Spool threshold = What point in the rev range where the car makes a specified level of boost. 1 bar in 4th gear is a common benchmark

Lag = Delay in response to throttle transitions from the turbo.

Bigger turbos generally have higher thresholds and more lag.

The SC46 is remarkable in both respects, particularly on a 2.5.

Mine produces 1 bar at 2700rpm in 4th and the response is better than the VF35 (which has superb threshold and response) that I had on my old 2 litre!

Ns04

 

Ah, so harvey's test of flooring it in 4th from 1700rpm to see at what rpm 1 bar happens, is literally what he meant by "the spool point" (or "the spool threshold").

 

Ns04 wow 1 bar @ 2700
;-) impressive

 

"...Most impressiiiiiive."

 

yes harvey your right

you know my engine well, after building it - my sc46 performs amazingly on the set up recommended/built by you

its is most certainly not laggy atall!!

my posts are really more about me laerning more on forced induction set ups, than anything else

im always asking too many questions lol

 

Cheers Jeff. The SC46 was the best choice for your application, big enough to count with your forged engine but not so big as to be laggy, unresposive at low revs and late spooling.
NS04. That extra 500cc makes all the difference.

 

Quote:
Originally Posted by wrx9181
"impressive..."
"...Most impressiiiiiive."

Lol joz

 

im very interested to know how the SC46 performs on a 2.0ltr engine as im torn between the MD321H...SC42...SC46 turbo`s,i know the MD is supposed to be unbeatable on a 2.0ltr car but with the introduction of the SC42 and the amazing all round performer the SC46,im still unsure which way to go.

my car`s spec...

STi v5
JDM STi 8 Twinscroll bottom end
Simtek ECU AL/LC
550cc injectors
Fuelab fpr
RCM large cone/ally trumphet induction kit
RCM ported tubular headers
Harvey smith HSP18G ported turbo
Harvey smith special uppipe
Autobahn FMIC
Afterburner vortex R 3" straight through zorst
scoobyclinic lightened pulleys
new clutch and lightened flywheel coming soon
sfs silicone intake hose
3 port bcs
NGK pfr7b plugs

we need some results for the SC42 Kev,lee is having the SC46 mapped on friday on his forged P1,hes also having a meth map so fingers crossed it works well on a 2.0ltr car.

 

Hi,

SC42 or 46 Billet for yours.

We removed a 321 H from a 2.0 ltr car and replaced it with an SC42 Billet, no more power, but we feel the engine was maxed out so not a great back to back, slight improvement in spool, but lets not forget the 321H is still a great little spooler, the biggest result was the SC42 Billet cured compressor surge completely which the car had suffered from since the 321 was fitted.

Its fair to say it was a result.

More SC42 billets coming in today so we will get some graphs up asap.

cheers
Kev

 

cant wait for some good 2.0 graphs with good mods and a built engine if they can hit 400hp evry time then id be tempted

 

Very interested in the 36 kev (p1)
Let me know please when you get anything
Mick

 

Thanks for the info

 

I had my sc46 mapped today by Jgm but arrived at clinic too late to put on the rollers to get any figures.I will speak to kev and sort out a day so everyone can see how the sc46 performs on a 2.0.it pulls
really well

 

good man i take it is v power only as thats want i would really like to see
has im waiting for the sc42 as well so i can make my mind up which one to go for 42 or 46

 

im in the same position as you mate with the 42 or 46,but after speaking to lee and jgm today about the sc46 and how it performed on his car my mind has been made up for me,hopefully we`ll have some vpower and meth map graphs for us to ponder over real soon.

 

Yeah,,, its not too bad I suppose

 

Hi,

we will have some graphs on both V power and a 20% meth mix as soon as we can sort a mutual time/day for Simon to meet lee at our place.

Looking forward to seeing the results.

cheers
Kev

 

So are we, Kev!

 

That'll be three of us on the sc46 then glen lol
You Gunna take me out in yours now then Lee and I can see what it's like on your classic;-)

 

as soon as its finish i will mick.hopefully some time next week if it can be arranged

 

;-)

 

Yes mate it will,i was impressed with yours mick at 1.5 bar on vpower so god only knows what lee`s will be like at 1.8 bar on meth,its awesome at 1.6 bar on vpower and he said it scares him now.

 

Lol things do get a bit blurry when you put your foot down hard and mines a lardy newage
So I imagine it's mental on lees glen ?

 

Hi Kev its great to see you all still getting great results in 2011 !!! See you all in November

 

I witnessed a newage STi with an SC46 billet run 421bhp yesterday on V-Power alone

 

FWIW, in your position, providing your internals are good for 450 bhp I would simply go for the SC46 billet. We have fitted and mapped a lot of these and have not had any car fitted with this turbo with the appropriate spec that has not brought a smile to the owner's face.

 

Hi Harvey
I've still not got round to getting more figures since the headers uppipe new filter and 20% meth map from bob
I'm useless
Mick g

 

lol well come on then mick we like results haha

 

I know lol prob end up with three results at once if glen joins the sc46 club

 

Thanks Harvey..ive just fitted a low mileage JDM STi 8 twinscroll bottom end as the crank let go in the other engine,this should easily cope with the jump up in power.Also with the ability to run much higher boost im hoping this will really make the SC46 come to life,especially when mapped on 20% meth.