De Lorean EuroTec

Well the engine was still very hot when that spark plug came out. We only took one out as the car was in the queue for the start line! But it was the same plug that got pulled out at Eurotec and was completely black.

As for whether the cylinder was far too lean - possibly. At this point the engine as a whole wasn't too lean - it was later that I leaned it off.

Which brings me to this mornings updates... Took the car down to the local garage to check the mixture - CO was at 0.9. So my leaning off antics yesterday had gone too far. Reset it to 2.5, put on the air filter and suddenly it jumps to 3.5. Hmm! Checked the air filter and it was completely clogged. So put it back on and reset the mixture with the air filter on.

So that certainly won't have been helping up the strip on a hot and muggy day...

Next stage - try and clean the bugger out. Not convinced that simply replacing disposable ones isn't the way to go!

The way to go is to replace K&N filters! - the air flow is higher through a K&N. Plus I got a 14bhp improvement just by replacing my air filter with a K&N - honest!

o.k. well it was Admin-bloke himself who replaced it, and he may have sorted out the vacuum hoses at the same time I suppose!

arranj wrote:The way to go is to replace K&N filters! - the air flow is higher through a K&N. Plus I got a 14bhp improvement just by replacing my air filter with a K&N - honest!

o.k. well it was Admin-bloke himself who replaced it, and he may have sorted out the vacuum hoses at the same time I suppose!

Yes to the hoses plus primary fuel pressure and final mixture setting.......

Everyones power drops off at 5500rpm, actually 5252rpm.

The word horsepower was introduced by James Watt, the inventor of the steam engine in about 1775. Watt learned that "a strong horse could lift 150 pounds a height of 220 feet in 1 minute.

Torque is what twists the tire, prop, or pump. Horsepower helps us understand an amount or quantity of torque. (Torque + time and distance).

Pretend the force of 150 pounds is "applied" tangentially to a one foot radius circle. This would be 150 foot pounds torque.

Next we need to express 220 feet in one minute as RPM.

* The circumference of a one foot radius circle is 6.283186 feet. ft. (Pi * diameter; 3.141593 * 2 feet)
* The distance of 220 feet, divided by 6.283185 feet, gives us a RPM of 35.014.

We are then talking about 150 pounds of force (150 foot pounds torque), 35 RPM, and one horsepower.

Constant (X) = 150 ft.lbs. * 35.014 RPM / 1hp

35.014 * 150 / 1 = 5252.1

Therefore 5252 is the constant.

Below 5252 rpm any engine's torque number will always be higher than its horsepower number, and above 5252 rpm any engine's horsepower number will always be higher than its torque number. At 5252 rpm the horsepower and torque numbers will be exactly the same.

That concludes todays lesson.

From Dan's chart in 2009 I would guess he should short shift from 4250rpm and 5500rpm. The Bosch system chokes the engine creating the acute torque curve. This does not happen on carburated engines

Thanks for the lesson Matt Maybe one day I'll dish out some engineering shit too, If I'd could remember any of it... http://en.wikipedia.org/wiki/Fourier_tr ... on_formula. Remarkably it all looks like complete gobbledy-gook to me now, I think I deleted it from my brain immediately after exams and replaced it with random football facts and images. Like Roberto Carlos's free kick against France in Le Tournoi 1997. OOOOHHHH

As for the car - I am aware that power will tail off slightly at the very top - my experience was that it was tailing off rather more than it should. Also, my cam perversions mean my power is shifted further up the curve than a standard D too. Going to go home and wash my K&N air filter now. Given how absurdly clogged it was, this could have easily been worth a few hp...

Gez, if it were me I would get the mixture right, then replace all spark plugs and injectors

Matt, great post!

A Van wrote:Gez, if it were me I would get the mixture right, then replace all spark plugs and injectors

That's pretty much what I'm doing... except to avoid splashing out £250 on injectors alone Nick is going to test mine and I'll only replace those which are sufficiently knacked.

If you not already make sure you give all your fuel lines a good flush out, don't want more crud in your new injectors

jerzybondov wrote:

A Van wrote:Gez, if it were me I would get the mixture right, then replace all spark plugs and injectors

That's pretty much what I'm doing... except to avoid splashing out £250 on injectors alone Nick is going to test mine and I'll only replace those which are sufficiently knacked.

When I get round to fixing my tester !