J Chen

Hi Pauerman,
You misunderstood my meaning. Please re-read my thread.
If you put the 2 unmoded heads on a flow bench, even at low
valve lift, there no way that a 2V head will outflow the 4V
head. Hence my point about port velocity.

NZ951

Yup the only reason to go for a 8v over a 16v in an engine project is a cost cant afford it factor.

J Chen

Who say's so NZ ? Theres many ways to skin a cat.
Putting aside real race prep engines, to get the 16v
head to work on our cars does not necessarily mean
that you've got to spend big big bucks. Just more fab
work involve that's all.

NZ951

Speaking for the typical yobbo send it to a shop and just wait around for the odd pic on the update its probably why... but you are right, if you can wrench, make an intake or exhaust etc, then its viable...

J Chen

It's much chaeaper than you think NZ. Even after
upgrading the guides & valves on the exhaust side.

hosrom_951

So much for a turbo thread

jimbo1111

J Chen Why do you say it's to big? I get 1 bar at 3200 rpms. Shift the rpm over to 3500 and your 65% efficient.Plus I have a clipped version witch lowers the surge line to below 3000 rpm. When on boost all I have to say is catch me if you can!

J Chen

Jimbo,
Firstly is your turbo sold by Precision Turbo ?
What hot housing & turbine trim are you using ?
Clipped version, so the compressor is clipped ?
If so, the compressor map will no longer apply
cause the flow rate will be altered. BTW, I suspect
your turbo is actually base on 60-1 hifi if not it must
be another compressor but surely not 60-1. Look at
the plot Pauerman made for you. AT 3000rpm it has
not even started to make boost & yet you say you are
making 1bar at 3200 rpm. Does this not make you
feel suspicious ?

J Chen

Jimbo,
O.K now I know. Is it an Innovative GTS61 turbo ?
Did you remember how many blades were there
on the compressor wheel ? If it's exactly the same
as the picture posted in their website, your compressor
wheel is more likely a TO4E 60 trim.

jimbo1111

No it's not a 60 trim. The major is 80mm thats about 3.4" not 2.95" like the 60 trim. This turbo is a garrett gt wheel. Very similar to the wheel used in the gt35r and gt40 if not the same. The hotside has a t4 wheel installed. Witch one. I will leave that up to you to speculate. I gave you a hint. 3200 rpm 1 bar!

Stage3GTI

The GTS61 uses a GT35R compressor wheel mated to what is equivalent to a Stage 5 turbine wheel. Precision uses there own housings for the unit.

The GTS61 ball-bearing is a full GT35R center section with Precision's own compressor and turbine housings.

Precision rates these units at about 630hp while the full GT35Rs with the bigger housings are rated at about 680 by Garrett.

I'm using the ball-bearing version now in another car after using a T3T04E 50trim. The size difference is huge.

Hope this helps.

J Chen

Jimbo,
Is it from Innovative or not ? Can I have more details.
Which hotside are you using & what AR ? Are you
sure that that compressor map is the correct one ?
To generate 1 bar boost at 3200 rpm will require a
relatively small turbine wheel something like a Stage
II or III wheel but the set back would be that you will
not be able to capitalise on the high flow of the potential
of the compressor. BTW, how much clipping was done ?
The other way around is to have a very small AR hot
housing to help boost threshold.

J Chen

Hi Stage,
Stage V turbine. Can you really hit 1 bar at 3200 rpm ?

jimbo1111

I am running a true t4 wheel not a t3 stage 5

J Chen

Jimbo,
Looks like you're not gonna share info hah.
I was studying the SC61 from Precision &
it look very interesting especially on the hot
side. But it's very difficult to buy a turbo with
no hard figures cause all you get is quoted hp.