Jump to content


Photo

Vf28?


  • You cannot start a new topic
  • Please log in to reply
54 replies to this topic

#1 dnok

dnok
  • LocationElland West Yorkshire

Posted 04 July 2016 - 08:19 PM

Looking for an upgrade. Was looking for a vf34 and would still consider one BUT I have the chance of a vf28 that's nakered and dirt cheap. my thinking is get turbo dynamics to fully recon it and end up with an as new turbo for little more than a second hand one. The idea of a second hand turbo is OK but for all I know it could blow up within a month.

On paper the vf28 should be a decent enough match for an xt.

Would I have any fitment issues? Banjo bolt? Oil, water lines etc?

Any other info people want to throw at me? I'm real close to pulling the trigger on the vf28 a mate has it and just sat not advertised. I'm just waiting for turbo dynamics to get back to me to confirm they can rebuild it as I've heard the warnings of the ball bearing turbos not being rebuildable

#2 Blastertrev

Blastertrev
  • LocationSunny Cumbria (NOT)

Posted 04 July 2016 - 09:18 PM

Ask me again in a week or two for a proper answer when I finished getting my head around the maths involved in turbos :acute:. I can't find a compressor map for the '28 anywhere but from the stuff I've collected it seems to be that a  VF28 should be able to get you to 300 horses you're after. I've no knowledge of the oil/water fitment details, anyway those are matters that can be sorted with a few bits of pipe and ingenuity I guess. I did find this in a turbo comparison on an Aussie site though, to quote:

 

"A Splitter made for a VF turbo will be too long for a TD04/05 (the exhaust simply wont bolt up) and a splitter made for a TD04/5 will be too short for a VF and hence allow gases to mix too early causing an increase in lag and less power"

 

Worth a chat with Mr Carr I think if you're going to get him to map it.


May the Foz be with you....


#3 dnok

dnok
  • LocationElland West Yorkshire

Posted 04 July 2016 - 11:27 PM

Thanks for the reply mate. Can I get his contact number from you? Cheers :)

#4 dnok

dnok
  • LocationElland West Yorkshire

Posted 04 July 2016 - 11:32 PM

I've also found a vf35 complete with oil and water pipes, banjo bolt etc for £350 in supposed excellent condition. Very tempting. Decisions decisions

#5 brownpantsracing

brownpantsracing
  • LocationBucks

Posted 05 July 2016 - 09:31 AM

I'd go VF35 over the 28 or 34 personally.


2004 FSTI, Modified 2006 Impreza, 1963 VW beetle. All on the road for once! Woo hoo! :)


#6 Blastertrev

Blastertrev
  • LocationSunny Cumbria (NOT)

Posted 05 July 2016 - 09:57 AM

You have mail. The VF35 has a smaller exhaust side which should give better bottom end at the expense of some top end. Have you considered using a better Mitsubishi turbo?? should be a direct fit and available new for less than 200 notes.


May the Foz be with you....


#7 dnok

dnok
  • LocationElland West Yorkshire

Posted 05 July 2016 - 09:58 AM

Why over the 34? And easy to say for an sti driver lol you already got the balls to crank that sucker lol.

Actually i am reading a lot of good things about the 35 sound promising. Thought it was a bigger turbo hence the sti comment lol. With its smaller housing it should spool well. Ive driven the 28 well a different one on my friends impreza and it is Savage with plenty early spool hence my initial interest in said 28.

The 35's looking promising tho :)

#8 brownpantsracing

brownpantsracing
  • LocationBucks

Posted 05 July 2016 - 10:07 AM

Not a lot of difference between the VF34 and VF35 to be honest, They are roughly the same and produce roughly the same power.

 

The VF34 is a roller bearing turbo with a slightly bigger exhaust housing than the VF35 unit. The benefit of the VF34 is that it can easily be rebuilt and roller bearings changed. The VF35 is a sleeve bearing turbo and needs a whole new cartridge. These are not earth shatteringly expensive though, £350 for a complete new billet cartridge I saw recently.

 

The VF35 picks up slightly lower down the rev range but the VF34 will pull harder towards the top end (just).

 

My preference for a road car is to get as little lag as possible and have the turbo coming in at lowest possible revs, which ultimately makes the car far more driveable on the road.

 

Both units are well suited to the 2L engine so both good.

 

I want to upgrade my FSTI from the VF41 to something bigger at some point. This may also come with a forged build eventually. :D


2004 FSTI, Modified 2006 Impreza, 1963 VW beetle. All on the road for once! Woo hoo! :)


#9 dnok

dnok
  • LocationElland West Yorkshire

Posted 05 July 2016 - 10:12 AM

You have mail. The VF35 has a smaller exhaust side which should give better bottom end at the expense of some top end. Have you considered using a better Mitsubishi turbo?? should be a direct fit and available new for less than 200 notes.


Such as which turbo mate? School me I'm all ears.
Are you thinking td05? I was lead to believe even the 16g doesn't do well on the xt

#10 dnok

dnok
  • LocationElland West Yorkshire

Posted 05 July 2016 - 10:16 AM

Not a lot of difference between the VF34 and VF35 to be honest, They are roughly the same and produce roughly the same power.
 
The VF34 is a roller bearing turbo with a slightly bigger exhaust housing than the VF35 unit. The benefit of the VF34 is that it can easily be rebuilt and roller bearings changed. The VF35 is a sleeve bearing turbo and needs a whole new cartridge. These are not earth shatteringly expensive though, £350 for a complete new billet cartridge I saw recently.
 
The VF35 picks up slightly lower down the rev range but the VF34 will pull harder towards the top end (just).
 
My preference for a road car is to get as little lag as possible and have the turbo coming in at lowest possible revs, which ultimately makes the car far more driveable on the road.
 
Both units are well suited to the 2L engine so both good.
 
I want to upgrade my FSTI from the VF41 to something bigger at some point. This may also come with a forged build eventually. :D

Cheers. Yes I agree keeping some usable low down pull makes much more sense on a road car.

I think you should just go for the rebuild and bigger turbo now and sell me your vf41 :) Happy campers all round lol

#11 Blastertrev

Blastertrev
  • LocationSunny Cumbria (NOT)

Posted 05 July 2016 - 12:33 PM

Think of it like a gearbox: the smaller exhaust side on the VF35  (P15 vs P18)gives a "higher ratio" to the compressor and hence pumps more air at low rpm, just like you get more speed per 1,000rpm in 5th gear than you do in 3rd. However at high rpm the smaller turbine has problems developing enough power to keep pushing the compressor, like trying to drive up a steep hill in 5th. So there has to be some compromise between low end spool-up and top end power. The ideal would be a turbo with a variable ratio gearing between turbine and compressor, but making one that can cope with spindle speeds of 175,000rpm isn't easy. I believe there are variable-vane turbos used on bigger diesels that kind of do this, but never seen one for a Scooby  :cray: 

Cheers. Yes I agree keeping some usable low down pull makes much more sense on a road car.

I think you should just go for the rebuild and bigger turbo now and sell me your vf41 :) Happy campers all round lol

From that point of view I think you might find the VF41 a tad disappointing, it's more about mid-range power, likely your motor in it's OE form will pull better at 2500rpm: above 3300 of course the FSTi is superb. I'm looking at ways to improve the low end grunt, but want to get a proper handle on the engineering behind it before thinking of making any changes.


May the Foz be with you....


#12 t1gger

t1gger

Posted 05 July 2016 - 05:08 PM

I might be wrong but i got a vf34 with seized bearings thinking i could get it rebuilt but it did not matter who i contacted about a rebuild got same answer it cant be done unless things have changed in the last couple of years.still got it dont ask me why lol

#13 dnok

dnok
  • LocationElland West Yorkshire

Posted 05 July 2016 - 05:33 PM

I might be wrong but i got a vf34 with seized bearings thinking i could get it rebuilt but it did not matter who i contacted about a rebuild got same answer it cant be done unless things have changed in the last couple of years.still got it dont ask me why lol


This was my understanding also re rebuilds. I've asked turbo dynamics to confirm they can do the work on those specific turbos, those and the 28. I would imagine if they can't no one will

#14 dnok

dnok
  • LocationElland West Yorkshire

Posted 05 July 2016 - 10:06 PM

Ok so blaster had me revisiting the td05 16g route. I didn't know (not very turbo savy although at this rate I'm quickly learning lol) the td05 16g came in different flavours. Seen that they do a small td05 16g with I think a 7cm wheel? Apparently spools quickly and makes good power. Now I'm also thinking what basis have the previous things I've read about 16g not working well on xt being based around? What state of tune where they running?

Let's not forget I'm not considering putting the turbo on my engine as is and just remapping.
The list is.......

Ported and polished Sti exhaust manifold.
Decat sti up pipe.
Swrd 290 or 340 l/hr fuel pump (price difference is about £10).
Swrd 3 port boost solenoid.
Bigger injectors if needed (been told it won't but if it needs it so be it).
3 inch turbo back decat exhaust.
Silicone intercooler pipes (so no crap y pipe).
Colder plugs.
TGV delete.
TGV to block 3mm phenolic spacer between two OEM gaskets.
Header tank spacing/relocating.
Throttle heater line bypass.
Cosworth panel filter (although seriously considering a cone filter for the sound. Yes I've read the scare stories).
Andrew Carr remap.

Supposedly port and polished sti manifold and the decat up pipe can help spool earlier as much as 500rpm. And the silicone y pipe is also meant to offer slight improvement in spool time and midrange too.

With such an improvement in spool time surely a 16g should still spool reletivly early and give a great bang when it hits. It sounds like a good turbo to me. On paper at least anyway

#15 Blastertrev

Blastertrev
  • LocationSunny Cumbria (NOT)

Posted 06 July 2016 - 07:45 AM

Your decat exhaust will help a lot too. A turbo is a pressure difference driven animal and the quicker you can get stuff away downstream of it, the quicker and harder it will work.


May the Foz be with you....


#16 stockcar

stockcar
  • Locationthe grim north

Posted 06 July 2016 - 07:46 AM

vf34 is a far superior turbo to a 35 IMO as the 35's tend to suffer cavitation issues when mapped and we would always port them before fitting for this specific reason - roller bearing is both more robust and assist response anyhows

the 34 also has a greater potential for both torque and power

 

none of the VF range are easily rebuildable in the way TD's are for example as IHI generally wont re;lease individual parts so its an expensive cartridge in most cases (often cheaper to simply buy a new complete turbo!!)


asperformance  / 0191-4103770

E-shop

MOTUL, EXEDY, FERODO, MILLERS OILS, AP RACING, TRS, PAGID, PERFORMANCE FRICTION, BREMBO, WHITELINE, SUPER-PRO, POWERFLEX and the list goes on................


#17 stockcar

stockcar
  • Locationthe grim north

Posted 06 July 2016 - 07:46 AM

vf34 is a far superior turbo to a 35 IMO as the 35's tend to suffer cavitation issues when mapped and we would always port them before fitting for this specific reason - roller bearing is both more robust and assist response anyhows

the 34 also has a greater potential for both torque and power

 

none of the VF range are easily rebuildable in the way TD's are for example as IHI generally wont re;lease individual parts so its an expensive cartridge in most cases (often cheaper to simply buy a new complete turbo!!)


asperformance  / 0191-4103770

E-shop

MOTUL, EXEDY, FERODO, MILLERS OILS, AP RACING, TRS, PAGID, PERFORMANCE FRICTION, BREMBO, WHITELINE, SUPER-PRO, POWERFLEX and the list goes on................


#18 dnok

dnok
  • LocationElland West Yorkshire

Posted 06 July 2016 - 08:08 AM

vf34 is a far superior turbo to a 35 IMO as the 35's tend to suffer cavitation issues when mapped and we would always port them before fitting for this specific reason - roller bearing is both more robust and assist response anyhows
the 34 also has a greater potential for both torque and power
 
none of the VF range are easily rebuildable in the way TD's are for example as IHI generally wont re;lease individual parts so its an expensive cartridge in most cases (often cheaper to simply buy a new complete turbo!!)

Thanks for your input. Would you have any input on a td05 16g with the mods listed above.
Thanks

#19 stants

stants

Posted 06 July 2016 - 09:38 AM

Thought of a hybrid td04 ? Or do you have to crack the 300 mark ?

Sent from my SM-G930F using Tapatalk



#20 dnok

dnok
  • LocationElland West Yorkshire

Posted 06 July 2016 - 09:56 AM

Thought about it yeah and know that there is good argument for it but I'd get bored and want more. Figured im best aiming for the bigger turbo straight off the bat so long as I can get it to work right. Don't mind some loss in low down spool if I get the hooligan hit after it but don't want something too late. Like wouldn't want to wait till 4500 until I hit boost lol.

And yeah 300 is a pretty set in stone target tbh. Theoretically that should last long enough for me to Save for the impending forged rebuild with impreza heads and cams, stronger gearbox etc etc lol




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users