Turbo Diesel vs V8

[Josh n Kat]

yeah i'd defineatly say that for outright performance a v8 is the way to go!
but i'm just finishing my petrol to turbo diesel conversion and i'm looking forward to seeing the performance differences between my rooted old 4.2 petrol to the 4.2 turbo diesel.

i considered dropping a v8 in when the petrol motor packed it in but for i wanted better fuel ecconomy for longer trips and i like idea of more torque down low for the kinda weekend fourbing i do. so do you wanna beat commodores at the traffic lights or do you wanna drive past the servo on your way up the coast while your mates have to fill the tank up again

[Nelso]

Have a SWB GQ with a turbo diesel & 3' exhaust and used to go 4WDing with a SWB GQ with a 5 litre quite a bit (before he sold it due to his fuel costs!!!) Both were running 35's at the time and had the same power both on and off road. The difference was the distance we got out of a tank of fuel. I dare say he would've been rebuilding it before I had to as well.

Wouldn't bother with a diesel without turbo though. You feel yourself age as you wait for it to accelerate.

just my 2 cents.

[iwanahuma]

what about a turbo diesel V8?

[MissDrew]

An EFI V8 will beat a TD everytime.

I know which one I`d prefer to pay to have rebuilt.

Also I think mud guts is talking stock motors here not 10, 20 grand motors. In this case the V8 will still win every time.

[mud guts]

I think you could get a v8 to rock for less than ten grand, and bloody lot easer to drive, and not waiting for this boost to work, but i’m not nocking it, just trying to work out where all this money is. And for what?

[Freakazoid]

How much does the weight difference count? An alu block V8 like VH45 is super light, whereas the TD42 is bloody heavy.

[CWBYUP]

I built a 253 holden engine for my old ute, cost me 4K reved to 6500rpm all day long and loved being flogged. Its still in another ute and never been pulled apart and would have close to 300,000 kms on it.

It wasn't a big HP engine but the money was spent in the right places.

Personally I think it come down to is a comp truck or do you want to compete in it and the tour in it ?

Like eveyone has said it comes down to personal choice, For me the V8 would be the only option because there easier to get parts for and a hell of a lot cheaper to rebuild.

Cheers Nick

[mule75]

a few mates have 350's in there trucks, pretty even dragging on beaches under a bit of load. they beat me on bitumen though. v8's are cheap hp but after 7-8 years of 4x4 i have wasted no time waiting for a broken down turbo diesel but my mates v8's would owe me years of wasted time waiting for them while they work on them on the side of a track. at one stage i cracked the s!@t's and wouldn't go away with v8's because i was sick of towing them around (and i still push my truck harder!!!!!!!!). can't beat turbo diesel reliability, but i can't throw a cam in my t/d and make an extra 100 ponies!!

[mud guts]

I think that the modern V8’s are more reliable with injection and a lot aftermarket parts available, there more people working with them, where as a while ago only a few gurus new what they were doing. Dynos are getting good use and find faults before there on the road. The factory’s Ford v’s Holden game, are continually pushing the boundary’s of reliability and performance. And fuel emissions are coming down without sacrificing power. They go longer without servicing, do that to a diesel and you’ll get no where. V8’s will never die one day.

[Freakazoid]

I am getting a VH45 delivered to my front door for Aus$1250. With a correct ECU and a good extractor it is supposed to do about 240kW. Not touching anything in the motor. In order to get 240kW out of a TD42 you are going to spend a lot of money and then the reliablity is out the door anyway. The VH45 will rev to 7500 comfortably and does 300Nm from 800revs through to about 5500 and peaks 380 at 4500. So very flat torque curve as well. And the VH45 weighs 230kg all up. I don't know what the TD42 weighs but me thinks it is quite a bit more.

[weeman]

I am getting a VH45 delivered to my front door for Aus$1250. With a correct ECU and a good extractor it is supposed to do about 240kW. Not touching anything in the motor. In order to get 240kW out of a TD42 you are going to spend a lot of money and then the reliablity is out the door anyway. The VH45 will rev to 7500 comfortably and does 300Nm from 800revs through to about 5500 and peaks 380 at 4500. So very flat torque curve as well. And the VH45 weighs 230kg all up. I don't know what the TD42 weighs but me thinks it is quite a bit more.

Yeap thats all good in theory and on paper a guy that just did his VH45 made 130rwkw (36 Simex) with his stock VH45 and computer. Un reliable did a bearing at this years outback.

Motor was rebuilt head work cam work + motec and pushing the same amount of power however the power is more down low as the VH45 were a bit sluggish off the line. For the amount of money spent doesnt look like it was money well spent.

[Ossie]

No one engine is better, there are a lot of things that can detemine 'best'.

I was fortunate enough to spend the week of the OBC with both Cass and Kym this year. On indivual stage times there was not a lot between the two.

Cass had one DNF on the Tuesday when his winch failled on low mount. kym had two dnf's one on SS1 due too a fuse, and one in the sand when he broke a pitman arm.

Cass probably had the edge on the higher speed stages, partly because of the instant acceleration out of corners, partly because of the suspension an his ability to hit thimgs harder. but speed stages are not everything in the OBC. In 2005 there were two TD's on the podium.

It depends on what you are doing, the Ateco is a different story No v8 on the podium but there is a TD?!

I have competed in in V8 and TD, and FOR US the TD is a better option.

As Weeman said you don't have to spend big $ to be competative in a TD, we beat Kym in one speed stage and was 1 sec slower on another. an I can tell you we have no where near the rwks of Kym.

My 2c

Jason

[Ossie]

Another consideration is fuel.

Our first refuel in the OBC this year at Packsaddle was Monday night. Kym and I used $75 worth of Diesel each (within 2lts of the same consumption). Cass had a bill of around $175 (if I remember correctly) for the same time, he used more than double the amount of fuel.

This seems like nothing to some people willing to wear the cost, but I get away with carry 80lts of fuel (and meet the 500km rule), Cass carried around 200lt.... that’s an extra 100+ kgs.

Jason

[Jimbo]

How does a 4.2 TD compare with a turbo Tb42? Will the TB42 have similar low down torque?? If so its a cheap option


Jimmy

[weeman]

How does a 4.2 TD compare with a turbo Tb42? Will the TB42 have similar low down torque?? If so its a cheap option


Jimmy

TB42 arent a cheaper option.

They are more expensive to setup properly and running costs.

A diesel has a smother torque band where the petrol is all up high no matter what turbo setup you use.

A proper setup diesel will out perform a turbo petrol, except for birdy you dont see many people placing in high position in the OBC with a turbo petrol.

[Jimbo]

How much do you think it costs to turbo a tb42 compared with a N/A diesel???? I cant see much difference. Yes i know u need inkectors, computer and fuel reg but compared with pump mods to a diesel it seems cheaper, and if u use lpg u dont even need that.

You can always put a smaller turbo on a Tb42 for better low down torque.

[weeman]

How much do you think it costs to turbo a tb42 compared with a N/A diesel???? I cant see much difference. Yes i know u need inkectors, computer and fuel reg but compared with pump mods to a diesel it seems cheaper, and if u use lpg u dont even need that.

You can always put a smaller turbo on a Tb42 for better low down torque.

well LPG no good for outback.

i'm talking about a proper setup turbo petrol wont get much change under 10k.

which is just about on par with turbo diesel.

the turbos are the same cost, manifold as well intercooler same .

The computer for a petrol is the same price as a modded pump.

[Jimbo]

Fair enough with lpg, but you can pick up an aftermarket computer, fuel pump, reg and injectors for pretty cheap and you will be making some serious hp and still have torque. If your that worried about torque u can always change diff gears and use the revs a bit more.

Not having a go at your opinion, i just think that a turbo petrol has a much wider and more usefull powerband.

Although if i had my way i would have a 350 chev sitting in my engine bay!!!

Jimmy

[Tiny]

depends on the application, for most comps I would say v8 all the way, but for my driving style and most touring cant beat the diesel (turbo of course )

at the end of the day it come down to application, driving style and plain personal choice

I always say that the sound of a v8 is worth the fuel bill

[MissDrew]

A few years ago it was nearly all TD`s at winch challenges, these days the petrols are taking over again either turboed 6`s or V8`s.

[sheriff]

i have just done a EFI V8 conversion on my cruiser ute and its a rocket and it sounds tuff with the 3" stacks on it to

[badger]

you put stacks on a ute?
do they suit your wrangler and xxxx stickers?

[Gabriel]

well i'm a diesel fan,

And you can get a high performance diesel for under 10k....

Depends what your wanting to use it for, speak to a person who was in the outback with the new 6L motor and its already got a knock in it and only done one event the V8's just dont last but they do perform. For reliabilty a diesel is still better in my opionion and with few others i know. The main problem with the diesel is not enough low down torque till the turbo kicks in.

Well, the problem of the low boost until the turbo goes up can be solved with a supercharger. Of course there are up and downs for a supercharged turbo diesel, but overall I think it can be a good solution: power durring all the revs (of course, more power as you push the gas pedal...;-), good reliability, simplicity in installation...

I do own a Chevy K5 with a V8 6.2 diesel, 4 speed g/box. It works very well also...but with a twin turbo set-up would be much nicer...

...and I own a GQ LWB with a 6.2 diesel (same engine), but with a TH400 (3 speed) g/box. And the difference is huge...the K5 goes much stronger...even I have 4.1 r&p into the GQ vs 3.73 in the chevy. same 35" wheels.
What I want to point out is that the engine power is not everything...the gear box, r&p, tire diameter can affect the car as well as the power...

Sorry for interupting the discussions.

Regards, Gabi

[sheriff]

you put stacks on a ute?
do they suit your wrangler and xxxx stickers?

yeah mate i did dont have wrangler or xxxx stickers its a clean skin at the moment

[75 cruser]

after having the old 2h diesel in my 75 series and putting a late model efi holden commodore engine in to it, thier is no way in the world that i would even look at going back to the diesel, just driving on the road flying up hills and so much lighter to drive than the old diesel. and if every one is so worried about fuel ecomony like it matters when your in the bush having a great time any way. but if its a cost thing than the turbo diesel will be the way to go, i havent added it up but i reackon $8000 easy for the v8 conversion but im talking from start to finish, not encluding your engine price.

rob

[sheriff]

yeah my conversion cost me around 7 to 8 with motor i done all the work myself piss easy to do just done it as i got the cash and the fuel doesnt worry me all that much to diesel as unleaded is cheap then diesel here

[scotyz]

I have both and love them both for different reasons

[MQSWBUTE]

i agree with what someone said to me at ateco winch challenge anything over 170rwkw is useless power ......u can get that with a v8 carby fed of injected and can prob get close with a aftermarket turbo bolted onto a td42

[zagan]

what about a turbo diesel V8?

You also get EFI V8 turbo Diesels, BD do twin turbo versions as well, but they do it in a different way to a twin turbo petrol engine which was interesting to see, I watched a TV show which was at BD, I recoreded it as well.

They also had 250's spinning the back wheels going around in circles.

Quite supprised as their chip upgrades will put out 600-700+ of torque to the wheels, and up the HP to 500+, anything else you so just goes up from there.

[ludacris]

For me it came down to cost.

Converting the old 4.2 Petrol to an EFI V8 cost me $1000, conversion kit cost $1000 and little bits and pieces would have cost $1000.

To buy a 4.2 Turbo Diesel motor I would have been looking at around $7000 for a good standard turbo - motor only. Then on top of that you have all the little bits and pieces.

Because of the extremes that these motors are pushed to, to destroy a motor and rebuild it the V8 is still cheaper.

When you start adding turbos in racing conditions, you are adding potential problems from the heat, dust wrecking the turbo especially in OBC.

It also comes down to the kind of V8 you want to put into your vehicle.

I don't think the petrol V8's have any problems dealing with water. It just comes down to prior preparation.

LudaCris