kezwaldo

Hi my car is running 298bhp witha VF35 turbo, sport cat ,sti genome centre and back box ,japspeed up pipe ,pink injectors, STI tmic , cossie filter ,walboro fuel pump and re-map by dynamix............im told i should be producing more power myabe an extra 10-15 bhp and im putting that down to having a sport cat and not a total decat !!! my qeustion is what would the next step be to gaining more power ??????? what would i need to do on top of the mods i already have???????? The car is a 2002 wrx bug by the way. i feel i want a extra 25-30 bhp maybe or to some how increase the torque too!

6VOLT

iTrader: (1)

My sti is 353 with a 3inch system and sports cat, remap and 80mm RCM intake.. I would have thought that yours would be a little higher. Maybe it's the sti avcs heads and cam profiling that is the reason for the higher bhp .

Not sure about yours though... What boost you running.

kezwaldo

im running 1.42 boost i THINK id have to check my ps3i but its def about that at max boost pressure.......sorry mate but i dont even know what avcs heads are or a 80mm RCM IS lol .......

Jolly Green Monster

iTrader: (4)

Does seem a little down. Uppipe standard?

53

iTrader: (41)

Your mods should have seen 325bhp/310ftlbs IMHO

What size is the crapspeed uppipe ? I bet it's a whopper 3" jobbie and raping your torque and power !

53

iTrader: (41)

20:20 posting FTW aye Si

kezwaldo

its a japspeed and have no idea what size it is it was on car when i bought it......where is the up pipe i thought this was the pipe between turbo and centre section which is a cat covertor standard .......but isnt that my sport cat????????? confused !!

kezwaldo

ok this is the exact description of mods i was handed on paper with car.......VF 35 turbo ,forge uprated actuator, turbo ported on hot side and wastegate to avoid boost creep.pink STI injectors .cosworth filter ,jap speed up pipe ,std headers,prodrive sportcat ,prodrive second cat delete ,de resonated centre pipe, STI genomeback box.....................this is all i have on the mods and all seem to be present under the bonnet and car ill post my map session

kezwaldo

53

iTrader: (41)

Even if it's a Japspeed 2" which they do do

http://www.ebay.co.uk/itm/JAPSPEED-S...item256e1f88c4

It's still not ideal IMHO

44mm or 1.75" is what most people run as stage one IMHO

Talk to Alyn at AS Performance as he is now selling the ported matched uppipes that Harvey used to sell

53

iTrader: (41)

Double posting scoobynet shyte

kezwaldo

so IYO this is my weak spot the up pipe????????? also where is that located on the car im so still learning lol

kezwaldo

i thought the prodrive sport cat was the up pipe?????????

53

iTrader: (41)

No the PD sportscat is a down pipe

Have a look at this it might help as I am feeling too lazy to play teacher tonight lol

jura11

iTrader: (7)

Remove this Up pipe and fit OE STI up pipe which will be better than Japspeed Up pipe,which is too big

Jura

kezwaldo

ok brill thanks for diagram 53 makes things easy to understand how easy is it to change ???????? and secondly how much is a decent up pipe to suit my car?????? im getting excited now tha some extra ponys can be achieved without to much hassle but will i need it mapped again if i swap pipes?

53

iTrader: (41)

Yes will need mapping Uppipe is about £129 for a nice ported jobbie IIRC

It can be a **** of a job but about an hour-ish for a good mechanic who knows what he's doing Make sure you have nice straight studs if replacing as lining up a pissed stud is no fun at all

gazney101

iTrader: (5)

Can anybody explain why a larger diameter up-pipe has this effect

jura11

iTrader: (7)

Hi there

Flexi up pipe would create more turbulence, which "could" reduce effiency and horsepower.

Second thing uppipe with a larger than stock diameter results in noticable turbo lag over another up pipe of stock-like diameter...

These are maybe my point of view,but someone with more experience prove me i'm wrong

Jura

pflowers

Same volume of air passing through a smaller pipe equals faster flow therefore better spool up of turbo.

YoungY25

iTrader: (5)

Mate, I think there's some other unidentified issue there on your car other than the uppipe. There's absolutely nothing wrong with the japspeed exhaust and your just wasting money getting the uppipe swapped IMO. Put the money towards getting it diagnosed properly.
My bugeye is running the exact same mods as you, with a full Japspeed decat exhaust including uppipe, and I'm hitting mid 340s @ 1.3 bar. Even with a sports cat I'd be looking for around 330 from yours.

53

iTrader: (41)

2" flexishyte uppipe is a feckin waste of free power on a standard stage 1 car mate

lofty35

don't mean to hijack your thread mate, could I just ask aswell my bug wrx is 250 bhp i have an sti up pipe to put on and if i get a remap would i make 280 bhp ?
mods are full decat cobra exhaust
sti tmic
standard injectors
K and N air filter
thanks
lofty

Jolly Green Monster

iTrader: (4)

270-280 yes

lofty35

cheers simon I have a td04 hybrid turbo to put on what power would I get on that or should I sell it and buy a vf35/34 or td05 16g ?

Jolly Green Monster

iTrader: (4)

Dent td04 hybrid 300

kezwaldo

how would i diagnose the problem????? if im under power????????

YoungY25

iTrader: (5)

Get a Subaru specialist to plug it into a laptop and take it for a run. It should show up any issues. Why not ask Jolly Green Monster to have a look at it for you? He is a mapping specialist, bet you he could sort your power issue easily provided the car is in good health.

jura11

iTrader: (7)

Hi there

Speak with Neil@Slowboy racing,he is located just near Brands Hatch and he can or will diagnose what is wrong with yours car

I still think this Up pipe can be cause,but can be too Prodrive Sport cat etc.

I would swap for full decat downpipe and decat centre pipe for sure,some sport cat are not restrictive(like RCM or others),but with Prodrive I'm not 100% sure

Jura

53

iTrader: (41)

You're also assuming it's a PD Sportcat that's been fitted They should get 325+ without too much bother if fitted and mapped as they should be