spec a turbo to your engine?

i mean like some people on here just buy a turbo off the shelf or ebay when others get them specced propperly to there engine spec?

so what is it that comes into it & what do you look for?

as thats the next step on my engine

 

I would say from past experiences this is one of the most important factors of an engine build(turbo) .

If you speak with Ian mate and tell him what you want the car for... track road or top speed, he will be able to work out or recomend the spec and size

 

"specced properly" turbos are almost always off the shelf ones (even if they told otherwise), just the most seemingly suited to the engine and what they want from it.

and you can do as many calculations as u like, a lot of it is down to experience/knowlege rather than anything you can work out in theory.

needs to be specced with the engine and all other components though to be totally suited.

 

ok cheers stavros & m4dyeti

so what do cut back blades do for you then why get it done?

& the differant compressor housings whats the differance?

when i order a turbo do i just say like...can i order a gt30 please ta

cheer smits

 

Changing compressor sizes affects spool up time - so this needs to be matched to spec so you have an effiecnt turbo rather than a turbo that only works for 2ooo rpm.

Im no exprert but you MUST get the right turbo, my turbo i had on the cvh was rather laggy for road use on track it came on boost instantly but revs where kept high...

 

cut back blades are a kind of bodgey mod, just gives more turbine flow at the expense of response.

different compressor housings? usually only comp housing options are ported shroud or maybe for bolt on pipes rather than slip on ones.

different turbine housings are always an option tho, bigger they are the more flow but less response and higher boost threshold, smaller they are the quicker response, but may be restrictive, and more likely to surge.

and off the top of my head i can think of 3 main types of "official" GT30, plus the hashed up hybrids various companies call GT30s.
of each of the official ones you will get 3 turbine housing side options, a couple of compressor housing options, plus about 8 different turbine housing styles/fitments.

so no, just asking for a GT30 aint wise

 

i was just using a gt30 for egsample but it is a turbonetics turbo i fancy, any way i'll speek to the builder/tuner & see what he says

cheers for your help folks

 

Cut back blades are no such thing as a bodgey mod, and don't give more turbine flow at the expense of response.
A cut on the blades is used where there is not an EXACT spec that is wanted, ie one trim wheel is too small the next is too large, you then take the larger wheel and trim it so it has a total surface area somewhere in between the two.
The most important aspect of a turbo is the USE to which it is to be put, if around town all day long you don't want a T4 for example as they are shit low down and don't get real until around 4500, but they will produce big numbers at big rpm, if that is what you want fine then go for it.
As a general rule, go for the smallest you can get away with, as you will have less lag, and better response.
Do bear in mind though any future upgrades you may want to make and get one man enough for this.
A certain size turbo will flow a certain amount of air, BUT if the turbine wheel is too small it will not produce the goods due to the flow being lost, remembering that it is losing boost pressureall the time the engine consumes the air it is producing.
I went for a T34, on a T3 compressor housing, which is the same CORE as a T34, but std .48 turbine side.
It starts to produce usefull boost at 1800rpm, and comes in with a mighty kick at 3000rpm, it is not a sharp on/off like the T3 was but you can drive all day at normal speeds with less than 2000rpm in top gear, it will pull from around 800rpm in top gear without complaint as well.
Whatever one you get consider mods such as 360 bearing and step gap seals, these will cut down the oil consumption through the turbo by about 90%.
It is best to speak to people who have done your spec before about turbo choice as experience is a massive bonus.
A modded head can allow loads more boost loads earlier as well, usually de shrouding the inlet port area where the valve seat is.
tabetha