Denmark

iTrader: (2)

John,
There is still a little booscreep, but not much, so i simple decided to run 1,3bar tappering to 1,2bar/7000rpm.

Moray,
I know not to run the vf-29 at 1,5bar top end ,but i dont even think it can....

The great thing is that the gtec-pro is now showing 20whp more than before the inletpipe.
3rd gear/1350kg...256whp. thats about what the injectors can take on higher fuelpressure.

I am really in need for new ones,before i make my frontmount

Skassa

MorayMackenzie

John,

You don't appear to have answered my question. My question was: do you recommend running 1.5 to 1.6bar boost on standard internals.

You pointed out that you were writing a generic answer, which makes it look more like general advice to everyone. You state that the guy can make his own descision re boost, as he maps his own ecu, fair enough. You state that you, yourself, run 1.6bar on standard internals. All of this seems to be in favour running 1.5/1.6bar on standard internals.

So, do you recommend running 1.5bar to 1.6bar on standard ej20 internals?

Moray

MorayMackenzie

Thanks for mostly clearing that up, mostly, John.

Denmark

iTrader: (2)

Itīs a silicone inletpipe from airfilter to turbo
I was thinking that the wastegate needed porting,but why is that it only shows now(after the inletpipe)
1,5bar on a vf29 dont think it would last long LOL

Thanks for the info.

Just what do you do too the wastegate(Dremel??)
Mayby i will go for the higher boost

Skassa

[Edited by Denmark - 3/5/2003 10:15:31 PM]

Bob Rawle

Denmark, concentrate on the ecu settings, raise the rpm setting to around 3800 (assuming its at or about 3200 now?) and reduce the sens to about three (again assuming its higher) which should steady that back (or drop to 2 if its three). The new inlet pipe is a more open system making the turbo work harder hence the boost float. Settings seem to be just a bit too sensitive.

Edited to say whatever you do DON'T port the wastegate its totally unnecessary and will screw up the spool.

cheers

[Edited by Bob Rawle - 3/7/2003 9:14:07 PM]

john banks

I was answering the generic question of how to cure boost creep. The guy maps his own Link so should be able to decide what boost to run

Running more boost is a valid solution to boost creep in some situations. Several interesting turbos are quite unusable without an external wastegate if you only want to run 1.2 bar.

1.4 bar top end on a VF29 is IMHO overdoing it though, but the VF29 info came later in the thread.

I would rather run a 20G at 1.6 bar top end than I would a VF29 at 1.4 bar top end standard internals or not.

In fact... I do run a 20G at 1.6 bar top end on standard internals But I am not doing a prophylactic rebuild for nothing. If I had STi pistons already I would probably wait for it to blow up first as I actually suspect the rest of the engine would be quite happy if det free, and quite possibly the cast pistons would be also if det free but a bit closer to the wind.

In cylinder pressure peaks from a doubling of charge density only typically increase 20% with a doubling of BMEP. RPM and det are far more significant factors in engine demise than boost IMHO.

[Edited by john banks - 4/7/2003 6:45:27 PM]

john banks

I indeed run 1.75 bar (midrange) on standard internals at present. Do I recommend it? Depends....

If they want to go as fast as possible for the least outlay, are tuning it themselves and are prepared to accept more risk of replacing the engine then 1.5 bar+ is clearly the way to go if done properly. Some are willing to pay out more for the probability of improved reliability, some will take the risk.

I've not mapped anyone's car on cast pistons to run over 1.3 bar, but if someone has monitoring equipment and can tune it themselves there is clearly more available for the taking. People that are tuning their own cars and changing turbos etc are generally prepared to accept that there is a risk of needing an engine. Frankly a lot of them see it as an opportunity to rebuild

Don't know any data that tells us exactly what the risk of failure on a 1.5+ bar detonation free cast piston EJ20 with the right bits is. As in all things pick the perceived risk you are comfortable with and then live with it.

[Edited by john banks - 4/8/2003 11:22:39 AM]

john banks

I think he said open neck too. Wonder why then?

Just looked at the IHI data, 24 is listed as a C418 rather than C395 actuator, but they all say 8 PSI. Is there any practical difference, only ever seen this one VF24 so wasn't aware. Does this mean the 24 and 28 are not interchangeable with no other mods?

How about one last thing unless I missed you'd done this:

You said you had disconnected the wastegate, is this what you meant: Remove the circlip and then the wastegate control arm so that the wastegate penny can just flap. Ordinarily the boost would be zero all the way, if it still creeps at the top then OK, if no then suspect a sticky actuator which can open enough to relieve the turbine speed at moderate flow (midrange) but not at high flow (top end).

[Edited by john banks - 3/9/2003 9:31:28 PM]