Gt30 or s206
 

As above ? Pro's and cons :thumb:

Why just them 2 ?

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

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

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. :thumb:

Oh and 550would be nice but more would be better:thumb:

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.

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

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 :)

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




Jura

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

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

Just the up pipe, down pipe and an external wastegate :)

We have, as I mentioned, race fuel :thumb:

Attachment 68598

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.

Attachment 68599

So what power can you get from a 35 ?

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 ?? :thumb:

Seen over 700bhp from a few ;)

Those results look promising :D

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

God this is hard there's so much to choose / decide from :confused:
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 :confused:
If so it all depends on what you are using the car for :thumb:

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.

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

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

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

Why is that?

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

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?"

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

I'm looking forward to getting my billet S206B mapped I know:norty:
Can't beat a bit of billet action!
Attachment 68605

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

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.)

Attachment 68600

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

Attachment 68601

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

Attachment 68602

The finished result will look similar to this;

Attachment 68603

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! :thumb: