Been Searching - Where is the post on boost gauge accuracy
Been Searching - Where is the post on boost gauge accuracy
Oct 24, 2005, 02:42 PM
#5
No. I'm under the impression that my VDO (any boost guage for that matter) is off by 3psi. So when I do a pull in 4th gear and see the gague read 23psi (in actuality I'm only boosting 20psi). I'm looking for confirmation on this where I'd like to safely increase my boost to 21psi (which should be a reading of 24psi on my guage).
Anyone
Anyone
Oct 24, 2005, 02:47 PM
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Have you looked at your boost line to ensure that there are no pinches in it causing it to read too high?
Originally Posted by 4-BNGR
No. I'm under the impression that my VDO (any boost guage for that matter) is off by 3psi. So when I do a pull in 4th gear and see the gague read 23psi (in actuality I'm only boosting 20psi). I'm looking for confirmation on this where I'd like to safely increase my boost to 21psi (which should be a reading of 24psi on my guage).
Anyone
Anyone
Oct 24, 2005, 02:51 PM
#7
FOund the post:
"20G turbo upgrade from Buschur Racing. Jul 26, 2005, 09:28 AM #1
--------------------------------------------------------------------------------
Alright guys, it has been a long time coming. Well over a year now and you guys have gotten all the news as things have progressed or haven't.
The original idea on this turbo was to actually make an exact duplicate of the Mitsubishi 20G compressor wheel in reverse scroll. Well I never really got what I wanted, the wheels were always a little or a lot bigger than that. I tested anyway and tried new things and the turbo in the last form I got it did actually gain MPH at the track (2.1+mph) the turbo didn't feel good on the street and had horrible part throttle surge problems. The reason the turbo has been called the 21g from the beginning is it was always larger than the actual 20G turbo I wanted to have built and run on the car.
Last time the turbo went back to the turbo shop I think I said something like, "I am tired of swapping turbos, send me an exact 20G wheel with the same clipping we run on our old DSM turbos and I'll test it, if anything else comes I won't even bolt it on." I am sure I am not the easiest guy to deal with sometimes.
I got the turbo last week (in the correct size, thus the new name of 20g) and had planned to run my RS at the track on race gas, which I never have before, and then switch over to the 20G. Well as luck would have it the time I did take the RS to the track on race gas the performance wasn't there and the next day I found a blown out intercooler coupling on the car. I fixed the coupling and another leak and was ready to go. Friday night I semi-launched the car and just as it made high boost I heard this horrible explosion. Lifted and eased the car home, no boost. Figured I blew a coupling. We get the car in the shop and find that the turbine wheel actually exploded, YES, exploded. I have been letting this turbo hit 30 psi of boost (on the gauge) for a long long time. I guess the excessive shafts speeds have finally taken its toll. I have NEVER seen a failure like this. There are pieces of the wheel actually imbedded in the turbine housing. I will post pictures later.
At this point I needed a turbo, I don't have anymore stock, clipped ti/al turbos to put back in my car. This meant we put the 20G turbo on now.
The turbo got put on right before we closed last night. I drove it home and got on it a few times. The boost was rock steady compared to the stock turbo. No huge spikes no huge drop offs at redline.
On the gauge on the way home it looked like the boost was 25-26 psi all the way to redline in 1-3 gears.
**I need to get side tracked for a minute. The guages do NOT match what the AEM logs say. I had an explanation a while back from someone at AEM, "What are you going to trust a $20 boost gauge or a $100 medical grade map sensor?" That was good enough for me. Recently a customer of ours, thanks Seth, called for the same explanation as I don't think he liked what I passed on to him. He got a real reason. Boost gauges are built to go to -0-. This means on a day when the weather sucks it is going to start reading from -0- no matter what. The AEM map sensor will read actual atmospheric pressure. Normally that would be 14.7, which if it was on the AEM it would -0- when you turned the key on and watch the Engine Load. Now it makes sense. The AEM always reads below -0-, which once you hit boost would read lower than the boost gauge that starts at -0- in the first place. To show how bad the weather was here yesterday the gauge was off 3-4 psi from the AEM log I looked at this morning."
DOes this mean that it's safe to turn up the boost by 3-4psi
"20G turbo upgrade from Buschur Racing. Jul 26, 2005, 09:28 AM #1
--------------------------------------------------------------------------------
Alright guys, it has been a long time coming. Well over a year now and you guys have gotten all the news as things have progressed or haven't.
The original idea on this turbo was to actually make an exact duplicate of the Mitsubishi 20G compressor wheel in reverse scroll. Well I never really got what I wanted, the wheels were always a little or a lot bigger than that. I tested anyway and tried new things and the turbo in the last form I got it did actually gain MPH at the track (2.1+mph) the turbo didn't feel good on the street and had horrible part throttle surge problems. The reason the turbo has been called the 21g from the beginning is it was always larger than the actual 20G turbo I wanted to have built and run on the car.
Last time the turbo went back to the turbo shop I think I said something like, "I am tired of swapping turbos, send me an exact 20G wheel with the same clipping we run on our old DSM turbos and I'll test it, if anything else comes I won't even bolt it on." I am sure I am not the easiest guy to deal with sometimes.
I got the turbo last week (in the correct size, thus the new name of 20g) and had planned to run my RS at the track on race gas, which I never have before, and then switch over to the 20G. Well as luck would have it the time I did take the RS to the track on race gas the performance wasn't there and the next day I found a blown out intercooler coupling on the car. I fixed the coupling and another leak and was ready to go. Friday night I semi-launched the car and just as it made high boost I heard this horrible explosion. Lifted and eased the car home, no boost. Figured I blew a coupling. We get the car in the shop and find that the turbine wheel actually exploded, YES, exploded. I have been letting this turbo hit 30 psi of boost (on the gauge) for a long long time. I guess the excessive shafts speeds have finally taken its toll. I have NEVER seen a failure like this. There are pieces of the wheel actually imbedded in the turbine housing. I will post pictures later.
At this point I needed a turbo, I don't have anymore stock, clipped ti/al turbos to put back in my car. This meant we put the 20G turbo on now.
The turbo got put on right before we closed last night. I drove it home and got on it a few times. The boost was rock steady compared to the stock turbo. No huge spikes no huge drop offs at redline.
On the gauge on the way home it looked like the boost was 25-26 psi all the way to redline in 1-3 gears.
**I need to get side tracked for a minute. The guages do NOT match what the AEM logs say. I had an explanation a while back from someone at AEM, "What are you going to trust a $20 boost gauge or a $100 medical grade map sensor?" That was good enough for me. Recently a customer of ours, thanks Seth, called for the same explanation as I don't think he liked what I passed on to him. He got a real reason. Boost gauges are built to go to -0-. This means on a day when the weather sucks it is going to start reading from -0- no matter what. The AEM map sensor will read actual atmospheric pressure. Normally that would be 14.7, which if it was on the AEM it would -0- when you turned the key on and watch the Engine Load. Now it makes sense. The AEM always reads below -0-, which once you hit boost would read lower than the boost gauge that starts at -0- in the first place. To show how bad the weather was here yesterday the gauge was off 3-4 psi from the AEM log I looked at this morning."
DOes this mean that it's safe to turn up the boost by 3-4psi
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Oct 24, 2005, 03:05 PM
#8
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Ive also noticed changes in my electronic gauge vs my hks gauge. When it is cold outside it reads higher by like 2-3 psi. I have two settings on my boost controller one for cold days and one for hot days. Im wondering if I should tune on a cold day and leave it like that or tune it on a hot day. I would love to hear some thoughts on this matter.
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