New Gtss Turbos Pulsing And Car Stalling When Slowing Down

[writeoff]

Hi All,

I've just had new HKS GTSS turbos fitted to my 1989 R32 GTR and when I hold a constant speed at either around 60, 80 or 100 kmph I get air pulsing from the turbos and AFMs (I think). The sound comes from the front left hand side of the engine bay and only comes on with light but steady throttle application. It sounds like an old steam train engine - chushh, chushh, chushh etc.

The current setup is:

HKS GTSS turbos

HKS dumps

Apexi 125mm FMIC

Apexi front pipes

3" Turbo back exhaust

Aftermarket coils

Aftermarket ECU

HKS EVC set at 12psi & 15 psi

Platnium spark plugs

Standard AFMs

Standard injectors

Standard engine

Blitz BOVs

The car made ~235rwkW @ 12psi and 272rwkW @ 15psi (it also made 292rwkW @ 17psi but I asked them to keep it below 280rwkW).

It also stalls when I slow down after getting the revs above 5000rpm. The revs drop below 500rpm and I have to heel-toe to keep the car from stalling. The workshop has adjusted the Blitz BOVs and this seems to have improved the problem but it still happens. Lastly when the workshop fitted the turbos they didn't use the black hose that comes with the GTSS turbo kit. What is that for?

[paulr33]

do a search on;

turbo compressor chuffing

compresor shuffling

its to do with the air intake setup

[R31Nismoid]

Put the stock BOVs back on there, it improved as you said when they fiddled with the blitz...

So go back to OEM, its the best item on the market anyhow

[Beer Baron]

i would say it's mostly tuning. could be the bovs, but then again I've been running twin blitz bovs for nearly 3 years and never had any problems or stalling, or unstable idle etc. so they can be made to work properly.

[jonn]

I've had a similar problem with the GT-SS on my gtr. Turned out that the actuators on each turbo were not opening at the same time causing them to fight against each other. It was only evident when just coming onto boost at lightish throttle.

[writeoff]

Put the stock BOVs back on there, it improved as you said when they fiddled with the blitz...

So go back to OEM, its the best item on the market anyhow

The Blitz BOVs were on the car when I bought it. I don't have the standard ones to put back on.

I've had a similar problem with the GT-SS on my gtr. Turned out that the actuators on each turbo were not opening at the same time causing them to fight against each other. It was only evident when just coming onto boost at lightish throttle.

What did you (or the workshop) do to fix the problem?

[jonn]

The rods have to be adjusted so the wastegate opens at the same pressure. It's on off the car job. They should have been setup, or at least checked, before they were put on. That's about the limit of my knowledge.

I'm not saying 100% that this is what's happening on yours. Can you get back to the tuner and get them to see find anything? If it's only just happened after you've had the gtss installed might be something simple. Hose left loose or a leak somewhere.