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gq td42 turbo size

Posted: Mon Jul 21, 2008 3:39 pm
by Daniel gq
lm currently getting a custom exhaust manifold made up and the guy thats making it recomended a gt2871r turbo and said its capable of 400hp.

Today l went to a well known diesel shop to see about getting the injecters done and a tune and the person that served me said the turbo would be to small.
From what l have read about it it should be more than capable of doing the job. or am l wrong? lm only planning on running about 10-12 psi

any help would be apreciated

Posted: Mon Jul 21, 2008 5:02 pm
by Dzltec
There is already a lot of info on here. To determine turbo size, you need to know what power you would like to make, where you want it to happen and work backwards.

On recommendations do these people have dyno graphs to show you previous vehicles. A cast manifold is good for 150rwkw. Will they back it up if you are unhappy with the results??



Andy

Posted: Mon Jul 21, 2008 10:31 pm
by PGS 4WD
The turbo is not too small but like Andy said it depends on your application. Be wary of power ratings as a way to asses a turbo's size. That depends a great deal more on the fuel, you won't make 400 HP on that turbo on a diesel, it would require a petrol engine with good quality fuel to make those numbers, diesels require large volumes of air compared to other fuels for the same respective power.


Cheers

Joel

Re: gq td42 turbo size

Posted: Tue Jul 22, 2008 7:08 pm
by vn15
Daniel gq wrote:lm currently getting a custom exhaust manifold made up and the guy thats making it recomended a gt2871r turbo and said its capable of 400hp.

Today l went to a well known diesel shop to see about getting the injecters done and a tune and the person that served me said the turbo would be to small.
From what l have read about it it should be more than capable of doing the job. or am l wrong? lm only planning on running about 10-12 psi

any help would be apreciated
Have the same turbo on my highly modified RD28T and it puts out around 250hp, lots of custom stuff, bigger pump, gas injection and water/meth as well :cool: :cool:

Posted: Sat Aug 16, 2008 6:24 pm
by coxy321
I spent all last night searching and reading, but couldn't find a definate answer, although this isn't exactly a "one answer fits all" type of question.

This ones directed at andy and/or joel...

What are your opinions on the two turbos below...

http://www.turbobygarrett.com/turbobyga ... 3347_2.htm

http://www.turbobygarrett.com/turbobyga ... 6541_1.htm

Looking at either, with a 0.64 A/R turbine housing. It for my TD42, which is a weekend only car. I'm not after huge power, as i dont have the money to spend on pump mods, and i generally keep my RPM below 3500 even when i'm giving it a bit.

Any suggestions welcomed. I am leaning towards the turbo listed first.

Coxy

Posted: Sun Aug 17, 2008 4:10 pm
by Dzltec
The turbos listed coxy will work on a td42, but at different ends of the scale.


As I keep saying, figure out your power you want and work backwards.
Im sure Joel as well knows what works for what power figures. I spent my own time and money finding out, proving it and know now what works and what doesn't.


I am more than happy to sell a turbo that works and offer a full money back guarantee if it doesn't. But I wont give secrets that I have found from research and development away for free, not to anyone.

I am seriously thinking of offering a sizing service for x amount dollars. If you buy a turbo then it gets credited, I will guarantee this as well.

There are at least 5 different sized Garrett turbos that will work on a Td42 all with good and bad points. Then comes exhaust a/r to set the tuning properly.

The Garrett website has a lot of good info, but it is all mainly aimed at petrol. Diesels work a lot differently.


Hope this helps the questions asked.



Andy

Posted: Sun Aug 17, 2008 7:11 pm
by coxy321
Thanks for the reply andy. I understand you guys cant divulge any information that you've researched and developed. Its pointless being in business and giving everyone your hard earned info.

One thing i see you and joel saying is to choose your power level, and work backwards from there. Given that i have absolutley NO idea (and i doubt anybody else really knows how much power they want/need, it makes it bloody hard to say "I would like xxx rwkw please." I think that this is where most of real questions lie - people not technically knowing what they want as an end result, just that they want to tow better/more economy/or a 6000RPM TD42.

Keeping in mind that i havent got fundage for pump mods, i reckon i'll go for the bigger unit, as it will allow me more flexibilty later on. I know ideally i know i should get the smaller unit to suit my current setup (or lack thereof), but most people including myself will always be after a tweak here or there down the track.

Thanks heaps

Coxy

PS. Bogged is working on a TD42/turbo section for the bible apparently ;)

Posted: Sun Aug 17, 2008 9:53 pm
by PGS 4WD
Dzltec wrote:The turbos listed coxy will work on a td42, but at different ends of the scale.


As I keep saying, figure out your power you want and work backwards.
Im sure Joel as well knows what works for what power figures. I spent my own time and money finding out, proving it and know now what works and what doesn't.


I am more than happy to sell a turbo that works and offer a full money back guarantee if it doesn't. But I wont give secrets that I have found from research and development away for free, not to anyone.

I am seriously thinking of offering a sizing service for x amount dollars. If you buy a turbo then it gets credited, I will guarantee this as well.

There are at least 5 different sized Garrett turbos that will work on a Td42 all with good and bad points. Then comes exhaust a/r to set the tuning properly.

The Garrett website has a lot of good info, but it is all mainly aimed at petrol. Diesels work a lot differently.


Hope this helps the questions asked.



Andy
We are all in business to make money and feed our families, I like Andy invest a lot of personal time and money on research and development, I am as open as is practical about the information I share. Every year I spend at least $10-20k on vehicle modification and tuning software to ensure I am up to date and well practiced. Most of us love our jobs and do it for the satisfaction cause I can tell you all none of us are retiring soon off the income.

Cheers

Joel

Posted: Mon Aug 18, 2008 5:56 pm
by RED60
Perhaps Joel/Andy can give a bit of a comparison like

std kw/tq...80/200 @ 3000rpm

turbo1 kw/tq...90/240 @ 2800rpm

turbo2 kw/tq... 95/260 @ 2700rpm

turbo3 kw/tq... 105/290 @ 3000rpm

turbo4 kw/tq... 120/330 @ 3300rpm

or something like this if it doesn't give too many secrets away...

NOTE: these figures are completely ficticious and any similarity between these figures and actual figures (living or dead) is purely coincidental. :D :D

Posted: Mon Aug 18, 2008 7:58 pm
by Dzltec
I would be happy to post dyno graphs, but they are not all on the same vehicle. This makes comparisons a little harder as diff ratios, tyres etc alter final figures.



Andy

Posted: Mon Aug 18, 2008 9:55 pm
by PGS 4WD
Yes, I have the same issue, tyre size and type does effect the rear wheel power, as does gearing effect torque. Haven't met anyone yet who wants to progress through all the options on the same vehicle, I usually try to asses the customers requirements early to eliminte rework.
I data log over time rather than rpm or speed which I use to indicate the lag of a particular turbo compared to stock. ie; how fast certain power figures are acheived.

Joel