vn v6 turbocharger choice

[vn304turbo]

Hey all, not sure if this is the correct section post this but I have aquired a stocko vn v6 as a bit of a side project and a weekend hack to have a bit of fun in. Im going down the budget turbo path that so many before me have trodden and I know a few blokes here have had dealings with turbocharging the vn 6, ill be doing all the work including manifolds etc myself but what I need to know ro get started is what size turbo I should be looking at. It will be bog stock engine with an auto (shift kit, vette servo and .500 boost valve and new accumulators im told will keep it alive for a while) altho I may want to convert to t5 later down the track. The turbo I had in mind was a chinese t70 or to4z with a .68 turbine and .70 compressor or would that be too small? Had also considered the .82 turbine with the .70 comp but I dont want it to be too laggy. Im not lashing out on good stuff for this project its just a cheap shit build as a proof of concept so there will be no roller bearing turbos here or name brand parts for that matter. Also need to figure out what size ID steam pipe I should be using for the manifolds, the will just be log manifolds with the drivers side being fed around the front of the engine .

[delcowizzid]

http://japrace.com/products/SRP-T70-Turbo.html these are what i use on everything gt3582 copy with 70 from .82 rear

[vn304turbo]

That looks the goods mate cheers for that, with an auto and stock converter and log manifolds of the right size when should boost start coming on? I dont mind sacrificing some top end in order to gain some response even tho there may not be alot to be had from an buus bearing turbo, at the ejd of the day im not that picky just curios. What sized pipe should I be looking at for the the primary and for the log?

[delcowizzid]

32nb schedule 40 steam pipe primarys and next size up for secondaries.this is how ive done 3 setups cost fark all and has gone 11.02 at 125mph .laggier than tuned length but well on song by 3000rpm crossover comes from stock vp cast iron drivers side manifold and is made from vn y-pipe bends LOL

[Holden202T]

my brothers Vp V6 is the same, GT35 turbo and boosting by 3000rpm!

[vn304turbo]

Thanks mate that looks like what ill want to do, on a vn vp do you run the dump pipe down between the chassis rail and the back of the engine then passed the box, saw a 5 litre setup with a hole cut behind the strut tower for the dump pipe to go out but would rather avoid cutting holes behind the struts, holes for cooler piping however I dont mind. I was thinking of running a raversed cast manifold reversed on the driver side to point forward and run the crossover low around the front of the engine but that idea was really just to help with extra clearance for the dump pipe if it will even fit down past turbo manifold. I knew I would have to use sch40 to hold the weight of the turbo but from what you said I dont think ill need sch40 for the crossover now so thats a plus ; )

Also with injectors, I hear 36lb are the go but are they a necessity? As I had said this is really just a proof of concept and im not expecting big things, I can get seccond hand engines, boxes and diffs I can get cheap so if it goes bang I wont cry lol. But if I can save 300 bucks by not buying 36lb'ers then thats a bonus. Or even if I can save 50 bucks buying a smaller but still suitable injector. This setup wont go passed 10psi without further supporting mods.

For the fuel system I have a a pair of vn v8 external pumps and a 2 litre surge, havnt decided on the intank pump as yet.

For an exhaust I have been looking at the off the shelf rage 3 inch altho its expensive at $450 but I can get 2.5 inch for about 170 or so. Or I can sack up and make my own lol which is more likely I think.

Diffs I have covered as for the brakes im going to use the vt twin piston setup off my vn v8 wagon with the wagon booster etc

[delcowizzid]

just buy seimens deka 60's off the bat once boost hits youll be addicted and want more LOL

[vn304turbo]

Awesome, had a look around and looks like I can pick up a set of 8 deka 60's for about 200 bucks. Works well as I get 2 spareinjectors and still cheaper than 6 36lb'ers. Is there anything else I sgould take into consideration if im going to get hungry for more?

Will a 38 mil external gate be big enough? Thinking about having the 'gate flange under the log on the passenger side so can run the screamer straight down, it may get plumbed into the dump at a later stage but to aid simplicity it well be vented for now.

Delcowizzid what sort of boost should I be aiming to run at the start? Im having a hell of a time finding wastegates with any less than an 8 psi spring. Lowest I have found is a 6psi but it looks a little shabby so will 8 psi for starters be alright? Will be posting for a tune once its all together, I already have tp rt and have been snoopong around attempting to familiarize myself with it, I dont want to have to bug someone for a new tune everytime I get hungry lol

[Holden202T]

Big fuel pump

[vn304turbo]

Got 2 vn v8 externals that I think should keep me covered but if you think I need more oomph then what do you suggest? Also not to sure on what I should use for the intank lift pump, any ideas on that one?