Kevin Groat

Produced a very healthy 277 bhp @ 6500 rpm on the Wallace Performance Dastek rolling road this afternoon. From memory it was 215'ish at the wheels.
Car is standard except for a H&S exhaust from downpipe back - 92k miles on the clock. Running on BP Utimate. Not sure what plugs it's running as I've just bought the car - but did fit a new Champion panel filter before the run.
Bizzare dip in the power band as the two turbo's swop over - knew about this before buying this model but still find it odd
Torque was 237 ft/lbs @ 5500rpm.
Thanks to the chaps @ Wallace performance - excellent setup.

Just need to get my STi3 down there now

Kevin.

StickyMicky

dont run it on BP ultimate

AJbaseBloke

Good numbers!

If it is decatted, I hope those numbers don't reflect any lean running, as the TTs are rather good at "hiding" det. But I guess the RR people would knwo what they are doing.

VoD is definitely wierd, but nothing that can't be tuned out <well, mostly>

GTB Limited

Kevin,

Glad to see she does exactly what it says on the tin

Mark

rich_russell

Nice figures - exactly what Subaru said it'd produce.

You get used to the VOD - it's just a matter of changing gear/revs so you're on the larger turbo when you need to overtake, rather than having to cross the transition area when you're halfway out...

So that's with just 97RON BP Ultimate, no octane boost? Excellent. Some of us have no choice on petrol, due to where we live, so I'm using Ultimate all the time. I've not detected any det using my listening device (ok, some 4mm hose and an old set of ear defenders), which you can very clearly hear it happening on my Renault 5, and on a friend's GTI-R. But to be fair, the flat four makes some odd noises compared to inline four cylinder engines! Nothing that sounds like det though under load.

Rich. (96 BG5B GTB)

Kevin Groat

I'll post the graphs when I get a chance.
No Octane booster - just BP Ultimate (sorry stickymicky - I work for BP )

Regards mapping out the power dip - Gavin @ Wallace said the way they did it was to increase the duty cycle of the bigger turbo.

Kevin.

GTB Limited

Dastek (unichip)


Southern hemishere boys were using these IIRC.
Piggy back the BG

Long way to go though

Kevin, whats the max torque figure on the primary?


Mark

Kevin Groat

205 ft/lbs @ 3,750, dip in torque is much more dramatic than the bhp drop - when I get home (tomorrow) I'll post the chart.

Wallace performance in Aberdeen remapped a Twin Turbo saloon a couple of weeks ago - give them a bell and ask to speak to Gavin.

Kevin Groat

Dyno plot links for those interested.

http://www.showoffyourcar.com/cars/SUBARU/6744.JPG
http://www.showoffyourcar.com/cars/SUBARU/6745.JPG

Also, couple of pics of the car.

http://www.showoffyourcar.com/cars/SUBARU/6742.JPG
http://www.showoffyourcar.com/cars/SUBARU/6743.JPG

Kevin.

jjones

bloody hell you weren't kidding about a dip!

Kevin Groat

Yeah, I struggle to understand why they built them like this. With the taller gearing if you're looking to overtake quickly it means dropping two gears. Gave it a blast yesterday in top gear - acceleration from 95 (2nd turbo cuts in) to 120 in top gear is impressive but a little impractical in the UK. That said, the low down torque is good and in general the cruising speed is still on the power band of the small turbo. Can't say the dip bothers me (yet) as this is only supposed to be a winter runabout...

StickyMicky

are you sure its supposed to run with a dip like that?

GTB Limited

The dip is the transition from the primary to secondary stage.
Tis normal.

Kevin, your dip is more pronounced than mine, is it decatted?

Nice pics mail me some and I'll put them on the site.

Mark

Kevin Groat

Mark,

Still has the downpipe cat - H&S centre and rear - do you have a plot for your GTB.
More pronounced dip - different models? Chaps at Wallace said it was the same as the RSK they had in for remapping. They managed to remove most of the dip. I'll email across the piccies tomorrow as we're off out...

Kevin.

StickyMicky

can you feel the dip when driving around??

what benifit do you get from 2 turbos over one?

AJbaseBloke

Yep - it can be largely tuned out, but never disappears totally. You can still shift into it for the old skool laggus maximus experience <when the engine isn't pushing quite enough gas to push both well, and the boost control system is also off on hols somehwere>

StickyMicky - the benefit of the TT system is lots of low end pull. Even std things are waking up at just over 2k rpm, and well on the way around 2.5k, making for a nice torquey drive. Well tweaked cars are hauling in the low 2ks, which is quite nice as you can imagine. That also makes them deceptively quick, too.

Once beyond the VoD, there is a dollop of top end (wallop with decent exhaust and tuning) that'll see off many a car, esp since most have no idea that TT Leggy is almost as quick in most situations as its little bro WRX - the STi will still be quicker if that is what is most important to you of course. And finally, it is easier to tune the single turbo cars, because those wee turbos on the Leggy are not that far off their max in std format, and poor tuning can result in quick, and dramatic (read: expensive) failures in some instances...

Cheers

GTB Limited

Kevin,

graphs on my site UK Twin Turbo Legacy Register
In technical

Mark

Kevin Groat

Mark,

Emailed pics across to you.

Is your car standard engine wise?

Any idea if UK Legacy steel wheels (15") will fit the GTB - I'm needing to sort out some snow tyres and the 17" snow tyres will be pretty expensive.

Kevin.

GTB Limited

Kevin,

Got the pics

Mine running H&S centre (with cat) and back box, plus a JR panel filter.
other mods are brakes.

not sure about 15's, but 16's should fit.

Mark

davedipster

Hey these GTB's are nice, never seen one before.

Dipster

AJbaseBloke

Kevin - the OEM 15s won't fit on the later cars with 294mm fronts. 16s should be fine, but if your car has 4 pot fronts you need to make sure you get wheels that clear them.

Good idea to get decent winter rubber though IMHO - will make for a pretty unstoppable combo. Well, that is until you meet someone not as well prepared who slides into you

Cheers

Kevin Groat

Need to check what brakes are on the car - if the GTB 4 pots are the same calipers as the Impreza then I must have the 2 pots as there's no 'Subaru' on the caliper. Discs look about 294mm - time to get the tape measure out...

Thanks

GTB Limited

Kevin,
B & C revs have 295mm frt discs, with 2pot sliders as standard.
Is yours a BG5B or C?

AJ,
Do 4pots calipers clear the std GTB wheels, with just the raised lettering (subaru) hitting the spokes?


Dave,
Glad you like them


Mark

rich_russell

Mine's a P-reg too, and is BG5B - with 294mm discs and 2-pot calipers.

You'll get 16"s on, but I doubt 15"s would fit.

I've beaten Imprezas on the drag strip in standard form, with no weight savings (even had about 50 litres of fuel in the tank). The GTB does surprise people, as they don't expect a huge estate car to accelerate like it does, right up to the speed limiter

Rich.

AJbaseBloke

Rich, What limiter? muhahaha~

G'day Mark,

The BG era 17"s were not even close to fitting IIRC, but I assume the lettering can be filed off the 4 pots (if that is what you mean) without killing the caliper, but don't personally know of anyone who's done it. I don't know if they'd fit at that point, either.

IMHO, it ain't worth it. Either stick with the std calipers and go with DBA rotors (yep, tried a few other brands, and they are still the best IMHO), lines, fluid and pads. They'll stop brilliantly with good pads and rubber, you'll just have to watch for the pizza slice wear habit on the inside pad...

Or, ideally, get the BG/BH wheels (same as UK Impreza turbo) when you go for the 4 pots. They are cheap after all (but anything is more than not buying new wheels at all ).

HTH

GTB Limited

AJ,

If I can get some cheap, and the main body of the caliper misses the spokes, I'll machine the lettering off
If they don't come close, sell them on.

I don't want to change wheels, like the style (legacy only).

B4 rims are a let down

Mark

rich_russell

I've got 17" Team Dynamics wheels on my BG5, which I reckon will clear the 4-pot calipers. But money's tight, so I'm just going for some decent pads and discs this time.

And yeah - that tendency for the inner pads to go triangular is a pain.

Rich.

AJbaseBloke

Hi Rich,

That was what drove me to the 4 pots in the end... After eating 3 sets of expensive pads I got sick of chukcing them with about 40% useable left... Even grinding them to match them up didn't help, just meant they wore as fast as before, but more evenly

Decent pads and discs should get you a fair result m8. Quite a few people are going with brake cylinder stoppers and lines now too (as the std ones are getting old + the firewall flex), and seem to say they are getting better feel at least, and better initial bite according to some.

I really got big results when I upgraded the rears too (rears wore out, so had to change anyway, and good rotors were only a touch more then OEM). Again went with DBA on the rears, still on the single pot floaters but immediately saw a big improvement. The feeling that the rears are scrubbing off energy is rather nice as it also sits the car down for better stability under heavy braking (particularly nice when braking in corners IMHO).

Mark,

Each to his own on wheels - I only mentioned them coz they tend to be cheap, not stupid heavy, and reasonably strong. I have bling bling golds on mine Nice and light (in weight, not just bright colour wise ) too!

Cheers

dij

I have a set of 15" wheels with snow tires,from a legacy tt 95.let me know if these might interest you.

The vod,(IMO) is a right pain in the ****.(sorry all you owners).
I have driven a man my95 tt for a while and,it would always annoy me at how it would start off feeling like its about to take off,and then have a break whilst stage 2 activates (this is a 2 stage turbo,and you feel it),shooting the revs up,giving you half an orgasm,and then hit the rev limiter.

Its ok if you are on the motorway but,its still not nice.Perhaps I think this coz Im used to an Impreza.

To top it off,under the bonnet is crammed with vacum pipes and sensors,(and loads more goodies),that make you want to drop the bonnet down at the thought of doing any work atall on it.The second turbo requires a huge actuator to get it going (IMO this is what takes up the boost pressure and gives you vod),and the exhaust system is quite complex when compared to a single turbo.
Its just that,all this extra weight,technology,etc and not as much fun as the easier,cheaper,less complex younger brother.

I know Im gonna get a pasting for this so,"KEVLAR SUIT ACTIVATED".

(Just to try and dilute it a little)

If the Legacy twin turbo could perform in the same way as a wrx,then I would have one,as its a much much more higher spec car and very well equipped.I like the extra toys inside,and a sunroof seems to be available on alot of cars.
They are basically the same underneath,and its just the let down of the VD problem that it has that puts me off.

Sorry,but this dose not perform like other twin turbos.

Nice car though (gulp)

rich_russell

You're right - it doesn't perform as well as other twin turbos. No argument there.

However, no other twin turbo cars have the boot space of a Legacy estate

And cost under £7000 (for a 96-98 BG5B/C in good condition).

I can still beat standard WRXs of the same age on the drag strip with my standard GTB. Then go to IKEA and fit furniture in the back without any problems.

As for the VOD - you just need to learn to drive round it. Don't expect it to accelerate like a non-turbo, and don't expect it to accelerate like a single turbo. Pay attention to the revs, and you can have a very nippy car without going onto the 2nd turbo. Then when you want to overtake or pull away quickly, get the revs up to over 4500rpm by dropping a gear, or use of the clutch. If you've got an automatic, unfortuately there's not a lot you can do. Swap to a manual gearbox I suppose!

Rich.