Thijs53

Hello from The Netherlands

I have bought myself a 2007 Toyota Aygo.

My mom does have a Aygo too wich I use everyday, I takes me to school and back, about 80 miles a day.

It's not a very fast car, it has from the 998cc 3 cilinder engine with VVT-i.

I have no experience in turbocharging a car at all, but I have some technical experience though.

Some specs about the Aygo engine:

3 cilinder
998cc
68hp @ 6000rpm
10.5 :1 compression ratio


If i'm correct 10.5 : 1 cr is too high for a turbo setup?

What is the cr I need, and how can I reach it? (here in The Netherlands we have 95 octane fuel)

What turbo do I need and how much boost can I run?

And the injection and ignition need to me modded if i'm right, how?

Thanks in advance, Thijs.

busa4

10.5:1 cr is high but it will work for low boost applications. 8-10 psi with premium fuel. im not sure what your octane rating on your premium fuel is but its 93 octane here in the states. 95 octane is pretty good. if you want more boost then you will need to lower the compression.

fuel system mods: all you need is larger injectors and a tune for low boost(high volume pump for high boost).

engine mods: for low boost: stock is ok. for high boost: stonger connecting rods with low compression forged pistons, cometic head gasket and arp studs is a must.

most important part of this is a custom tune. dont waste your time and money unless you budget for a good tune. most places charge ~$1000.00 for a dyno tuning session.

Thijs53

Thanks for your reply.

Premium fuel here is 98 octane, but that's quite hard to get here. So i prefer an engine that can run on 95 octane.

Can you give me a indication of the amount of HP I wil gain if I run 10 psi of boost (which is about 0.7 bar)? Stock it has 68hp.

Where can I get larger injectors (and how many cc injectors do I need?)

And by a tune you mean a remap of the stock ecu? That also inlcudes the ignition I asume?

What kind of turbo do you advice? And does it help to fit an intercooler?

Do you think there are forged pistons for this engine? Otherwise I would consider running it on a bit higher boost.

Thanks in advance!

busa4

if 95 octane is your lowest then you should be fine. i turbo'd a few motorcycles with 12.5:1 cr on 93 octane. i ran them to 6 psi max. i think your ok with 95 octane and 10 psi or less.

hp gains depend on engine displacement and rpm but a rule of thumb is for every 1 psi boost expect ~10 hp.

injectors can be purchased anywhere. ebay has 1000's. make sure you purchase high impedence injectors. injector size depends on hp goals. there are many injector size calculating sites, just google it.

yes a tune is a computer remap. a remap/tune consists of fueling and timing changes from the factory setting to compensate for boost or other performance mods.

you have a very small engine so finding a turbo shouldnt be a problem. i would recommend a garrett t25. should spin up quickly. an intercooler is only needed when boosting over 6 psi but i would recommend installing one reguardless of what psi you plan on using. cooler intake charge temps equals more power.

as far as engine internals you would have to research that. im not a toyota guru and i dont even think we have that model here in the states so i couldnt tell you. my guess is toyota took one of there 4 cylinder engines and just removed a cylinder on it so the pistons and rods on the 4 cylinder version may work. this will require research.

Thijs53

Allright thanks!

I believe it's a Daihatsu/toyota engine, so qualilty isn't to bad I hope, you see this cars a loooot here in Holland, very cheap to run with this gas prices here (about $8.5 a gallon).

As base engine i will probably use a engine with approx 10k miles. So it's pretty 'fresh'.

And can I buy just every injector and fit it? Or are there differences?
What does high impedence mean?

~10hp per psi is crazy, that means if I run 10 psi i will have 168hp? Should be a lot off fun in such a lightweight car ! The car redlines at 6500rpm. (rev limiter at 7000rpm if i'm correct)

To be a little more safe, let's say 150hp (but that 165hp would be great!) Do you guys think that's realistic?

I will look for a garret t25, are there any other brands to suggest?

Do you have any pressure loss trough an intercooler?

Thanks

busa4

damn!!! 8.50/gallon??

you have to check which style injector you have on the engine. there are two types of connectors. high impedence is the resistance of the injector. most oem injectors are high impedence. aftermarket performance injectors are low impedence but require a resistor box to use on a oem computer.

10hp/1 psi is an average. you may get more or less depending on engine efficiency and rpm.

168hp from an engine that only produces 68hp can be slightly unreliable. most n/a engines are not designed for boost so the engine internals are not designed to double the hp output. you may want to keep the boost low. i wouldnt go past 125hp as reliability maybe an issue. thats roughly 75% more power than stock. 168hp would be ~125% more power over stock--- dangerous!!!!!!!

theres many other turbos but i dont know much about them.

a quality intercooler will only have a pressure loss of 0.2 psi

Thijs53

Yeah, prices are crazy here, and they keep rising!

So the best is to get high impedence injectors.

So it will be better to run some lower boost, let's say 8psi, is that a safe number?

What kind of things do I need further? How can I adjust the pressure the turbo is giving?
And if i want to adjust the turbo pressure later, does the ECU needs te bo remaped?
And is every stock ECU remap-able?

Do I need a BOV, and how can I adjust it?

And what kind of sensors do I need? A wideband lambda sensor I assume, and a pressure gauge. Anything further?

And how do I get oil from the engine to the turbo?

Thanks!

busa4

high impedence injectors are what the factory uses so stick with them

i would run low boost. 8 psi should be fun.

the turbo will have an internal wastegate. you can adjust boost pressure by adjusting the wastegate actuator rod. shorter rod = more boost, longer rod = less boost.

if you increase boost later on you will need larger injectors and another tune. its better to size your injectors for more than what you need just in case you decide to turn up the boost. either way you will need another tuning session every time you make a large change.

all stock ecu are tuneable. the problem is you have to find someone who has hacked the computer to be able to tune it.

a bov is required. without it you will damage the turbo. purchase an adjustable bov so you can adjust it to your specific engine vacuum at idle. you want to adjust the bov to where at idle it stays closed but just barely.

a wideband afr gauge and a vacuum/boost gauge should be all you need to watch engine vitals.

oil feed is usually spliced in from the oil pressure switch by use of a tee fitting.

Paul RR

Our european octane rating differs from the one in the USA. European 95 is roughly 91 in USA, and the same goes for the higher octane (93 in USA => ~97-98 in EU).
As a guidance, you can add 4-5 units to your USA rating to find out the equivalent fuel in Europe.

Paul RR

Oh and by the way, i used to own an Aygo, and there is a company in UK called TTS performance and they offer a supercharger kit for the Aygo. You should study their kit, see what their are using, similar parts could work for you. I think the power was around 150 HP (not bad, over 100% power gain on stock engine). Good luck