Bogging on gear change....after hard pull...

[darrenjlobb]

Right this is a bit of an odd one....

Im running a pretty big pump, and finally a bigger turbo....and finally my car is able to make its power up the rev range...but im having a problem with drivability...

Basically if i drive it hard through second, or third, when i change up, and give it some again, it just bogs, smokes like hell, dosnt build boost properly, etc...if i lift off, wait a second, and slowly give it throttle again, it will build proper boost, and pull hard as ever... It just hates changing gear and me suddenly asking full power of it...

Used to spool straight up on the old setup, but would never have been revving it so hard before change.....

Any ideas / similar experiences?

Thanks guys,

[burn_your_money]

What turbo are you using? What gauges do you have?

[darrenjlobb]

T3....EGT / Boost / Oilpressure / oil temp....

The boost doesn't climb to its full peak, and you can just hear it doesn't sound right, goes very flat in sound, rather than the big rasp it normally makes...seems to blow grey smoke to, just not work, but by lifting off, and gradually bringing it back in, it l pickup and pull again...

[anto]

Darren that sound smuch like you previous problem, just not on as harsh a scale?

[darrenjlobb]

Hm, its not really, it really wants to go, like if you let it catch up again, and then go, itl go just fine...just seems to get starved up or something...

[burn_your_money]

Do your EGTs go up? Does boost start picking up and then just drop?

You could also be drawing air into the fuel.

[Rabbit on Roids]

Do your EGTs go up? Does boost start picking up and then just drop?

You could also be drawing air into the fuel.

x2 on the air..

[darrenjlobb]

Ah.....not thought of that...so your thinking possibly the pump is sucking hard for diesel, and sucking in air somewhere where it leaks a tad?....

Hm,lots of joins to check i guess....

[darrenjlobb]

Ok i have replaced all the fuel lines and clamps now to make sure everything is sealed....as all seems to be ok...

Just to explain the setup i have...as maybe this could be something to do with the issue...

Basically im running a lift pump in the tank, that feeds fuel to the engine bay, but seems to build alot of pressure, which i dont like, so i have a T piece right before the VE inlet, and right after the VE outlet, as a bypass, so fuel just flows round and round, and the pump takes what it wants... Can anyone see any problems with this?