hopefully somebody can help me with the questions i have on the A500 and the turbo it uses.


what is stock boost on the A500?

how much boost can the standard turbo produce before it turns into a large hair dryer?

and what boost can the internals take before exploding?


thank you in advance for any help on this?

Standard turbo is a very small IHI item, it's good for about 170ish bhp before it starts to get beyond its opperating parameters and heat the intake charge up to much reducing power and turbo lifespan.

The slightly larger Garrett as found on the Punto SS is good for about 215bhp.

Stock internals I've heard from with the Trofeo series is that they are good for about 260bhp.

Stock exhaust is very restrictive and holds car back so nothing over about 185bhp will ve made until it's changed. Monza exhaust nothing but an overpriced mild steel gimmick (exhaust bypass valves are only needed on large capacity Ferraris or Lambo's to pass EEC drive by noise regulations, not need on a small capacity naturally sound supressed by the turbo Fiat) that sounds a bit like a wet fart or even a diesel though they all sound a bit dieselly, better off going to a proper exhaust manufacturer like BTB & paying for a purpose built stainless system.

thanx for your input.

does anyone know what the stock boost pressure is?

and also what type of boost the block can handle, eg is 1.4bar possible through the standard turbo etc?

Given that every A500 has a boost gauge on the dashboard this shouldn't be too much of a brain strain. In terms of absolute max I don't know but from observation it peaks at about 1.0 bar (I'm pretty sure it has tickled over that figure on my car at times but not by much).

Historically speaking Fiat engines have utilised their turbos at about 85-90% of their intended maximum boost capacity. So you might squeeze the boost up to 1.2 bar or maybe even 1.3 bar but anything more than that is going to be heating up the turbo excessively which is just a waste of effort.

The higher capacity Garret unit from the AGP SS is likely to be more appropriate and achieve better results but that has already been pointed out so I won't bother elaborating.

sorry to sound thick but can somebody explain "boost" to me please

^^ boost

a simple way would be boost pressure,

the amount of air thats pushed/compressed into the engine by the turbo.

can be measured in psi or bars

1bar = 14.7psi

A normally aspirated engine generates a lower than normal pressure within the induction system. A supercharged or turbocharged system forces air in rather than letting the engine simply suck it in and this results in a significant positive pressure in the induction system. That positive pressure is what is referred to as boost pressure.

The maximum boost pressure is either the limited pressure managed by the ECU and wastegate or the maximum pressure that the system can generate.

Anyone noticed that the car boosts higher in 3rd or 4th gear than in 2nd? My 3rd gear seems to have more torque and the turbo definitely boosts higher.

Have you noticed how the boost is limited while the engine is cold?

It is harder for the engine to generate high levels of boost in lower gears as the engine accelerates too readily anyway. You would need to be on a very steep slope before it could attain maximum boost in lower gears but in this case there is definitely a bit of control from the ECU to limit the torque as well.

We use a similar trick on my race car to create some very impressive performance figures from an unnecessarily large turbo charger.

500oc said:

^^ boost

a simple way would be boost pressure,

the amount of air thats pushed/compressed into the engine by the turbo.

can be measured in psi or bars

1bar = 14.7psi

Click to expand...

I thought that 1 bar = 14.4 but when I checked it - it worked out at 14.5
http://www.clubwrx.net/forums/gener...ting-accidents/158757-1-bar-boost-14-psi.html

not that it matters.

When I test drove an Abarth some time back, it seemed to be hitting 1.2 bar. Is this 'normal' in a Standard Abarth or do you reckon it has had the ECU changed - there was no evidence of a TMC on it. Unless the TTC ? was on it seemed to spin the wheels in the 1st, 2nd & 3rd when the road was only a little wet. When it was dry it seemed to keep its grip.