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Hi Fella's,

How do I check/determine what am I currently boosting at? The only tool I have is a Turbo guage as pictured below.

107031665_e83f39a371_m.jpg

I drive an R34 GTT - RB25DET.

Edited by sarnil
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press far left pedal to the floor with left foot.

using left hand, put little knob in front of stereo, between your seat and passenger seat in to 1st gear.

apply a little bit of pressing on the far right pedal with right foot, and increase this pressure while releasing the far left pedal slowly..

DON"T BE ALARMED!!!!

Car will start forward momentum.

when the big hand on the dash reaches about 30km, change gears in to 2nd as described above for 1st gear.

now let go of the far left pedal, and stick far right pedal to floor.

keep eye on the road and take small glimpse at this pictured turbo gauge above.

when car is making lots of noise and big hand on dash reaches about 70km, take foot off far right pedal and put it lightly on centre pedal.

while you were taking small glimpses at the turbo gauge you should have taken notice of what the red stick got to..

once you have done this, post back on here and tell us what marker the red stick got to.

we can then tell you how much boost your engine is eating.

any questions?

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Unfortunately, I don't have a far left pedal. Gosh it must be missing ;-) I forgot to mention, but mine's a auto/tiptronic model.

Anyway, so what formula do I apply to provided I get red stick reading at an instance of speed?

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press far left pedal to the floor with left foot.

using left hand, put little knob in front of stereo, between your seat and passenger seat in to 1st gear.

apply a little bit of pressing on the far right pedal with right foot, and increase this pressure while releasing the far left pedal slowly..

DON"T BE ALARMED!!!!

Car will start forward momentum.

when the big hand on the dash reaches about 30km, change gears in to 2nd as described above for 1st gear.

now let go of the far left pedal, and stick far right pedal to floor.

keep eye on the road and take small glimpse at this pictured turbo gauge above.

when car is making lots of noise and big hand on dash reaches about 70km, take foot off far right pedal and put it lightly on centre pedal.

while you were taking small glimpses at the turbo gauge you should have taken notice of what the red stick got to..

once you have done this, post back on here and tell us what marker the red stick got to.

we can then tell you how much boost your engine is eating.

any questions?

ROFL

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Johnny,

If I knew, I wouldn't be asking.

Given you know, perhaps you could tell me the conversions I am asking for. My boost guage reads in kg/cm2 and mm/Hg. Which is what? And what do they mean.

Edited by sarnil
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OH! Now I get what you mean! Your question wasn't clear.

You want the conversion rate from your boost gauge's readout to psi???

This website converts any pressure reading to various other units of pressure measurement. Go nuts!

http://www.convert-me.com/en/convert/pressure

Hope I could be of help. Sorry for my earlier criticism, but the way you phrased the question suggested you didn't know how to look at a gauge, not interpret what your looking at!

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Thanks Johnny,

That was a lot more helpful. Apologies for the unclear phrasing of my question. I guess I've got the deserved amount of ridicule for that :-(

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I guess what I was really looking for was for someone to volunteer to explain to me why my boost guage is setup as it is. I understand that anything over the 0 mark is what would be boosting at, but what about the numbers below the zero? Why do they have different scale?

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1.0 Bar = 14.5 psi.

you have 20 little lines on your gauge from 0 - 1.0

therefore each little line on your gauge is 0.05 bar.

which is equal to 0.725psi.

go for a spin, plant your right foot and see what it gets to at say about 4500-5000rpm.

WARNING: lack of far left pedal can cause boredom to the driver and piss taking of them, by their mates.... or people on intraweb forums..

any other questions?

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vacuum is measured differently to possitive pressure. and to keep the same scale would need a huge gauge. below the 0 on your gauge is in mm/hg I think which is mm in Mercury if I remember correctly.

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Because when your engine is running at idle, the turbo is not building any boost yet. That's why it goes below 0. Once it gets to 0, it means that all of your intercooler and inlet pipes are pressured and your turbo is ready to make boost.

A good way to test this is to go out for a drive, and in 2nd gear, get the boost gauge to read around the 0 mark. Then flatten your foot and it should increase quickly.

Then try it again at negative boost (e.g. less than 0) and it will take some time for the boost to wind up. Thats the difference. All those pipes that carry boost need to be pressurised before you can gain any power.

Which is also why cars running 4" intercooler piping and giant turbos and intercooler get really bad lag. That 'lag' is all of those pipes filling up with pressure before power can be made.

Hope I helped.

Adrian.

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OK. Will do the read for between 4500-5000 as recommended. Will post the results no doubt.

The decision to have my Skyline even without the left pedal and extra two doors was a long, hard and an agonising one, I assure you. In the end, the wifey won and I still got to have a skyline. I guess it's still better then any other alternatives, don't you reckon?

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I'd probably say drive your car for a while, and see how high you boost gauge goes?

1 bar = 14.7 psi

I thought you were after a reading of the boost gauge, hence my posting that 1 bar = 14.7 psi..

I have the same boost gauge.. But as for the different scale below 0 compared to above 0.. I have no idea why they're in different units?

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