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Discussion Starter · #1 ·
From what ive read on here, our stock cars dont have boost till 3rd but when i get on it in first, my boost gauge goes half way up, and in second, it goes a little over 2/3rd the way up. does everyones do this or do you think my car has been tuned by a previous owner?

also, with the stock boost gauge, at which piont does the gauge reach 0 psi? i know there is negetive boost(vaccuum) before the turbo kicks in but im just wondering when it starts creating positive boost.
 

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i have found with my car that i can start to gear the turbo spool at the middle of the yellow. im getting a after market boost gauge put in and if no one answers on that time i will let you know then.
hope this helps at least a little bit
 

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Reading the Turbo Gauge:*The White is the vacuum in inches meaning that there is vacuum only in the intake manifold while in the white zone. The yellow means that you are in boost (pressure in the intake). In most cases the red color is noting that the boost pressure is exceeding approximately 10 PSI of boost pressure. As the red part widens the pressure is increasing.
 

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Unless your turbo has siezed you will always see some boost. The only way to tell is to get a real gauge. The stock guage is not accurate, but it's also not way off.
 

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The turbo will always spool up somewhat, but in first and second gear the stock car limits boost to help avoid wheelspin
 

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Discussion Starter · #7 ·
i had a lot of wheel spin with the stock tires. i still have wheel spin with 215s and thats base model. i like to control wheel spin with my foot, not some computer. i definitly need a tune and an actual boost gauge.

i also need the plastic undercarriage stuff cause all the air that is suppose to go through the IC and rad, goes under the car cause its all gone. my car never overheats tho so i think the fan still pulls enough air for that.
 

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Notice I said to help avoid wheelspin, it doesn't work all too well, especially in first gear. You can get an SMBC to make full boost in 1st and 2nd I had one before my tune and it made 2nd a little more fun.
 

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OP, on t7 cars like ours the "boost" gauge doesn't measure boost at all, but rather airmass. And the requested airmass is set by the tune.

So assuming you have a stock tune, if you floor it in 3rd on a hot summer day, it should go to the end of the yellow. Floor it in the middle of the winter, at high altitude.... same thing. The airmass will always stay the same (and that is what the gauge is reading), but the boost needed to get to that requested airmass can vary quite a bit. You won't see any sign of the different boost levels on the gauge, though.

t5, on the other hand, I believe is a true boost gauge. I don't think that system uses a MAF sensor like t7. But double check that.
 

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Discussion Starter · #10 ·
i see what your saying. i do want a true boost gauge, and once i get everything for my t7suite program(need to get the cable) ill pull my maps and see if any have been modified yet. but if what your saying is true, then its just saying air is flowing through the MAF sensor so it will always read "boost" when i get on it. and from what i see while driving, i think your right. ive notice more "boost" when it was cold out but in reality, it was just denser air flowing by the sensor.
 

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i had a lot of wheel spin with the stock tires. i still have wheel spin with 215s and thats base model. i like to control wheel spin with my foot, not some computer. i definitly need a tune and an actual boost gauge.

i also need the plastic undercarriage stuff cause all the air that is suppose to go through the IC and rad, goes under the car cause its all gone. my car never overheats tho so i think the fan still pulls enough air for that.
I run my car without all the plastic undercarriage junk. I believe it's there to help keep snow out as these are designed for over in Sweden where they have to actually drive thru mounds of snow in rural areas/roads that aren't salted like here in the States.

I believe it also keeps the heat locked into the engine compartment as it has no where to go, thus increasing heat soak on hot days. It's not needed ;ol;
 

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Discussion Starter · #12 ·
alot of its for aero dynamics. it keeps drag under the car down and keeps the car on the ground(kinda) at high speeds. also it builds up air pressure infront of the IC to force air through it, path of least resistance. if you dont want the plastic, ill by it from you.

it doest help keep snow and mud from getting into stuff but thats not what its only for.
 

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I run my car without all the plastic undercarriage junk. I believe it's there to help keep snow out as these are designed for over in Sweden where they have to actually drive thru mounds of snow in rural areas/roads that aren't salted like here in the States.

I believe it also keeps the heat locked into the engine compartment as it has no where to go, thus increasing heat soak on hot days. It's not needed ;ol;
Some folks have reported front end lift at highway speeds when the shields are missing. YMMV.
 

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t5, on the other hand, I believe is a true boost gauge. I don't think that system uses a MAF sensor like t7. But double check that.
Naw, it approximated something else on the T5 too, but I forget the explanation.

Without a true boost gauge, I believe he butt dyno is the best measure of our car's performance.
 
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