Blip that throttle

[Styria]

Many years ago (longer than I care to remember), I was given the opportunity to drive an Aston Martin, both DB 5's.

Sitting in the driver's seat, starting the car and blipping the throttle, I was enthralled at the beautiful sounding exhaust of the straight six twin ohc engine, and the fact that the tacho needle immediately jumped to at least 4000 rpm. The engine just seemed to be so finely balanced, and the response was immediate.

At the time, I owned a 3.8 litre Jaguar 'S' Type, and sort of using a similar 'blip', about 3000 rpm seemed to be the equivalent response. This was despite the fact that some people contented that the Jaguar twin cam was every bit as good as the Aston Martin unit.

So, let's jump the time frame by at least thirty years and look at the 6.3, 6.9 as well as the 5.7 litre Chevy unit in the Statesman.

6.3 - will take you to about 4000 rpm - very similar to the Aston Martin unit.
6.9 - fairly close in Gleaming Beauty, but probably closer to the 3500 mark.
Chevy 5.7 - about no more than, say 2000 rpm.

Does this tell us anything at all ?

Incidentally, as a matter of interest - Statesman fuel consumption according to mileage recorded by on-board computer:

Steady trip on F3 - sitting on 100 km/hr, Air Con operating - 27.2 mpg

Very short round trips - about 16 kilometers - 17.5 mpg

Total consumption since purchase (I think !) - 22.4 mpg.

Regards Styria

 

[s class]

The W140 S500 I had was wild - blipping the throttle even modestly would send it to red line with a fantastic noise. The 6.9's are comparatively low revving lazy beasts.

My '83 Ford XR3 (1600cc, OHC, tuned branches, BIG exhaust, twin choke Weber), also spins very freely and willingly. That was in direct contrast to the Opel (GM) Corsa 1600 Sport (2005 model) my wife had.

With something like your statesman, I wonder if there isn't some intervention from the engine management using its intelligence to realise the car is in neutral?

 

[Styria]

Hi S-Class, the point that you raise (in neutral - computer) in your last paragraph is very, very interesting. Obviously, I don't know, but perhaps Mercules, more tuned in to more modern engine management systems, might be able to elaborate further.

Incidentally, he reckons he could very easily "chip" the Statesman, and get an extra 20-30 ponies from the engine.

As far as your own 6.9's are concerned, have you noticed any difference in revvability, or even a different intake roar under 'hardish' acceleration ? Go on, off you go and try the two cars ! Regards Styria

 

[s class]

The red car isn't running at the moment. When it is, it is not such a happy animal as the blue one. The blue car is more lively and free revving. I think most of the red car's woes are fuel related. I simply haven't had the time to get stuck into the problems.

 

[BAR]

Blipping the throttle on a mechanically operated engine [no real engine management computer] will give a rise in revs, depending upon the amount of fuel / air and time that the throttle is held open and also depending upon the throttle opening as governed by one's foot pushing on the pedal.

Now from my experience with engine management systems, well these are all resultant from a 'map'. Some may referenece the engine temperature, air flow, crank angle and throttle opening: also the throttle position sensor, when it is a 'fly by wire' unit and the throttle isn't physically connected to the engine. Thus if the throttle position is moved to a much more 'open' setting and in a short period of time and then released quickly , the engine management may be programmed to only gradually open the air flow and fuel flow: resulting in a smaller increase in engine revs. This will be more obvious in neutral and at idle. After all why dump a lot of fuel in when it will not all be converted to useful energy! Ah the joys of tuning for economy.

It's quite interesting to hook up a laptop and watch all the possible 'measurements' and 'tune' the engine on the fly. Some programmes I have used give you a huge number of guages and dials. Much more fun than an arcade game.

If anyone needs to consider 'chipping' or programming, well send me a PM and we can discuss the merits of this.

 

[Andrew280SEL]

I couldn't tell you how well my 280 responds exactly, since the tacho doesn't work, however, from memory my 350SE revs very nicely to 3600 or so RPM with a quick firm blip.

This is after recently putting in a "new" second-hand distributor from a 450 parts car, since my old one had excessive vertical shaft movement.