably outlast your engine. Superchargers have the advantage of giving you that extra power from idle all the way to redline. Normally turbos take a second to build up speed from idle so you have turbo lag, that is the time that passes from the moment you hit the pedal to the moment you start feeling the engine deliver all its potential. Lately that advantage is becoming really slim, with the use of wastegates you can use smaller turbines that have lower inertias and spool up much faster, also some turbos are now coming with ball bearings that have lower friction and also help the turbine gain speed (and consecuently gain boost) in less time. One advantage of turbos over superchargers is the reason why trucks and buses use them. Both the turbo and the supercharger are basically air pumps, the difference lies in where the power to drive those pumps comes from. In the case of a turbo that power comes from exaust gases with energy that would otherwise have been tossed into the atmosphere. In the case of a supercharger that power comes from the flywheel; of course it drains lees power than what is gained by its use but it also means that overall the engine is less efficient. This means that for the same final power output a turbocharged engine is likely to burn less fuel than that same engine with a supercharger. How much more fuel? possibly not enough to make a difference unless you drive as many miles as a commercial truck. Its also true that greater top end power gains can be obtained with turbos but in a GQ I don't think you'll care much about that.
Years ago the advantage in terms of low end performance and response of the supercharger was evident, but lately turbo systems have been perfected to imitate the performance of a supercharger with the advantage of being quite less expensive.
If it were my truck I'd install a turbo + intercooler, but in the end it will boil down to costs and how much confidence you have in the manufacturer of either kit.

Hope this helps you in making your choice.
Regards,
Marcos.

Hi Peter, I know this is a late response and by now you may have made up your mind. I have an 80 series with a Sprintex 102 s/c put on by Power House in WA, done 90k no problems at all,cost $5200 fitted, The low down power is great when you need to crawl over rocks etc, 1200- 1500 rpm, most turbos are still sleeping and under the turbo they are gutless.