How To Raise Bhp On My St 205?

[maddi68]

hows things, im looking to raise the bhp on my st 205, ive had it on the rr and its 250bhp at the moment and id like to get it to the 300bhp mark, it currently has a dumpvalve apexi induction kit, back box and a apexi afc but i dont think that it is set up right at the moment, when i had it on the rr they told me that it was over fuelling and that if i got the afc set up right it would stop the over fuelling, increase fuel economy and raise my bhp figure, is this true? also any recommendations on how to get my bhp up are welcomed thanks.

[GT4 BOOSTER]

fitting a manual £25 ish or pre programmed boost controller £200 ish will see you to 300 bhp easily on stock parts, after that you will need to be spending on engine internals and cooling.

[maddi68]

thanks yea 300bhp i would be happy with, stock internals would be alright to hold that??

[GT4 BOOSTER]

yeah .

[bothwell_buyer]

The fuel is often set too rich at high revs so to safeguard the engine - thats what the stock ecu does.

[jeffrosie]

Start with

Complete exhaust change. 2.5" or 2.75" but not 3.0" as you will get boost creep with std turbo due to the design of the turbo wastegate. Keep the cat as it will make minimal difference to power gains and will keep you legal on the road.

Good panel Filter. If you go induction kit, then make sue you build some sort of seperation to keep the hot air away from it.

Std dump valve is good enough, and if you remove the airbox, can be made to dump to atmosphere and is quite loud.

Turn up the boost by manual boost controller or electronic which is better.

Give it a good service - oil, plugs, rotor, cap, and make sure your base timing is spoton.

Wsh out the charge cooler with some petrol, just to make sure its as clean as it can be so that it can do its best at what it should do.

Make sure your coolants in rad and charge cooler are up to the correct level and also not old and discoloured.

If I've missed something out, sure somebody will add to this :)

Forgot to say, best to add a Blitz Access ECU that will tramsform your engine and put a huge grin on your face.

[philip5660]

agree with Jeff

Get yourself over to GT4oc.net if you want more info.....

[GTForbes]

The blitz isn't the only ecu option out there, if you go for a piggy back you'll only be able to tune the on boost area's. Personally I'd go standalone, worth every penny. We sell the 'Link' system and cannot fault it

[bothwell_buyer]

I had to take the cat out as the exhaust flow was being hampered and the turbo fans overheated and broke up.

On my number 1 RAV, I was lucky enough to find a Apexi Power FC Djet secondhand but hardly used from a tuning shop down south.

[maddi680]

thanks for the replys lads, can anyone fault the manual boost controllers? money is a bit tight at the moment so was looking at the manual ones on eBay?

[GT4 BOOSTER]

if you go the manual route , dont exceed 1 bar of pressure to be safe as the ecu is only mapped to 1.1 bar for fuelling , fitting is fiddly but doable.

you will also need to fit a boost gauge and start off with the screw turned not all the way in at first on the controller and gradually turn it out overs to reach the 1 bar , but run it a while first to bed the spring in . boost will also be available in 1st and 2nd gears , so go easy on cold starts.

[maddi680]

i get full boost in 1st and 2nd by blocking off the pipe going from the actuator diaphram back towards the engine??

[Leeky]

Keep the cat as it will make minimal difference to power gains and will keep you legal on the road.

On stock boost maybe, but once you up the boost the cat is a proper restriction and needs to go in the bin.

Besides, if you have a JDM ST205 you probably wont need a cat to pass an MOT. Any import first registered on or before 31/07/1995 can pass an MOT without a cat as long as there is no identical UK Equivalent (i.e does not appear in the Service Emissions book).

The UK ST205 doesnt have the same horse power as the JDM ST205, so an MOT tester (at their descretion) can argue the toss that the emissions would be higher than a UK car because of the extra power and therefore cant be tested as a uk car.

Always worked for me. 3 GT4's later and never had a cat once.

[GTForbes]

i get full boost in 1st and 2nd by blocking off the pipe going from the actuator diaphram back towards the engine??

no, you get the lower boost in all gears, the hose to the rear of the engine bleeds boost in 3,4 and 5th gears to increase it. fitting a manual boost controller you'd be best to block it off so boost is stable in all gears.

on the same note if money is tight are you sure you want to modify one of these? modifying on a shoestring budget normally ends in a dirty great hole in you pocket