Boost Gauge Question

[Rated S]

I just installed a mechanical boost gauge.
When my cars off it reads at 0 - good.
When my car is on/idle it reads at 20 VAC - (ive read that is normal/good)
When I go in to boost the needle takes its time to go "up" and only reaches somewhere around 5-10 psi - not good.
I'm on K04s but no fueling (STG 3-)


I put the tee fitting on the FPR hose about 2-3 inches away from the FPR nozzle.

Car still pulls really strong and how its always pulled, whats causing this? Is it possible that I didn't make the hole big enough behind the vent and it's cramming the tube?

[The_Jerbel]

Which gauge is it?
What kind of air line did you install? The white/clear stuff is really easy to crease. That could cause air restriction.

Log block 115 with VAG and see what kind of boost the MAP sensor sees.

[Rated S]

Which gauge is it?
What kind of air line did you install? The white/clear stuff is really easy to crease. That could cause air restriction.

Log block 115 with VAG and see what kind of boost the MAP sensor sees.

The new AWE gauge. It is the clear tubing from AWE, I don't know exactly what type. I will log boost tomorrow. It still feels very strong, so I doubt I'm in any sort of limp mode or have a boost leak. Would you recommend any more resilient tubing?

[The_Jerbel]

You can use whatever type of tubing you want. I would use rubber personally, or you can just make sure the stuff you've got isn't kinked.

[Rated S]

You can use whatever type of tubing you want. I would use rubber personally, or you can just make sure the stuff you've got isn't kinked.

When you say kink you mean have bends in it, like creases? What about if it's being pinched a little going through a hole. Like the rubber grommets in the engine bay/ecu box or if I made the hole too small behind the vents. Thanks for all your help.

[Rated S]

So I was able to floor it today. I was in third gear going on the freeway, from about 30-70mph. It took all of that time for the needle to go from 20 VAC to about ~15 psi, even though the car pulled as should, normally.

Any help would be appreciated. The tee-fitting has a brass insert in one of the three sides, I put the hose to the boost gauge on the brass fitting nipple side. Just making sure i did everything right.

[S4Per]

log it via vag-com so you can be sure boost there is OK. sounds like you might be 'squeezing' the line to the boost gauge, but do the logging first.

[Rated S]

VAGed it and I'm boosted as request so that was fine. I then bought a thicker rubber hose and put that on, wired it on the outside of the car through the engine with the hood open and that didn't help at all.

Then I went to Pepboys and bought a 0.50 vaccum tee and it works. It shoots as fast as I'm boosting. Apparently either the tee that AWE sent with my boost gauge was faulty or the brass resistor in the tee doesn't work very well.
With the new pepboys tee it spikes to 20 strong and steady, which is good, but then when I'm holding and going through the rest of my powerband the needle flutters a little violently from 16-18 psi. Anymore help is much appreciated.

Thanks!

[The_Jerbel]

You running an MBC?

[AudiSportB5S4]

the fluttering is from not having the brass restrictor in, CHECK out my thread "what a difference a T makes" LOL

http://www.audizine.com/forum/showthread.php?t=195710

[AudiSportB5S4]

you could of while installing broken the flimsy little POS T that AWE gives you, i had normal fluttering guage T in there forever then got a T from AWE, lubed it up real nice, stuck it in, and BAM, nice easy to read boost. =] i know that sentence sounded greattt

[Rated S]

You running an MBC?

No MBC.

And regards to the AWE T fitting with the brass resistor. I had that in originally and that was the problem which made my gauge read horrendously slow. I spike at about 20 psi and tapper to 15 (roughly) and when I had the AWE T with the brass it would take the entirety of a gear to get from VAC to about 10 psi and slowly go back down. In neutral I would rev the car and VAC would not move. I didn't break the T fitting AWE gave me. Unless I am retarded, but I choose to think I'm not. I didn't force anything and there were no leaks.

I'll call AWE I guess, just glad the gauge "works."

[The_Jerbel]

Also, log the car with VAG using block 115 and post it.

[The_Jerbel]

Unless I am retarded, but I choose to think I'm not.

Wishful thinking.....

just kidding bud, I couldn't resist!

[Rated S]

Also, log the car with VAG using block 115 and post it.

I already logged it. How would you like me to post it? Just copy/paste the Excel sheet? It logs in mBar, and I don't know how to convert that to psi. i doubt I'm boosting at 2.5 bar
I also called AWE and they are sending me a new Tee for free.

[The_Jerbel]

Sweet deal. If you can graph the data with the rpm, requested, and actual boost. Save it as an image, and then use some image hosting site to host the image, you can then post the image on here.

[Rated S]

Sweet deal. If you can graph the data with the rpm, requested, and actual boost. Save it as an image, and then use some image hosting site to host the image, you can then post the image on here.

Should I leave it as mbar, or how would I convert it to PSI?

Either way, is there an easy way to explain it to me to convert it to PSI from mBar, because I would like to know. I know I have to subtract a number because I remember seeing 25XX mbar of boost at one point (and at idle its like what, 1900/1800 mBar) and I know I'm not boosting 2.5 bar. That's like what, 30-something PSI . Thanks for all your help.

[The_Jerbel]

It doesn't matter if you leave it as mbar or convert it.

1000 mbar = 14.5037738 pounds per square inch

You have to subtract whatever your atmospheric pressure is where you live. Go on a weather website and get the barometric pressure, then put that number (with units) into google with "to psi" or "to mbar" and it will spit out the appropriate conversion.

[Rated S]

I
You have to subtract whatever your atmospheric pressure is where you live.

That's exactly the part I was always missing. I always got confused when it said I was boosting at 36 psi. MY VAG laptop is home, I will post it up tonight. Thanks again.

[S4-ORCE]

put back the T fitting with the brass and check the boost gauge line

[Rated S]

put back the T fitting with the brass and check the boost gauge line

VAGed it and I'm boosted as request so that was fine. I then bought a thicker rubber hose and put that on, wired it on the outside of the car through the engine with the hood open and that didn't help at all.

Already put it on with a hose I knew did not have a single bend or deviation and it did the same thing.

[Rated S]

I am stage 3- with NO TCD. I feel the throttle cut off which I'm assuming is the dips in boost.

[The_Jerbel]

Which software are you running?

Looks like you could use an MBC and maybe some new DV's...

[Rated S]

Which software are you running?

Looks like you could use an MBC and maybe some new DV's...

I was running GIAC before the K04s. Then Wicked tuned it (it i dont know if its GIAC or their own brew. I'm assuming they just based it off my alleady GIAC chip). And I have 710ns, what I believe I need most is a TCD. Are the dips because of DVs or because I dont have a TCD?

And I was going to wait till I had proper fueling before I used a MBC.

[The_Jerbel]

A TCD would prevent the minor dips in requested boost, but wouldn't solve the slow drop in actual boost after the requested falls off. Looks like dv's to me.

You need an MBC in parallel to cap off your boost spikes. An MBC in standalone would be ok after you get fueling.