Turbo high flowing!!

[mollins]

unreal mate. thats great work. very thourough.

i have tool envy...

[twin eng, twin turbs]

unreal mate. thats great work. very thourough.

i have tool envy...

Cheers mate, do you remember that alloy cam cover i bought off you? Its in the first pic with the fins machined off and polished up!

[abreut]

Nice work. I like it when people use some ingenuity to get more power instead of just forking out cash for new parts.

[gldgti]

nice work mate - couple of questions:

1) is the exhaust housing material easily welded to? is it a simple mig job, or tig? what gas you using?

2) did you increase the turbine size purely for max output advantage? do you envisage a slower spool up now?


cheers

aydan

[twin eng, twin turbs]

nice work mate - couple of questions:

1) is the exhaust housing material easily welded to? is it a simple mig job, or tig? what gas you using?

2) did you increase the turbine size purely for max output advantage? do you envisage a slower spool up now?


cheers

aydan

Yes the exhaust housing is easily welded as it is cast steel, and i simply "v" prepped it and mig welded it with flux cored 1.2mm wire and argo sheild as the sheilding gas. If the housing was cast iron it would still be weldable with eutectic spray welding techniques but this would not be as strong with less penertration into the base metals and the possibility of cracking occuring under the torque of the bolts through the flange. You can weld cast iron with a mig but it will crack! and it is very difficult to machine requiring industrial diamond ceramic cutting tips at around $300 each!

I have increased the turbine and the compressor wheel sizes and flow rate capabilities by a large amount in doing this modification but the size of the wheels is not as important as the design of them! The original vf22 turbo is the highest flowing of the vf range used on the wrx sti's but also the laggiest aswell, this is due to its 10 blade compressor wheel compared to 12 blades on every other vf series turbo. The Garrett GT i used has 14 blades and a more advanced design aswell for improved airflow. The exhaust turbine on the garrett GT is back cut for improved flow in the top end and has a more aggressive rack angle where the exhaust gas hits the wheel but it is a compromise between low rpm response and high rpm power flow. I envisage a little slower spool up but only by a maximum of 500rpm, it spooled up from 1500rpm in each gear with around 5psi at 2000rpm and had usable strong torque across the entire rev range. I am after more top end power for sure and peak boost from 4000rpm up to 7000rpm of around 20psi. This should net 200 plus kw at the wheels, ill post a dyno print out when i get it tuned in coming months.

[twin eng, twin turbs]

Nice work. I like it when people use some ingenuity to get more power instead of just forking out cash for new parts.

Cheers thanks mate!

[gldgti]

Yes the exhaust housing........................................

thanks mate, very helpful. between mollins and i we have a few turbo parts lying around now, and i'm curious to start playing around with stuff.

now knowing the specifics of the turbine wheels you're dealing with, your logic about retaining a good spool up becomes more obvious to me. cheers.

next time i'm out at orange i'll have to meet up with preeny and yourself for a chinwag.

[Jarred]

*watches with intrest*

defiantly want to keep an eye on this one. Good info here

[twin eng, twin turbs]

thanks mate, very helpful. between mollins and i we have a few turbo parts lying around now, and i'm curious to start playing around with stuff.

now knowing the specifics of the turbine wheels you're dealing with, your logic about retaining a good spool up becomes more obvious to me. cheers.

next time i'm out at orange i'll have to meet up with preeny and yourself for a chinwag.

Yeah for sure, allways keen to talk dubs and performance mods. We could go for a cruise aswell. Cheers

[twin eng, twin turbs]

Just a update, everything has been back together for a week now and going harder than ever before with boost on only 13psi. In the first two gears it makes a bit more power than before but once into third the turbo gets loaded up and the rate at which it excellerates is unreal hitting redline in a few seconds and forth much the same. Before i turboed the car it would hit a wall of aerodynamics at 170km per hour and slowly gain speed to a 195km but now it hits rev limiter in fifth at 7200 rpm with a 020 16v box, on a closed road of course..... Heres a pic showing the size difference in compressor wheels from before and after. I couldn't photograph the machining as the camera was flat when i did it.