SillyFezzaMk1

iTrader: (1)

looking for a very punchy setup to give me arround 450bhp (although for a yr it'll be run at arround 400bhp)

My question is that this turbo is 'supposedly' rated to 450bhp but I'm not 100% sure at how to analyse the flowgraphs etc.... The turbo can come on a T25 or T3 flange with a choice of housing sizes so really stuck on choice... the options I have for trim are on this link..
http://www.atpturbo.com/Merchant2/me...egory_Code=GRT
If I stay with the T25 exhaust housing setup I can make my own manifold, If its best to go T3 housing then i'll probably go for a Tial wg as only the T25 housing has the 'super internal gate'




Also probably best to know my engine spec...

Ported & Polished head, 3angle, bronze guides
ported & polished inlet trumpets and manifold (4wd)
Pair BD10's
MSD 1000cc Injectors
5 bar map sensor
L8 ecu

Bottom end (200 block) is an unknown..... so being rebuilt to whatever c/r I fancy and will have a 4 layer wrc gasket when built.

So What do you turbo peopl suggest? I'm sorry if this q's been askled before but to be spending this kind of $$ on something you have got to be sure yourself

Cheers
Dan

SillyFezzaMk1

iTrader: (1)

bump...someone must have had some experience with the gt28 rollerbearing turbos

Dan

abdr500

iTrader: (1)

do you want it internal wastgate or external

sbd16v

now i am no expert so i am going to give my understanding

if someone wants to correct me if i get it wrong please do as i am always on for the learn


the way to read the compressor map is on a map you have loads of islands the closer you are to the center one the more happy the turbo will be as you go to the outer islands the turbo looses efficiency

so in the case of the one above it will be really happy at 2 bar and 30lbs per min (that 2 bar is including 1 bar of atmospheric pressure we live in so what we would call 1 bar of boost)

now if you make the engine more free flowing it will consume more air so if you stayed at the same pressure but the engine could swallow more it your point would move the the right of the graph.

the more you move to the right the more strain on the turbo

so if you want it to give 40lb of air what you do is use more boost as if you look at 40lb if you try to give it at 1.8 bar its off the islands

but if you try to supply the same amount of air at 2.5 bar its back inside the one out from the center island.


now to spec the turbo correct for yourself you need to decided how much air flow you need for the power you want

i really dont have a clue about the yb

but lets say you needed 40lb of air to make 350bhp this turbo will quite haply make that @around 2.6 bar or 1.6 bar corrected.



but in answer to what turbo you want to use it depends on how much air your engine needs to make 450 and that is something i dont know sorry

SillyFezzaMk1

iTrader: (1)

thats very helpful mate...i'll try and search some threads to see what kind of psi is required to make the power I want on a YB

SillyFezzaMk1

iTrader: (1)

If I wind up having the T25 exhaust housing then its internally gated but if I end up going for the T3 exhaust style then i'll get a tial gate

Not really fussed as i'll end up making my own manfiold as i'm not paying the prices people are asking when I can make one myself to a good standard.

If you click the link to the site I was using for reference then you'll see what I mean about trim and exhaust housing styles.

Cheers
Dan

yrkesman

Hmm, was it so that BMEP has the same turbo that you are talking about...

https://passionford.com/forum/viewtopic.php?t=151775

Badman38

iTrader: (2)

i've ran this turbo for four years now but it is on an 2.0L 8v fast spooling mine has the t25 flange 0.64 exhaust


thanks

sean

SillyFezzaMk1

iTrader: (1)

Right so what rpm do you get full boost? And what boost do you run to get what power...i'm looking to make about 450 (which the turbo is rated to by garrett on their site)

Cheers
Dan

leecavturbo

i have this turbo , currently making 315bhp @ .9bar,
there is so much more to come.
don't ask why i only ran .9bar of boost its a
soul destroying story
good spool up even on the .86 hotside which i have.
if i had a strong transmission or a lighter car i'd go for the
.64 hotside and have torque much earlier.
i've had it 2 years now and very happy with it.