high boost?!

[bl1tzk1213g]

We installed my boostgauge today, its an autometer and i forgot which kind. We went out for a ride, when we WOT 1st goes up to 23-24, then slowly goes down. I dont kno how low because 1st gear aint that long. shifted to 2nd gear and it spiked to 23-24 again then went down 20, then around 16-17-18? I thought it was weird. i have a vid but its kinda messy, i was taking the video and driving and my bro had the flashlight. first scene around 17 psi on i believe 1st gear around 4.5k then ull see me shift then it was at 20 on that.

http://media.putfile.com/weird-boost

sorry for the quality, i haven't hooked up the light for it cause we went to bestbuy.

Mods: Aftermarket Intake, SSQV, BCS mod. stock turbo.

[Killa]

i cant see a dam thing

[viet_boiiiii]

Your boost gauge is f'd up. If your on stock turbo i doubt it will last long if that gauge was right. Did u messed up on installing anything? Leaking? Not even a MBC? Check your pipes.

[crunchymilk55]

wait...did you remove the BCS without some other sort of boost control? You should NOT be running boost that high. With your mods, you should be around 12. You are frying your turbo and your engine right now. Either the gauge was isntalled incorrectly (where did you tap?), or you are warping your motor at those boost levels. I don't even run that high on the street man. Quit boosting that high before ya ruin the engine and turbo!

[bl1tzk1213g]

i tapped right on the BOV. I used a T-tube to connect both boost guage and boost line to the intake manifold.

[crunchymilk55]

try tappin closer to the intake manifold. Look at where mine is tapped, thats the best place IMO because it's what the motor actually sees. (T is right above the spark plug wires)
http://img385.imageshack.us/my.php?image=10004764yx.jpg

Make sure you still have a boost source line going to the wastegate actuator arm. Make sure it's not pinched off or anything. If possible take a pic of your lines cause I'm kinda confused what's going where on your car. good luck Whatever you do, DONT boost that high again, so many things are going wrong there.

[bl1tzk1213g]

ok i did that. now it doesn't go up to 24psi, now max is 20 WOT then goes down about 18-19 =/. is it because i dont have a manual boost controller or something else?

[91clipsedude]

Originally Posted by bl1tzk1213g

ok i did that. now it doesn't go up to 24psi, now max is 20 WOT then goes down about 18-19 =/. is it because i dont have a manual boost controller or something else?

your hks bov shouldve come with 2 white fittings to choose from when tapping into the wastegate line, you should have the fitting with a tiny hole in the middle of it. what does your boost gauge say the vac in is? 15-20 is ideal. Again, go thru your lines, the 2 that are on the bcs, the one coming off the wastgate, the one coming of the back of the hks. without any type of boost controller there is no way you should be getting numbers like that. Btw, did anyone mess with any of the vac lines that are on the throttle body, I heard one kid looped one of those lines, not sure which one, back into the throttle body instead of where it was supposed to go resulting in high boost, around 20-22 psi if im not mistaking. hope some of this is helpful.

[crunchymilk55]

I still think the line going to your wastegarm arm got pinched off. And for future reference, if you see your boost getting above 13 or so psi, let off immediately, don't let it go as high as it wants. Something is wrong with those lines, you only installed a boost gauge correct? When did you install the intake? what intake? how many ports are there on the intake?

[bl1tzk1213g]

i bought it from a friend, i believe its a bomz intake. it has 3 ports, all the ones from the stock intake. i'll have to check all the lines tomrrow from the bcs and intake manifold. BTW i dont have a vac reading on my gauge, only boost.

[91clipsedude]

Originally Posted by bl1tzk1213g

i bought it from a friend, i believe its a bomz intake. it has 3 ports, all the ones from the stock intake. i'll have to check all the lines tomrrow from the bcs and intake manifold. BTW i dont have a vac reading on my gauge, only boost.

After checking all your lines, if you dont find anything weird, if I were you, I would send the boost gauge back if you can, and get a new one. I have always ran autometer- get the one with the 30 in vac. That will give you info on any vac leaks you might have also, just to give you a little piece of mind. I have never paid over 50 bucks and I believe they are a must for turbo cars.

[kjewer1]

It is not uncommon at all to see spikes over 20 psi with the t25, a slow boost control system, and an aftermarket BOV. Mine only spiked to 17-18 psi (1g BOV ol style profec B), but several poeple locally spike to oever 20 psi and run that way for years.

I'm assuming it's boost spike, but these days no one even knows what that is or how to properly describe/diagnose it. Shifting at 4.5k is useless. Make a full gear pull, preferably 3rd. If boost spikes initially to 23 psi then drops to set boost (~15 psi) to 5500 then tapers off, it's normal. If it holds at 23 to higher rpm, like 5k-5500 where it starts to taper, then look for damaged lines/parts.

A simple test that should be done any time there are boost control problems is to run a line straight from the compressor housing or manifold to the actuator, eliminating all boost control fuckery. Spring pressure is around 7 psi or so on the T25. It should run right about there to redline. If it still goes high start looking into the actuator itself and the rod, flapper arm, and boost guage.

Edit> Tapping into the FPR signal line as seen in the picture linked to above is the most risky place to tap in. If anything goes wrong with the guage or its line fuel pressure will not rise 1:1 with boost, causing a lean condition. People have had this happen and lived to tell about it, but it a good setup that is tuned to the edge it would be enough to cause damage. I have used this line in the past as well, but be aware of this potential problem and keep an eye out for signs of leaning out.

To use my car as an example. I'm running the stock 580 injectors at ~90% IDC, target AFR of 11.5:1, fuel specific gravity of .76, and airflow of ~40 lbs/min at 20 psi. To see what would happen if that line failed, subtract the boost pressure, fuel pressure drop of 20 psi. The 580s become 26% smaller and act like 424s, and max airflow supported becomes 32 lbs/min. Projected AFR would be over 15:1! A setup tuned at the stock target AFR of 9.5:1 would go to ~13:1, which the motor would probably survive in short bursts at this airflow.

I know its a long drawn out example and everyone uses that line, just wanted to illustrate the point, and like I said above, I have seen this happen to people. Carry on...

[tsipsi20]

Originally Posted by Killer7

i cant see a dam thing

With that filming, it was seriously like the blair witch of a boost guage

[bl1tzk1213g]

ok on the BCS there are two tubes. which one does the wastegate connects, on the top tube on the BCS or on the bottom tube?

Originally Posted by tsipsi20

With that filming, it was seriously like the blair witch of a boost guage

YEA! i told my brother that and he said he hasn't seen the movie lOl

[bl1tzk1213g]

that right?