Turbo Choices for ScoobieWRX

[ScoobieWRX]

To be honest, unless you 'need' to take it above 350, I would keep with the std turbo and gearbox. It is diminishing returns from there on for you.

The expense of changing gearbox, turbo, fmic, clutch and whatever else does not justify just hitting 400. If you are going to spend that money you may as well smash the 500 level.

So what you're saying is if i'm going to spend the money on all the ancilliaries i may as well get an engine rebuilt that will take all the extra ponies and go the whole hog!! Fair point

And thanks Duncan for moving this thread to it's own bit. All these discussions with you knowledgeables will i hope be very useful in the decision making process.

Sorry for hijacking your thread earlier

[ScoobieWRX]

I'm saying that, for a start, 400 is very optimistic. Also, on another car, it may have been closer to the magic figure. I don't think you can get identical results from the same set ups, there's too many variables once things are altered.

I know that sounds contraditory but I've seen reported power figures, better than mine, on lesser set ups. To the point where I felt like giving up.

Probably why I don't go near dynos very often

Fair comment Gerry, i was merely playing devils advocate to stir the mix a bit. :twisted:

However, I'm glad you didn't give up!!

[ScoobieWRX]

Good point about the right foot Gerry!! :thumb:

I've found it's the best speed limiting and traction control device on the market no matter what you drive!!

[ScoobieWRX]

What i have sussed out from all this, and having done some more logging today, is that i'm not sure now if the decat 3 bolt uppipe that's part of the GT Spec GenII headers is a bit much for the VF35, and i'm now thinking a smaller diameter pipe would be better suited to the VF35 producing better spool up lower down.

I'm almost at full boost by 3300/3400rpm and i am sure the VF35 is meant to kick in a bit sooner than that. Any suggestions Duncan??

In hindsight i maybe should have gone for a more standard set of tubular headers with the smaller diameter 2 bolt uppipe.

I think i need a bigger Turbo :lol:

[ESL]

I realise I'm arriving late on this discussion, but is this all on a 2.0 rather than 2.5?

I'm used to standard turbo scoobs (STi4 and now an STi6) plus various bikes including a few years of racing. The other week, my brief first impression of a 400+bhp 20g 2.0 (clue: it's a red wagon near Cambridge) was how narrow the powerband was. It rips straight to the redline and you're changing gear all the time (newage 6 speed). Now, that's fine (in fact it's sublime) on a 2-stroke racebike on a circuit, because you've got a near-instantaneous easy gearchange and you've got your race head on. On the road, with an ordinary car gearbox, I found it a bit much!

Andy

Its on full boost (1.6bar) before 4k so the powerband isn't ridiculously narrow (I've set the redline at 7.5k). It accelerates quite crisply though so the short gearing does require some stirring of the stick. I have a printout showing 407hp on TEGs rollers on a forged 2.0 but it was running 12.5AFR when it was delivered to me so I guess that headline figure will be reduced now the AFR is set at 11.5. I use V-power and 2ml/litre NF.

[ScoobieWRX]

Mine runs mid 11's too. It seems really happy at that and no det on Tesco 99RON/no additives.

Doesn't like V-Power though and i can genuinely feel the difference.

[duncan]

Have you got a wideband now Francis?

[Gerry H]

I realise I'm arriving late on this discussion, but is this all on a 2.0 rather than 2.5?

I'm used to standard turbo scoobs (STi4 and now an STi6) plus various bikes including a few years of racing. The other week, my brief first impression of a 400+bhp 20g 2.0 (clue: it's a red wagon near Cambridge) was how narrow the powerband was. It rips straight to the redline and you're changing gear all the time (newage 6 speed). Now, that's fine (in fact it's sublime) on a 2-stroke racebike on a circuit, because you've got a near-instantaneous easy gearchange and you've got your race head on. On the road, with an ordinary car gearbox, I found it a bit much!

Andy

Its on full boost (1.6bar) before 4k so the powerband isn't ridiculously narrow (I've set the redline at 7.5k). It accelerates quite crisply though so the short gearing does require some stirring of the stick. I have a printout showing 407hp on TEGs rollers on a forged 2.0 but it was running 12.5AFR when it was delivered to me so I guess that headline figure will be reduced now the AFR is set at 11.5. I use V-power and 2ml/litre NF.

Nice to see you're back Andy

Having been on TEG's rollers I wouldn't read too much into the figures. Prefer also to believe the general concensus, 'a 20g won't see 400.' Well, not and live for long.

[ScoobieWRX]

No wideband yet and i'm just going on what my logs are telling me, but it drives really welll, very smooth and pulls well.

I remember what you said about the O2 Sensor and AFR via the ECU not being accurate. The wideband is still on my shopping list

[Gerry H]

Group buy on widebands? Mine's packed up