Looking for ideas - Fiat Punto MK1

[jabb]

I am a proud owner of Fiat Punto MK1. It's a basic S version with 1108cc, 55HP engine. My average fuel consumption is at around 7,5l/100km however 90% is city driving and I tend to push it too hard once in a while. Based on spritmonitor.de stats this car can achieve real world average consumption under 5.5l/100km.

I want to aero-modify my car and I'm looking for ideas.

Current limitations:
-My budget is tight
-I am concerned about how the car looks
-Punto is currently the only car in family so it has to stay functional

My plans:
-Full underbody pan
-Flat dish hubcaps
-Wiper air deflector

Visualisation:


Any ideas for cheap but not nasty\invasive mods?

[vinny1989]

If im right, the basic s version doesn't have a rev counter? install one and keep below 4k rpm.

I've had a mk1 punto, they are quite happy up shifting at 2.5krpm and can do 30mph in 5th easily. Try it.

good luck, and keep us updated.

[Piwoslaw]

Welcome to EcoModder.com, Jabb

I remember many years ago I read in an auto magazine that someone modded the I gen. Punto and got 3 l/100km. This was a while back, so I don't remember everything, but I do remember smooth hubcaps. Maybe narrower tires and lowered suspension, too?

Since the Punto has high-mounted rear lights, a kammback would be tricky. See this thread I started a month ago.
Rear wheel skirts would be nice, but finding coroplast to make them in Poland (or in Europe) is almost impossible, as I keep finding out
So my advice is as follows:

• Belly pan
• Flat hubcaps
• Wiper deflector
• Rev counter
• Partial or whole grill block (openable)
• Rear wheel skirts
• Folding passenger side mirror whenever possible
• When replacing tires, replace with narrower
• Pump tires to at least max sidewall pressure minus 10% (i.e. 40psi if max is 44psi, etc.)
• LED daytime running lights
• Keep reading EcoModder.com, and ask as many questions as needed

[jabb]

@vinny1989 - 30mph in 5th seems a bit too low for me but I do think ~35 is enough to shift it.

I've already acquired rev counter, just need to hook it up.

About LED's - I'm using them in fender indicators and front position lights. I've used them for rear plate illumination but one of them got damaged so I've installed regular bulbs and the remaining LED tube replaced the interior light. If I can acquire a nice, powerful set of LED bulbs for rear lights I will be very happy.
Proper LED daytime running lights are not a cheap mod though...

So the list:
# Belly pan - will try soon
# Flat hubcaps - will try soon (where do I get the dish like that?)
# Wiper deflector - will probably try
# Rev counter - in progress
# Partial or whole grill block (openable) - I'm not sure about this, summer is coming...
# Rear wheel skirts - I like the idea but it looks pretty weird
# Folding passenger side mirror whenever possible - That is not really a good idea for high traffic
# When replacing tires, replace with narrower - I have full set of pretty new summer rubber, but snow tires need a new pair
# Pump tires to at least max sidewall pressure minus 10% (i.e. 40psi if max is 44psi, etc.) - first I'd have to change my shock absorbers because ride gets pretty harsh with high pressure
# LED daytime running lights - Not a priority but I am going to buy a set if I get some cash

Kammback seems pretty invasive to me and I have doubts about it being useful for this shape of body.

Is regular corrugated plastic going to last when in close contact with exhaust or catalytic converter? Catalytic converter is the lowest point of Punto underbody (if my eyes were not fooling me).

[vinny1989]

Trust me it can do 30mph in 5th, on level ground. At approximately 1.6k rpm.. Yea its just over idle, but on level ground it will do it. Keep your hand on the stick and just drop to 4th/3rd when you need to.

Check when the rev counter is in though.. (I had the punto 55 sx - had a built in rev counter) Just keeping it under 4k rpm still got still got power and decent economy.

Your right , the catalytic converter is the lowest point. And it gets b****y hot. (The book recommends not parking over dry/tall grass after a long drive!

Oh, and give it a service - new plugs, oil and filters. It does wonders, a dirty air filter can really cut the amount of power you get.

[Peter7307]

jabb,
Welcome from me as well.
Can you remove the radio aerial ?
It sits at a very high air speed point and may be creating some disturbance just at the start of the roof panel.

Pete.

[Bicycle Bob]

I saw a very nice article on how to make Lincoln-like wheel skirts for the '36 Ford. They used steel cut from the roofs of junk cars to get a gentle curve. Very nice.

[Piwoslaw]

Originally Posted by jabb

# Partial or whole grill block (openable) - I'm not sure about this, summer is coming...

Trial and error. Start with the small slit between the bumper and hood, then start closing the lower opening on both sides, leaving the middle open. If your fan starts cycling too often, open a bit.

Originally Posted by jabb

# Rear wheel skirts - I like the idea but it looks pretty weird

I think 'cosmic' or 'futuristic' would be a better word

Originally Posted by jabb

# Folding passenger side mirror whenever possible - That is not really a good idea for high traffic

I keep my mirror open when in the city and fold it only for long distance trips, when I don't need it since I don't pass too often. It is also supplemented with a wide-angle interior mirror.

Originally Posted by jabb

# When replacing tires, replace with narrower - I have full set of pretty new summer rubber, but snow tires need a new pair

My car's recommended tire sizes are 195/65R15 and 205/65R15, but for the winter I bought 185/65R15 with no problems. The summer set is fairly new, and with my driving they won't need replacing anytime soon, but I'd love 175-width LowRR tires...

Originally Posted by jabb

# Pump tires to at least max sidewall pressure minus 10% (i.e. 40psi if max is 44psi, etc.) - first I'd have to change my shock absorbers because ride gets pretty harsh with high pressure

I checked with my car and didn't notice a difference. The suggested pressure is 2.6-3.0 bar, but I keep them at 3.2-3.3 bar (max is 3.5 bar). On a few occasions I tried 2.6 bar, and once 2.3 bar, and the ride wasn't softer, but it was much harder to accelerate.

Originally Posted by jabb

Is regular corrugated plastic going to last when in close contact with exhaust or catalytic converter? Catalytic converter is the lowest point of Punto underbody (if my eyes were not fooling me).

Maybe leaving an opening in the undertray for the cat would be a good idea, letting it cool in the air? For the rest of the exhaust, I'd glue a thin piece of styrofoam with aluminum foil on it to the belly pan.

[jabb]

Thank you for your tips

@Peter7307 - I've already broken the radio aerial while leaving garage so it's not a problem anymore.

[aerohead]

jabb,if you'll go to the aerodynamics forum you'll find some seminars and modification/benefit lists,4-lines down from the top of the first page.there's enough data to build your Punto on paper and evaluate costs-benefits.My initial impression is that you won't see significant mpg improvement without significant alterations to the Punto,and they'll have to be at the back of the vehicle to address the large wake there.