thatHEMIguy

I am having a little issue right now.
When i had my car on the dyno 2 weeks ago i have my AEM Tru Boost set at 10% duration. During the first pull boost went up to 18psi. Tried it again, same thing happened. Unhooked the lines going to th econtroller and just did wastegate spring pressure, which i had an 11 lb spring in it. Next pull it did the same thing, went up to 18psi. My wastegate at the time was some cheap ebay deal so we didnt know if it was an actual 11lb spring in there so we ended up throwing a known 8lb spring in. During the next pull it went up to 13psi. We went around a checked all the lines going from the turbo to the wastegate to the BOV. zip tied every end just to make sure there were no leaks. Next pull it did the same thing, went to 13psi.

We figure since it was a crappy cheapo wastegate that it was leaking internally so we set boost cut at 13.2psi and i ordered a Tial. The tial came in today. I swapped out the 8lb spring for my 11lb spring that i also ordered with it. Hooked everything up nice a tight. Went for a pull on the street and in 2nd i saw 16psi then in 3rd it hit boost cut at 5k (remember boost cut is set to 13.2). what could be causing this problem?

my set up is lsvtec, 2.5" IC piping, 3" DP and 3" thermal r&d, 38mm wastegate with the dumptube dumping sraight out to the ground, t3/t4 .60 compressor/.63 exhaust. i also have a cheapo cxracing BOV on right now but my HKS SSQV will be in tomorrow.

boostedBLUfg2

is it a FR manifold? all i can think of is that you have a cheapo manifold and it's not flowing into the wg well enough

habib

What manifold are you running

TheShodan

iTrader: (14)

how are the vacuum sources? is the source to the wastegate to BOV to intake manifold independent, or "T-d" into one another somehow?

SovXietday

1) What manifold?
2) ID (inside diameter) of your dump tube?

If I had to guess, I'd say you're running a ramhorn with a 38mm TB, not a lot of backpressure (which is good) but the ramhorns are not too great at regulating boost. Also if you're running 1.5" piping for your dumptube that will also be an issue, as the ID is actually smaller than 38mm. You really should run no smaller than 1.75, ideally 2".

thatHEMIguy

Here is my mani setup

thatHEMIguy

I bought the mani off of a buddy who was running it on his LS for a while with no issues.

The lines have are as follows:
Top of WG - Open
turbo line teed into bottom of wastegate and bottom of BOV
top of bov goes into the pcv port on the IM, straight into it

thatHEMIguy

ID of my dumptube is just over 1.5" but just under 1.75"

dpetro1

just wait for the wastegate to fall off. then you will make no boost and wont have to worry about it.

seriously though, that manifold has a poor design. the wastegate is at an acute angle to the exhaust flow, making it hard for the exhaust to actually flow through the wastegate and control the boost.

and technically you are not creeping but instead just overboosting due to poor boost control. boost creep would mean you hit 11psi (spring pressure) and hold steady for a bit then slowly the psi increases with rpm.

TheShodan

iTrader: (14)

As with the wastegate placement itself, these are the two issues I see being possible sources of issues

With electronic wastegates, you need to use the top portion of the gate connected to the solenoid of your boost controller, while the side port goes into the intake manifold alone.

Do not have bottom wastegate line connected to the BOV in any way, (meaning don't have it tee'd off). Have them as separate sources going into the Intake manifold.

As illustrated here:
http://www.tialmedia.com/documents/w..._wginstall.pdf

thatHEMIguy

im not running the tru boost right now, just going off of spring pressure. thats why i left the top port open to atmosphere.

So i do not have to hook the bottom port of the BOV to anything? top port goes to manifold pressure i know that. and i have the compressor port hooked to the bottom port on the wastegate

jdm602

most hondas/mitsus creep a little. 8lb spring creeping to 13 lbs isnt huge. better wg placement fixes it somewhat. and if you had a better flowing manifold; it would creep less.

what turbo are you running? smaller turbos make a bunch of tq, so combine that with bad wg placement and a somewhat low-flowing manifold (compared to a topmount or ramhorn) makes it all that much harder to regulate it.

thatHEMIguy

ebay turbo FTW!

but yeah, i just unhooked the bottom port on the bov and it hit boost cut quick again. i think im just gonna bite the dust and purchase a good manifold. once it comes in ill go from there.

dpetro1

the bottom bov port can be hooked to a pressure source. it is not required. the compressor housing is a good pressure source but i would not tee into the wastegate signal. if you really want to run the lower bov port, tap a charge pipe

SovXietday

Definitely just have a single source for the bottom of the wastegate. No tees on that line.

However, I suspect it's the manifold design. Comparing it to your buddies car is hard. Do you know what turbo/downpipe/etc he was running? What engine are you running, a VTEC head?

Again, another guess based on information I don't know. Buddy was running an LS, you're running a VTEC head. LS moves a lot less air, so much easier for the manifold to control pressures. Put the VTEC head on there with a setup that will flow nicely and you've just gone beyond what that particular manifold can control because of the 110* angle the gases have to travel to get out of the manifold and through the wastegate.

Try this, pull the spring COMPLETELY out of the wastegate (just pop the top off) and try again. It will pop the wastegate wide open at .1psi lol. I'd bet you get about 5psi at redline. This test rules out any kind of possible vacuum issues to see if it is the actual flow of the manifold. If you never build any kind of boost ( < 1psi) then you're manifold is clean and you have a vacuum line issue.

Something to try and cure it. Bigger dump tube may help (2"). Also look at where the wastegate tube meets the collector and make sure the inside is portmatched. If not, do so. You may benefit from porting that out so that it's even. I did that to mine and it fixed all of my boost creep problems.

vtechjunkie

iTrader: (2)

5psi of creep isn't bad? On a tune that is pushing the motor, that could mean failure no? I'm no expert, but I would like that problem fixed! Better to fix the problem than to say " 5 psi isn't bad for a Honda". Just my opinion.

jdm602

i was wondering what size turbo...but nuff said. sounds good.

jdm602

i never said it wasnt bad. i said it wasnt huge. it can deff be bad depending on a list of variables even though it can handle a lot more than that. a few of us have run 20-22 lbs on stock motors making mid 400's to the wheels around here; pushed for over a year from street to track.

shoot about a month ago on my evo i had a 1 bar spring and it creeped to 20 lbs on cold nights. bigger wg (38mm now 46mm), equal length and the same spring it doesnt go above 16 lbs now off the gate.

wantboost

iTrader: (2)

yup its the manifold.... thats an ss autochrome and if they dont break, they creep like mad.
if you pull the wastegate off you'll probably notice half the port is blocked by welding slag and what not. no to mention the angle of the wastegate flange is completely wrong.

exhaust gasses dont like to make 100 degree turns.

get a better manifold and all of your creep issues will vanish.

and he's right, this is more of a boost "spike" situation as you simply have no control over boost levels

thatHEMIguy

I will try the spring removal tomorrow, i have to go to work in an hour.

But i will be ordering a BoostFlow ramhorn here in a bit.

SovXietday

Like I said, test out a few things before you buy your manifold. Also it is definitely worth porting the wastegate tube to collector joint. If you can get it down to something like a 1-2psi creep that's completely managable and more than likely you'll end up with the same thing when you switch to a ramhorn. They like to creep as well. Save yourself the money and try out the free stuff first, if it works awesome. If not, get the other manifold and hope that fixes most of the problem (but you will need to redo ALL of your plumbing).

Whoever said 5psi creep is "normal"... no, no it's not.

wantboost

iTrader: (2)

but nothing will creep like as ssautochrome manifold... actually its not even really creep, its complete lack of boost control.

a ramhorn might creep 1-2psi depending on setup, but with a properly sized turbo and wastegate there should be 0 creep.... but not a lot of people on here have any idea on how to do either

thatHEMIguy

well when i had the old wastegate on it "creeped" up to 18psi at 7k on the 11lb spring... only reason i saw 16 was because i was in 2nd gear and tires broke loose and it hit 16 veryyy quick. on the 8lb spring i was hitting 13psi at 6.5k which is where the boost cut is set at. now with the new WG and 11lb spring im hitting boost cut at about 4.5k

SovXietday

Completely agree, although a lot of that has to do with two things.

1) This is one of those things that people usually learn the hard way, because it's simply not discussed enough during manifold suggestion posts and usually only in "OMFG BOOST CREEEEEEEP" posts.
2) A lot of what is offered, even by reputable companies, is a ramhorn with a 38mm at a 90* angle. Then when people actually do the right thing with a 3" DP and all of the stuff they SHOULD be doing, they overwhelm the reputable manifold.

OP, you are getting a ridiculous overboost there. Are you sure there are NO vacuum leaks anywhere? I mean, I am absolutely positive that you are overboosting due to the manifold, the real question is, how much is the manifold and is it getting exaggerated by other issues?

thatHEMIguy

unless both my old cheapo wastegate and the brand new tial are leaking internally, then im 100% sure that i have no vacuum leaks. ive checked both ports on the old and new wastegate to see if theyre leaking, they arent. check the port on the compressor, no leaks. checked the line going from the compressor to the bottom port on the waste gate, zero leaks. same with the BOV