Thread: 3.9 v8 supercharged with NOS?help

Originally Posted by Chops

means pics, nothing happened without the pics,,,,
aaaand more info on whats been done etc,,

Pics have been posted previously:

Originally Posted by isuzurover

Pics have been posted previously:

You beat me to it! http://www.aulro.com/afvb/attachment...t-27052009.jpg

Looks like one of those Toyota Supra turnouts.

Originally Posted by Rangier Rover

The supercharger is very difficult to engineer Especially when LPG is mixed with it in my case.

As for NOS, like you Brian, I really have my doubts with legality on road.

Just pinch some from the local Dental practice and give it a sniff like the A Team used to

I have no doubts at all. It is illegal on registered vehicles in Qld. I can't speak for other states.

Originally Posted by discowhite

how bout you lot stop doubting the bloke and have a look at his other posts
then you can get an idea of wether hes for real or not.

I'm not doubting him. I am simply pointing out the legality of the proposed modifications.

Generally if found with an unapproved supercharger/turbocharger by a Qld Transport inspector, you will be ordered not to drive the car, to only remove it by towing, and to take the vehicle to a Departmental inspection station for a going over. You may also get a nice fine and a few points.

I'm no expert on this and as mentioned in another thread supercharging does take some science and frustration to set up.
As doing my own here, believe me I know how difficult it is to get it right

In plain english,
with that type of set up you can run a front mount intercooler and more boost with a different pulley ratio if that wee little blower can do it.

Looks like your running a standard 3.9 plenum, EFI and ignition set up. It will never work well


At a minimum, you will need a variable pressure fuel regulator and possibly larger injectors if yours cant flow enough at full duty.

Then comes the ECU, it will need remapping via a chip. A good chip will conect to the two signal wires and then look after the advance curve.

This is why I have dumped the 14cux and using HSV Delco with a Haltech ECU.

Supercharging/turbocharging petrol engines not designed that way is a complex and frustrating business. The old saying of two steps forward and one step back often applies. Detonation always raises its ugly head once boost is over about 6-8 psi above atmosphere. So you need ways of controlling ignition timing when detonation occurs. You add an intercooler and have to add more fuel as the air charge is now denser, and have to increase initial boost as there is a pressure drop across the intercooler. Add water injection and the same problems occur. If using SU carburettors then a rare as hen's teeth device called the Additional Weakening Device may be needed. Good luck finding one.

For anyone new to supercharging, recommended reading is "Supercharged! Design, Testing and Installation of Supercharger Systems" by C. Bell, 2001, Bentley Publishers.

Originally Posted by Brian Hjelm

Supercharging/turbocharging petrol engines not designed that way is a complex and frustrating business. The old saying of two steps forward and one step back often applies. Detonation always raises its ugly head once boost is over about 6-8 psi above atmosphere. So you need ways of controlling ignition timing when detonation occurs. You add an intercooler and have to add more fuel as the air charge is now denser, and have to increase initial boost as there is a pressure drop across the intercooler. Add water injection and the same problems occur. If using SU carburettors then a rare as hen's teeth device called the Additional Weakening Device may be needed. Good luck finding one.

For anyone new to supercharging, recommended reading is "Supercharged! Design, Testing and Installation of Supercharger Systems" by C. Bell, 2001, Bentley Publishers.

A recommended read, although a bit dated. I have a copy here that belongs to a mate in the aviation industry.

We have a lots of discussion on flow versus intercooling.

Originally Posted by cooper8888

I have a Defender 1988 that has a disco engine , the 3.9.
i installed a supercharger to it, but i still want more power, what NOS system do you think is the best for my case, and will the car hold that NOS system along with the .5psi supercharger?
please help me

Mate are you sure 0.5 psi ?? have you got the clutch turned on

Is the blower a "sc 12" or "sc 14" or is it someting else? if it is the toyota blower then i reckon you'll need a few more of them to keep up - they struggle to do anything meaningful on a holden 3.3 litre six.

What pully ratio are you running?

What country are you from?

cheers

My friend had a supercharged 4.0L in a rangie. I think it ran an eaton blower, bosch injectors and Motec M800 computer, it also had a custom a/c intercooler which helped substantially, makes it safe to pump more boost in less detonantion. Biggest problem was blowing tailshafts and diffs On 31in tires we dragged off a porsche to 80kmh, no more power needed so I would look at the blower and make sure it can provide enough air, the computer will definately need tuning as well. A piggy back computer would be your cheapest option. My current car runs the new wolf computer, but the standard one controls startup and low rpm. Makes 118kw at wheels with a 4.6 block and all drivability is maintained.

My old car had an autronic computer which was awesome however low speed work and cold starting was lost. made 140kw on 35's with a vortech v1 supercharger, but that was in a gq patrol so a bit irrelevant

Rob