Is it possible to increase the turbo boost without changing the ECU? Back in the early 90's I brought a new Fiesta RS Turbo. I complained about the lack of performance, the head mechanic played around with the turbo/ignition timing. The car came back with loads more power. I've mentioned this to my local Subaru garage but they are not willing to do anything as it will invalidate my warranty.

 

You could use a variable boost controller. I use an HKS EVC4 electronic boost controller. It's a piece of **** to fit and can be easily removed and you can set the boost to what you want, just remember that over 1.2bar on a UK car will **** the pistons. I run mine at 1.15 safely. The ECU can self compensate for fuelling and ignition timing up to 1.2 bar. Beyond this you need to remap or change the ECU and shortly after the pistons no doubt!

Nito
ps. the boost controller cost about £550 from Torque Developments (my car has 41,000 miles now with no problems yet!)

 

I would recommend that you take a look at Lee Christie's site

 

Is it not possible to increase the boost by changing the length of the actuator arm ??

I might be wrong ?

Darren.

 

Thanks fella's that's useful, I like the idea of trying a bleed valve first since it's a lot cheaper. I'm not too mechanically minded so does anyone know a good performance garage in Yorshire?
ps. Lee's site is great but it runs a bit slow on my old P90, prehaps I need a bleed valve for my PC too!

 

If you use a bleed valve, make sure you fit a boost gauge otherwise you would have no idea what boost you are running!

As milky says, you can also increase boost by shortening the actuator arm but it's a very crude method and you would have no control over the boost you would be running. A bleed valve would be safer used with a boost gauge, but you're still better with a boost controller which is a sophisticated bleed valve using electronics with the advantage that you can reach and maintain (for a period) max boost in all gears!

Nito

 

nito,
does the boost controller peak at 16 psi and hold it there through the revs,can you set it higher for link ecu etc.
i recently tried a bleed valve and here's what happened my00 std boost peaks and holds 14 psi, bleed valve peaking at 17 psi then dropping right back to 12 and even when at peak car pulled worse than standard seemed a bit strange to me.
paul

 

forgot to add has anybody any experiance with the hks fuel cut defencer,does it allow you to run over 17psi on standard ecu.

 

Howdy...

Yes.. Yes.. and dont bother...

The limit is there for a reason.... dont pass it...

I have one if u want to try it... I will drop it in the post.

Although I did run it for a year..with EVC.. no probs.... but dont go crazy with boost.

J.

 

Paul,

The boost controller will hold the boost at peak or just under through most of the rev range. I run mine at 1.15bar but I did experiment at 1.25 and never experienced the fuel cut out so I don't think you even need to bother with it! 16psi is just over 1 bar I think. (divide/multiply 14.7psi=1bar)I run mine at 17.64peak or 1.15bar. It goes up to 1.15bar and then tails off down to about 1 bar after 5,000rpm but thats probably more to do with the Turbo. I would recommend the HKS EVC4 to any UK car as your ECU will compensate for all other parameters eradicating the need for a remap which will only put your engine into more jeopardy by leaning out the mixture. It is worth a rolling road setup to check the fuelling is rich throughout the rev range and provided you stay below 1.2bar you shouldn't have any engine problems!

Firefox, was that your car with the blown Turbo at Donington in November last year?? I only ask coz I wanted to have a chat about some of your mods if it was your car!

Nito

 

cheers j and nito,will you be at pod on sunday?
paul

 

Hi guys...

It was indeed my car.. and dead turbo..

I even managed to take an Elise with it gone... lol

I wont be at the Pod this time.. sorry..

J.