Thread: vzr turbo project

Hi guys, been on the forum for a bit now, haven't posted anything yet.

Bought a pulsar vzr in england, and after getting beaten by a diesel in a drag race and wanting a bit more power anyway, have decided to go down the low boost turbo route, for now

ideally I want to keep the fuel economy of the 1.6 and gain a lot top end

Some basic turbo math I've done said I should see 275 at the fly on 8.7psi at 9k rpm, which is perfect for a start

Just wondering what others have chosen in regards to parts, turbo, intercooler etc. I know people tend to turbo the 20ve instead, which will obviously flow more

Any comments welcome, don't think it has been done in england yet

Steve

The 2 most important things you will need for your goal

S15 480cc injs ( 305 WHP @ 3bar )
GT28RS turbo

Thanks miko, vvl guru

the injector choice confirms my predictions as I need some to flow 472cc/min at 85% cycle

Turbo choice is confusing me, gt28rs, on the compressor maps I'm at the bottom left of the graph at 9psi. So was wondering, is that going to give me a quick enough spool? I know the low lobe action will take care of a portion.

Also, I worked out a 17.7:1 effective comp ratio, that to me seems really high (but I am running 95 Oct over here), so I'm guessing any higher in boost and I will need to get custom pistons?

Steve

There are 2 things in my opinion that get a turbo spooling, engine size and compression.

Engine size being air flow
Compression being heat generated


These compressor maps dont tell you everything that is going on.

A SR16VE motor vs a standard SR20DE motor.

The SR16VE will be faster, has more WHP 175 vs 140. The VE head has way better flow potential.

Now on a standard SR20DE-SR20DET motor with stock cams with a GT28RS you will see 300 WHP at 10 PSI and 350 WHP at 15 PSI.

This translates very well to a SR16VE motor. Yes it is smaller than the SR20DE but it has better compression 11 to 1 vs 8.5-9.5. Better flowing head and cam setup. So the SR16VE with the smaller cams on the small lobe will help to spool up the turbo while the bigger side of the cam will carry the HP.

Look at it like this, if you followed the chart just on engine size. what would you say by comparing to engines from Nissan with the same engine size.

SR16VE ( 175 hp vs GA16DE 115 hp )

Make sure when you get that GT28RS, it has a .86 turbine housing.

Yeah, my maths was based on practically a 1.6de that revs to 9k rpm, but gave me a rough idea

So I don't need to worry about DET then? with such high compression?

And why the .86? I've seen most are .60. Anyone know what the standard gti-r trim is? Guessing its not the rs? As I think I can get a manifold + turbine cheap

Sorry for the noob questions by the way. I'm using my phone, and the search just annoys the hell out of me

Steve

Oh......

You are mixing up wheel trim and compressor housing AR and front to rear housings

The GT28RS Turbine housing has two popular ARs, .64 and .86

Turbine
-Wheel: 53.85mm w/ 76 trim
-Housing: .64 or .86 ar

Compressor
-Wheel: 60mm w/ 62 trim
-Housing: .60 ar

ok Disco Potato it is, cheers Miko

have done a bit of research, people are saying that the high compression will definitely cause detonation above 8psi?

was wondering if this was true, as reliability is going to be my MAJOR concern

(as i used the 8.7psi boost pressure target with the 11.1:1 static comp ratio of the 16ve pistons, gave me 17.7:1 effective ratio)

Steve

uhh from what i've seen the sr16ve puts down nearly identical 1/4 mile times as a sr20de.. same car, same tires only diff was we swapped a 16ve an tranny in.. (got from you) 16ve put down 159hp 115tq an we never tested the de.. im assuming the extra tq the de has makes up for the diff in hp..

I have not done the calculations yet but i reckon you should be right. You might have to switch your cams early to avoid detonation though.

These people would be basing their opinion on det stats and not considering the huge 280deg cams and longer rods you are running.

I put this link in another thread but it should be usefull to you. Dynamic CR

your dcr should always be lower than static.

In fact i will go out on a limb without doing the calcs and say that i doubt your engine will be any easier to make detonate than a 10:1 20de

a disco with a .86 hotside would suit nicely but i would go slightly larger injectors providing cost is equal as you will most likely end up running higher boost.