Rob_DOHC

iTrader: (4)

Just wondering what people opinions of them were?

I want a turbo that can flow enough for between 250 and 280 brake that has minimal lag and good spool up time. I have heard a few contradicting stories about stage 3 turbos and t34's. Im aiming for 240bhp realistically but secretly hoping for a few donkeys more.

Im not after nothing and then a big bang @ 4-5000rpm, im looking for smooth power delivery and torque, but something that pulls hard to 6500rpm instead of tailing off etc.

I'm looking at using a kent cvh34 with my set up, any ideas how these cope with high(ish) boost?

Any power curves people have would be great

Cheers

Rob,

botters

iTrader: (2)

i think daz c runs that turbo iirc maybe worth speaking to him

Rob_DOHC

iTrader: (4)

Cheers for the heads up mate, i'll do a search for him.

Rob,

Rob_DOHC

iTrader: (4)

Cant see a daz c in the search mate theres a daz g though?

Rob,

pani_k

iTrader: (1)

I was looking at a 2WD Cossie T3 for an engine build I was planning that has gone up the spout now same sort of delivery I wanted too.

Rob_DOHC

iTrader: (4)

That's pretty much what I have now, just with a 360deg thrust. Performed really well but can only flow enough for 230ish brake, and I'm sure that's ringing it's neck.

Rob

Karlos G

iTrader: (4)

It is! lol
GT2560R (GT28R) would be my turbo of choice if I ever change.

Rob_DOHC

iTrader: (4)

Lol, just want to get a few comparisons and hints on fitting it before i take the plunge.

Nissan s15's seem to be the biggest donators of them, unless i find a new one for good money. Went to see one a while ago which was fairly knackered.

Rob,

pani_k

iTrader: (1)

What's your engine spec mate?

Rob_DOHC

iTrader: (4)

me?

It was (lol)

Standard bore
Standard cam (i think)
Standard compression
Standard head
Stage 2 t3 (pretty much like the 2wd cossy turbo)
Scorpion exhaust

Pretty standard lol

And made 185bhp and 205 ft.lbs @18psi

My new engine is
standard skimmed mahles 7.7:1 Cr
DIY ported head with standard valves
matched inlet and exhaust manifolds
Blue printed bottom end
forged h-section conrods with the obligatory arp's
possibly a kent CVH34 cam
And possible the gt28r
All on efi.

Pass on what power it will make, just more than it did before lol, Maybe 250? and similar torque (unless i've done a really really bad job on the head )

Rob,

crazycage

for the power you want i would fit one of my manifolds and a gt2845r mate

Rob_DOHC

iTrader: (4)

Is the gt2845r bigger than the gt2560r mate? what about a gt2560r and one of your manifolds

Rob,

crazycage

oop's i ment the gt2854r ,and its smaller , the 54 part is the size of the comp wheel in mm

Rob_DOHC

iTrader: (4)

Cool, know of any one who has one fitted gary? Interested to see what sort of power it makes and delivery etc..

Rob,

crazycage

tbh tho is it really worth spending 1k on a gt turbo for that sort of power ?

i would fit something like this to a nice manifold.

http://cgi.ebay.co.uk/Turbo-Charger-...item1c18a20785

Rob_DOHC

iTrader: (4)

Gary just had a look at the GT2854r, looks pretty spot on for what i need! good suggestion mate... just need to hunt a reasonably priced one down.

Rob,

Rob_DOHC

iTrader: (4)

yea, the subaru range was another option, the to4b and the IHI turbos etc. Think they do a small one VF30??? that looks fairly ideal as well. But from what i have heard gt2560's have slightly better spool, a bit more head room and are easily found......

I don't want to be spending a grand. more like 4-700.


Edit, the VF23 seems like something good to look into.

http://www.surreyscoobies.co.uk/index.php?page=Turbos

Rob,

Karlos G

iTrader: (4)

I dont really understand your recommendation here Gary, the GT2854R will be slightly laggier and flows for less BHP, unless I have misread the compressor/turbine maps?







Rob why have you gone for such a low CR, are you going for 300bhp+ at some point mate?

Rob_DOHC

iTrader: (4)

No, probably not. i can't be fucked to chase numbers. They came up for a really good price, and at the time i couldn't justify the price of forged pistons, and now i have bought them i can't justify buying more

Karlos, i could be wrong as i've never really looked too closely at compressor maps, but, the bottom two graphs show the gt2854r flowing more?? not less... like i said, never really looked at compressor maps enough to understand them.....

Essentially i want 250-280brake with minimal spool up time and lag. If i could find a turbo with the same characteristics of the stage 2 t3 but with a greater flow potential it would be a done deal. But i get im going to have to compromise some where.....

Rob,

Karlos G

iTrader: (4)

lol
Fair play Rob, will just be a bit laggier and need more boost to make the same power as a stock CR engine.

The turbine maps show the GT2854R flowing more yes, but thats exhuast side so more flow = more lag.
If you look at the compressor maps the GT2854R will only flow for about 275bhp flat out and the GT2560R will flow just under 350bhp.

So, less BHP and more lag vs more BHP and less lag..

DazC

iTrader: (1)

My turbo is a GT2871R which is quite big for a 16 CVH. Bit laggy but the best has yet to come from it as it's not been fully mapped yet. It is not ideal for 240-280 BHP however as it's too big.

crazycage

karlos ,theres not alot in it on the exhaust side . why would you want a 350hp capable compressor if the aim is 250ish? the bigger the comp the more lag you get too

like i said i wouldnt buy one anyway ! far to much out lay for that kind of power

crazycage

what exhaust housing do you have on your gt28 ?

zippyobrien

iTrader: (2)

What about a hybrid y28 from a pulsar.

andy130

iTrader: (2)

what about a TD05 Turbo from Mitsubishi EVO 6? is that to big?

zippyobrien

iTrader: (2)

Ment to say t28 wank predictive text

pani_k

iTrader: (1)

Hmm if you are not number chasing a worked Cossie T3 would be really good coming in but couldn't tell you if it will start getting lethargic later on just thinking that a GT28 variant may be on the laggy side. GT2560 may be the better turbo to get the most power without having to work it so hard and be pulling well up top too but again couldn't say how laggy it would be. You can work the T3 though up to about 25psi or so from what I understand and it will still be OK.

Karlos G

iTrader: (4)

Your right there isnt much in it and with a bigger comp wheel you do gain a little lag too, but the poor GT2854R is really working hard at 250bhp where as the GT2560R is at it's most efficient, in real life they may both respond very similair but you'll be generating loads more heat and running the turbo almost flat out all the time.

Just my thoughts of course!

Rob_DOHC

iTrader: (4)

Cheers for the ideas lads, think it will be something from the IHI range or the GT2560, purely for availability's sake, new and used.

Gary i think our aims are a bit different mate, your after a shit lot of power and don't mind paying for it, im after a lot less power, but minimal lag etc, which i don't mind paying for.

Essentially im trying to decide if its worth the extra money over a stage 3 t3. If it comes on boost 500-1000 rpm sooner and gives me a much larger power band and hence a much better fast road car, im happy.


Rob,

Rob_DOHC

iTrader: (4)

Not bad points there mate, but i think you are confusing max boost pressure with flow rates and power. I can run my stage 2 T3 @ 25 psi as Karlos does and maybe hope for 230brake... or i can run a gt35 @ 25psi and hope for 400 brake, (albeit @ 6000rpm! maybe).

A happy compromise for me is 250ish bhp with power coming in strongly from 2500-3000 rpm. I don't know if this is possible.

Rob,

pani_k

iTrader: (1)

That's obviously the best case scenario with a really drivable engine. I reckon the T3 or the GT25 could do that but for future's sake I'd probably go for the GT25 more scope for power later on.

crazycage

rob my old cvh made 261hp @ 16psi on a stg3 t3.
started boosting about 2600rpm and made peak power around 6200 iirc

had a ported head
newman cam and solid lifters
gotech
a pair of my manifolds
8-5-1 cr.

Rob_DOHC

iTrader: (4)

Thats pretty bloody good going! mate.

Really regretting my piston choice now, wish i had stuck to my guns and gone high Cr.

Rob,

crazycage

skim the head mate you wont have to take much off to get into the 8's

p-s thats all the boost i could run to keep it safe on the standard rods.

DazC

iTrader: (1)

.6 back end...

Rob_DOHC

iTrader: (4)

Have you got any dyno graphs with it on mate? would be interesting to look at.

andy130

iTrader: (2)

rob are you runing NMS pistons an
rods??

Canada1

Hello Rob,

The main bottleneck your engine combination has is the standard cylider head.
Sure one can just keep increasing the boost, but this has diminishing returns.
A more efficient turbo may help somewhat - but not much.
The standard head (and inlet manifold) do not flow enough air to make the power you are looking for (at a reasonable boost level).
Crazycage made 261 hp at just 16 psi boost.
Don't spend your hard earned dollars on a "better" turbo. You certainly will need a .48 turbine housing to get above 230 hp.
Spend your money on the head flow and inlet manifold flow. I also suggest having these mods done by someone who knows what they are doing. Just making the ports larger doesn't mean anything.
I have spent significant time developing cvh heads - there is a significant amount of power properly reshaping the ports. I would say a gain of 50 hp at 15 psi boost is very possible with a properly modified cylinder head.
It is true that big flow numbers do not mean everything, but poor flow will ensure poor power output.

Just my 2 cents.

Karlos G

iTrader: (4)

His head is ported and manifolds matched already so the turbo is his current bottleneck

Canada1

A garrett T3 .48 turbine with 60 trim compressor will be very adaquate for the 250 to 280 hp range.
If money is no object, than a roller bearing turbo would be best.

I am not sure DIY ported head with standard valves is not a bottleneck.
I am sure it still will be.