Not worth the extra money
If you look at graphs etc
Add meth instead pal
As Alot needs changing to make your car twin scroll
Ie sump uppipe headers etc
But looking at the hs graph maybe it is ?

 

Hi,

to convert to a twin scroll set up in our opinion and I stress our opinion only, its not worth doing, you would need to change the sump, headers, up pipe, down pipe for what I feel would be little gain in spool.

The SC42 on a 2.0 ltr STI is a perfect combination, I would advise upgrading to an after market ecu, such as the syvecs to get rid of the air flow meter, add an inlet pipe and a set of injectors & an FPR and there will be 400 BHP on tap with great spool.

cheers
Kev

 

Currently, my set-up on V8 2.0STi is: MD321H, 650 inj. GT spec headers with Harvey's up-pipe, full 3" Milltek system, Hyperflow CAI, AVC-R boost control, Std STi top mount. Mapped by Paul at Zen it's just nudging 400 with 365lbft
I'm intending to go to a FMIC and am considering an SC42
Can you give a good, honest appraisal of what I could expect from the SC42 over the MD321H? It's a 90% road car so I would be reluctant to lose the current spool and would like to see a hike in torque as a priority.

Thanks for your time JohnD

 

Sorry mick but i have to disagree with you mate,although the car made decent figures when the water/meth was introduced it is still lazy spool wise low down and through the midrange imho,and on just 20% meth it made less power and worse spool compared to lee`s single scroll SC46 on his 2.0ltr car with 20% meth,so for me NO its DEF NOT worth the expense of converting to twin scroll.

 

okey...but how big is the inlet? I can see that lateral performance has a option os 58mm or 76mm on their turbos. Does scoobyclinic have that option to? And the bigger one is the prefereble right? I just have to buy a bigger 76mm inletpipe and intake manifold spacers to make it fit right?.

Or can I make 400-420hp on a 2.0L with a 58mm?

And the smaller exhaust inlet can it make 400hp?

 

Off the shelf the comp. inlet is the std. 58mm. But there might be the 76mm option too(?).

Yep, it should have no trouble flowing the appropriate CFM on the 58mm/7cm^2 combo, on a 2.0L, for 400+ bhp.

But best confirm with Kev....

 

double post

 

Great results..... you've gotta be pleased with that!

You on a 6sp box Harvey?

 

Just a quick note on how the Scoobyclinic billets got on at TOTB !

Andy Forrest with the overall win with two gt30s on his flat six, also won drag final in 8.77 seconds. Also completed the standing 1km at 202.4 mph !

Mikee Singh in the scoobclinic drag car finished forth on drag with 9.40

Myself in 5th position on drag with 9.51

Rob Wakelin on the handling course in 8th place

Not a bad result

Overall the team beat the gtroc into second place and MLR in to third !

 

It seemed that right through the classes, getting a clean start off the line was a governing factor? The juggling act to get the power down without bogging for the four wheel drive and the mad scrabbling for grip and hitting rev limitors for the front wheel drive?
Once start phase was over it was amazing to see the top imprezas blitz the others.

JohnD

 

It's difficult getting the LC right to launch on the strip on concrete. We certainly don't get the 60fts there like at pod or Shakespeare. My best of the day was 1.50, Andy and Steven in the banana did manage to get as low as 1.41 which is impressive.

 

Clive do you have any 60ft times for the GTR`s as they are renowned for there incredible launch control and certainly looked like a force to be reckoned with on the strip.

 

Best I saw was 1.31 ! And he did 9.52. Beat that with less than 10 mins left of qualifying

 

1.31 and 9.52..Not bad for a big heavy barge of a car,but obviousley not good enough to take on the all conquering subaru team,WELL DONE.

 

If you read what I said Glenn I didn't say it was worth it
Said it wasn't but then looked quickly at 520 hp on a 2 litre and Compaired it to my own car pal
And its deffo better than mine at 460 hp
That's why I put maybe it is

 

From my personal experience I have to say that WRX9181 expresses my own beliefs fairly well. Not everybody will extract the same power I have achieved from the SC46T/S at under 2 bar of boost, certainly not unless they follow my spec exactly and even then careful attention to detail is required.
What a refreshingly honest post from The Gaffer #3962 as is his style. In addition to the items listed don't forget you need the oil pickup and dipstick!!! Unless the turbo can be encouraged to spool a bit earlier which may well come from further development of the turbo then I don't think the expenditure to convert to twin scroll on this occasion is worth the expenditure but that would change if we could shave a couple of hundred RPM or so off the spool to 1 bar. What is really impressive, apart from the headline figure is the area under the torque curve once the car gets going and the immediate response at anything past 3500 rpm in any gear and the facility to tootle around below 2000 rpm in 6th gear and pull away cleanly without a gear change in not too shabby a manner.
All in all I am very happy with the result and with slightly improved spool it would have to be a resounding yes. If you already have a twin scroll setup then this becomes very viable.

Not quite. The printout does show slow spool because of the way the rollers are loaded but that is not the experience on the road. I have a lot of SC46 experience (conventional) on quite a few cars and Kev did say that if I was not happy with the TS he would take it back and give me a single scroll with no cost penalty. It can't be fairer than that, thanks Kev but the kind offer was politely declined because the advantages on the road far outweigh the slighly slow spool which I believe will be improved with a bit more work. My interest in trying the twin scroll was just to see what was possible and it has been very interesting even without further gains.
Yes Shaun. Very pleased and yes, UK 6 speed for relaxed long distance travel. If I find the time some quarter mile runs should come up with more interesting data.

When I was involved in regular quarter mile running I think that every fraction of a second saved on the 60 foot translated into double that for the overall time.

 

Would you recommend me to go twin scroll or single scroll with a Sc42 billet? Aim is 400-420hp on a 2.0L new age block. Weekend + trackcar.

I got another sump, and I'm going to buy new headers and up pipe either way so the extra expense for me would be the pricier turbo(since it's part exchange, or am I wrong?) and a downpipe or flange to re-weld the downpipe.

 

Congrats to Mikee Singh and the SC team supporting him on his new PB at totb!

 

You cant compare the same model turbos on different cars mick,or even similar cars for that matter as they all behave differently,and i do remember kev saying yours was a tired engine mate and that was all it would give.

I just thought it looked a little slow to respond for a twinscroll running 2bar off boost harvey,but as you say the rolling road doesnt show the true on road performance of the car.It would be nice to see some back to back testing of the single and twin scroll units to show the true advantages and disadvantages of each of them.

If not a twin scroll car already then single scroll would be my choice,i dont think the performance difference between them outways the cost of the conversion from single to twin scroll,just my opinion tho for what its worth.

 

Tired .... Well how very dare you lol
He said it was lazy fri afternoon car but 460 hp enough for me and 320 @ 4500 and 400 @ 5000 does me glenn
Are we having are first aguement lol

 

yes well done

 

pmsl..no mick i dont argue you know that pal,and its also one of the best looking newage cars ive ever seen and would love to own.

 

Lol

 

What you need is already detailed see posts above, particularly by Kev to which I added a couple of bits.
If it was not for the purposes of testing I would not have gone to the expense of converting to twin scroll. Now I have the SC46 T/S I am very happy with it. However if I had an SC46 conventional in other circumstances I would be happy with that and not go to the time and expense of the twin scroll. If further development on the SC46 T/S improves spool then that turbo in T/S has to be worth converting to.
I cannot add to that because I only have limited experience of the SC42 and no experience of the SC42 T/S.

I agree this would be a nice thing to do but let us be practical and look at what is involved even with no cost for the bits I already have. Swap a turbo over plus swap over headers and uppipe so I guess that is four hours of time. Even at £25 an hour workshop time £100.
Then remap for the SC46 conventional with rolling road time and a bit of open road time to perfect the map.
Now the SC46 conventional goes from being a new turbo to being a used turbo even if it is well under 50 miles useage, more if I drive home and then the exercise has to be repeated again to go back to the T/S.
While it would be nice to have the results it is a lot of work and I am not exactly sure it will prove very much that we do not know already.

 

what size injectors would you need to run on an ej20 to keep the sc42 T/S happy? does this have a 8 or 10cm turbine housing? not sure on the full spec on it

 

Question was never answered and i wonder the same.
In all fairness, a FCD is only supported on the deck as the name suggests, it's not supported all the way down the liner at all.
A proper pinned engine would supply proper support IMO, or am i missing something ?

 

I know of pinned engines that have taken more than that. However I have a built 2.5 with AS Performance cnc inserts to close the deck and will be running a clinic billet gt30, I have no concerns.

 

Are there any spool up gains to be had if i convert my gt35 to billet?

 

Going to have to be Specific here......
Has anyone a result for Billet GT30, 2.35, V5/6 Heads and standard STI cams?????
Preferably 97+ 20% meth....

Have had a look through thread but am finding other variations,
Be great help to find the above spec.
Cheers

 

From my own limited experience of building turbos the gains from going to a billet wheel are not from the billet wheel being lighter per se but from the redesign of the wheel and slightly different tip geometry which is a natural progression as technology improves and experience is gained in the field and trickles down the chain through the constructor's, builders and eventually to the end users.
Not all billet wheels are lighter than the previous cast incarnations and while a lighter wheel must be beneficial if it retains the strength it is the advances in design that have a bigger impact on the spool and air moving capabilities.