Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Kevin Wood]

Do not underestimate the importance of a cool intake charge.

Which explains why I have always felt that my car runs better at night then!

Yes. I've noticed this too. My other car has the intakes poking out of a hole in the bonnet (it's a Westfield, not a Nova, BTW) and the difference between performance on a warm day and a cool evening is ... well, .. like night and day!

Kevin

[bob.dent]

In addition to what my co forumists are saying i would suggest that the best way to tune the 3lt engine is by doing the following mods. You need enlarged throttle/cams and mapping on a dyno by a person tha knows what he is doing. Chips are good but not good enough as usually they are modified standard maps and they are NEVER developed on a dyno. So eventhough you could get some extra performance you might actually strain the engine too much for no gain. For example in order to determine MTB(ignition timing point where the engine produces the max torque) ignition timing point for every throttle % and rpm increment you need dyno and a lot of time tuning. Having tuned engines myself i have found that for example on a rover K series you get 80NM with 3/4 throttle and 2000rpm at 20degrees BTDC ignition advance while remaining inside cylinder pressure limits while at 25 degrees the torque stays the same and the peak cylinder pressure goes sky high which on a long run will ruin the engine.

errrrrrrm??.............could someone translate this into English for me please!! :-?

[TOOL]

ran a cold air intake pipe direct from the front of the car into the end of the filter,so in theory it's getting plenty of cold air,when in motion,as I said sounds nice ...no improvement  8-)

[The Barge Captain]

Always found damp misty mornings best, high air density or something.

[Admin]

Cold morning are good, especially if you have a turbocharged car!
They were immense fun in the Saab!  

[M-Tek Performance]

There is no such thing as an accurate rolling road, especially if you have the figures in flywheel (which is just a guess).

Also, tuning on the rolling road isnt ideal simply because you cannot reproduce real world conditions! a fan placed infront of the car on the rolling road will put air into the car at what, 30 mph?  what about 70mph?

[Kevin Wood]

There is no such thing as an accurate rolling road, especially if you have the figures in flywheel (which is just a guess).

If you guess at the losses of course your result will be a guess. If you measure them accurately using a coast down test and the dynamometer itself is calibrated you'll come close to the results you would see on an engine dyno.

Most rolling roads work on the "Guess" principle however, IME. Either that or the "tell the customer the figure he wants to talk about down the pub" principle.

The problem is, measuring power "at the wheels" isn't any good either because the figures are very sensitive to tyres, tyre pressure, weight on the rollers, etc. OK if you're comparing runs from the same car on the same day but not between vehicles.

I think rolling roads have their uses in tuning, especially when making comparisons between settings that the seat of the pants isn't sensitive enough to notice or when you need to be kicking out 200 odd BHP and tweaking a parameter at the same time. Having mapped a car solely on the road I wouldn't complain if someone gave me a rolling road. There's only so long you can spend at 200 BHP on the A31! Then again, map a car on the rollers and you'll need to finish it off on the road.

Cold morning are good, especially if you have a turbocharged car!  

In a Turbo you've got the double whammy of cold intake air to the compressor and an intercooler / chargecooler working really well too!


Kevin