Any sc42 billet results yet?

 

Hi,

we have done one so far, and are to do another next week.

The one we have just done wasnt conclusive, the car was fitted with an MD321 H, we know these are a good turbo but on this particular set up the car was suffering with bad compressor surge.

Turbo swapped out for the SC42 Billet, spool was a touch quicker but not as much as I hoped for, power was identical at 400 BHP but we feel that was as much as both turbo's could achieve on this engine, it was maxed out, how much further both turbo's would go I don't know, so a bit inconclusive.

One thing the SC42 billet did cure was the compressor surge, completely gone, happy customer.

Not to forget the turbo did achieve 400 BHP easily, spool was good so it looks as though it will be a winner.

Testing another next week on a version 5 with forged internals, should be interesting.

cheers
Kev

 

what type of engine was this kev?

 

Hi,

2.0 ltr forged bottom end with standard wrx heads on a bug eye, usual mods like de cat and inlet pipe but not a lot more.

cheers
Kev

 

I think that is still a good result though, as you say apart from it not being billet the MD321h is a cracking little turbo, and if you improved spool, cleared the surge and made the same power just by swapping it for the sc42 billet then that is by far nothing to be ashamed of.

 

Maybe you can advise me Kev,

I've just had my MY08 STI hatch engine rebuilt fully forged and pinned and am in need of a new turbo as my VF48 is cracked (not just around the wastegate either I may add ) - as it stands for the time being the car will be remaining on the standard injectors (which I think are 560cc - can anyone confirm?) and TMIC, but I'll be adding tubular headers. The car is decatted also. So realistically with those supporting mods I'm looking at 400hp, therefore I don't know which SC turbo to go for. SC40, SC42 or SC46. From what I've heard the 46 spools similair to the 40 (due to the different bearings), but I'm thinking the 42 would be the best spooler of the three. However, the 46 could be run at less boost than the 42 or 40 to achieve the same power, so my intake temps would be less, plus I'd have future scope for 460hp when and if I decide to add an FMIC / etc.

So what's your take on that?!

.. do we have graphs for sc46 vs sc40 on the same car / config?

BTW what price is the SC42?

Stuart

 

Hi,

thank you for the above, you put it nicely in perspective.

cheers
Kev

 

- Posts # 1863, 1994 & 2047 will help you out...


- Post # 1981 for price. But that's a cheaper 'introductory' price - so not sure how long that's for?

 

Thanks Kev, I am gonna get some remedial work and prep done on the car in the next month ready to bolt this turbo on. Will be in touch soon to buy one

 

Hi,

based on the fact that you are considering a fmic set up later I would go for the SC46 and run it at actator pressure or just above for now, let it loose when you go FMIC.

I doubt you will see 400 BHP due to high inlet temps but who knows you just might, reason I cannot tell you is any one fitting an SC46 Billet always goes FMIC, you will find the compressor outlet a little tight against the fly by wire throttle body plug, simply turn the throttle body upside down to clear, works well but not required when using the FMIC pipe work.

SC42 Billet £1250.00
Sc46 Billet £1295.00

all prices + vat, all in stock.

cheers
Kev

 

Thanks for the advice Kev. What if I was only wanting to achieve around 400hp? I'm guessing the 42 at 400hp would show higher inlet temps than the 46 due to the increased boost?

What I'm trying to say is, for someone wanting 400hp, wouldn't it be better regardless of supporting mods to run the 46 rather than the 42 due to the 46 not having to work as hard so everything runs cooler (elbeit with a slight loss of spool)?

Cheers,
Stu

 

Don't forget the SC46 has a slightly bigger exhaust housing, so spool loss, relative to the 42, is inevitable on a 2.0L. The 46 will 'future proof' for more power (should you decide to), but the 42 more suited to your current goal's c.400/spool-up compromise.

That's my take on it - but obviously wait for Kev to respond...

 

I'm going fmic, but am going for the 42 after speaking to kev.

 

Hi,

spot on.

do you work here somewhere.



cheers
Kev

 

He's CIA gaffer
Jos has put bugs everywhere getting all info
Is it joz or the orical ???
Play x files music here , for effect
Lmao

 

after a brief chat with kev this morning im really interested in either the sc42 or the sc46.not sure which one to go for though.what do you guys think?ive got a 2.0 forged p1

 

Hi,

just a few quick questions.

FMIC ?

ECU ?

cheers
Kev

 

lol

Nah, I've just taken a real interest in this thread - esp. the 42 and 46 R.B. tubs.

 

Fmic,lateral injectors,simtek,3" hks,rcm induction kit etc.

 

Oh and one of your paddle clutches kev

 

finally some sc42 results coming through i will keep a close eye now as id like to se some graphs ona 2.0 with all the mods becuase i to trying to way up wetaher to have the sc42 or 46 duncan graham seems to think the sc46woudl go well on my nice quite forged engine and mods and im reallly want ot be sat round the 420 mark

 

Cheers mate; helpful chap!!

 

Yeah, makes sense but what I'm really trying to get to the bottom of is:

Given a power target of 400hp is it better to use a turbo capable of 450 (at a lower boost) or a turbo capable of 400 (at it's normal boost) - assuming spool differences are minimal / acceptable?

 

That's a fair question.

Obviously, for any given like-for-like power level, the 42's CHRA will be more 'stressed' (higher target boost), when compared to the 46. But that extra gas flow being forced through the 42's smaller exhaust housing will keep the 42's CHRA more 'energised', thus translating into keener spool-up/response to the throttle. But to what degree the difference would be - i.e. the all-important how it feels on the road - don't know.

Kev, what do ya reckon?

 

The 42 and 46 compressor wheels/covers are the same, so it's all about the difference in their different sized exhaust housings, and how that translates on the road... Are the spool-up/response differences really noticeable, or not - that's the $64k Q we're all after an A for! ? If "not" then, the no brainer would be to spend the extra £110 or so on the SC46. (That way you'll have scope for project creep, whilst still enjoying its lively response. Win-win... )

 

Lee get the 46 mate you've been in mine yours is lighter car capable of more boost with a better clutch
Simplz........

 

Kev,

Could do with an answer to that $64K question I need to be making a purchase on Monday due to my project timescales, a graph would help :-))

Stuart

 

kindof hi-jack an apologies in advance

but seems like "the" turbo thread,

could someone explain , compressor surge, and why its bad and how you get rid of it?

also exhaust housing, does a smaller size generally mean less lag, with a slight loss in top end power?

thanks in advance

 

Hi,

if your target is 400 BHP get a turbo that is rated around that figure, dont get one rated for 500 BHP as you will lose so much spool for no reason, unless your future target is 500 BHP.

Case in point, one customer insisted of seeing 460 BHP, on his set up the SC46 Billet managed 450BHP but sadly no more, spool was great and on the road car was very quick, however in his quest for figures he got us to swap it out for an SC50 Billet, this done and his target of 460 was achieved but at the loss of around 1000 RPM's worth of spool.

The SC50 was overkill for his standard heads and cams, get it on wilder cams and ported heads and we would have seen 500 BHP and far better spool.

Hope the above helps you make your decision.

cheers
Kev

 

Ok Kev, you're pushing me toward the SC42 , just one final question - in your above example you said the change from SC46 to SC50 (on the same car) resulted in a 1000rpm loss of spool, now I know things aren't as simple as this but since the difference between the SC46 and the SC50 is 40hp and the difference between the SC42 and SC46 is 40hp, does that also mean the SC42 would spool a 1000rpm quicker than the SC46?

As I say I'd love to see some SC42 dyno graphs (hint hint)

Cheers
Stuart