Outer Limits 4x4 Board

Are we talking positive displacement or centrifugal superchargers?

Drew off here had/has a twin-charged (one of each) 4AGZE in his Zook which from all accounts was an animal.

v840 wrote:Are we talking positive displacement or centrifugal superchargers?

Drew off here had/has a twin-charged (one of each) 4AGZE in his Zook which from all accounts was an animal.

Was that animal African or European?

If you were aiming for 'no lag' and you got 'lag' then you didn't choose the right turbo (And possibly setup?) for your application.
I have a 13 page excel spreadsheet of all the turbo combinations my guys use.

A high flowed TD04 (Maximum CHRA inducer/exducer) will be very responsive in anything 2.5ltr-3.5ltr, get the right manufacturer and they'll also hold boost.
I'd look into a TD05 16gtx-7cm high flowed with a billet wheel and 9 blade turbine... But its all about how much you are willing to spend. You can get great 2nd hand turbos aswell.

Chinese turbo's tend not to have the right characteristics for 'low lag'. (Heavy assembly, heavy streamlined turbine, thrust bearing setup instead of journal or ball bearing etc)

The beauty of turbo's is they last longer (pending manufacturer) and are adjustable on their boost quite quickly usually with a boost control solenoid or manual boost controller. Since you are already EFI, adding turbo should be easy done with the right ECU (if you can edit its ROM) or adjustable rising rate fuel regulator and other bits and pieces if you aren't keen to do it off the ECU. You will also get increased fuel economy if done properly.

If turbos these days make superchargers obsolete why are major manufacturers wasting their time with "twincharger" setups?

I don't get the whole turbos make a car more efficient statement. I'm happy to be corrected but the concept of compressing the intake is more fuel can be put into the system due to there being more air or more correctly more oxygen. Fuel = power, more fuel = more power. Is this statement relating to old engines that have poor burn ratios or something?

Tiny wrote:I don't get the whole turbos make a car more efficient statement. I'm happy to be corrected but the concept of compressing the intake is more fuel can be put into the system due to there being more air or more correctly more oxygen. Fuel = power, more fuel = more power. Is this statement relating to old engines that have poor burn ratios or something?

I've always understood the argument to be based on comparing a small turbo motor with a larger NA motor. The turbo motor can produce similar power / torque to the NA motor when it's on boost, but will theoretically use less fuel when it's not on boost. "Power of a big motor, with the economy of a small motor*".

*Economy of a small motor only when you're not using the power of a big motor.

See I can swallow that no issues but crisp products states above "if done properly will increase fuel econamy" which I have seen stated plenty of times by plenty of people.... This I can't swallow :s

You have more power and torque. Fuel eco is directly related to throttle possition and rolling resistance. At 100 after supercharging, your using less throttle possition for the same job. I can talk for turbo's. But definately got better eco with supercharger on mine. Although 1 good bootfull and thats out the door .

Turbos FTW

TheBigBoy wrote:You have more power and torque. Fuel eco is directly related to throttle possition and rolling resistance. At 100 after supercharging, your using less throttle possition for the same job. I can talk for turbo's. But definately got better eco with supercharger on mine. Although 1 good bootfull and thats out the door .

But adding a turbo to your engine spent decrease the rolling resistance of the vehicle. You still need x power to propel the vehicle. If you want to get to 100 faster you need more power, more power more fuel, if you add a turbo and use less throttle due to the turbo adding boost to get to 100 as you would have ore turbo but full throttle then you should be using essentially the same amour of fuel. After that point the fuel usage will continue to be greater.

Sorry type O. That should be "I CANT talk for turbo's"

Supercharger, definate increase in economy if driven normally. The if driven normally is the hard part. Say before boosting it took you 12 seconds from 0 - 100. After boosting, driven normally means still 12 seconds from 0 - 100, but alot less throttle possition for the same job. Highway driving is where all the gains are made.

Tiny wrote:

TheBigBoy wrote:You have more power and torque. Fuel eco is directly related to throttle possition and rolling resistance. At 100 after supercharging, your using less throttle possition for the same job. I can talk for turbo's. But definately got better eco with supercharger on mine. Although 1 good bootfull and thats out the door .

But adding a turbo to your engine spent decrease the rolling resistance of the vehicle. You still need x power to propel the vehicle. If you want to get to 100 faster you need more power, more power more fuel, if you add a turbo and use less throttle due to the turbo adding boost to get to 100 as you would have ore turbo but full throttle then you should be using essentially the same amour of fuel. After that point the fuel usage will continue to be greater.

With forced induction, you spend less time with throttle wide open to accelerate, but you are also burning more fuel per second than a NA vehicle.

I had a turbo diesel 80series (factory turbo) I now have a NA 105series, fuel economy is very similar, but the 80series has a larger fuel pump and the fuel screw was cranked up by 1 1/2 turns, it would use a stack more fuel when at WOT but also made a stack more power. My NA 105series is a slug in comparison, takes heaps longer to get up to speed, but It's using less fuel at WOT too, so I reckoning evens out to a large extent.

A turbo should be more efficient than supercharger as there is novadditiobal liad o the engine, a turbo supplies boost on demand, a supercharger is running constantly wether needed or not

i really dislike the "turbo's don't lag if its done right" thing.
you will always have lag with a turbo. turbo is exhaust driven, you have to burn fuel before it can make boost.

out in the field, supercharger wins for offroad. as its directly driven from the motor throttle response is instant, which is fantastic for low speed slow geared driving.. it really is just like driving a bigger engine. downside is that superchargers themselves are not overly efficient ie they turn a fair bit of power into heat which goes to waste. tho you can minimize that for onroad by switching off and bypassing the supercharger.

onroad, throttle response is not that critical in the higher speed driving where the higher efficacy from the turbo wins.

80's_delirious wrote:

Tiny wrote:

TheBigBoy wrote:You have more power and torque. Fuel eco is directly related to throttle possition and rolling resistance. At 100 after supercharging, your using less throttle possition for the same job. I can talk for turbo's. But definately got better eco with supercharger on mine. Although 1 good bootfull and thats out the door .

But adding a turbo to your engine spent decrease the rolling resistance of the vehicle. You still need x power to propel the vehicle. If you want to get to 100 faster you need more power, more power more fuel, if you add a turbo and use less throttle due to the turbo adding boost to get to 100 as you would have ore turbo but full throttle then you should be using essentially the same amour of fuel. After that point the fuel usage will continue to be greater.

With forced induction, you spend less time with throttle wide open to accelerate, but you are also burning more fuel per second than a NA vehicle.

I had a turbo diesel 80series (factory turbo) I now have a NA 105series, fuel economy is very similar, but the 80series has a larger fuel pump and the fuel screw was cranked up by 1 1/2 turns, it would use a stack more fuel when at WOT but also made a stack more power. My NA 105series is a slug in comparison, takes heaps longer to get up to speed, but It's using less fuel at WOT too, so I reckoning evens out to a large extent.

A turbo should be more efficient than supercharger as there is novadditiobal liad o the engine, a turbo supplies boost on demand, a supercharger is running constantly wether needed or not

Ah, but your talking turbo DIESEL. I have a turbo diesel 80 aswell. Petrol results are alot different. Never turbo'd a petrol so cant comment. And it will vary depending what engine we are talking about. 4.5 petrol got 12% better eco on highway. Bit thats not really why do it is it.

Turbo's re-use spent energy,
I see approx. 5-20 % fuel economy change when going from N.A to Turbo with correct fuel contol on petrol running a higher octane.
The change is greater on lower comp engines.

Going from small turbo to middle/large size also increases cruising fuel economy usually around 5-10%. (Also going from an old turbo to new turbo has some effect for sure)