GTO 3000 tuning

[Captain Carling]

Can anybody help me? My friend has got a UK spec 3000 GT twin turbo. Now hes had an exhaust and filter which should take him to about 300 bhp give or take, and hes thinking about a boost increase but has been told its a bit weak to be messing with. I personally think it should be ok seeing as the MR model has about 330 odd.
Any help or tips would be great :)

[The Admiral]

Hi m8!

Should be easy enough to get 350+bhp - see http://www.gtouk.com/ - great site & very helpful/friendly and for more technical stuff - here: http://www.stealth316.com/0-frames.htm

Cheers :)

Rog

[Marvin]

Most GTO's have had a hard life and in my experience underserviced too.
I'd call Eurospec (07768-196825) as they know all about these heavy beasts and run the fastest GTO in the UK too (11.0 without NOS) :eek:

HTH
Patt

[AIR FORCE 1]

we have a gto here and to get to 350/360 is easy,exhaust decat,frontpipe,induction and tweak the boost up to .9 bar

After that your looking at bigger turbos and engine management.Ours is now running autronic sm4 and it was the most worthwhile headache ive ever had. :D

If you have the older two bearing crank version be carefull with the pistons as they tend to break around the 450 mark.

Cheers Jonathan

[Captain Carling]

Cheers people, Its a P reg and hes after about about 350. Will it be reliable at that and how do you go about the boost increase. Is it a chip or something simple

[Captain Carling]

bttt

[AIR FORCE 1]

i just used a boost controller but any more than .9 bar on the std ecu and it started to run weak.I tried safcs and bigger injectors to see how it got on but at 1.1 bar it started to det as i had no ign control.So for .1 bar the safc is a waste of money on them.
Your better going straight to a proper ecu if you wan tot go farther than .9 bar.You will need to fit a walbro pump aswell

Jonathan

[Captain Carling]

Thanx. What boost do they run as standard

[AIR FORCE 1]

around 0.6 bar :)

[Eurospec]

The GTO is not the easiest thing in the world to tune because basically the fuel system is pretty much maxed already. Much more boost will require more fuel and it just isnt there in terms of either delivery or injector pulse width on the std system.

Having worked on a lot of these cars, you can see upto 95% injector duty cycle on a car with 0.6 bar. Most wont exceed 85% as std, but some do on occasion. As you add boost you will run out of ability to deliver fuel in terms of injector size. You will also exceed the flow capacity of the fuel pump.

On a 94+ car you will have the stronger bottom end on it already (ie the 4 bolt main). However on the -ve side you will very likely have the Hybred ECU or the Mitsu OBD2. The 'true' OBD2 wont log det which doesnt help you much and the Hybred logger cable and software is available only from one source in the USA.

As for chipping them, you cant, they dont have flashable e-proms or anything in there, so you are left with a choice of standalone or piggy back contollers. The latter can be used to very great effect in my opinion. It will never be as 'perfect' a tune as a standalone can achieve, but at a power output like 350 i cant see it being an issue, and it will require a lot less set up.

So how do you get 350, well it will be at the very edge of the fuel systems capability. One way would be to hot wire the std pump (or add a walbro 341 as Jonathan has suggested, but it MUST be hotwired), add an adjustable FPR, and turn up the line pressure a bit. An ODB2 or Hybred car will compensate for the overall richened mixture using its long and medium term fuel trims based on readings it is recieving from the O2 sensor. On the beans however, as the ECU will revert to an internal map rather than O2 sensor controled mixtures, you will be delivering more fuel through the std injectors per ms. Then you add the big exhaust (get a decent downpipe) and filter. Then turn up the boost with an electronic controller if needs be. I would very strongly advise getting a logger though before you turn up the boost. This will get you there, but it isnt perfect, as the fuel control will be a bit hit and miss.

Beyond this you are into bigger injectors and an afc. The std injector size is 360cc. Many people 'get away' with 1 bar boost on 550's without ignition timing issues, but some igntion control will help a lot. 450's are more than enough for 350 though and will need less adjustment on an afc type device.

I wouldnt worry too much about the cars being 'soft' but you do need to know where to start. The vast majority of post modification engine failures come from blown out pistons where someone has turned up the boost without monitoring afr or det.

Cheers,

Ben.

[Captain Carling]

Cheers Ben, so you are basicall saying, to be safe he needs a better fuel pump, bigger injectors and a boost controller. And what is an afc

[The Admiral]

Originally posted by Captain Carling
what is an afc See here: http://www.apexi-usa.com/product_electronics_detail.asp?id=202&pageNum=1

Rog :)