What would cause the dip you can see in these power plots between 4000 and 4500rpm?

 

wastegage opening/shutting.

 

engine decided it was time for a tea break

 

Mapping issue

 

So there is something a miss, thats not normal behaviour??

 

AFR plot and your ignition advance near those points would tell much.

 

A tight spot in the sleeves(turbo bearings) can cause this, but it is more likely to be a lean period, just as it starts to boost, so get it mapped and it will sort it out, or at least most of it.
tabetha

 

No wonder it feels so laggy

 

the point from where it moves to the full boost map may be wrong.

this kinda thing sometimes happens when you fit a larger turbo, thus moving the boost threshold further up the rev range.

 

What do I need to do to solve this, if it can be solved

 

It is terrible, even a monster turbo would most likely be better than this.
I would get it on the rollers, may be nothing more than a dodgy map/maf.
tabetha

 

Are you sure the TPS is connected/working properly?

 

I'll take it for a spin, what should I look out for on the Pectel monitor?

 

I took it for a drive and and couldn't feel any noticeable drop in power in that rev range, in fact the turbo felt like it came in earlier then that graph shows. I did notice a slight drop in boost in that rev range thou..

Got a rolling road day at TOTD on 6th Oct so will see how it performs then, maybe a silly question but could it be anything the rolling road operator has done as it was only a power run wasn't any tuning done etc

 

seen that a lot on turbo engines as they come on boost, usually just a dip in torque and power carries on rising.

there was a "nothings wrong" reason for it tho im sure?

whats the torque curve like?

 

The torque curve was underneath