Seem to be leaking ponies recently after a recent rr, I know results will vary from dyno to dyno but this is a loss of over 30bhp??

Car made over 340bhp twice last year just after it was mapped (sep time), car was mapped with a forge vta but I changed back to the standard recirc, along with an oil change and new spark plugs (pf7b's) in january this year, went on dyno at powerstation in februay and made 325bhp, I hear lots os stories about powerstation giving lower figs so wasn't too bothered about this, car fely fine to drive etc operater commented that it felt smooth.

Last weekend went to ajec racing in glos, their dyno is a dyno dynamics and my car pushed out 309 bhp, like I say I know results will vary but other cars there made the same as they made at powerstation earlier in the year so thought I should have been there or there abouts.

Only changes to the car since feb are 18" wheels, slightly larger front brake discs and a non resonated centre section. The car has had 2 oil change's too. It is my daily driver at the moment (although not for much longer), I have covered in the region of 8k miles since february.

Woud the extra unsprung weight of the wheels and discs cause that much of a negative effect?
Would the slightly larger wheels cause that much of a loss?
Could it just be in need of a good service, plugs and a new panel filter?

It will be getting a new cambelt soon as I've just passed 46K on the clock, I thought plugs would be good for 20K?

I had thought the car felt slightly slower recently but thought it was probably just me getting used to it ...

Comments and ideas welcome, the car drives nice and smooth, fuelling is good just a bit down on power ..........

 

bad batch of fuel by any chance?

 

that is a possibility ....

 

you've changed exhaust

 

Possibly due to increasing the rolling radius of the wheel/tyre combo....

The RR measures torque and calculates bhp, ( maths ), so lower torque at the tyres = lower calculated bhp.

IMHO

dunx

 

Have the ecu multiplier checked too, it could have knocked itself back.

Tony

 

only taken the resonator out of the centre section, shouldn't cause a 30bhp loss

 

plan is for new plugs, panel filter and a visit to my mapper to check everything over.One of the guys in my local club was also suffering with a lower than expected result and turned out to be a badly fitting hose causing a loss of boost so hopefully something similar / easy to sort on mine