I had a vf34 with 20g exhaust housing with front mount intercooler and it was still responsive enough, and yours will be better with top mount intercooler.. I think vf34 would be plenty or you'll end up with more problems/expense.

[QUOTE=Faz;700252]the VF34 and the VF30 are very similar in output, the only difference is the spooling times, as the VF30 has a different bearing design. I think i will look more into why its not boosting over 1 BAR, does any one know why that might be?[/QUOTE]

Shit wastegate, see tuna mods for quick fix!

When i decide to put a new engine in, I was wondering ... probably wouldn't be keen to put a bigger turbo, as i like the VF34 being really streetable.

So, I was thinking a crate 207, perhaps with cams, reconned heads, 1000cc injectors, STI TMIC with waterspray (already have), or FMIC if required, then boost up the VF34 to say 26-28pound, add a P20 housing (maybe), but keen to keep the P18 to bring it on boost sooner, get a tune and then winning?

Where are the sensible limits of the 34? She's tip top at 21psi right now, has been for ages.

The 207 should be alright at that boost level with regular services and maintenance?

Sound like it would give me 300horsies and 400+nm of torque at that boost level?

Would it be wise/should i require the P20 for better flow?
Reconned heads flow alright at higher boost levels?
For said boost, fuel system? Parallel rails, what fuel pump? Running a Walbro currently.

Am running a p20 on my vf34 Richi but I haven't pushed it to find the limit. I have destroyed a few hoses around the turbo and TMIC though. I do however want to see how it will perform with around 1.7bar boost through it soon just need more $.

Faz,

How many km's has your current motor done?

If you're set on keeping the VF34, stick with the top-mount. You won't see a lot of benefit going to a front-mount and you'll lose a lot of throttle response.

More boost will give you significantly more torque and more mid-range but the boost will taper off at higher rpm and the VF34 will be quite far out of its peak efficiency. Intake temps will soar and you've got a much higher chance of damaging your engine. The P20 housing will help a bit, but not a lot.
The improved heads/cams will give you more top-end but it'll be a little gain for a lot of coin. I suppose if they're coming out anyway it's a great time to do work.
I would say 300HP/400Nm is a about right for a highly boosted VF34 with cams.

Have you got a better wastegate actuator and a 3-port? You shouldn't need to upgrade your fuel pump or rails for 300HP. Injectors are a good idea (I saw you included them in your list).

[QUOTE=RichX;720596]When i decide to put a new engine in, I was wondering ... probably wouldn't be keen to put a bigger turbo, as i like the VF34 being really streetable.

So, I was thinking a crate 207, perhaps with cams, reconned heads, 1000cc injectors, STI TMIC with waterspray (already have), or FMIC if required, then boost up the VF34 to say 26-28pound, add a P20 housing (maybe), but keen to keep the P18 to bring it on boost sooner, get a tune and then winning?

Where are the sensible limits of the 34? She's tip top at 21psi right now, has been for ages.

The 207 should be alright at that boost level with regular services and maintenance?

Sound like it would give me 300horsies and 400+nm of torque at that boost level?

Would it be wise/should i require the P20 for better flow?
Reconned heads flow alright at higher boost levels?
For said boost, fuel system? Parallel rails, what fuel pump? Running a Walbro currently.[/QUOTE]

[QUOTE=RichX;720596]When i decide to put a new engine in, I was wondering ... probably wouldn't be keen to put a bigger turbo, as i like the VF34 being really streetable.

So, I was thinking a crate 207, perhaps with cams, reconned heads, 1000cc injectors, STI TMIC with waterspray (already have), or FMIC if required, then boost up the VF34 to say 26-28pound, add a P20 housing (maybe), but keen to keep the P18 to bring it on boost sooner, get a tune and then winning?

Where are the sensible limits of the 34? She's tip top at 21psi right now, has been for ages.

The 207 should be alright at that boost level with regular services and maintenance?

Sound like it would give me 300horsies and 400+nm of torque at that boost level?

Would it be wise/should i require the P20 for better flow?
Reconned heads flow alright at higher boost levels?
For said boost, fuel system? Parallel rails, what fuel pump? Running a Walbro currently.[/QUOTE]

Have a look at some of my previous graphs.

STi TMIC ~ 280hp
FMIC ~310hp Just have to wait another 1000rpm for it to come on.

If I was doing it again... TMIC all the way.

Why 1000cc injectors? Unless you are going E85 they are stupidly big. STi pinks or decapped stocks to 816cc are more than enough. I remember when we started with the decaps and everyone was saying how huge they were, now 1000cc is normal!

Walbro fuel pump is fine.

I can't remember if your car has AVCS (think it was 02 STi only), if it doesn't get some cams.

Get a 08+ STI TMIC instead of the GD STi one.

EJ207 is fine up to 3 bar :D

VF34 comes on song around 1.6 - 2 bar. 1.8 with TMIC is winning.

^ whenever there is a question regarding a vf34 you always have the answers to them!

TD04's and VF34's are all I know :p

[QUOTE=tuna;700507]Shit wastegate, see tuna mods for quick fix![/QUOTE]

Tuna is on the money. The initial diagnosis was that it isn't boosting past 1 bar, and the solution is to get a new turbo? Wouldn't it be wiser (and more cost effective) to either perform the mod tuna has posted, and failing that, get a decent actuator and see how it performs then?

EDIT:
Just for reference sake, before the rebuild my MY99 was pushing 240hp @ 1.3 with PowerFC, VF30, exhaust, APS TMIC, ultimately similar setup to yours, hence my reasoning for solving your low boost problem before outlaying for a new snail.