Rally car losing boost in heat?
 

Bit of an unusual one this- my rally car is losing boost as it gets hotter! And seems to give a little more boost on part rather than full throttle.

I tried a manual boost controller and no different, and anti lag on and off didn't impact it- launch control seemed fine too but probably a bit down.

New engine, new turbo (vf34), new wrc spec intercooler, 34mm restrictor, no bov, simtek.

A fairly unusual question so not sure will get any responses- I'm going to take turbo off to check actuator but lost after that other than map again

Vf34 is not a very robust turbo to be running with no BOV. I hope I'm wrong but check the blades on your compressor wheel.

Faulty BCS?
Or maybe just a map tweak needed,if your getting more boost on partial throttle then the WGDC may need adjusting on WOT.

Will check turbo in the week- it would hit 20 psi on the road in 4th when colder, but not when hot- bcs is new and it did it with manual one as well

What kind of temps are you seeing ?
Could it be the ECU protecting the engine when it is seeing high temps, you havent said if the car drives spot on when it is cooler ?

In between stages I can get it to boost in higher gears, but not lower gears- I don't know what temps but it was 25 yesterday and on stage will be run flat out- intercooler stayed cold all day (as it should at that price )

i did wonder if its ecu as mechanically turbo should have just run with manual boost controller, and did boost when cold! I would have thought an exhaust leak would be worse when cold not hot

As your running Simtek I take it you have ACT sensor. Log or watch your ACT and see is it pulling timing if it isn't as per pervious post unfortunately.

I am running simtek- will check turbo then log I think

So the update is ecu is all good, and when j went for a run with actuator disconnected from vacuum lines boosts really well, so turbo etc seems fine ffs

Crack in turbo maybe? Any noticeable new noise when it's not boosting as you'd expect?

Thanks to those that too the time to reply- short answer is pressure checked everything, got fed up, and bought a wrc core turbo, which goes on next week.

it would only boost the same with actuator disconnected so I think it's the turbo

Its been an expensive time- fuel pump and regulator went in a rally- you just need to know it's nearly impossible not to buy a Chinese fuel pump- those in the know said an aem one from demon Tweeks if that's helpful to know

we carry genuine Walbro & RCM fuel pumps (as well as most other things .....)

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