Running a VR6 turbo?

Dont dismiss these. That what was originally fitted to mine and it worked fine until the oil feed line burst. That was with a 1.06 hot side and it bloody flew. I can see folk not wanting to pay big buck for a turbo but when you get the like of a Garrett ball bearing you realise where the extra money goes.

 

I'd love a GT30...unless I get a second job or win some money then it really is a pipe dream for the moment

 

My Gt3040R will be coming off soon and becoming spare if you really must have one

 

The spacer plate, rod bolts and head studs route seems to be popular and handles plenty of power. Lugnuts got Tim Mullens to be ultra reliable on standard pistons and rods (mk3 dozens of ten second runs and abuse 511whp@20psi - 10.02@152mph, dyno looks sweet on Precision 6265 T4).
ARP studs are the ones to get, take into account the spacer route xtra height where Racewear do not according to some VRT owners (not used them on VR myself) and are easy to adjust.
Few different spacers about from 7.5 to 9.5:1 depending on thickness.
Rod bolts/Spacer/Gaskets/Head studs wil probably set you back around 300-400 so might be an idea to just chuck a spacer on and some peeps buy a 2nd hand engine to strip, check and add those (of course you generally know your VR so it's a gamble). With older engines you'll also need the usual rings, gaskets, belts, bearings etc and check bore wear, alignment etc.
Regarding turbo, what about a Garrett journal bearing, can upgrade to BB later. No one seems to mention the T3 or T4/60-1 and T4/T61's, great turbo's for VR's and around 500-650 so about half of DBB. Did you get a cheapy copy turbo? Opinion is divided on these, seems poor metal dont like any decent boost (1bar+) and blades bend and crack but some have been known to be okay for 20k+ miles, bit of a gamble it seems (was looking into using one myself in the past but couldn't bring myself to do it).
I'd get a 0.82 in T3 and 0.68 in T4 & wouldn't go below 45lbs min flow rate for the turbo as a well tuned 2.8 running 97%VE and 7krpm should hit 50lbs at around 1.1bar.

T3 turbines you will be looking at around 1bar+ at approx:
0.63 - 3000-3200rpm
0.82 - 3400-3600rpm
1.06 - 3800-4000rpm
Positive manifold pressure is around 2-3k , T3 0.82 should get you +psi at around 2500rpm on 2.8 depending on turbine and a few other variables.
Heard the larger T4 0.68 turbines (undiv) pretty much match the 0.82 for spool at similar boost but yet to try one on a VR, was talking to a USRT guy and he swears by a T4 turbine on a VR6.
Inlet mani's have been known to pop over 10psi so most upgrade to SRI mani and for RHD cars you'll generally want to run an underslung FI exhaut mani like SPA to avoid inlet mani probs like heat soak/turbo in way etc on std inlet manifold.
Watch for back pressure on exhaust side due to VR unequal length design, 3" seems to be best for DP/Exhaust rather than 2.5" on a typical 55-65lbs/min tubby. Never heard anyone complain about a loud VRT!

Did a few calcs about required boost pressures a while back as a rough guide to choosing turbo:
2.8, 97%VE and 95degF IA temp @ sea level, 7krpm max I think it was:
50lbs = 30.58MAP = 16psi/1.1bar boost
55lbs = 33.60MAP = 19psi/1.3bar boost
60lbs = 36.70MAP = 22psi/1.5bar boost
70lbs = 42.8MAP = 28psi/1.9bar boost
80lbs = 48.9MAP = 34psi/2.3bar boost

3.0ltr:
60lbs = 34.2MAP = 19.5psi/1.3bar boost
70lbs = 39.9MAP = 25psi/1.7bar boost
80lbs = 45.7MAP = 31psi/2.1bar boost

Lots of variables but to get from lbs/min times by 10 for general HP guide, 9 would be an inefficient engine and 11 a well tuned example.

Hope this helps anyone interested

 

Paair of ko3 pounds quite fun. If they normally have headroom for 200bhp then a pair should be sufficient. Controlling the boost/torque delivery could be fun though

 

The turbo I have is a copy and exhaust manifold is an ATP copy.

the turbo specs are...

GT3582 copy

Cold side uses a 66.6mm compressor wheel and a 0.70 housing
Hot side uses a 61.4mm turbine wheel and a 0.63 housing
Divided T3 exhaust flange
360 degree bearing





A bit too big for 350-400bhp?

 

Thats like the original turbo that was fitted to my old car, worked okay. It had a 1.06 hot side. Came on boost around 3500rpm and I ran it with 17psi. It certianly flew.
Here it is next to the pukka GT3582r that replaced it. You can see the smaller exhaust housing on the genuine item.

 

All you can do is try it. See how it goes. you can always turn the boost down.

 

so, in theory, my turbo shoulld spool earlier due to the 0.63 hotside?

 

With a 0.63 housing it will spool quite low I would have thought, probably about 2750 - 3000rpm. I would find that a bit too low, the 0.82 was a good comprimise. You can get the cheap manual boost controllers linked to a low wastegate spring i.e. 0.5bar that will allow you to change the boost easily. Crude but it worked perfectly fine with mine.

 

i would like to use a Apexi AVC-R for its engine rpm Vs Psi capability for each gear (a feature i never got round to using on the beige beast)

 

question regards to the spacer plate... do you need a slightly longer timing chain to do this? or is it just a case of the tension-er acting as though the chain is fitted tighter?

 

the tensioner takes up the slack so will still do its job but just not as far out as before due to the head height increase of 2mm

 

Demon Motorsport wastegates are supposed to be pretty good and decent price if your going external

 

thanks, they look good and go as low as 8psi

Can anyone confirm that my hotside is of the T4 variety?

 

No one considered rear mounted turbot?

 

Do you mean remote placement? Seems popular in the states but its easy enough to fit one on a VR so no real need IMO.

 

I was thinking in place of the middle box

 

I really can't see any gain from this apart from lowering under bonnet temps...lag will increase and the oil return would be a nightmare!

There is barely enough room for a 3" exhaust let alone a turbo

 

RE: Your PM Lreg - did you buy this off some bloke then I take it? I bet it's one of the ones I was looking at a bit back, the 0.82 divided autoshop spesh although ind/exd diameters different to that which you've said.

http://www.ebay.co.uk/itm/gt35-T3-f...r_Truck_Parts_Accessories&hash=item3cbdd091b7

Is that not an open flange mani and divided turbo? This can make spool worse due to turbulence. Peeps mainly use a tubular to match the ports/combustion cycle to each side but some have be known to file down the divide to reduce this when using a cast/log type.