Our Very Own 500BHP Fiat Coupé 20 Valve Turbo!

One of the most famous coupes known in Britain and now Europe has been quietly undergoing a few tweeks. All be it, known for its unreliability early on it has now started to behave.

After Barbz worked his magic yet again and built me probably the best and highest spec'd 20vt yet to date we took it on the rollers early in the year and maxed out the turbo at 440 bhp @ 1.85bar. This was enough to do very well around Spa in Belgium. Two months ago I purchased a Precision turbo (57-58 Trim) and managed to get 470Bhp @1.9 bar - quick car but it saw a midrange loss of 150 ibs/ft torque. lag monster and I didnt like it!

A few weeks back I fitted yet another turbo. Again one that had never been tried on a coupe before that im aware of. So I managed to get the ramp free at around 11 pm last night and performed some last minute tweeks to the water injection and fixed a few other little niggles. Got home at around 2am and then up at 6am to Bristol. Driving tired in the dark and rain like I have never seen before wasnt a good start to the day.

So i left it with Flea and went for a Coffee. I was a little upset that he didnt offer me his umbrella as he would be out of the rain but the offer never came about.

On the rollers it managed 492.5bhp at 1.7bar with a sheer drop of boost at 7k which was caused by lack of fuel. He capped the limiter at a safe 7300 ish and said it should have a good 20-25bhp more ontop once the fuel system has been upgraded.

So after a year of much expense and headaches the drive home saw a very linear power delivery followed by a punch in the chest on boost. Dangerously quick, and despite all the hassle its well worth it. What else for the money could put a smile on your face like it.

So thats it for this year, Exhaust, Swirl Pot, Inline pump and bigger lines will be the next on the shopping list to break the 500Bhp mark. But for now im well happy as its the best its ever been. Excellent power duration and all the vitals were constantly exceptional. So big thanks yet again to the man whos always in the shadows, Barbz for building such an absolute gem of perfection and for answering my technical problems at silly times of the night/morning for the last 6 months. Also for supplying me with various parts at short notice and taking the time to research the decisions he made prior to fitting the parts.

And Flea for spending all day perfecting and correcting ones and zeros. So now in second place on the leader board scratching the paint off Fleas bumper. The goal was set 3 years ago at getting 500+bhp on road fuel out of a 2.0 engine reliably. Who wouldve thought that we were struggling to break 300bhp 4 years ago.

FC Performance Post Map Report

What John is trying to say is that I offered (near as dammit insisted) on him taking my delightful compact green umbrella, but being the Gok Wan of the Coupe world, he decided that it would clash with his "down wiv tha kids" fashion sense. Plus, having just fertilised his shiny patch, he did note that a little extra rain may help it grow back quicker.

So to John's car, well it is a considerable handful in the wet, especially with the current track focused suspension settings. That said, it does put the power down very well as the ramp rate is smooth and linear, which is perfect for a very powerful front wheel drive car. There were a couple of issues on the day:

1. A misfire above 1.5bar was down to plug gapping, so this was corrected from 0.8 to 0.7mm.

2. Fuel starvation at high rpms when running 1.5bar+. The fuel pressure was increased (injectors now flow 710cc per cylinder), but the in tank Walbro 255 pump is starting to struggle thus pressure dropping at the rail. These pumps really are on the edge at this level, so an inline pump is now required.

The boost drop off is something else though (not fuel John!). It is likely we have reached a restriction with gas flow, as the new compressor has no issues flowing the required air at this level. If the boost held another 500rpm the power would keep climbing and sail past the 500 mark.

The track setting is 1.3bar, this was good for 440bhp without breaking a sweat, so should make for a very good time at Donington.

Tuning is a tough game at this level, it's big ask to get 500bhp out of a 2 litre engine that still has perfect road manners, driveability and of course reliability. But you know what, 2012 will be the year of the 500bhp Coupe.