gremlin

looking at swaping my n/a my95 leggy wagon for a similar vintage twin turbo and extracting about 400 bhp from it(gas flowed heads, forged pistons, increase in displacement? free flow exhaust, higher boost, bigger intercooler etc etc).
i would still want it to be a daily driver so the question is this; how reliable would 400 bhp be? i ask as a mate with a 380bhp imp is almost a resident at the workshop geting it fixed and that would get on my titends.

richrussell

Big peak power is difficult on a twin turbo. The twin setup works best at giving a huge wide power band, not a high peak at the top end.

So you'd be better off sticking with a single turbo if you want a high peak power.

Personally, I prefer having masses of torque at low revs, and content with 280bhp. I've got my Renault 5 GT Turbo for mad kick-in-the-back sudden turbo boost fun

Rich

gremlin

i must admit that i was impressed by the torque on my test drive of a p reg import so maybe that is the way forward, after all what use is top end speed in england?

DuncanG

I'd love to hear how to get 400hp out of a twin-turbo Legacy. Has anyone ever done it before?

I have a MY97 Leggy GT and have done a bit of research on it wrt to tuning, although I sure don't know everything about it. A few points:

1) the standard turbos are very small, and really pushing the boat out and driving both turbos optimally I recon you could get 330hp.

2) the oem electronics don't drive the turbos optimally; there is no system in place to keep the turbos balanced and because of the design of the sequential system most serious attempts at tuning end up with the primary turbo over-spooling to an early demise.

3) the non-optimal oem control causes a large dip in the torque-curve at around 4000rpm. You can drive round it but its a pain.

4) there's no aftermarket ecu that controls the twin-turbo setup

5) the choice of bolt-in upgrade turbos is almost nil (Power Enterprises do one set)

6) the existing twin-turbo plumbing and specifically the secondary up-pipe exhaust valve are very restrictive. If you want serious power then you'll have to engineer a replacement for that valve and that will be difficult and expensive (maybe modify a high-flow wastegate?).

Perhaps a better approach would be to keep your NA leggy and drop-in the engine, ecu and drivetrain from an Impreza. Then your tuning options would be well proven and relatively easy. You might even end up with lower insurance.

Check out the legacy group at http://autos.groups.yahoo.com/group/legacyb4, but don't expect anything too technical from them.

Duncan

gremlin

with regard to an engine swap that would be a good idea for the simple reason that, at least for a while, all the little saxo muppets in town who know me would not know what had hit them. plus it would be good to be able to keep up with my dads rs6 off the line. i'm warming to this idea more by the second.

Pavlo

keep engine, ditch turbo, get FMIC and TD05/06 turbo, injectors, ECU.

400hp no problem.

Next step is 2.5 US sti engine.

Paul

DuncanG

Leggy turbo wagon has to be the ultimate in stealth, especially if you have a tow-bar and a nodding dog

If you went the transplant route going for FMIC would mean not having to faff about with bonnet scoops and allow more power, but I think the plumbing would be more difficult than with an imp since the front spoiler has less space behind it. You could fit an imp spoiler, though not very pretty, see www.nebbs.com

Pavlo

leggy has more space up front, but an extra bumper cross member.

If removed you have a lot of space available, I know an HKS can be 'made' to fit.

Paul