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Boost gauge reading


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Connected the boost gauge up at the weekend (thanks to everyone for the advice - especially john who pointed out where the bonnet was :))

 

What readings should i be seeing.

 

At idle it somewhere down the bottom 30/40 ??

 

At about 70-100mph putting my foot down hard it goes up to about 0.9 to 1.0 - is this about right - should it be more/less ??

 

Why are they different types of readings at the top and bottom ends of the gauge

 

Dean..

 

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I think I have the same gauge, I get about the same reading on idle, possibly up to about 60 on the vacuum. I can hit right round into the red area and get 1.4kg on full boost. 1kg is about 14.3psi. You will get higher readings in higher gears, so floor it in 3rd and see how far round it goes.

 

I cant remember if you are fully decatted with stock exhaust or not?

 

JB

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Mine is in PSI (+ve) and mmHg (millimetres mercury)

(-ve).

 

I run about 10psi (0.8 bar) on the first turbo and 19psi(1.3ish) with both.

 

Your vac sounds about right and the boost is 13-14psi which is just above the standard 11psi.

 

What mods are you running, sounds like at least a zorst and filter for that boost.

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Hi Dean

 

you're readings seem about right.    before i fitted bleed valve, i was getting about 0.8 - 0.9 bar maximum in 4th or 5th gear which is about same as you.

 

Mine gives about -0.65bar at idle.    not sure what that is in mmHG though.

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Current mods are :-

 

Decatted with a Leon special.

HKS induction kit.

 

Thats it - other than lowered, but don't think that makes much difference to the boost :)

 

Going to go for the NurSpec at some point - as a UK car believe that creep/over boost etc.  is not such an issue

 

 

Dean..

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Dean

 

As you know i've got a UK car and have had zero problems with the NUR spec :   no grounding, no overboost, no boost creep.    (In fact the boost was still too *low* after the de-cat and NUR spec was fitted.   so whacked on a bleed valve and it's quick now.)

 

All to do with the turbo bypass system that the UK's are supposed to have, although i can't find anyone that can confirm that this is the case.

 

the NUR makes a nice noise and i'm very happy with it.   Last w/e I drove to Le Mans for the race with about 20 TVR's and i took the removable baffle out to try to compete in the noise stakes !!

Incidentally the car held up very well performance-wise.   I followed a guy in a 355 Spyder and on the exit of roundabouts, he initially got the jump due to his instant engine response, but after 2 or 3 seconds i was right with him.

 

nice!

 

 

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Yes, I can confirm the UK car does have a bypass pipe in the exhaust system. Though quite how it is connected I am not sure as the drawing is unclear. It seems to run from No2 turbo's exhaust outlet to the exhaust system. Well, I can definitely see it is connected to the No2's exhaust outlet, but cannot see where the other end is connected.

 

On the strength of what I can see, there is no "turbo bypass system" as such on the UK car. In the sense there is some extra pipe that "bypasses" the turbos. Because the entrance to the pipe is located *after* No2 turbo.

 

HTH,

J

     

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