Going 3.4" pulley on DASC, few questions

[denglish318ti]

I felt the need for a bit more boost so have gone for a 3.4" pulley from pulleyboys. I have a boost gauge (getting about 8-9psi currently) and am getting a fuel pressure gauge.

How much fuel pressure should I run at 10psi? Should it be about 90psi?

Also, currently I am using 95 RON (about 90-91 US) and plan to use 98 RON (about 93 US) petrol. If I can't find anywhere selling 98 can I fill up with 95 and will the timing retard enough to stop detonation? I do a lot of long journeys and not all garages sell it so it could be a problem.

And finally, could I run larger injectors, but not so big that the ECU cant adjust to them under normal conditions. So they would provide more fuel, but the ECU would adjust and decrease the cycle time. I dont like the idea of running so much fuel pressure!

Cheers
Dylan

[xxxJohnBoyxxx]

Originally Posted by denglish318ti

I felt the need for a bit more boost so have gone for a 3.4" pulley from pulleyboys. I have a boost gauge (getting about 8-9psi currently) and am getting a fuel pressure gauge. How much fuel pressure should I run at 10psi? Should it be about 90psi? Also, currently I am using 95 RON (about 90-91 US) and plan to use 98 RON (about 93 US) petrol. If I can't find anywhere selling 98 can I fill up with 95 and will the timing retard enough to stop detonation? I do a lot of long journeys and not all garages sell it so it could be a problem. And finally, could I run larger injectors, but not so big that the ECU cant adjust to them under normal conditions. So they would provide more fuel, but the ECU would adjust and decrease the cycle time. I dont like the idea of running so much fuel pressure! Cheers Dylan

I would try to run 93 octane at all times, if you can't get it on a long trip then don't do long WOT runs or beat in it until you get some good fuel back in it. Are you a OBD-I or II? I don't know the fuel pressure for 10psi but it is not a big difference. I think the OBD-II will better adjust or tune the adaption values in the DME. Knock sensors will detect ping and adjust timing. If detonation happens on a OBD-II it will flash the CEL multiple times limp mode for few seconds then reset all adaption values (at least that's what my car does). Many people have run a 3.4" pulley with the stock tune with no issues. I've heard of someone doing a 3.2" on a stock tune but don't do it. I have been told too much fuel pressure can pin the injector closed but have never had it happen to me. If you are OBD-I install larger injectors and burn a chip, install and enjoy.

[denglish318ti]

Cheers John, your replies are always quick and full of info! If I can't find good gas then I will only put enough in to get me where I am going. I don't think it is full OBDII (in the UK I dont think it was implemented fully) but it is a 1998 car, so I can read codes using my peake code reader. It has knock sensors which is the main thing though I guess. Nice to hear that other people have done the 3.4 pulley! Good thing about these engines is that if they blow you can pick another up for £200, whereas a M3 (euro) engine is mega bucks!

[markrnorton]

I fitted the 3.4 pulley about 2 weeks ago, pulls 9.6psi of boost now at max revs and abot 4.6psi at 2000rpm. My last rolling road session showed lean again at wot, tweeked it with the rrfpr by about 3/4 turn. Hp increased by 18hp and 20torques. It does run a bit warm now though.