Aygo with a twist

[JohnnyJerry]

Hi Eco folks, on this god forsaken place - the internet forums.

I'm new, and do have a somewhat misplaced agenda - I'd like to get my Aygo faster! Car enthusiast, when asking for performance mods have often been dumbed with the phrase - "you should have bought another car". I'll prove them wrong.
And before you call me an idiot - I know it won't be fast - fast. I own a 400hp 1985 MR2 running 11s, so I know what a fast car is

The build
Will have a high focus on lower weight, areodynamics, gearing, lowering resistance and in general being on a budget. The car it self weigh in at 680kg dry. So far I've estimated a drop to 560-580kg depending on the actual weight and what is included in the specified weight. The car will make about 90-100hp. Goal is 6s 0-100.


I have some questions that this place might be the best to answer.

How much does better areodynic impcact acceleration? Specific examples at 50-100-150km/h will be much apreciated.

Alternate delete:
Does anyone have any idea of how much power a car would need pr km - only running cars vital components like sparkplugs, fuel pump/injectors etc.
-Any example with running a battery flat withouth alternater is appreciated, especially with battery specs listed.
- Goal is to lower weight and power consumption.
- I'm planing on running a 12v 3.5Ah Lithium battery, so power is limited.

Lowering a car vs underbody panels
Ofc now I can't find the link, but basicly it explained that a flat-bottom and smooth object would actually increase cD when bringing it lower to the ground. Can anyone shed some light on this?

Lastly I'll list my ideas to the curiosity folks:

Areodynamics:

• Duck tail/semi-tail
• Underbody panel
• Side mirror mod or delete
• Lock/handle delete - side smooting
• Lexan windows sealed to smoothen window/door
• Sealing small gaps
• Front partial closed off and/or changed
• Lowered as much as possible - chop chop is considered over expensive coilover
• Rearwheel side skirt
• diffuser

Performance/engine mods

• Lower gearing 7% with wheel setup
• Lighter wheels - Enkei with 165 50 R14 10,5kg front - if traction is less of an issue Lupo wheels will be used instead lowering it 500g (4,4kg vs 4,9kg-Enkei)
• 3-1 manifold with 1,75" straight piped exhaust
• Ram air "forced" induction with little to none filtration - from an open spot on the front.
• Generel porting and flow optimizing
• Low viscosity oils
• Lighten flywheel
• Alternater delete or full throttle off switch
• Electric water pump - Depending on battery/alternater situation.
• Lastly getting i ECU tuned and rev liv to 7500rpm

Weight
All in on weight reduction, cut'n remove etc.
Lexan window
Lithium battey

Lastly - and this might be controversial, but are there any facebook groups with eco modding in focus. I am sorry if this voilate any rules. But I dont expect much activity on these old forums. So a bigger user base might be achieved on facebook.

Greeting from Denmark
Johnny

[teoman]

Welcome to the forum.

There are quite a few alternator related threads that are active at the moment. From measurements on a completely different car, the minimum the ecu and ignition needs is approx 6-10A. So your lithium will last about 10-20 minutes before it needs to be recharged, assuming it can deliver the necessary amps.

I’ sure others will chime in shortly.

[Stubby79]

12v, 3.5ah? I'm hoping that's a typo...I have bigger batteries for my cordless tools!

It might work for voltage stabilization while the lead is disconnected, but not much more.

[JohnnyJerry]

Thank you for your reply. I guess low battery power also will lead to bad fuel beffeciency if fuel pressure drops.

I think I'll go with a bigger battery pack, electric waterpump and an alternator full throttle kill switch.
According to what I read here and there, although it seems a bit high, the water pump draws about 8-10hp and the alternator 8hp at high rpm. So the increased power overrule the loss of 15kg.

[teoman]

Those figures seem a bit high.

If you want the exact same effect, you are kooking ad delivering a kW.

1HP is roughly 3/4 kW

At 12 V you are looking at 80A per kW.

[teoman]

Lithium batteries if big enough do not have a voltage sag as they are consumed. And they have a higher voltage compared to lead acid.

[JohnnyJerry]

Cant find much about info on alternators, but electric water pump dynoed shows a straight up 6-8hp! On stock Water pump delete. Some state that a water pump power consumptions multiply by a factor of 4 every time the RPM doubles. And like a boat propeller the speed exceed what can actually move at high rpm.

Look at pictures google'ing "electric water pump dyno".
Sorry cant linke urls yet due to have posted less than 5 times :/

[freebeard]

Hi Eco folks, on this god forsaken place - the internet forums.
.....
Lastly - and this might be controversial, but are there any facebook groups with eco modding in focus. I am sorry if this voilate any rules. But I dont expect much activity on these old forums. So a bigger user base might be achieved on facebook.

Maybe Ecomodder isn't the place for you?

How much does better areodynic impcact acceleration? Specific examples at 50-100-150km/h will be much apreciated.
....
Lowering a car vs underbody panels
Ofc now I can't find the link, but basicly it explained that a flat-bottom and smooth object would actually increase cD when bringing it lower to the ground. Can anyone shed some light on this?

The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.

The plenum between the ground, the underbody and the tires is complex. Smoother is better. Lower has less frontal area (the tires). A central jet and correct diffuser angle are important.

One of these? https://en.wikipedia.org/wiki/Toyota_Aygo

First or second generation? Gas or diesel? This vehicle is already probably well sorted, there might not be much low-hanging fruit. You probably won't gain much without a full boat tail. That would gain you about as much as the engine modifications.

[JohnnyJerry]

Don't get me wrong, I love these forum, but they're dying unfortunately

It's the 1. Gen.It's lighter. Though the 2.gen does have about 15% better fuel economi on paper.

Would just be nice to see an example of an optimized car vs stock.

Every little detail will have a significant impact, because of the low weight.
Lowering gearing feks pretty much has a 1:1 in lowering acceleration times. Light wheels can easily shape 5+% off. And every HP will count.

So if aerodynamics could be put to play a positive role that'd be nice

[freebeard]

Don't get me wrong, I love these forum, but they're dying unfortunately

And Facespook is not?

An other alternative would be Reddit or an Aygo-specific forum

Any serious attempt at weight reduction would lead to removing sound insulation and upholstery. Unfortunately.

Toyota designed the vehicle for a very general use case. Look at what you're intended use is and design accordingly. An in-town commuter would be different than an Interstate road tripper. Camping? Hauling building materials?

If you do the engine mods will you do some short-course racing? What does the undercarriage look like?