1 bar = 14.5 psi and 1.1 bar = 16 psi approx.

what sort of performance boost should i gain if i bump the dawes up from 1.0 bar to 1.1 bar. i have had a variable rate fuel reg fitted to supply more fuel with more boost as well as knock and lambdalink fitted so i am feeling pretty safe. not looking for mega gains just trying to edge my way to 300 brake

cheers

big sinky

 

What turbo and intercooler?

 

sorry to hi-jack, I'dlike to know a safe boost level for a UK MY'99
Turbo also.


Just bought a dawes.

 

16 PSI James.

 

its on a 95 wrx standard turbo and tmic

cheers

big sinky

 

Hi James
I fitted a Dawes and had phase 1 power engineering ecu about a month ago,i fitted a boost guage and set the boost to 1.1bar.No problems with fuel cut.I also have a full decat hks hyper system and downpipe + k&n panel filter.The car was dyno'd at 287bhp.
Still think the biggest improvement came from the downpipe,transformed the car.
Good luck with your Dawes,If you need a hand let me know.
Are you going to bolney meet saturday.

 

bttt

 

bigsinky- you will need a fuel cut lifter to run your car at 1.1 bar as the fuel cut on your car is set at 1.05 bar of boost.
you can get a dawes one from JWRACING for around £30

i have ran my car at 1.2 bar for around a year and had no problems at all but i also have a walbro fuel pump.

i also use optimax only with NF octane booster and do not suffer from det at all

since you have a lambda and knocklink give it a go

 

got the car back last night and it is currently running 1.1 bar WOT in 4th and 5th. problems is in 1st 2nd and 3rd the knockling lights up as i get to red line in these gears. lamdalink is ok. question - for that fraction of a second that the knocklink lights up as just before i change gear am i doind any damage to my car?

cheers

big sinky

 

Could well be knock, or could be other noise. The way to tell if you can't hear anything is to manipulate one of the causes of knock - the two available to you are boost and octane. So turn the boost down until it goes away - go back to last known good and it shouldn't knock then. Or increase octane which should reduce it. More fundamentally improve breathing or intercooling. If you are in the mood get a copy of Maximum Boost by Corky Bell and read it to understand what you are doing and why.

 

thanks john,

i checked on amazon and i suppose another £25 is nothing in the great scheme of things

based on the previous posts what do you think another 0.1 bar of boost will get me. talking to the mechanic last night he said that he tried 1.2 and the car definately didn't like it so he dropped her down to 1.1 bar and she seemed to run ok. i am running 97 octane (we don't get optimax in NI) and putting 100ml of NF black bottle per tank of 50 litres, so i should be near enough to 100 ron, so the fact that the KL lit up surprised me.

cheers

big sinky

[Edited by bigsinky - 4/25/2003 11:17:04 AM]

 

With that octane you either need to retard the ignition (assuming the fuelling is fine) or free up the breathing & improve intercooling to run more boost at the same timing.

 

talking to the mechanic this morning. he said that it was normal engine noise and the fact that you are "giving her the gun" creates more noise specifically when you redline in lower gears and snap a nice quick gear change, for a fraction of a second the warning light will come on. Is this normal? i just need reassurance not that i doubt my mechanic (coz he knows his onions big time, his 400bhp legacy at the street car shoot out last year proved that).

cheers

big sinky

 

I would rather assume it is knock until proven otherwise. If reducing the boost gets rid of it there is a much stronger case for it being knock. When third gear went on mine the knocklink was a disco for about 10 seconds on the red, so clearly other noises can do it.

 

John, what about transient det? Could that be the case here?

Brett
MY00 (Aust Spec)

 

It could be, but I still don't want any of it. From what I've seen the slightest tinkle very soon turns into rather a lot of tinkles.

 

I'd be inclined to listen to John.

When Bob Rawle mapped my STI-V, I used to be able to floor it in any gear (1.4bar) and the knocklink would never go above the 2nd light, I was using 75ml of NF and Optimax every time....Plus the knock sensor was at the most sensative point which is at the bottom of the block rather than the top.

 

Thanks for the responses guys.


Martin, YHM.

Could meet up for a Bolney convoy if you like??
Anyone else travelling up from East Sussex / Crowborough area?
If not, I may meet up with the West Sussex Posse.


James

[Edited by Jamesn - 4/25/2003 5:43:18 PM]

 

I have my dawes set at 16 psi, at 17 psi the fuel cut out comes in, is it safe to buy a cut-out raiser and run at 17 psi??

MY98 UK
full decat
ITG filter
Dawes
Knocklink
AFR meter (well into the green at WOT in 4th/5th uphill)
Runs on Optimax all the time

 

Hi James
I havnt had an email yet
If you up for bolney call me around 9.00am in morning
07748645964.
hope to hear from you

 

Waggs,

Strange, sent a mail on 17th to: -

martyn_csmith@hotmail.com
I'll Give you a shout in the morn'

James

 

Yes Pogue if it doesn't det.

 

Cheers, not detting at 16 so will get a fcd and try it out.

 

we seemed to get a bit off topic, yet i found the replies most interesting - but and this is a big BUT a conservative estimate of the extra 0.1 bar of boost is what in BHP terms?

thanks

big sinky

 

The best possible you expect is a 5% increase in power at the engine speeds where you increase boost by 0.1 bar (you are going from 2.0 to 2.1 bar absolute).

However, this does not account for losses which chip away at this from retarded ignition timing, increased charge temperatures and increased exhaust gas back pressure which could reduce the gains or even turn them into losses.

Yes I am going to weedle out of a specific answer as it isn't that simple to give you one