Deep Singh

I know this has been asked before with little success.Anybody in Oz/on the continent/USA tuned this to the limit of its ability?

john banks

With so little info on VF turbos there is a way to find out if no one can tell you... but not for the fainthearted...

You could keep mapping it to run more and more boost at wherever it seems to make peak power, obviously paying due attention to fuelling and detonation, you would probably want to monitor turbo discharge and EGTs whilst doing this.

Stop when the turbo blows up or the power plateaus whichever is first... slightly tongue in cheek there... but you could overspeed the turbo with this method. Monitoring discharge temp and doing small increments and doing a power run with Delta Dash each time is the way I did it (the third time with a TD05 , the first time I blew the turbo up, the second time it lost power with more boost). My TD05 plateaus at about 320 ATW.

Also the turbo seems to like to roll off the boost at high RPM naturally. If you tighten the actuator whilst still retaining excellent midrange control and try a flat duty cycle it will give you an idea of how happy things are.

Depends on what Pat and you are up for testing - he will have his own methods of course... don't ask me I blew a turbo up Also I would not be happy doing this to a customer's car, especially on a TMIC

You may also find you hit other problems first - inadequate induction flow to the turbo, excessive charge temps etc, uncontrollable detonation at the level of boost and octane you are using.

If only there was a compressor map, but also the 1.5 BHP per CFM that is traditional wisdom seems not to tie up with power figures being achieved... which is wrong?

Pavlo was suggesting on 22b a turbo tacho which you might want to look into.

The long and the short of it IMHO, is that the VF30 is likely to top out by 350 BHP. Yes I have pulled that number out the air. If you want more get a bigger turbo.

I will post a few Delta Dash logs of duty cycles and boost if I can find them...

[Edited by john banks - 2/22/2003 5:52:51 PM]

john banks

These are in 4th gear... note the boost is in absolute pressure and bar Note that as the RPM increases especially over 6000 that the duty required goes up dramatically, I do have it rolling off by design, but you can see how hard you have to work it to make the boost. This turbo is on the limit. The actuator is the 0.5 bar one but fully tightened. Still controls fine in the midrange. No doubt by tightening it more or playing with restrictors you could get the boost higher, but from the power runs it was plateauing here and felt sweet.

It required more octane (a bottle of NF per tank!) to keep the timing sweet, otherwise it would have plateaued at lower boost I have no doubt. As it was a whole bottle of NF allowed at least 6 degrees more timing, and considerably more power to go with it.

I expect with the next turbo (bigger) that will go on, I will probably not need the NF for at least the same power and timing.

Deep Singh

Hi John.Is that the dd from your car or from a VF30 equipped car?
I was hoping someone had already done the experimenting with the VF30 so I could benefit from it!! I've decided to definately install a fmic.Just wondering if it was worth seeing what I could get from the car on the VF30(with fmic) or change the turbo at the same time and be done with it.I am hoping for 375+.Probably not possible on the VF30 I know.Just seeing if I could save a few quid mate! Many thanks for the input,Deep.

john banks

Go for something bigger IMHO. No it is from my TD05, just illustrative of the process and issues involved.

Deep Singh

Thanks monster turbo it is then.