JohnA

ure rite

Mark, that's all they do! It would be the best place to go for the first layer of empirical information, so you can avoid making 'newbie' mistakes that could cost you the engine.

This is not surprising, as training at Motec would focus around specific fuelling needs for specific conditions. The fact that there can be safe (and cleaner) power at 'lean' AFRs (close to stoich more accurately) is not new. There are several SAE papers on the subject and it is the main reason behind the manufacturers' trend towards direct injection. The closer to stoich under load, the easier it is for them to meet the new emissions regime. They avoid excess fuel that won't burn at all or won't burn completely. Yes, by design. Water is four times more efficient in absorbing excess heat during the compression stroke, so it's a good start.

I'll elaborate further: In an *ideal* world max power would be available not far from stoich (14.7 for petrol) even at full boost. No excess oxygen, no excess fuel. Of course we don't live in an ideal world, so there are inefficiencies everywhere and we try to patch them up. The most prominent of these 'botches' is thermal-related: Chargecooling: it goes over ambient and we have detonation? No problemo, we'll squirt a bit more fuel and it will absorb some of this heat (but it won't burn, because there not enough oxygen molecules available) Also fuel distribution*: not trusting all injectors to be delivering the exact same quantity per cylinder? No problemo, we'll squirt a bit more fuel in general, so we'll make sure no cylinder runs less than stoich. (but it won't burn most of the time because it is excessive by design!) Fuel atomisation: dodgy patches and turns? Does it fall out of suspension? No problemo, we'll throw in some extra in order to make up for this during cold days or whatever You get the idea: for all sorts of potential deficiencies, we add fuel to mask the problem (real or imaginary). So we feel 'safe' and all is well. It makes economic sense since the fuel system is already there, has extra delivery capacity and we simply use some of that. But let's not forget whythe extra (over and above stoich) fuel is there;) The excess fuel is not free or totally inert either, so it costs in ultimate power and emissions. With this in mind, we can better regulate the need for excess fuel in the combustion chambers. There is no need to run pig-rich if intercooling is really good, fuel atomisation is also really good and delivery is uniform. Even more so if we can substitute the in-cylinder cooling function of the excess fuel (it is not very good at that, water is much better at it) That's why I don't agree with the one-size-fits-all AFR theories. The only AFR that I see as a 'standard' is stoich (where every oxygen molecule finds a fuel partner and vice versa) How much excess fuel is wise to have under boost is dependent on variables that need to be clearly listed. * Also let's not forget that the wideband only shows the average of all cylinders. If one is running 16:1 (blocked injector) and the others at 10:1 we'd be looking at a 'safe' 11:1, wouldn't we

£3K, the market is not very boyant is it... Wouldn't it have been better if you were to wait until springtime?

Looks like your attitude was right and the veiled threat didn't hurt either. You didn't try to claim that you weren't speeding (implying that he's incompetent or lying). Yet you did hint that he could have a fight on his hands 6 months later on, asking from him to attend court and perhaps to answer questions. More paperwork and potential embarassment. If you play it right and he comes out still looking cool, you can get off with a warning Maybe his mph figure was plucked out of thin air and he couldn't support it in court (which you indicated that he'd have to). Who knows. Who cares now. I'd be very pleased with this result:d

Yes of course. In my setup the difference between AFR 10.5 and 12.5 is around 20bhp at 1 bar. Another 15bhp at 14:1 The variance is quite a bit more pronounced at 1.5bar but I haven't done lean runs at such boost so I can't quantify it. All it takes is one semi-clogged injector and you risk a ride on the AA truck. Yes, lots of it before and after the compressors. Lots of steam too. Every setup is different, we can't just issue blanket statements like "at AFR 12 everything melts" without people laughing behind our backs. In the same vein, we can't just say "at 11:1 everything is safe" because that can prove to be untrue as well. When I melted my kawasaki turbo pistons during a very long full-boost run it was running rich as hell, single figures. Don't know if at 11:1 it would have detonated to death half a mile earlier, but the lethal mix of high ambient temps and fizzled-out fuel took precedence. Maybe too much timing for those conditions, too. Rich AFRs didn't save me. The bottom line is that generalising is dangerous without listing the assumptions made. It will look less impressive but it will be more useful, and people won't be able to pick holes so easily...

You'd have a lot more exh gases produced, so you'd see higher boost figures if you don't make mechanical changes (boost controller, wastegate spring perhaps) Have a look at the Wizards of NOS forum, they know the subject intimately.

They are different figures because the underlying assumptions are different. Don't assume that your mechanical setup and usage patterns are identical to someone else's. In fact they might not even be comparable. Even identical engines may respond differently to the same AFR at the same load conditions (if say the spray pattern of an injector is different) Hell, even mentioning 12:1 AFR at WOT can mean different things to different people: Someone means a five second peak on a hub dyno, while someone else means full throttle in top gear for much longer on a long stretch of road (autobahn, whatever). The 'safe' dyno AFR will be freaking lean in the second scenario (the load is different) It really is down to the (long) list of assumptions if you want to make comparisons. Bit like comparing camshafts: just because a 272 set works well on your friend's single, would you automatically assume that they'll work well on yours?

No offence but personally I wish I could bottle this seller's enthusiasm

UKSpec Ryan. Have a look at my garage, it's almost stock running 1.5-1.6 bar currently:innocent: Without listing the assumptions made, any theory can be made to look silly. There are conditions that allow you to run perfectly safe at almost stoich under high boost. (done it) There are other situations where even at 10:1 you'll get your pistons perforated. (done this too) That's why blanket statements with universal AFR figures need a bit of explaining:)

Bit of a sweeping statement this one. So according to you mine should have blown up ages ago, since it runs 12.5-13.5 regularly (and silly boost figures on top). But it hasn't;) So maybe you should reconsider the 'period' bit and start listing assumptions. This is a very interesting subject with no single answer that fills all the blanks.

Wouldn't he get almost as much by selling the bling wheelz? To be perfectly honest, in my humble opinion the market looks stale at this moment in time.

More favourites: At this moment in time (as opposed to moments outside time mr Hawkings?) Real people (i.e. not androids, replicants or old-fashioned robots Deckart?) In all fairness In my personal opinion (is there such a thing as an impersonal opinion?)

Here's some more: To be perfectly honest In all honesty With all due respect No offence but In my humble opinion

The description goes: "....High performance non turbo..." It gets better: "...VERRRRRRRRRRRYYYYYYYYYYYYYYYYYYYYYYYYY FASTTTTTTTTTTTTTTTTTTTTT. Dey see me rolling...........Girls love it !!!!! ..." I guess that's proof eh OK, let's be positive. I like the monkey.

It might be cheaper to buy a full-size n/a (judging by the used price freefall) But for performance from a standstill the RC might be quicker (composite body) http://www.max-boost.co.uk/stuff/firesuit1.jpg

What exactly is the problem here? It's not like he claims 1000bhp is it? Probably a dyno run would fall short of his expectations, but it is not inconceivable that it would meet them. The gasket and head porting point towards at least one previous meltdown, so I wouldn't pay much for such a project. As for the ridiculous rear wheels...if it makes him feel more virile who are we to judge? lol

Speaking of stock twins, the UKSpec ones can be pushed rather hard if done right. Not sure about ceramics though, haven't experimented with those. Wouldn't bother with hybrids, all the weight and complexity, if you have to forgo the sequential, why not go single?

I've used Forte years ago in the Calibra and it did feel like it worked. (feeling ain't measuring though!) Not sure if it's in the same class as the STP total system cleaner (which freakin works), but the fuel additives that are NOT snake oil are very few and far between.

I've been a Giger fan ever since I got my first Brain Salad Surgery LP Alien pushed things further. The supra theme *could* work if it was done a bit more dramatically, and (unfortunately) trade off some function for form. His bio-mechanics work well with exposed pipes for example. So it could be part of protruding intercooler pipes and non-standard ducting. Something like the 'back to the future' DeLorean would work well. Supra sleek aerodynamics --- not so well... this one looks a bit like Carn Evil 9

Welcome to the brave new world of Googling!

It's meant for lubricating injectors etc if you have particularly large concentrations of of brew. And of course cold starting may be compromised a bit, but hey...

Ah, so it's safe to grind them eh? Nice to know:)

*grind* the shims? Surely not, you'll lose the surface hardening won't you?