My sc46 is mental on the standard 2.0 l block. So god knows what it will be like on a 2.1.

Isn't that gona be laggy Steve?

I've been considering further changes on my STi Currently using an MD321H, GT spec headers with Harvey's up-pipe, 650 inj., Hyperflow CAI, full 3" Milltek system but still retaining the top mount IC It's nudging 400 with 365lbft It spools quite well an pulls from around 3300.
I would consider an SC46 billet and go to front mount IC but would be reluctant to loose the spooling characteristics I've got. A good road car is one that pulls from way down but we know this not available with these turbo cars and adjust driving style to compensate, but there comes a point where it simply becomes a chore having to keep the revs way up to make the whole lot work on the public road!
Who is using the SC46 on a 2ltr and what are the spool characteristics like?

JohnD

Doh!!! lol Sorry Dude!!!

But the T spools better than a 20g....it isn't that laggy at all as Simon JGM will back up

Did you drive a 2.0 with a T ?

Yes i dove T on the 2.0L STi,still pulls well on the 2.0L,but if you are comparing to the Billet T feels laggy,tried both like normal T or Billet T,both on the 2.0L

On 2.1L i've tried only Billet T




Jura

It rather sounds that your conclusion is based on a cheapo Chinese copy TD05-20G.
My experience, all based on 2 litres on road petrol is that the SC42 will outspool an MD321T but the 321T will have greater headline bhp.
Also compare the prices. I am not sure a comparison with an SC42 and MD321 is particularly relevant. 420 bhp turbo against 450 plus turbo.
I have a hybrid 20G on one of my Subaru Wagons on road fuel. 1 bar in 4th at 3160 rpm which I think is good and last rolling road was 422 bhp. Some 20Gs are head and shoulders above others.

SC42 can outspool MD321T,but if you comparing to the billet T,not sure how this compare,i know from mine experience billet T works amazingly.Comparing non billet turbo to billet is in my view little bit unfair.

More relevant will be test of the SC46 vs MD321T both are billet,both are 450bhp turbo,worth to do back to back tests

Second thing worth to do test both turbo with your Up pipe like on ported headers and GT spec


Jura

If some one buys my SC42 I may just get an LM420 or 450 and put this issue to bed.


Is this for sale?

Cheers!

I am referring to an MD321T. Billet.

I am prepared to do this but over 400 bhp the ported headers and matched uppipe have generally lost the edge to GT2 tubular headers and my trick uppipe. Unfortunately the GT2 supplied uppipe greatly slugs spool and responsiveness.

At 450 bhp or thereabouts there is absolutely no point testing my ported headers and matched uppipe against my GT2 Spec tubular headers with 3 bolt trick uppipe. The tubular hedaers and trick uppipe will have it every time. Subject to the turbo, at around 400 bhp it is worth considering moving from ported headers and matched uppipe to tubular GT2 Spec and trick uppipe. The GT2 tubular headers and trick uppipe come at a cost however.
These figures are not set in stone as it depends on the turbo and the rest of the spec.
What would be very interesting would be testing an SC42 and MD321T with tubular GT Spec headers and uppipe as supplied against tubular GT 2 Spec headers fitted with my trick uppipe. This would demonstrate the outstanding gains to be had from the trick uppipe. I am quite happy to provide a trick uppipe for these tests providing they are carried out on a well controlled rolling road and the same rolling road is used on all tests. Subject to what we are doing we also have fitting facilities here in Darlington to fit the uppipe(s).
As all of the trick uppipe users that previously ran the GT Spec uppipe can tell you, the improvements in spool, crispness and torque are quite remarkable so much so that I now do a trick 2 bolt uppipe purely for use on GT1 Spec 2 bolt flange header sets that are no longer produced but there are many of them in service, particularly on older cars.
Do not confuse the trick 2 bolt and 3 bolt for use on GT Spec and GT2 Spec tubular headers with the purpose designed uppipes (2 bolt) to replace the OE uppipe where standard Subaru headers are in use or supplied with ported headers and matched uppipe.

Note that once the trick uppipe, 2 bolt or 3 bolt is fitted a remap is required because it makes such a big difference that you need fuel in the map that much earlier as earlier spool is promoted.

Hi Harvey how much would a set of gt2 spec headers and trick uppipe for 53 uk blob sti be? I am looking to upgrade my turbo shortly tho, so is there different pipes for different turbos as I'm unsure? If so would it be best to wait untill I have purchased the turbo and go from there?

Kind regards
Craig

Haha no worries pal, I thunk the OP would he better off with one of you sc42's and scrap the idea of a certain figure and stick with a drivable road car. A 321t in my opinion would be far to laggy albeit a hoot at the too end with when it kicks in but the faster spool would make for a more fun road car.

Just my view but soo many people get carried away with wanting a car with xxx bhp when in fact a car with half of that can be more useable to an "average" driver. Very few can use all of the power at 300 let alone 450+, don't get me wrong its all very nice and puts a smile on your face but other than the straight line stuff what's the point of having a car you can't use properly.

Just my two pence worth but a well set up car with a little more power in the hands of most will be more fun to drive that one with 450+

I posted quite recently on another "*** bhp is not enough" thread and said pretty well the same thing but also admitting that, like most others, the thought of 'a little bit more' tends to overcome all sensibility!
I VERY rarely use WOT (last time was on a rolling road!) and sometimes, after a little blast, think "that felt quite good" then check the AVC-R to find I've used a max. of 65% throttle!
It hasn't stopped me from following this thread to contemplate the next stage:norty:

JohnD

i agree John its noice to have the power, my last classic was running 480bhp and was a cracking car but as you say i probably used a simialr % of the throttle in most occasissions all though it was a fun % lol

look at the times set at the Ring by Lichfield in the type 20/25's and the times set at the isle of man TT course in the new impreza none of them are running huge power but are not exactly slow are they. the £1000's of pounds spent on forging etc is it really worth it

imo the sc42 will do the job !

What's the sc46 like on a 2.0 classic without avc heads with Sti 4 heads ? I've just got one for my build it's an sc46 billet

It will be a touch laggy if not kept up the gears but will pull hard when in boost!

I've been told it won't be really laggy tho?

GT2 Spec headers are £445. Trick uppipe currently £149. The price will be reviewed shortly. That comes DEI heat wrapped, slip jointed to reduce the possibility of cracking the headers and five new Subaru studs.
Wrapping the headers £105.
The choices between ported headers and matched uppipe all DEI heat wrapped £369 exchange or the above. There are six uppipes for ported headers or replacement OE subject to turbo and there are four uppipes for 2 bolt trick for use with GT1 header sets only and a choice of four uppipes for 3 bolt for use with GT2 header sets only. All trick uppipes are currently £149 and all matched uppipes are currently £139. All obviously heat wrapped, slip jointed and supplied with Subaru studs.

That's why I said a touch Ad,it won't be bad but on the same hand it won't be like a vf34 or td05 for example.
Put it this way if you were travelling along in top gear at 60-65 you will need to change down a peg to get it moving in any sort of quick time instead of just putting your foot down like with the example turbos:thumb:

I did find that my current 20g was laggy like that, changing down gears to put revs up! But with the trick up pipe, I'm seeing a big improvement.. just turbo lacking the power n kick I'm after.

Cheers bud if it's to laggy a spot of meth it is lol

If thats what Andy F sells ;)

But then some of us use our cars for track and quarter a lot and need that extra power to not be left behind :thumb:

Lots of reasons for poor spool. Crap turbo, crap mapping, crap spec, wrong uppipe/headers just to name a few. On a 2 litre 1 bar before 3200 rpm from a 420 plus bhp turbo is not bad going.

Kenny, incidentally, what boost is your turbo running at the moment given you're still on standard internals? 1.5?