Hybrid S5 Turbo Q's
 

Apologies if this question has been asked but consolidating the info is a bit tough amongst the junk. So I have a blown S5 turbo laying around and was seriously considering building a hybrid. I'd be using a TO4B 60-1 wheel, backplate, a .60 a/r comp housing, and a stock turbine wheel and housing. I was curious if anyone was running this setup? What rpm are you seeing full boost at?

thatt at setup should have great spoolup and transient response, you should see 15 psi by 3000, but it will creep without wg porting and backplate mod. the factory S5 manifold was built for low-end. I was running a p-trim (a lot laggier hot side) on that setup and got 15 psi by 3300.

That's basically a BNR stage 3, except they clip the stock turbine wheel. You'll probably get slightly better spool, but the turbo will be choked and the compressor won't hit it's best efficiency ranges.

If you aren't going to clip the turbine, a v-trim (stage 2) is going to be a better fit spool-wise and work more efficiently. Just doesn't have the same potential as a 60-1.

I read about BNR turbos. I'm not entirely too worried about top end power. More importantly, if prefer better response in lower to mid range power. Hopefully the stock turbine will allow for that from what you guys are reporting.

I've had 3 hybrids. The first one had a stock turbine wheel & an H trim compressor. It had great response & good midrange. I ran this for years until the stock turbine wheel blew up. I rebuilt it with a 60-1 compressor wheel and wasn't happy with it, I had expected a lot more. Response suffered & it really didn't seem to have any more on top. So I took it apart and rebuilt it with an O trim turbine wheel (1 size smaller than a P for response) then it really came alive. I love it now. Consider how much boost you want to run.

Did you have to have the stock turbine housing machined in order to fit the O-trim turbine wheel? I'm curious about the clearance since I've read that the P-trim turbines need the housing machined to fit.

My target goal for power would be something along the lines of 350hp. Doesn't necessarily have to be exactly on the number, but it's a figure I can be completely content with for now. I think this would be doable with maybe 12-14lbs of boost. Correct me if I'm wrong at all.

going the bigger compressors ( than the 58mm H ) demand 360 thrust bearing upgrades and eventually need for large shaft t04 turbine wheels
and ultimately these large frame highflows have lots of inertia and spool suffers

staying with the H and under TO4B compressors allows you to retain standard type thrust bearings and the low inertia t3 turbine wheels

the ta34 turbine wheel ( stage t2 turbonetics t3 turbine ) is direct fit small shaft with reverse thread and will help response with a small increase in the major diameter
and helps backpressure issues at higher boosts with a slight decrease in the minor diameter

mixed with T, U , V or H TO4b fronts these ta34 turbine highflows max out just over 300 rwhp at 1 bar ish boost
-but give almost stock response while still addressing backpressure ratio issues up top

Yes, the turbine housing has to be machined to fit the O trim wheel. It's only smaller than the P trim on the minor diameter. O= 2.922/2.296 P=2.922/2.544. Since it has the same major diameter as the P trim wheel it has the leverage to turn the 60-1 compressor wheel better than the stock turbine wheel. It also flows more than the stock wheel. I picked the O trim wheel because some people have said the P trim can be lagy. For 12 to 14lbs boost I would say the H wheel is the best fit from my experience.

So you'd suggest agains using a ta34 paired to a 60-1 wheel? just trying to get one the same page

the post was trying to put highflows into two classes ,, those that are common t04b sizes
.. and those that are 60-1 or to4E sizes that are bigger compressor wheels in both major and minor and are at the point where they demand the t4 turbine wheels and external gates to get around thrusting/ backpressure ratio issues that will break/ cause multiple issues with small shaft turbine wheels
( stock and t3 turbine wheels )

going these larger compressor wheels tends to have jumped in the all out flow at expense of response boat .. they make 350 rwhp at 1 bar.. but it has come at large cost..

the to4b options ( T,U,V, H ) are smaller at the major diameter and have much lower inertia
matched to stock.. or better,, to the TA34 turbine wheel ( stage 2 turbonetics )
then they work with much better response than the O or P with 60-1 or 57 / 60 trim to4E options .. but may fall 25- 40 RWHP short in the top end.. they more than make up for that on the street with the area under the curve under boost.. they are much easier to drive fast on the street...
they also get away much better on the internal gate.. and the compressor cover fits in FC without mods to LIM or cover

however--
the stock turbine finds it limits when flowing around 300 RWHP.. with a nasty shape on the boost curve with spike and creep ///

to get the best out of the compressors which obviously can flow much more in other applications then you need to uncork the rear

usually this is a backcut stock rear turbine wheel -- BUT in doing so you just threw out that response and that area under the curve

the bigger compressors also tend to load it up axially with unfavourable back pressure ratios .. .. wiping thrust bearing quickly and often undoing compressor nuts



the correct solution for all of this is to make a much better effort of matching front and rear wheel sizes .. that is why i push that tA34 wheel .. and its reverse threaded nut
go there first.. and try them with U and V trim compressors.. and find there is much more in these compressors with the right turbine wheel than when matched to stock rears
. you will have a much better turbo all round that looks closer to stock,, doesnt stress components ( still only requiring HD 270 bearings ) and boosts quickly like the stock one.. but can handle 1 bar of boost without cooking crap out of the air

my original post suggests you look again at the lesser t04B options.. there is much more to them when you fix up that rear turbine wheel ..

when considering a hybrid turbo u need to consider the boost creep, you also need to monitor that very closely because if you don't u end up cracking a plate.

But that being said you can get really good power and amazing response from a hybrid.... i would suggest an upgraded internal wategate and porting.

I have a t04b .60ar on stock exhaust housin. Love it by 2000 im hitting 1/2 bar 2800 1bar and 3000 1.2bar

My power is 370 but I do have other mods greddy front mount 25% meth 75% water spray kit. Rx7 fd upper inlet greddy emanage ultimate and 1000cc injectors can is now off road for suspension and fuel tank work.

How are you liking the emanage ultimate the rotary?

I had a holset hx-40 put into my s5 turbine for ~800$, solid setup for 14-15 psi

I'm selling a setup right now that's designed to use the principle design of the S5 Turbine Housing and Exhaust Manifold and a BorgWarner EFR 8374 or 9174 Supercore. Massive Wastegate porting, Fully Divorce downpipe, and 0.865 A/R Divided (Twin Volute). Selling it for half of what I paid to build it. PM me for pictures/inquires.