The sc46 is actually more geared for a 2.5 engine so would be easy to squeeze 400+ and low boost, but generally the figures they produce I see that of a sc42 which is more of a 2.0 turbo.
Don't rule out the 46 on your car though, then later if your brace and had a few tins, up the boost lol

 

to be fair mark @ thwaites was chatting to me about the sc46 for my car, he says its perfectly suited to a 2.5. i think the thing that scares me is that is a 460bhp rated turbo so surely its daft to only run it around 400bhp

 

A few 2.5's are making 480 off the sc46 now!

 

now that would destroy my rods

 

As someone with an sc46 on a 2.5 making 440/440 @1.5bar I can second it' a great setup. Spools pretty much from idle.

this was through a rcm manifold and Harvey up pipe, then 3"downpipe to a 2.5" h&s centre and back. When mapped I limited it to 1.5bar as was on standard rods. So maybe save some cash on changing the exhaust to put towards the right turbo.

 

how long have you been running this set-up? have you got a graph? whats the rest of the spec for your engine?

 

Heres a link to a video at Keevil. ..... not great video but as I get a fair bit wrong it shows how well it spools when in the wrong place in the wrong gear.

https://www.youtube.com/watch?v=b5tbQAZUcSQ&sns=em

 

Unfortunately it' now dead! Not through any mechanical failure but it consumed fire extinguisher powder. Reshelled the car after the fire and it was still pulling well but was using 2 stroke levels of oil.

have a graph but its now trapped in photobucket with all my other build pics.

standard crank and rods, cp pistons, cosworth 280kpa studs. V3 heads. Flowed 440 injectors. Wasn't a fancy build but worked really well.

 

thats a shame mate

were you not bothered about pushing the std rods? one thing mine doesnt have is the cosworth studs, we assume its arp 11mm head studs

 

 

Depending on who you speak to, you'l always get different answers as to whatse safe. I cant recommend running X amount of power on Y engine. And no engine builder would either as if they say 440s OK and you then tune for that with a bit of det or bad cooling system or a restriction somewhere else etc then it might not last long ...... then you'd be knocking on the engine builders door asking why his work has failed.

as stonejedi says, every build is different, in my case I was confident as I'd taken extensive steps everywhere else, the map was bang on, and I always knew what the temps were doing.

If I were you though, and everything else was right, I wouldn' be scared of an 46 or 42 capped at 1.4/1.5 bar if driven with a bit of sympathy.

 

Who mapped yours? I think I will be getting thwaites to do mine on ecutek racerom

 

Mines on a syvecs...... fantastic bit of kit!

Mapped by a friend who' sadly not with us anymore.

 

Ok thanks for your input, I guess I'm gonna just have to grow a set and slap on the 46.......

If it dies..........it dies

 

Most 46 I see, make 420-440 tbf. The odd few have made over but that's with some Gucci mods or trick mapping lol, and pushed

 

remember, just because you'e got a 460bhp turbo, that doesn' mean you cant cap the boost and see less to keep it safe! Downside usually being that that suggests you'e over spec'd the turbo and you'e compromised spool. However seeing as the sc's spool from nowt you may only see a 100rpm or so of difference. But, you will then be future proofed if you go for more in the future.

or, just go for a 42.

Whatever you do, don' get caught up on top end numbers with a road car! Low down grunt and drivabilite is loads more important and real world quicker. This is fairly difficult to get wrong with the 2.5 as there' so much torque low down, but if you get it right its incredible! Possibly the fastest road subaru I've had a go in was a 2.5 with a vf34. OK it ran out of puff a bit at the red line but was amazing everywhere else.

 

I Agree with legacyNumbers is good down the pub,but real world drivability or as they say the sweet spotmakes for a quicker point to point car everytime,but saying that once you get use to high levels of power its hard to go back,as my bottom map is 450bhp and even that is more then you really need on any uk road.SJ.

 

im not too caught up in numbers really i just feel this lacks a little thwack mid-range, my last 2.5 blobeye was running a gt3071r with 440bhp so perhaps why this feels a little dull.

thanks for everyones input

 

I’ve just gone rotated from a sc46 on a 2.1. It hit full boost by 3400rpm so it should be earlier
on your 2.5. Great turbo.

 

What turbo you running now and how is it performing on the 2.1 compared to the sc46?

 

Gone to a gt3076 .63 on a rotated setup. It’s not finished yet. Just got the last few upgrades to do in the next few weeks.

 

sounds good matey, looks like a 46 it will be

 

Running a GTX3076R stock location on my Closed deck 2.5, made 471.8 Bhp on straight V power @ 1.7 bar.

 

Laggy? Have you a graph?

 

I've not scanned them in. But it's not laggy, makes full boost around 3750rpm, lower than that in the higher gears and it goes like hell .

And the turbo was just under a grand all in, brand new.

 

cant grumble at that although its probably too powerful for my engine