Low Pressure or High Pressure

Nov 22nd, 2004, 21:31

Can anyone enlighten me as to the difference between low and high pressure turbos?

Nov 22nd, 2004, 21:43

Hi Mark,

Well, more or less what it says on the tin really. A LPT will produce a lower air pressure than a HPT. Therefore, a HPT obviously produces more power by compressing more air thus creating a higher pressure.

If your question is in terms of what engines they're fitted to then the 2.5T is a LPT as are the more modern 2.0T and 2.4T engines. The T5 is HPT.

Regards

Andy

Nov 22nd, 2004, 23:03

The compression ratio is different too.

Adam.

liuleichan · Nov 23rd, 2004, 10:44

>The compression ratio is different too.

Plus the internals are reinforced, aren't they, on the T5s to deal with the higher pressure, greater stresses.

That's the reason why the capacity of the engine is slightly less for the T5s compared with the LPTs and NA engines - the cylinders are lined, I think, plus other things are beefed up.

Nov 23rd, 2004, 12:18

But some other HPT cars I have driven have been produced between 12-15 psi of boost (Smart car, Escort Cosworth) where as the T5/R is running at 7psi which 1 psi higher than my fathers Saab 93 LPT. So I'd say the the T5/R is a medium pressure turbo. I have also seen a Toyota Supra running at 32psi!!!

Nov 23rd, 2004, 12:28

It's still a HPT engine, with 8.5:1 compression which is quite low. And the T5R you mention is running low on boost!!!

Adam.

My 850R runs 32 psi too - in the tyres!!! :)

Nov 23rd, 2004, 16:43

So what boost do the 2.3T5/2.4R engines run at then. I can remeber reading another thread that said the 16T and 17T run at 7psi....

Nov 22nd, 2004, 21:31	#1
markhan Guest Location:	Low Pressure or High Pressure Can anyone enlighten me as to the difference between low and high pressure turbos?

Nov 22nd, 2004, 21:43	#2
mraldonnelly Guest Location:	RE: Low Pressure or High Pressure Hi Mark, Well, more or less what it says on the tin really. A LPT will produce a lower air pressure than a HPT. Therefore, a HPT obviously produces more power by compressing more air thus creating a higher pressure. If your question is in terms of what engines they're fitted to then the 2.5T is a LPT as are the more modern 2.0T and 2.4T engines. The T5 is HPT. Regards Andy

Nov 22nd, 2004, 23:03	#3
volvotuning Guest Location:	RE: Low Pressure or High Pressure The compression ratio is different too. Adam.

Nov 23rd, 2004, 10:44	#4
liuleichan Premier Member Last Online: Apr 17th, 2019 22:01 Join Date: Dec 2001 Location: .	RE: Low Pressure or High Pressure >The compression ratio is different too. Plus the internals are reinforced, aren't they, on the T5s to deal with the higher pressure, greater stresses. That's the reason why the capacity of the engine is slightly less for the T5s compared with the LPTs and NA engines - the cylinders are lined, I think, plus other things are beefed up.

Nov 23rd, 2004, 12:18	#5
Matt_Watkins Guest Location:	RE: Low Pressure or High Pressure But some other HPT cars I have driven have been produced between 12-15 psi of boost (Smart car, Escort Cosworth) where as the T5/R is running at 7psi which 1 psi higher than my fathers Saab 93 LPT. So I'd say the the T5/R is a medium pressure turbo. I have also seen a Toyota Supra running at 32psi!!!

Nov 23rd, 2004, 12:28	#6
volvotuning Guest Location:	RE: Low Pressure or High Pressure It's still a HPT engine, with 8.5:1 compression which is quite low. And the T5R you mention is running low on boost!!! Adam. My 850R runs 32 psi too - in the tyres!!! :)

Nov 23rd, 2004, 16:43	#7
Matt_Watkins Guest Location:	RE: Low Pressure or High Pressure So what boost do the 2.3T5/2.4R engines run at then. I can remeber reading another thread that said the 16T and 17T run at 7psi....

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