Hi guys, I've just emptied my wallet and fitted my car with a T04z turbo/1.16 rear exhaust housing, Tial 44mm waste gate, new 3"dump pipe, twin 2.5" exhausts, straight through 3" muffler on the dump pipe and a 2.5" racing beat mufflers on either side, 1600cc secondary injectors, Sard fuel reg, Walbro in tank fuel pump, Haltech Platinum 1000 ECU and PSI 300x600 front mount intercooler. The motor is a stock rebuilt S5 13bt with stock ports and good compression.

The car made 320rwhp on 17psi My old set up made 300wrhp with a high flow S5 turbo. Just before the old turbo came out the car had lost power, about 60rwhp. At the time the car had old plugs; the turbo housing had loose bolts and was leaking gases so we blamed these two factors for the loss of power.

The things we have done so far is: Removed the Cat, checked the intercooler for blockages, checked coils, leads, checked intake manifold, visual check for vacuum leaks, checked exhaust for blockages, checked engine compression and checked clutch for slippage and Still no power

I was wondering if anyone has come across a faulty T04z turbo. Mine does not blow smoke, the blades are not cracked, shaft play seems reasonable. My mechanic thinks it might have bad clearances??

I'd grateful for any help, running out of ideas fast. Thanks

 

I realize you lost power before the turbo swap so was your new baseline 240 rwhp? Was it retuned when the new turbo went in? What was the air temp difference between old/new? If you're monitoring EGT, was there a difference? Could it be as simple as having loaded the wrong map? Silly question, but have to ask. That still doesn't address the initial 60 rwhp loss. Any noticeable idle quality difference? You checked the compression, what was it? Have you compared compression figures at ambient temperature and near operating temperature?

 

Thanks for your reply, compression is 79 & 79 at ambient. Idles like a kitten, drive very smooth. The tuner that installed my new Haltech does development work for Haltech Aust, he is one of the most reputable tuners in Australia. EGT's were a constant low 50.

 

What units is the pressure reported in? PSI? If so, that's a hair low. It's also best to measure the cranking speed to compare the compression reading against the compression/cranking speed relationship chart.

 

It was measured in PSI. We don't believe the comp is the problem, my tuner has made lot's more power with similar set ups on tired engines.

My mechanic is going to try another turbo, he seems to think the turbo could be a dud.

Thanks for your imput, very much apprieciated.