Forgot to mention!! I also have my prodrive back box ebay!! 8 days left to run just in case any of you lads are looking for one!!pics there also.

 

Thanks for the heads up, hope it goes your way. I have got used to the nail varnish that's on mine and I am collecting loads of stone chipe all over before I finally get the re-spray done...hoping some decent paint and top coat will be much better. My old Audi has done 100K+ miles on the same roads and guess what, hardly any chips...the paint on the STI is a joke (a very expensive joke!)

 

Had a re-map session on the road and dyno with the Jolly Green Monster (Simon) yesterday

I went to see him because a previous mapper had left me with an intermittent fuel cut problem...

I have the following relatively minor engine, exhaust & induction mods:

1. Milltek turbo back de-cat 3" exhaust system - I left the high flow sports cat off this time to see what difference it made
2. Forge/Litchfield (in the wing) Cold Air Intake - I have taken the fog light out to let more air flow into the inside of the wing
3. Magic Tree Air Freshner - Pine Flavour

Made 370bhp & 380lbft on the first few runs, but due to the quad pipes (dual exit) on the Milltek back box, it was flowing differently on each run i.e. on one run the exhaust gases would take the shortest route out of back box, other times they would not. So we were getting lean then rich runs with the same ecu settings. So to be on the safe side Simon knocked it back to 366bhp & 375lbft in the end.

I was running 355bhp before so the difference is not that big, but after a long test drive last night I can say that the power delivery is much smoother and progressive than before, very good map, I am very happy.

The only downside is seeing other monster Impreza's at the dyno that make you want to re-mortgage the house to get a forged bottom end, big injectors & fuel pump, a big turbo and all the other supporting mods and go for 500bhp!

 

Know that feeling Dave. I had a play with a 335D on the lanes going home last night. Corners weren't that much of a problem, but its still a sponge at each corner. However the straight was seriously depressing. He left me for dead.

3 litre, 289bhp / 580 nm torque 0 - 60 in 5.9 seconds.

I am now wondering how much power the stock diesel fly will take.

 

What flaps are on it Paul?

I've got the Rally Armors and they've been fantastic

 

Once rolling those 335's are rapid Simon... I'd imagine they'd give an STI trouble.. so don;t get too hung up over it.

Nice figures Dave, mid 300's seams a happy medium for the hatch and plenty of oomff for overtaking... mines so much better since Dunc tweeked it, with overtaking even more effortless than before, if that was possible..

Iain mentioned the hatch has no maximum boost limit set on s#, so with a full decat everything boosts up too quickly (Dunc said with the 2.5L holding the boost back is half the skill) causing the boost spike and then cut.. I'd have thought Simon programmed in a limit to solve this?

 

Scooby L, keep saying nice things about Duncan, I shall be seeing him Friday and cannot wait!!!

Just hope my decat pipe arrives tomorrow so I can fit before he arrives, otherwise a trip to H&S early Friday morning will be called for!

 

I'm not, but I ain't having some poxy jumped up german lump get away from me that easily!!!

Besides, I'm getting bored of 147 bhp and 258 lbs/ft torque.

 

You going down the whole de-cat route? Or loosing the 2nd cat

Dunc's a great guy and you'll have a fun 2 hours... his conversation skills are quite good at mach 1 too

 

a: Pick a road without a long straight

b: You'll never have enough.. I bought both STI's because I thought they had enough... then within 18 months (both times) I've got bored and had them mapped..

 

Paul,

You not including the prodrive de-cat front section?

3 Weeks ago I'd have probably snatched your arm off, but Iain sorted me out.... good luck with the sale

 

Just loosing the 2nd cat as you did, so will have PPP spec exhaust essentially, have a Scorpion decat on order with Revolution for a good price.

 

I am a bit confused why the gas flow would change in the rear box - apart from the gas entering centrally on the Milltek rather than at the n/s as the OEM back box does, the outlet pipes are similar to the OEM outlets - one at each end of the back box branching into 2 tailpipes?

Would this not be a problem with all dual exit back boxes??
Or depend on internal construction?

 

a) With the power output of the BM, it don't need to be that long!!

b) As long as it puts a grin on my face. I'll be happy, but 400+ lbs/ft torque would be nice.

 

In under 2 weeks my hatch is getting a custom made straight through 3" SS exhaust with dual pipes at the back, not going for the quad as more interested in gas flow rather than looks. Litchfield CAI
but no magic tree

Tips done hopefully like this


Will let you know how i get on, 370bhp & 380lbft is very respectable though Dave

 

No idea, I wasn't aware if Dunc was having the same issues or not, but we were not chasing 370+BHP

Maybe at that power level & de-catted, the Millteck quad design has too many branches and becomes unstable?... Not sure if the Prodrive b-box shares this symptom or not.

H&S have a much "cleaner" backbox solution..

 

Yeah, I'd been looking at H&S a while ago.

Their system spilts mid car with 2 seperate back boxes and ( 1 or 2 each side ) tailpipes. As long as the Y split allows roughly even flow then should be fine, but if all in balance then I forsee no problems?


Hmmm I see a picture above me now... !

 

That steup looks minging. Why on hell would you design a Y section (look just below the mating face).

Sport users have been getting rid of theirs for years.

 

Yes I agree the Y section isn't the best... I'd rather they stuck a smooth radius in just before and made it more of an equal 50/50 angle to either quad...

But then again, if they did that they'd need a tighter curve to the backboxes..resulting in a less direct route...

STRIKE

What back box solution are you going for?

 

ScoobyL Dunno. Untill someone starts tuning the WRXD I'm ****'d.

 

No one mapping them yet?

 

Yes, Iain at LI and a couple of dealers. Thats only to 180 though, haven't heard of 1 higher, and also heard a rumour that the fly is only good to 200.

 

What's the torque quoted. Usually Diesels create much better torque than bhp when chipped (100Nm+ increase not uncommon)

 

Heres the maps

EcuTek FlashCAN Subaru Diesel Software

 

341lbs of torque, that's quite handy!

I'm sure that'll bring a smile to your face.

Same torque figues as the 170 Audi lump with more bhp...

 

The 170 A3 is 170ps with 350nm (same figs as a mates Fr 550) and same torque as mine for 20ps less.

 

I'd not be too upset with that Simon, VAG diesels are the world leaders, so to be in the same ball game with the same size engine is better than most.

I'm not 100% sure but I think my torque is circa 350lbs post map also

 

I was going to get the equal Y section/pipe split into 2 small back boxes either side. Is or has there been a problem with equal Y branches? I can see the gasses in this picture would take the easiest route out the RHS box? The Y in this exhaust is not equal.


No quad tip, more like cusco kids dual tip. As for noise


I will listen to the man making the exhaust as they have a good reputation.

Any thoughts folks?

 

It wasn't Simon that mapped it previously mate (or Ian), so it should be fine now Simon has had a look at it (fingers crossed).

I would have gone to see Ian at Litchfields (as I trust him the most and he gives the best service) but it is a 270 mile round trip for me...Simon and the Surrey Rolling Road dyno are just round the corner from where I live...

 

Thats the system thats fitted to mine.... No problems with it at all extremly good gas flow rates better than most crap systems I have seen about...

380bhp from it, managed to max the injector cycle out at 400 bhp