2.5 Turbo Motor which Turbo to use

[fbssub1]

I have a td05 and a vf30 do not want alot of boost 8-12lb for my legacy so which turbo will suit me better or should I be looking at vf 22.

[gotasuby]

Td05 runs out of puff real fast. Get a big turbo they spool them fast

[funkytown]

vf30 on a 2.5 motor dies at about 4000rpm.. waste of time, as would the td05 be.

minimum td06

[RSB]

chuck two td04's at it.

[funkytown]

 RSB said:

chuck two td04's at it.

yikes no that would run out of puff so fast, minimum twin td05's

[Kiwi_Fozze]

A single td04 in my forrie runs out of puff at 5k.... More doesnt always equal better....

[ADIKT]

[RSB]

Optical had a 2.5 with twin td04's running in parrallel didnt he?

iirc, it made something like 245kw atw.

[funkytown]

No its running twin vf28s so closer to td05s than td04s

[RSB]

 funkytown said:

No its running twin vf28s so closer to td05s than td04s

Was originally running td04's, and was dynoed at 225kw atw from what i have found?: http://www.ozliberty.com/home/forum/topic/fs.-prova-b4-show-and-go-car-3406/

(I have a dirty desire to do something similar)

Anyway, to the OP - consensus seems to be that you should go for something big, as the 2.5 will spool a bigger turbo quite happily.

[G-unit]

what do the sti 2.5 turbos have?

[vorigan]

 funkytown said:

vf30 on a 2.5 motor dies at about 4000rpm.. waste of time, as would the td05 be.

minimum td06

+1+1+1

min ive done and supplied is the td05 with a backcut plus 46trim e comp wheel or 20g full td06 is better again

[sultan]

fully depends if it's a built motor or a stocker though. as well as other aspects of the car

[grego0o]

 G-unit said:

what do the sti 2.5 turbos have?

They run they same as the 2.0, vf37 or something?twin scroll but still poos as their on so quickly n all done by 5000rpm

Gt3540 ftw ;D

Will destroy your stock block in a second tho...

[funkytown]

Or even several built ones... tehehe

[Optical]

 RSB said:

Optical had a 2.5 with twin td04's running in parrallel didnt he?

iirc, it made something like 245kw atw.

that;s the one. made 240ish at 18psi on td04s but over very quick. two vf28s made 240ish at 1bar and what feels like lots more at higher boost, but has been road tuned and not on a dyno at higher boost

[fbssub1]

 sultan said:

fully depends if it's a built motor or a stocker though. as well as other aspects of the car

2.5 block new bearings forged rods and pistons 1.6mm mls gaskets V3 sti heads standard, In my BC5 to be my daily, dont want a lot of boost 12-16lb its not my track car, so going with those specs above would you still say TD06, running a electronic boost controller just to keep from creeping up, currently have a td05 and a vf30 so whoild like to use 1 of those to save money and so that car is up and running for track day in September

[WRXONP]

with a built motor like that - crack that gt3540 on there ! would be mint

[Stoffa]

A 3071 would be on boost in no time and still make awesome power

[Wiretap]

The factory turbo for the 2.5 STi is the VF39, if that is of any use.

[sultan]

With standard 2.0 heads the ports are the wrong shape which causes higher compression and higher combustion temps. If you've used anything other than ej257 block the bores are hardly the strongest. I wouldn't push it too hard. Any of your turbos sound good to me for a nice driving daily with reliability

[fbssub1]

 WRXONP said:

with a built motor like that - crack that gt3540 on there ! would be mint

sick of fabricating track, my car swallows money because of that, want straight bolt up no fraking around. That is what im after

[fbssub1]

 sultan said:

With standard 2.0 heads the ports are the wrong shape which causes higher compression and higher combustion temps. If you've used anything other than ej257 block the bores are hardly the strongest. I wouldn't push it too hard. Any of your turbos sound good to me for a nice driving daily with reliability

was told the pistons that I brought would lower compression, and the engine builder wasnt worried about items supplied for build, bugged him for ages and others for information

[Wiretap]

 fbssub1']

[quote name='sultan said:

With standard 2.0 heads the ports are the wrong shape which causes higher compression and higher combustion temps. If you've used anything other than ej257 block the bores are hardly the strongest. I wouldn't push it too hard. Any of your turbos sound good to me for a nice driving daily with reliability

/quote]

was told the pistons that I brought would lower compression, and the engine builder wasnt worried about items supplied for build, bugged him for ages and others for information

The problem has nothing to do with the ports and everything to do with the edges of the combustion chamber. They form sharp edges which can cause hotspots. Hotspots cause pre-ignition. 'Hybrid' motors of this type typically run quite low timing because of this. The edges can be smoothed out by an enginebuilder to allay this issue.

[fbssub1]

low timing???