I have a tial wastegate(.3bar spring) and Revhard turbo kit.. Ive been running the kit for 2 months with no issues.. When I run the kit without a boost controller I only hit .25bar.. it is not pressure drop through the intercooler, i know that because I have my vacum line teed off the manifold, not the comrpessor..

the other day I had many factors change on my set up.. I got a 3" thermal exhaust, I hooked up a turbo XS high performance boost controller, and I almost screwed up my wastegate...

After I got everything back together I took the car out and ran it without the BC.. I hit .3bar for the first time but then it would only hit .25bar sometimes.. Hooked the BC up and took it out and set the BC to hit 7.5psi, did the testing in 2nd, it hits the same in 3rd, but then when I take it out in first it will spike to like 8-9-10 and ill shift, then when I get to the next gear it stays at a steady 7.5.. also if I keep RPMS at like 5k in 2nd and spool the turbo hella fast it will spike slightly to 8-8.5..

"I almost screwed up my wastegate"- ill explain this, well I cross threaded the side port on the wastegate so in order for me to get the fitting back in their I had to take apart the wastegate and retap the threads.. Borrowed my dads tap and die set and retapped it, fitting fit great.. hooked everything back up.. Well I found out the threads on the port are tapered to prevent vacum leaks..
-I am thinking it is a possibility that maybe it is not completly sealed since I could not retap it tappered the same way.. possibly my wastegate is loosing vacum, possibly causeing me to spike..

Another factor that changed was my 3" exhaust.. before I had been using a stock sized exhaust and possibly the 3" exhaust is causeing the boost spike, i seriously doubt it though.. Ive heard of this on Drag 3 but never Revhard..

3rd factor is the boost controller, possibly when I spool the turbo too quickly it cannot react in time to regulate the boost.. maybe thats why it only spikes when I floor it and spool quickly, and then it regulates itself down..

4th possibility is a wild guess.. BOV, I think my BOV might possibly be leaking boost.. at first when I floor it the BOV stays closed but when I shift it opens and closes again, well maybe after it opens wide that first time it doesnt close all the way again, causing it to leak boost.. that would explain why the only time it doesnt leak is the first gear i boost in, and when I set my BC im actually setting it to 8-9psi but the BOV is causing a leak.. That would explain why I only see .25bar without the boost controller.. although I highly doubt this is the problem

1)I really dont want the cause of this to be the wastegate, I dont feel like shelling out 200$ because my dumbass crossthreaded a bolt
2)I highly doubt the spike is caused by the 3" exhaust but ill keep it open as a possibility..
3)I dont think its the boost controller cause that doesnot explain why I dont hit full boost without it..
4)BOV is a wild possibility, If I can swap BOV's with someone and it works, then I guess I would need a new BOV, but I doubt the fix is that simple..

vacum lines is the last potent factor I can think of, I have my vacum lines hooked up the same way everyone else does except I dont have a port in the side of my compressor..


This boost spike is boggling me, I have no idea what it is and I do not want to spend money only to find out that it doesnt fix the problem.. Anyone got any ideas that maybe I didnt think of? anyone have a similar problem ever? Out of all my factors which one do u think has the best chance of being the cause?

chris(tires and stumped)

 

I have a simular problem but mine will boost to 7.5psi in the lower gears (around town driving) and then on the freeway it will boost to 9.5-10psi.It sounds like your problem may be related to the b/c.How long is the hose from the boost controller to the wastegate? If that line is to long it will cause a spike because it takes a second for the boot controller to open and then for the pressure to get to the wastegate.Make sense?

 

sounds like the 3in exhaust is to blame...
or you just focked up your wastegate...


[Modified by TurboITR, 2:09 AM 1/15/2002]

 

true.It sounds like a combination of the exhaust (because the turbo will spool faster and higher with a free flowing exhaust) and the boost controller.

 

The waste gate would be my guess. Try using some teflon tape on the fittings or something that might better seal the vacuum. Im not sure that will work but its worth a try before you buy another wastegate. Also i think i saw that you said you dont have a vacuum port on the side of you turbo.... how come? I have my boost controller "tee'd" out of a line running from the side of the wastegate into the turbo and then the other side to the vacuum port at the top of the wastegate. I have NEVER had a problem spiking with it hooked up this way. And it seems to build boost way quicker

 

Do you have any exhaust leaks? When my wastegate elbow cracked I would see spiking when I floored it in 2nd and 3rd gears around town. My turbo would spool sluggishly as well. I run a Tial as well. My crack was small at the flange mating with the elbow.

 

That sounds like the qualities of a manual boost controller to me Chris

 

I'm not sure if this is the same thing that newsense is saying, but I think the problem might be that your wastegate signal is off the manifold instead of right after the turbo.

As I explain this, keep in mind I don't have any experience with turbos, this is all theory....

say you're running 5psi of boost, and for whatever reason, your boost spikes. It will take some time for that extra boost to reach the manifold, and hence the wastegate. By the time the wastegate reacts, the entire intake is fully pressurized and.... basically it will take a while before the boost settles down. If you run the signal after the compressor, the wastegate will respond before the entire intake is fully pressurized. I imagine this would be worse depensing on how much volume your intake holds.

This is the way I understood it after reading Maximum Boost. Makes sense to me, but might be off.




[Modified by Lsos, 4:04 PM 1/15/2002]

 

I have the deltagate and it never spiked on me over the summer and fall. When winter hit here and it started to get cold it was spiking all the time. I don't have any vac leaks and my bov is set properly to my knowledge. Is it getting cold over there???

 

it has been cold....

well, try the BOV first, easiest way to figure it out....

and I know you don't wanna hear this, but my turbo seems to spool faster with top port of tial connected to vacuum lines, instead of just running it from the side port...

stan

 

you guys running EBCs? I got a tip from a Blitz guy who had me run my Tial with the side port hooked between the inlet and outlet of solenoids. The feed is off the compressor. Then, instead of setting the BC to external wastegate, set it to internal actuator type and manual settings. This allows for faster spool, quicker response and absolutely no overspike ever!

This is good up to 12psi, after that, its best to use the top of the wastegate spring as well

torin

 

My turbo didnt come with a port in the turbo, I dont know why but i am gonna tap a fitting right below the turbo, hopefully that will work.. I think I used teflon tape, I had it out and I was ready to use it but now that I think about it maybe I didnt put it on.. ill check that

 

I am going to tell you what you tell me Chris, fock it dude!


[Modified by Damon501, 12:58 PM 1/15/2002]

 

I dont think I have any exhaust leaks, but an exhaust leak would explain why when I ran open downpipe for one night the turbo took forever to spool and the car didnot feel fast..

 

I think what ill do is make sure I have that port on the side of the wastegate sealed first, then tap a fitting right under the compressor.. If I still am having problems I guess I can swap BOV's with a friend, and if it still doesnt work I can swap wastegates...And if I STILL havent fixed i can get an electronic BC and If that doesnt fix it maybe its an exhaust leak..


FID- Fock it dude



[Modified by DIRep972, 7:07 PM 1/15/2002]

 

his turbo has garret housing, no side port on the housing..

 

oh.... stoooops... my bad.... my kit came with a turbonetics... i wonder why his has no port... thats strange...