yrkesman

Has anyone measured GT3076R garrets pre turbo backpressure, with boost more than 1.5bar? I just did a run with my current Holset HX35 setup and the backpressure was less than boost pressure (1.6bar) 4000-5700rpm, after that backpressure was 2bar and after 7200rpm the backpressure went to 2.2-2.3bar. I'm wondering if that is too much and if should think of changing my current turbo.

ECU Monitor Enthusiast

iTrader: (1)

Where and how exactly are you measuring this pressure ?

GARETH T

i think he means TIP, turbine inlet plressure!

ECU Monitor Enthusiast

iTrader: (1)

Inlet to which one of the turbines ?

I assume its between the exhaust and engine.

yrkesman

The sensor is before turbine housing, in the exhaust manifold. I have VDO 5bar sensor which is connected to Autronic SM4 ecu.

Stavros

i think people read far too much in to this and go for big turbos too quick.

some wont go any further than backpressure and boost being the same, and thats a total waste IMO.

the general opinion in these theory books etc seems to say even 25% more backpressure is fine/expected.

they reckon anymore than 25% and you could go to a bigger turbine side without losing any real response (sounds fishy to me, esp at low rpm, no more lag maybe, but higher boost threshold).

ive seen people happily running twice the backpressure to boost on plenty of cars.

IMO change the turbo when its not giving you the gains you want, not by relying on these theory books.

And Holsets are MUCH more suited to big boost, esp 2bar+, than Garretts, so dont think swapping a HX35 for a 3071 is a real good plan.

leecavturbo

doesn't the turbo(hotside) just use what pressure/flow it needs
then the "waste" is exited thru your "WASTE"gate?

yrkesman

I have tought of swapping to 3076r not 3071. I'm not saying that the current setup is bad, I'm just thinking if it could be better. For the money invested it works very well in my opinion.

Stavros

Holsets are awesome IMO, and by everyone who has used em they seem to rate em over Garretts etc esp considering the price.
I got a HX40 with 16cm2 housing to go on the Chaser, and as long as I can keep on getting them cheaply, ill keep on using em

leecavturbo

Stav what sort of prices?
what flanges do they use typical garrett patterns?

Fiecos Dan

Not tested internal gt3076.82 yet,



but will be tested once back on the road.

Big Will_

That the one you were telling me about at Knockhill Time Attack mate?

Stavros

I cant remember mate Ive had a few

capri-rs

what partnr is that sensor

cheers

yrkesman

360-410, it has floating ground. I bought it from USA, since the price was there lot less than in Finland.

RWD_cossie_wil

iTrader: (9)

How many turbines does a turbo normally have?

ECU Monitor Enthusiast

iTrader: (1)

2 the inlet and exhaust wheels are both turbines

yrkesman

I use compressor when I'm talking about inlet and turbine when exhaust.

RWD_cossie_wil

iTrader: (9)

How have you worked that out??? I think you will find that the inlet is a compressor, as it uses the energy from the turbine to compress air, the turbine extracts energy from the air to drive the compressor

Chip

iTrader: (3)

Agreed, but lets not drag what is an interesting topic off at a pointless tangent over semantics.

Chip

iTrader: (3)

The short answer IMHO is that it is too much, but its only too much when you are absolutely flat out, and then not by much, so I wouldnt upgrade over just that unless absolute bhp is your aim (as opposed to coming on boost fairly quickly etc)
What do you use the car for?

RWD_cossie_wil

iTrader: (9)

Not semantics,an important distinction between two completly different parts of a turbo.

yrkesman

The car is a daily driven, but it's also a hobby for me. I do some track days, but that's about it. I just spoke to one Finnish turbo seller and the response was that I could try one size bigger turbine housing and that it would probably not sacrifice low end power. I'm currently very happy with the setup, but I'm interested of making it better if it's possible.

Stavros

What size housing you using at mo?

HX35s, and all Holsets really, have tons of different housing sizes, if anything with them its kind of annoying as its really hard to find 2 Holsets with exactly the same spec, lol.

yrkesman

It's number 12, and I have tought of trying number 14.

ECU Monitor Enthusiast

iTrader: (1)

LOL, No need for you to teach me how a turbo works, I am fully aware. Thanks

You refered to turbines, not the compressor and my original question is valid
and was genuine as you can have pressure differences on ALL parts of the
turbo unit as a whole.

I agree this is an interesting topic but if people choose to try to make me look
stupid then I will correct them.

Chip

iTrader: (3)

Will, fair enough, then I will comment.



Thats the ONLY turbine in a 3076R.

There isnt more than one to choose from.

Chip

iTrader: (3)

The ONLY person making you look stupid, is you by claiming there is more than one turbine in a 3076R turbo, there is NOT, its that simple and if you try and argue that there is, then you will look more stupid.
The only post you can make to make you look less stupid IMHO is
"oops, my bad, agreed, there is only one turbine, the other thing that looks similar is a compressor, and even if he had said 'wheel' or other generic term its still obvious which one he means as the inlet to the compressor wheel will only ever be at atmospheric pressure or below when the turbo is spooled anyway except for a possible momentary peak of a few psi during surge."

ECU Monitor Enthusiast

iTrader: (1)

Chip,

See here... http://en.wikipedia.org/wiki/Turbine

It says a turbine is a device that extracts energy from a moving flow... Exhaust wheel

That says a compressor isnt a turbine

Confused now. I was taught both are turbines... !

Chip

iTrader: (3)

Yes a turbine EXTRACTS energy, the compressor wheel doesnt, it does the opposite in fact.

So, now thats cleared up, if everyone is happy, we can get back to the original very interesting topic

ECU Monitor Enthusiast

iTrader: (1)

Well, I stand corrected then thanks We cant all be as clever as you LOL

Lloyd

cold side wheels are termed impellors,or they are on all the invoices,order forms.lmfao

Lloyd

http://www.doncasters.com/groupcompa...p=5&sp=0&id=25

Chip

iTrader: (3)

Lloyd, I think that bit has been done to death now.

Lloyd

iam right thought

Chip

iTrader: (3)

Wow, congratulations

ECU Monitor Enthusiast

iTrader: (1)

Chip,

I am surprised at your attitude to lloyd and myself for that matter.
Its not like you IMO ????
Just because you dont want to discuss a fairly relevant point raised doesnt
mean no one else isnt allowed to do so.

Not everyone is as knowledgable as you as I have found out myself today !
(no dissrespect intended)

Lloyd

chip is trying to win cunt of the month award again,and only has a few days left in feb to impress the judges lol .no offence intended

Chip

iTrader: (3)

Hang on a sec here, my attitude with my first post about what you said was to try and just get the thread back on topic, then when Will said it needed discussing, I gave my opinion on the names of the bits.

You then acknowledged you had got it wrong, there was NO confusion left, and then Lloyd started going on about it again, all I was doing was trying to get the topic back on track as its an interesting topic, if people want to discuss the names of turbo components, surely they should start a thread for that rather than inundate this one with it?

Ive not tried to be "clever", I just want us to discuss back pressures as I think its an interesting subject.

Lloyd

if you check the link it is to a company that makes cold side impellors for holset,relevent?