Hello,

I'm french and i possess a saphire sierra cosworth 2 wd so excuse me for my bad english.

I have this configuration on my saphire (all to have 380 hp) :

- cometic gasket with ARP nuts
- BD 10 cams,
- T38 turbo charger : the same like an escort cosworth but with a compressor trim of 54.
- 403 's injectors,
- Norris Motorsport chip.

I have a problem : my engine have some cuts from 3500 rpm and from 1.1 bar.

In fact, below these values, my car run with no problem. But from these values, my indicator of the turbo pressure panic and i feel some smalls cuts.

I test when i start at 2000 rpm in full load and at 3500 or 4000 rpm when i put full load : no change.

I change the chip, all the ignition system (sparks plugs, coil, leads..) and test all my injection system (filter, pressure regulator, injectors...) and my turbo system (T34 actuator, regulation valve, dump valve) : no change.

Before, i run with a stage 2 ( 300 hp) and i run perfectly.

Between my 300 hp stage and today, i just change the turbocharger, the chip and the cams.

My 3 bar map, my fuel pump are new and run before with a 300 hp stage with no problem.

I don't understand.

Can you help me?

Thank you verry much.