I've been asking some of the local turbo workshops if they'd rebiuld my S5 turbo with a garrett TO4 S front cover and new compressor wheel, and from the few I've spoken with, they are not that keen on doing it, they all seem to want to sell me their new turbo's!



Is this option worth while, what are the reasons for not Hybriding S4/5 turbos? Or, should I take the other approach and ask, 'what are the advantages of a S5 Hybrid turbo'?



If anyone has used these Hybrids, could you give me some feed back on the size of compressor wheel I should be using or A/R ratio?

from what i've read elsewhere, it's a decent setup for a relatively stock setup that can fetch about 14 PSI and roughly 300HP (flywheel). advantages would be overall costs and virtually no custom work to your engine bay.



i'm sure people with experience can make suggestions. i'm not knowledgable enough to do so.

About 4-5 years ago I had mine rebuilt by Turbonetics, with a "super V" hybrid. You will also need more fuel and a way to control it. I had my stock engine computer reprogramed and used a SAFC to control the 6 550cc injectors. Also the engine had a street port. I made 325hp at the wheels.

if you're just changing the compressor wheel its a good option, of you're putting a larger exhaust wheel in there too, the cost gets to the point of being not worth it. buying the wheels, plus balancing and assembly and you can buy a new t4 and maybe a wastegate or a manifold

For compressor upgrades...

http://fc3spro.com/TECH/MODS/TURBO/comphy.htm





-Ted

http://fc3spro.com/

what does a machined compressor housing look like?

[quote name='Cheers!' date='Jul 7 2005, 05:04 AM']what does a machined compressor housing look like?


[/quote]



stock, they bore out the inside for a larger wheel.

[quote name='j9fd3s' date='Jul 7 2005, 08:35 AM']stock, they bore out the inside for a larger wheel.


[/quote]



How much do the bore out? Do they maintain the same curvature to have the same flow characteristics? What about surface finish? What RA?

[quote name='Cheers!' date='Jul 7 2005, 07:13 AM']How much do the bore out? Do they maintain the same curvature to have the same flow characteristics? What about surface finish? What RA?


[/quote]



it kinda looks like stock just the hole it larger, to fit the bigger wheel

[quote name='j9fd3s' date='Jul 7 2005, 09:41 PM']it kinda looks like stock just the hole it larger, to fit the bigger wheel


[/quote]



They don't have to machine the inside of the curvature?

The "bore" it to fit the curvature of the compressor wheel you're trying to stuff in there.

This takes precision machining to do right.

If done wrong, you lose efficiency from the compressor section, since there is excessive blow-by in the compressor section.





-Ted

http://fc3spro.com/

would that modification justify a different wastegate size? IE machining the wastegate "hole" and using a larger valve?

nah you wanna run higher boost anyways

rx-7store.net



Im planning on the bnr stage 2 on my s4 turbo