+- Austinsevenfriends (https://www.austinsevenfriends.co.uk/forum)
+-- Forum: Austin Seven Friends Forum (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=1)
+--- Forum: Forum chat... (https://www.austinsevenfriends.co.uk/forum/forumdisplay.php?fid=14)
+--- Thread: better in the rain (/showthread.php?tid=6338)
better in the rain - andrew34ruby - 03-07-2021
My Ruby has done about a thousand miles now, so is about run in.
The power is adequate, but only just.
Last time I had it out was a hot dry day. Not happy to pull beyond about 37 mph. On a slight incline soon dropping to 25 and asking for third gear. In third gear soon going onto the flat and screaming to be back into 4th gear. Just not enough power to be happy in a County where most roads have an incline one way or the other.
Today, the first time I've driven it in the rain, it seemed noticeably better. A bit more power up an incline, so no need for third. Pulling better on the flat. Happy to accelerate from 22mph in top on the flat. just so much more flexible with a bit more power.
Is this normal?
RE: better in the rain - Ruairidh Dunford - 03-07-2021
Damp cold air is denser and improves combustion - consider how intercoolers work and why they are fitted.
RE: better in the rain - Tony Betts - 03-07-2021
i guess thats the next idiot idea for someone then, fit an intercooler to there seven
RE: better in the rain - Ruairidh Dunford - 03-07-2021
I just live in Scotland, works tremendously!
RE: better in the rain - Dave Mann - 03-07-2021
My experience is Sevens go better the hotter it is. Returning from Scotland we had to negotiate a roundabout onto a dual carriageway with a long gradual incline. Every year the traffic meant it was a standing start and we could never getup into top in a 3 speed RN, then one year it was blistering hot and both cars got into top and stormed up the incline. Another time returning from Falmouth the Seven on another blistering day was quite happy at 45mph almost flat out leaving Truro by the time I was at Exeter I was having to back the throttle off to keep down to 50mph.
RE: better in the rain - Nick Lettington - 03-07-2021
Would this be a hood time to talk about a water injection/ venturi system again?
RE: better in the rain - Ruairidh Dunford - 03-07-2021
Mine is the complete opposite experience Dave.
When touring in Europe, for example, the cars go tremendously well in the cold damp air of early morning and not so well as the heat of the day sets in.
RE: better in the rain - Steve kay - 03-07-2021
Beat me to it, Ruairidh, Dave’s comment is the opposite of my experiences. Driving either a Seven or a 2CV the power is so little that the slightest increase, or decrease is noticeable. Early summer morning, not too damp but temperature quite low helps a lot, by the time late evening has been reached at this time of year, again hills are that bit easier. The Burton 2CV air inlet tube system is not really any sort of blower, but makes sure that air is not hot from under the bonnet, but cooler, and therefore more dense, from outside.
RE: better in the rain - andrew34ruby - 03-07-2021
(03-07-2021, 02:10 PM)Ruairidh Dunford Wrote: Damp cold air is denser and improves combustion - consider how intercoolers work and why they are fitted.
I understand the principle, but wasn't expecting much of an effect.
And at 16 degrees it wasn't really 'cold air'.
Thinking about it, the ambient temperature isn't what matters, it's the underbonnet temp. Today was two trips of about 5 miles, an hour apart.
RE: better in the rain - Ruairidh Dunford - 03-07-2021
How do you explain the difference then Andrew?