patrol GQ td42 twin VNT thesis project

[zjuul]

Hello folks,
Some may know me already a bit but I’m a 20 years old car student. Next year I need to do my last year of high school and then we need to do a thesis. My project is to build a parallel twin turbo setup on a td42, but it aren’t regular turbos that we will use, no we will work with variable turbo’s. Now I’ve been looking and reading for some time about turbos and the technologie behind it so I can choose the type that I need. I’m now came out by the garret gtb1749vk, this turbo is used bij Audi and Volkswagen on their 4.2 liter V8 engine, also bij Mercedes on ther 420 (4.0liter) engine. So these turbos are used in the same range as the TD42 of Nissan. I have read also a lot about the gtb1756vk, lots of people use them on 1.9tdi engines. So now I’m a bit struggling whit my chose, is here anyone that know the td42 and can help me a bit with my chose? I want a vnt turbo setup whit a low turbo lag and fast boostpressure so no huge turbos that only spool above 3000rpm but something that starts at about 1500 rpm until 3500 and give a high amount of torque, that is why we will work with vnt technology.

My search to find the right car is almost done, I go and look at a td42 high roof of 1993 whit in 2 weeks. I will properly buy that car and then we can start the project. I will post up the progress up here.
I hope to get some help from you guys! If you’ve got questions for me just ask!
Grtz Zjuul

[MudRunnerTD]

G'day Grtz,

Sounds like a great project and very keen to follow his thread, sorry I have nothing to offer you in terms of info but guys like NissanNewby will probably be able to chime in.

Good luck mate.

[BigRAWesty]

Sounds awesome.. Will be watching for sure..

I guess one thing you have to look at is the air flow of the engine..
Those aldi v8's probably rev out to 7-8000 rpm, the td struggles with 6000 rpm..
So although the cc's are the same the air flow is greatly different..

A bloke here did start a twin build. Took his setup from a supra twin 3ltr.. Now the supra's do rev high, so the air flow will be similar..
I think the pin was pulled on it but the initial build thread is here somewhere...

Anything more than this is above me... Lol

But enjoy the build

[zjuul]

thanks for the reply guys,

I don't think the gas flow is that different? the audi is also a diesel engine so it won't make 8000rpm? these turbo is also used on a 2.2litre ford van and 2.2 liter mercedes engines so I think it will be possible to use them?

[nissannewby]

Are you set on VGT turbos?

[zjuul]

yes, that is the whole idea of my thesis project.

[nissannewby]

I do not know the audi engine you have referenced but it could have far better head design, common rail, direct injection etc so it could be a completely different beast. However if they are working on the smaller 2 litre engines then they might work ok on our 4.2. I would probably use the turbos that are used on the audi as they will porbably be closer suited.

What its really going to come down to is your control system. This is ultimately what makes them work.

[zjuul]

yes indeed, the control system is a case of write the correct program. but at school we have a lot of knowledge in electronics and programming so that will be ok.

[warner01]

i have a twin turbo 3l toyota (2jzgte) and they run the same size turbo. in series as standard the first turb spools from about 1700 rpm but set in parallel they wont boost till 4000 rpm. im pretty sure it does this by sending all exhaust to one then swaps to the other. so if you set it up to all go to one turbo then go from that one to the next one maybe thatl achieve ur low rpm boost from both turbos. the gtr skylines that run the twin turbo where set in parallel im pretty sure. less common than the yota but if you google them it might help. hope that helps u a bit.

[zjuul]

thanks warner01, the biggest problem for a series turbo setup is that I would need a larger turbo. as we will wokr with vnt technologie I can't find a proper turbo that isn't to small or to big. looks like the 4 liter engine is a bit of a midrange class engine that havent got much vnt options.