johnnybon

iTrader: (70)

As above ? Pro's and cons

B0DSKI

iTrader: (17)

Why just them 2 ?

johnnybon

iTrader: (70)

What else Is there they seem to be the most common for between 500-600 bhp

RICHARD J

iTrader: (4)

500-600 is quite vague, what is your power target & with what spec?

johnnybon

iTrader: (70)

This is my spec
Newly built by Engine Tuner
Closed deck block
Rear Thrust conversion
Spec C Black Nitrated Crankshaft
Cosworth pistons
Eagle H beam rods
Eagle rod bolts
ACL race bearings
1.1mm cosworth head gasgits
Simtec that will be upgraded

heavily ported V4 sti heads, JUN retainers and titanium retainers, 3 angle valve seats, Piper 276 cams, piper oversize shims
a ported version 3/4 rotated manifold

Oh and a 6speed DCCD.

johnnybon

iTrader: (70)

Oh and 550would be nice but more would be better

MartynJ

If you want to get the best from your setup, I'd recommend going rotated and fitting a Billet GT30R.
Few bolt on turbos can achieve 550bhp+ on VPower or a meth mix, race fuel of course is different.

johnnybon

iTrader: (70)

I thought you was getting that sort of power from your s206 turbos

banny sti

iTrader: (68)

The billet 30R is the turbo of choice for between 500-600bhp and the power delivery is so much more aggressive than any standard position turbo. Also it future proofs you, should you decide you want more power then just move on to the billet 35

jura11

iTrader: (7)

As above GT30r will be better choice and you can later on swap for GT35r if you will want more power




Jura

johnnybon

iTrader: (70)

Thats sorted then the 30 and a rotated kit it is then thanks guys

Another question I have a RCM headers so do I have change them or is it just the up and down pipe I need

banny sti

iTrader: (68)

Just the up pipe, down pipe and an external wastegate

MartynJ

We have, as I mentioned, race fuel



My car ran a 10.8 1/4 mile in this spec in full trim.

However, a Billet GT30 will see you to this on a meth mix and over 600 on race fuel.

gooner 1

iTrader: (11)

So what power can you get from a 35 ?

johnnybon

iTrader: (70)

Just looked on the scooby clinic websit and there's only £75 difference in the 30 to a 35 may as well go straight for the 35 no ??

MartynJ

Seen over 700bhp from a few

johnnybon

iTrader: (70)

Those results look promising

need4speeduk

iTrader: (26)

I've just changed down from a billet 35 to a billet 30.

Yes I've lost top end power, but the car, as silly as it sounds, feels quicker due to the improved spool.

Definitely not disappointed and I wouldn't swap back if you gave me a 35 for free

johnnybon

iTrader: (70)

God this is hard there's so much to choose / decide from
So. If I went the gt30 route it would spool earlier so that Would make it faster and the 35 spools later but spools longer is that right
If so it all depends on what you are using the car for

MartynJ

I'll be mapping 2 GT35 Billet equipped 2.1 strokers in the next few weeks, so I'll post results if it'll help.

johnnybon

iTrader: (70)

Yes Martyn that would be great with a little explaining of all those squiggly lines

KAS35RSTI

iTrader: (73)

How different would a gt30.62 be compared to a gt35 with a .62 hotside?

MartynJ

Approx 4-500rpm from my experience.
The Billet 35 is only recommended with a .82 exhaust though.

KAS35RSTI

iTrader: (73)

Why is that?

224

nice graphs! are both these cars still running? or have they gone pop?

Alan Jeffery

Martyn's car is having full rebuild from top to bottom ready for next season.
Mike's ran really well at the Spa track day and is currently having further head work done.

Please explain what you mean by "gone pop?"

224

just wonderd if they were still running this power (as shown in graphs) or wether either of them had failed? by further head work i take m grimleys heads failed? not trying to bitch just interested to see what is actually being achieved with these 2.1 strokers on either of these turbos behind the sales pitch so to speak. cheers

prodriverules

iTrader: (52)

I'm looking forward to getting my billet S206B mapped I know
Can't beat a bit of billet action!

need4speeduk

iTrader: (26)

Dont think a 35 on a 2.1 is a very good combo tbh. Be quite laggy unless using NOS to aid spool.

Alan Jeffery

If you look at Martyn's graph, you'll see that was logged three years ago!
As you appear to be interested, Mike's developed a slight misfire at idle which we investigated. It turned out that the stock seat in one head had shifted due to cracking from the plug thread (a common problem) so we've cut out the offending seat area, rewelded, and now we're rebuilding it.

This is how it all looks

Head cracking; We've seen plenty like this, one or two with a compromised seat. (This is a head we took a picture of some time ago and is for demo purposes only.)



We prepare them by cutting out the seats and welding the affected area



This is the same head (Mike's) after counterboring and restoring the seats and plug threads, ready for final fettle



The finished result will look similar to this;



We're taking the opportunity to carry out more port and throat work while we're at it.

Of course, it takes engineering to be able to carry out this sort of work, not merely spanners or box shifting.

Please note that we are talking about Subaru cylinder head problems here, and this sort of issue will be applicable to any engine, not only 2.1's (stating the bleeding obvious I know)

If you'd like to know anything else, just ask!