The_Judge

Up until Saturday, my Knocklink had never gone any higer than second green. But as I've said before, why should it? MY00, lowish mileage, with FSSH, "careful" previous owner (apparently ). Apart from fitting the KL, AFR, boost gauge, and replacing the lambda and MAF sensors, the only mods I've made are H&S open neck split downpipe, H&S silencer, K&N panel filter, and GBE MkIIa MBC (set to circa 16psi).

Since the KL has been installed, I've always used Optimax from the same filling station (without octane boosters). The second green seems to appear mainly in 5th, 3500rpm, WOT. I've read other posts that this is not un-common, and the debate goes on as to whether this is det or background noise.

Anyways, I had to drive down to Weston-Super-Mare to strip out LAN/WAN equipment from one of our companies (recently closed ). I was on my second tank of BP Ultimate, and hadn't been on a motorway since fitting my mods, so was keen to see how the Mule would perform. So with my Snooper keeping a watchful eye on the road ahead I set off onto the M5. Not much traffic, bright and cool (which was nice ).

Obviously, you get used to driving to and from work, with the occasional dinner-time blast , and then weekend driving with all the old farts [img]images/smilies/mad.gif[/img]. This was my first opportunity to wring its neck, as it were. First impression; WOW. She just went. And went. And went... you get the picture! I don't remember how fast I got it to, and wouldn't post it anyway, even if I knew (don't know if my nan's on-line ). I was just blown away by the torque. I can't even begin to imagine what it must feel like to have 300-400+ lb/ft...

Suffice to say, by the time I got to Weston, my fuel was a tad on the light side . If I'd used my brain, I'd have stopped off at one of the services on the motorway, but I was having too much fun! So I had a wander around, looking for a Shell or BP. Do you think I could find one? The ONLY filling station I found was Texaco. And they only had rank UL. So I stuck half a tank in (it was that or stay in Weston... ). I think filling stations that sell sh!te petrol should be forced to sell octane boosters. Better still, they should provide them gratis, as an apology for selling sh!te petrol...!

So off I set, back up north. Got stuck in a traffic jam, not long having joined the M5. Great. Crawled along for 30 mins, then, in the distance, I saw that wonderful sign, the black stripe on the white background , so I dropped down to third and floored her. The usual flicker at 3500rpm. Then into fourth, but had to back off as a numpty pulled out in front of me. When he moved back into the middle lane (after several polite gestures), I floored her again, and as she went through 3500rpm, green, green, amber flicker. Stuck her in fifth, and, you guessed it, christmas tree bang on 3500rpm. So, what's so special about 3500rpm...?

As you can imagine, the rest of the journey back wasn't quite as enjoyable as the journey down. I was OK feathering the throttle, but I really didn't want to go anywhere near WOT. As soon as I got back home, I turned the boost down a quarter turn (as I'd seen 17psi several times earlier), and headed for my nearest Ultimate station. And here's the daft bit - the car absolutely flew! And still on Texaco dregs. Why was this...?

Anyway, the point to all this is thank God for Knocklinks (and yes they do work, for you cynics who only get a couple of greens!), and higher octane fuels!

If you've read this far without falling asleep, fair play to you!

Regards,

Ade.

Ps. Oh my God I.T. can be slow some days...

[Edited by The_Judge - 10/29/2003 8:33:15 AM]

Nezz10

3500rpm cause that it when your turbo comes on full boost.

Delboy2

The significance to 3500rpm is probably associated to the torque rising rapidly due to the speed at which the TD04 spools. In 5th gear the engine load will also be high.

The_Judge

Cheers guys, that makes sense. What about the increased performance after turning the boost down...?

mr smash

cool m8 interesting read has put some of my own knocklink fears a t rest...incidentaly have u fitted a seperat knock sensor from your oem 1?

Delboy2

Performance increase could have been attributed by the turbo not working so hard (Small TD04) therefore producing less heat ie denser charge air = more power
Knocklinks should only be used with an additional sensor, don't connect to the OEM sensor as the impedance change will change the level of knock detection by the ECU.

Bob Rawle

If you used Texaco then thats a predicable result, that stuff is absolute pants, I'd rather trailer the car than use it. 3500 rpm is where you can get max load so again predictable event.

cheers

bob

The_Judge

Cheers guys.

Mr Smash, the sensor that came with the KL is attached beneath the N/S of the intercooler, where it's recommended to be fitted, and NOT to the OEM sensor...! Bad idea, that.

Delboy2, I suppose that makes sense. Is it also possible that with the boost set too high and low octane fuel, the ignition had been severely retarded, but by turning the boost down, the ignition learning allowed more advance? Or does advance only occur when higher octane fuel is used compared to base ignition map? My knowledge here is very limited, I'm afraid!

Bob, I think it's fair to say I won't be using Texaco again. I think it might be worth me getting a supply of NF, to keep in the car in case I get caught short again... (assuming I could resist temptation of sticking it in anyway )

Regards,

Ade.

TopBanana

And the moral of the story is... always carry a couple of bottles of octane booster with you for emergencies just like I don't.

[Edited by jlanng - 10/30/2003 2:04:40 PM]

Triple X

iTrader: (1)

Also heatsoak (stuck in traffic for 30 mins) into the intercooler wouldnt have helped the situation.

The_Judge

No, the moral of the story is don't mount your Knocklink over your fuel gauge...

Delboy2

LOL