TD04-13 - > Billet 19T worth it?
 

I'm currently using a WRX TD04-13T on my 99 1.8.

​Headline figures of 215ft/lbs 275bhp (Our flywheel figures appear to correlate with your whp figures based on my 1/4 trap speeds compared to say Greg Peter's car) with a very flat torque curve from 3200rpm(ish) to 6800 or so

I've no intentions of going down the built engine route but would like hold the torque closer to 7300rpm.

I understand a Billet 19T compressor wheel along with one of their 11 blade turbine wheels will improve flow across the entire powerband and help hold that power at the top end. I'm not too concerned about the 500rpm or so spool difference as I'm already holding the turbo back until 5000rpm to avoid big surges in torque bending rods

Question is would you consider it worth the $350+shipping/import duty and the cost of having it built and balanced for me?

Some items that might help:
1) Where are you located? EDIT: UK
2) Who is the supplier to which you refer... that is offering the Billet 19T compressor, and special turbine wheel?
3) Sounds like you are running EBC. Are you increasing the boost above 6500 to be sure you have nothing left on the stock CHRA, before going to the upgrade? I suspect you are maxed out, but just suggesting a reality check.
4) What other supporting mods do you have? Downpipe, exhaust, etc.

EDIT: Into 12's at 1/4 mile. Good show. My hope as well with TD04L-13T, but I may be too heavy.

1) UK
2) http://www.ardideas.com/TD04-19T-Conversion-Kit-Subaru_p_2211.html
Compressor wheel and cover in that link which also links to their turbine wheel
3) CL boost with MS2 and a MAC 3 port solenoid. Boost target 180kpa to 4500rpm, 190kpa at, 5000rpm, 200kpa at 5500rpm then 210kpa from 6000rom onwards.

​​​​​4) 2.5" downpipe + full exhaust with high flow cat, 20% methanol + 99RON fuel mix

Edit: 650cc EV14 Injectors too

Dyno graph before the 2.5" exhaust (Stock center and cat, 2.5" rear silencer)

https://cimg8.ibsrv.net/gimg/www.mia...38f1d48ce1.png

It's hard to answer "is it worth it" questions because everyone's opinions will be subjective and differ from everyone else.

I think if you're going for flow, and upgrading both wheels anyways, you may as well get one of the STi VF turbo's that not only has the bigger wheels, but the larger housings too, but should still fit onto your setup without any issues. it comes on smoother, and basically just carries the td04 torque curve to the right, resulting in smoother torque curve and more power overall. it might even be cheaper/easier than your current plan

^^ 18, I was hoping you would come in on this, with your knowledge of both Miata and WRX worlds. Thanks.

Glad to help, sir :)

I've actually sorta experimented this topic on Subaru's before:
large wheel/small frame turbo
vs
large wheel/large frame turbo

scenario 1 netted better spool, but choked up top, and required a ton of boost to make big power, which resulted in air temps skyrocketing
scenario 2 netted much lazier spool, but big top end gains without requiring really big boost

Neither scenario, in my opinion, was ideal. It's all about balance. That is key
In this case, I don't think the results would be bad, but I just don't think it's worth the effort of upgrading the wheels.

Hard to argue with your logic 18psi.

The Billet wheels and compressor cover alone would cost me the same as what a used VF35 goes for here.

Given the VF35 will spool to well over a bar by 3.5-4k on a WRX it's going to have no trouble spooling to the 10psi or so it's going to need to make 220ft/lbs on my motor, and so I'm likely to see the same 200odd ft/lbs of torque by 3300rpm.

I had only initially considered the "Hybrid" 19T route as to whether EJ25 WRXs in the UK were fitted with the TD04H-19T like the USDM models

I have a WRX and second what 18psi has said. The 19t doesn't really get you much more headroom. I think the vf43/48 would be a very nice upgrade and it'll hold the tq deeper into the band, it might spool 300 rpm later.

I want a subaru.

Ordered the kinugawa 19t upgrade. We’ll see the difference when it gets here.