GT3076R preturbo backpressure
#1
GT3076R preturbo backpressure
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.
Last edited by yrkesman; 25-02-2008 at 08:21 AM.
#5
#6
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.
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.
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#8
#9
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
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
#12
Borg Warner EFR Equipped!
Joined: Apr 2005
Posts: 5,810
Likes: 2
From: In the unit, building a 450bhp Time Attack Focus!
#14
#19
#20
Agreed, but lets not drag what is an interesting topic off at a pointless tangent over semantics.
#21
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.
What do you use the car for?
#22
#23
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?
What do you use the car for?
#24
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.
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.
#25
It's number 12, and I have tought of trying number 14.
#26
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.
#27
#28
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."
#29
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... !
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... !
#30
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... !
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... !
So, now thats cleared up, if everyone is happy, we can get back to the original very interesting topic
#33
#37
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)
Last edited by ECU Monitor Enthusiast; 25-02-2008 at 01:06 PM.
#39
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)
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)
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.